TLC3544, TLC3548
5-V ANALOG, 3-/5-V DIGITAL, 14-BIT, 200-KSPS, 4-/8-CHANNELS SERIAL
ANALOG-TO-DIGITAL CONVERTERS WITH 0-5 V (PSEUDODIFFERENTIAL) INPUTS
SLAS266C – OCTOBER 2000 – REVISED MAY 2003
D 14-Bit Resolution
D Maximum Throughput 200 KSPS
D Analog Input Range 0-V to Reference
D
D
D
D
D
D
D
D
D
D
D
D
D
Voltage
Multiple Analog Inputs:
– 8 Channels for TLC3548
– 4 Channels for TLC3544
Pseudodifferential Analog Inputs
SPI/DSP-Compatible Serial Interfaces With
SCLK up to 25 MHz
Single 5-V Analog Supply; 3-/5-V Digital
Supply
Low Power:
– 4 mA (Internal Reference: 1.8 mA) for
Normal Operation
– 20 µA in Autopower-Down
Built-In 4-V Reference, Conversion Clock
and 8x FIFO
Hardware-Controlled and Programmable
Sampling Period
Programmable Autochannel Sweep and
Repeat
Hardware Default Configuration
INL: ±1 LSB Max
DNL: ±1 LSB Max
SINAD: 80.8 dB
THD: –95 dB
TLC3548
DW OR PW PACKAGE
(TOP VIEW)
1
2
3
4
5
6
7
8
9
10
11
12
SCLK
FS
SDI
EOC/INT
SDO
DGND
DVDD
CS
A0
A1
A2
A3
24
23
22
21
20
19
18
17
16
15
14
13
CSTART
AVDD
AGND
BGAP
REFM
REFP
AGND
AVDD
A7
A6
A5
A4
TLC3544
DW OR PW PACKAGE
(TOP VIEW)
1
2
3
4
5
6
7
8
9
10
SCLK
FS
SDI
EOC/INT
SDO
DGND
DVDD
CS
A0
A1
20
19
18
17
16
15
14
13
12
11
CSTART
AVDD
AGND
BGAP
REFM
REFP
AGND
AVDD
A3
A2
description
The TLC3544 and TLC3548 are a family of 14-bit resolution high-performance, low-power, CMOS
analog-to-digital converters (ADC). All devices operate from a single 5-V analog power supply and 3-V to 5-V
digital supply. The serial interface consists of four digital inputs [chip select (CS), frame sync (FS), serial
input-output clock (SCLK), serial data input (SDI)], and a 3-state serial data output (SDO). CS (works as SS,
slave select), SDI, SDO, and SCLK form an SPI interface. FS, SDI, SDO, and SCLK form a DSP interface. The
frame sync signal (FS) indicates the start of a serial data frame being transferred. When multiple converters
connect to one serial port of a DSP, CS works as the chip select to allow the host DSP to access the individual
converter. CS can be tied to ground if only one converter is used. FS must be tied to DVDD if it is not used (such
as in an SPI interface). When SDI is tied to DVDD, the device is set in hardware default mode after power-on,
and no software configuration is required. In the simplest case, only three wires (SDO, SCLK, and CS or FS)
are needed to interface with the host.
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
Copyright 2000 – 2003, Texas Instruments Incorporated
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
1
TLC3544, TLC3548
5-V ANALOG, 3-/5-V DIGITAL, 14-BIT, 200-KSPS, 4-/8-CHANNELS SERIAL
ANALOG-TO-DIGITAL CONVERTERS WITH 0-5 V (PSEUDODIFFERENTIAL) INPUTS
SLAS266C – OCTOBER 2000 – REVISED MAY 2003
description (continued)
In addition to being a high-speed ADC with versatile control capability, these devices have an on-chip analog
multiplexer (MUX) that can select any analog input or one of three self-test voltages. The sample-and-hold
function is automatically started after the fourth SCLK (normal sampling) or can be controlled by CSTART to
extend the sampling period (extended sampling). The normal sampling period can also be programmed as short
sampling (12 SCLKs) or long sampling (44 SCLKs) to accommodate the faster SCLK operation popular among
high-performance signal processors. The TLC3544 and TLC3548 are designed to operate with low power
consumption. The power saving feature is further enhanced with software power-down/ autopower-down
modes and programmable conversion speeds. The conversion clock (internal OSC) is built in. The converter
can also use an external SCLK as the conversion clock for maximum flexibility. The TLC3544 and TLC3548
have a 4-V internal reference. The converters are specified with unipolar input range of 0-V to 5-V when a 5-V
external reference is used.
AVAILABLE OPTIONS
PACKAGED DEVICES
TA
20-TSSOP
(PW)
20-SOIC
(DW)
24-SOIC
(DW)
24-TSSOP
(PW)
0°C to 70°C
TLC3544CPW
TLC3544CDW
TLC3548CDW
TLC3548CPW
– 40°C to 85°C
TLC3544IPW
TLC3544IDW
TLC3548IDW
TLC3548IPW
functional block diagram
DVDD
REFP
BGAP
REFM
X8
A0
A1
A2
A3
A4
A5
A6
A7
X4
A0
A1
A2
A3
X
X
X
X
AVDD
4-V
Reference
SAR
ADC
Analog
MUX
FIFO
X8
OSC
SDO
Command
Decode
Conversion
Clock
CFR
SDI
CMR (4 MSBs)
SCLK
CS
FS
Control
Logic
4-Bit
Counter
CSTART
DGND AGND
2
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
EOC/INT
TLC3544, TLC3548
5-V ANALOG, 3-/5-V DIGITAL, 14-BIT, 200-KSPS, 4-/8-CHANNELS SERIAL
ANALOG-TO-DIGITAL CONVERTERS WITH 0-5 V (PSEUDODIFFERENTIAL) INPUTS
SLAS266C – OCTOBER 2000 – REVISED MAY 2003
equivalent input circuit
VDD
MUX
1.1 kΩ
Max
Ain
VDD
Ron
C(sample) = 30 pF Max
Digital Input
REFM
Diode Turn on Voltage: 35 V
Equivalent Digital Input Circuit
Equivalent Analog Input Circuit
Terminal Functions
TERMINAL
NAME
NO.
I/O
DESCRIPTION
9
10
11
12
13
14
15
16
I
Analog signal inputs. Analog input signals applied to these terminals are internally multiplexed. The
driving source impedance should be less than or equal to 1 kΩ for normal sampling. For larger
source impedance, use the external hardware conversion start signal CSTART (the low time of
CSTART controls the sampling period) or reduce the frequency of SCLK to increase the sampling
time.
14, 18
18, 22
I
Analog ground return for the internal circuitry. Unless otherwise noted, all analog voltage
measurements are with respect to AGND.
13, 19
17, 23
I
Analog supply voltage
17
21
I
Internal bandgap compensation pin. Install compensation capacitors between BGAP and AGND.
0.1 µF for external reference; 10 µF in parallel with 0.1 µF for internal reference.
8
8
I
Chip select. When CS is high, SDO is in high-impedance state, SDI is ignored, and SCLK is
disabled to clock data but works as conversion clock source if programmed. The falling edge of CS
input resets the internal 4-bit counter, enables SDI and SCLK, and removes SDO from
high-impedance state.
TLC3544
TLC3548
9
10
11
12
AGND
AVDD
BGAP
A0
A1
A2
A3
A0
A1
A2
A3
A4
A5
A6
A7
CS
If FS is high at CS falling edge, CS falling edge initiates the operation cycle. CS works as slave
select (SS) to provide an SPI interface.
If FS is low at CS falling edge, FS rising edge initiates the operation cycle. CS can be used as chip
select to allow the host to access the individual converter.
CSTART
20
24
I
DGND
6
6
I
External sampling trigger signal, which initiates the sampling from a selected analog input channel
when the device works in extended sampling mode (asynchronous sampling). A high-to-low
transition starts the sampling of the analog input signal. A low-to-high transition puts the S/H in hold
mode and starts the conversion. The low time of the CSTART signal controls the sampling period.
CSTART signal must be long enough for proper sampling. CSTART must stay high long enough
after the low-to-high transition for the conversion to finish maturely. The activation of CSTART is
independent of SCLK and the level of CS and FS. However, the first CSTART cannot be issued
before the rising edge of the 11th SCLK. Tie this terminal to DVDD if not used.
Digital ground return for the internal circuitry
DVDD
7
7
I
Digital supply voltage
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
3
TLC3544, TLC3548
5-V ANALOG, 3-/5-V DIGITAL, 14-BIT, 200-KSPS, 4-/8-CHANNELS SERIAL
ANALOG-TO-DIGITAL CONVERTERS WITH 0-5 V (PSEUDODIFFERENTIAL) INPUTS
SLAS266C – OCTOBER 2000 – REVISED MAY 2003
Terminal Functions (Continued)
TERMINAL
NO.
NAME
EOC(INT)
I/O
TLC3544
TLC3548
4
4
O
DESCRIPTION
End of conversion (EOC) or interrupt to host processor (INT)
EOC: used in conversion mode 00 only. EOC goes from high to low at the end of the sampling and
remains low until the conversion is complete and data is ready.
INT: Interrupt to the host processor. The falling edge of INT indicates data is ready for output. INT
is cleared by the following CS↓, FS↑, or CSTART↓.
FS
2
2
I
REFM
16
20
I
REFP
15
19
I
External positive reference input. When an external reference is used, the range of maximum input
voltage is determined by the difference between the voltage applied to this terminal and to the
REFM terminal. Always install decoupling capacitors (10 µF in parallel with 0.1 µF) between REFP
and REFM.
SCLK
1
1
I
Serial clock input from the host processor to clock in the input from SDI and clock out the output
via SDO. It can also be used as the conversion clock source when the external conversion clock
is selected (see Table 2). When CS is low, SCLK is enabled. When CS is high, SCLK is disabled
for the data transfer, but can still work as the conversion clock source.
SDI
3
3
I
Serial data input. The first 4 MSBs, ID[15:12], are decoded as one 4-bit command. All trailing bits,
except for the CONFIGURE WRITE command, are filled with zeros. The CONFIGURE WRITE
command requires additional 12-bit data. The MSB of input data, ID[15], is latched at the first falling
edge of SCLK following FS falling edge, if FS starts the operation, or latched at the falling edge of
first SCLK following CS falling edge when CS initiates the operation.
SDO
5
5
O
Frame sync input from DSP. The rising edge of FS indicates the start of a serial data frame being
transferred (coming into or being sent out of the device). If FS is low at the falling edge of CS, the
rising edge of FS initiates the operation cycle, resets the internal 4-bit counter, and enables SDI,
SDO, and SCLK. Tie this pin to DVDD if FS is not used to initiate the operation cycle.
External low reference input. Connect REFM to AGND.
The remaining input data (if any) is shifted in on the rising edge of SCLK and latched on the falling
edge of SCLK. The input via SDI is ignored after the 4-bit counter counts to 16 (clock edges) or a
low-to-high transition of CS, whichever happens first. Refer to the timing specification for the timing
requirements. Tie SDI to DVDD if using hardware default mode (refer to device initialization).
The 3-state serial output for the A/D conversion result. All data bits are shifted out through SDO.
SDO is in the high-impedance state when CS is high. SDO is released after a CS falling edge. The
output format is MSB (OD[15]) first.
When FS initiates the operation, the MSB of output via SDO, OD[15], is valid before the first falling
edge of SCLK following the falling edge of FS.
When CS initiates the operation, the MSB, OD[15], is valid before the first falling edge of SCLK
following the CS falling edge.
The remaining data bits are shifted out on the rising edge of SCLK and are valid before the falling
edge of SCLK. Refer to the timing specification for the details.
In a select/conversion operation, the first 14 bits are the results from the previous conversion (data).
In READ FIFO operation, the data is from FIFO. In both cases, the last two bits are don’t care.
In a WRITE operation, the output from SDO is ignored.
SDO goes into high-impedance state at the sixteenth falling edge of SCLK after the operation cycle
is initiated. SDO is in high-impedance state during conversions in modes 01, 10, and 11.
4
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
TLC3544, TLC3548
5-V ANALOG, 3-/5-V DIGITAL, 14-BIT, 200-KSPS, 4-/8-CHANNELS SERIAL
ANALOG-TO-DIGITAL CONVERTERS WITH 0-5 V (PSEUDODIFFERENTIAL) INPUTS
SLAS266C – OCTOBER 2000 – REVISED MAY 2003
absolute maximum ratings over operating free-air temperature (unless otherwise noted)†
Supply voltage, GND to AVDD, DVDD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.3 V to 6.5 V
Analog input voltage range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.2 V to AVDD +0.2 V
Analog input current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 mA MAX
Reference input voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AVDD + 0.3 V
Digital input voltage range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.3 V to DVDD + 0.3 V
Operating virtual junction temperature range, TJ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –40°C to 150°C
Operating free-air industrial temperature range, TA: I suffix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –40°C to 85°C
C suffix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0°C to 70°C
Storage temperature range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 65°C to 150°C
Lead temperature 1,6 mm (1.16 inch) from case for 10 seconds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260°C
† Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and
functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not
implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
5
TLC3544, TLC3548
5-V ANALOG, 3-/5-V DIGITAL, 14-BIT, 200-KSPS, 4-/8-CHANNELS SERIAL
ANALOG-TO-DIGITAL CONVERTERS WITH 0-5 V (PSEUDODIFFERENTIAL) INPUTS
SLAS266C – OCTOBER 2000 – REVISED MAY 2003
general electrical characteristics over recommended operating free-air temperature range,
single-ended input, normal long sampling, 200 KSPS, AVDD = 5 V, external reference (VREFP = 4 V,
VREFM = 0 V) or internal reference, SCLK frequency = 25 MHz, fixed channel at CONV mode 00,
analog input signal source resistance = 25 Ω (unless otherwise noted)
PARAMETER
TEST CONDITIONS
MIN
TYP†
MAX
UNIT
Digital Input
VIH
High level control input voltage
High-level
VIL
Low-level
Low
level control in
input
ut voltage
DVDD = 5 V
3.8
DVDD = 3 V
DVDD = 5 V
2.1
V
0.8
DVDD = 3 V
IIH
IIL
High-level input current
0.6
VI = DVDD
VI = DGND
Low-level input current
0.005
–2.5
Input capacitance
2.5
µA
µA
0.005
20
V
25
pF
Digital output
VOH
VOL
IOZ
High-level
High
level digital output,
out ut,
VOH at 30-pF load
IO = –0.2
0 2 mA
Low-level
output,
Low
level digital out
ut,
VOL at 30-pF load
4.2
DVDD = 3 V
2.4
V
DVDD = 5 V
IO = 0.8 mA
IO = 50 µA
0.4
DVDD = 3 V
IO = 0.8 mA
IO = 50 µA
0.4
VO = DVDD
VO = DGND
Off state out
Off-state
output
ut current
(high-impedance state)
DVDD = 5 V
0.1
V
0.1
0.02
CS = DVDD
1
µA
–1
–0.02
4.5
5
5.5
V
2.7
5
5.5
V
2.8
3.6
1.2
2
SCLK ON
175
240
SCLK OFF
20
SCLK ON
175
SCLK OFF
20
Power Supply
AVDD
DVDD
Supply voltage
ICC
Power su
ly
supply
current
ICC(SW)
ICC(Autodown)
CC(A t d
)
AVDD currentAICC
DVDD currentDICC
Conversion clock is internal OSC,
EXT.
5.5
4.5
V,
EXT reference,
reference AVDD = 5
5 V to 4
5V
CS = DGND
For all digital inputs DVDD or
DGND, CS = DVDD,
S ft
Software
power-down
d power
supply
lcurrentt DGND
AVDD = 5.5 V
For all digital inputs DVDD or
Autopower-down power supply
DGND, AVDD = 5
5.5
V,
DGND
5V
current
External reference
C suffix
Operating temperat
temperature
re
I suffix
† All typical values are at TA = 25°C.
6
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
mA
230
0
70
–40
85
µA
µA
°C
TLC3544, TLC3548
5-V ANALOG, 3-/5-V DIGITAL, 14-BIT, 200-KSPS, 4-/8-CHANNELS SERIAL
ANALOG-TO-DIGITAL CONVERTERS WITH 0-5 V (PSEUDODIFFERENTIAL) INPUTS
SLAS266C – OCTOBER 2000 – REVISED MAY 2003
general electrical characteristics over recommended operating free-air temperature range,
single-ended input, normal long sampling, 200 KSPS, AVDD = 5 V, external reference (VREFP = 4 V,
VREFM = 0 V) or internal reference, SCLK frequency = 25 MHz, fixed channel at CONV mode 00,
analog input signal source resistance = 25 Ω (unless otherwise noted) (continued)
PARAMETER
TEST CONDITIONS
Resolution
MIN
TYP†
MAX
14
UNIT
bits
Analog Input
Voltage range
0
Leakage current
Reference
0.01
Capacitance
V
0.05
µA
30
pF
4.07
V
Reference
Internal reference voltage
3.85
100
Internal reference source current
1.8
Internal reference startup time
VREFP
VREFM
4
Internal reference temperature
coefficient
2.5
20
External positive reference voltage
3
External negative reference voltage
0
External reference input impedance
External reference current
ppm/°C
No conversion (AVDD = 5 V,
CS = DVDD, SCLK = DGND)
100
Normal long sampling (AVDD = 5 V,
CS = DGND, SCLK = 25 MHz,
External conversion clock)
8.3
No conversion (VREFP = AVDD = 5 V,
VREFM = AGND, External reference,
CS = DVDD)
Normal long sampling (AVDD = 5 V,
CS = DGND, SCLK = 25 MHz external
conversion clock at VREF = 5 V)
mA
ms
5
AGND
V
V
MΩ
12.5
kΩ
1.5
µA
0.4
0.6
mA
Throughput Rate
f
Internal oscillation frequency
DVDD = 2.7 V to 5.5 V
t(conv)
Conversion time
Conversion clock is external source,
SCLK = 25 MHz (see Note 1)
Acquisition time
Normal short sampling
Throughput rate (see Note 2)
Normal long sampling, fixed channel in mode
00 or 01
6.5
MHz
Internal OSC, 6.5 MHz minute
2.785
µs
2.895
µs
1.2
200
KSPS
DC Accuracy—Normal Long Sampling
EL
ED
Integral linearity error
See Note 3
Differential linearity error
–1
±0.5
1
LSB
–1
±0.5
1
LSB
EO
Zero offset error
See Note 4
–3
±0.6
3
LSB
E(g+)
Gain error
See Note 4
0
5
12
LSB
† All typical values are at TA = 25°C.
NOTES: 1. Conversion time t(conv) = (18x4 / SCLK) + 15 ns.
2. This is for a fixed channel in conversion mode 00 or 01. When switching the channels, additional multiplexer setting time is required
to overcome the memory effect of the charge redistribution DAC (refer to Figure 8).
3. Linear error is the maximum deviation from the best fit straight line through the A/D transfer characteristics.
4. Zero offset error is the difference between 0000000000000 and the converted output for zero input voltage; gain error is the
difference between 11111111111111 and the converted output for full-scale input voltage. The full-scale input voltage is equal to the
reference voltage being used.
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
7
TLC3544, TLC3548
5-V ANALOG, 3-/5-V DIGITAL, 14-BIT, 200-KSPS, 4-/8-CHANNELS SERIAL
ANALOG-TO-DIGITAL CONVERTERS WITH 0-5 V (PSEUDODIFFERENTIAL) INPUTS
SLAS266C – OCTOBER 2000 – REVISED MAY 2003
general electrical characteristics over recommended operating free-air temperature range,
single-ended input, normal long sampling, 200 KSPS, AVDD = 5 V, external reference (VREFP = 4V,
VREFM = 0 V) or internal reference, SCLK frequency = 25 MHz, fixed channel at CONV mode 00,
analog input signal source resistance = 25 Ω (unless otherwise noted) (continued)
PARAMETER
DC Accuracy—Normal Short Sampling
EL
ED
Integral linearity error
TEST CONDITIONS
MIN
SINAD
Signal to noise ratio + distortion
Signal-to-noise
THD
Total harmonic distortion
SFDR
Spurious free dynamic range
ENOB
Effective number of bits
SNR
Signal to noise ratio
Signal-to-noise
Channel-to-channel isolation (see
Notes 2 and 5)
Analog input bandwidth
MAX
±0.8
See Note 3
UNIT
LSB
±0.6
Differential linearity error
EO
Zero offset error
E(g+)
Gain error
AC Accuracy—Normal Long Sampling
TYP†
LSB
See Note 4
–3
±0.6
3
LSB
See Note 4
0
5
12
LSB
78.6
80.8
fi = 20 kHz
fi = 100 kHz
fi = 20 kHz
dB
77.6
–95
–88
fi = 100 kHz
fi = 20 kHz
90
97
89
fi = 100 kHz
fi = 20 kHz
12.8
13.1
12.6
fi = 100 kHz
fi = 20 kHz
79
81
78
fi = 100 kHz
Fixed channel in conversion mode 00, fi = 35 kHz
100
Full power bandwidth, –1 dB
2
Full power bandwidth, –3 dB
2.5
–90
dB
dB
Bits
dB
dB
MHz
AC Accuracy—Normal Short Sampling
SINAD
Signal to noise ratio + distortion
Signal-to-noise
THD
Total harmonic distortion
SNR
Signal to noise ratio
Signal-to-noise
ENOB
Effective number of bits
SFDR
Spurious free dynamic range
fi = 20 kHz
fi = 100 kHz
78.9
fi = 20 kHz
fi = 100 kHz
fi = 20 kHz
–95
fi = 100 kHz
fi = 20 kHz
78
77.6
–88
79
12.8
fi = 100 kHz
fi = 20 kHz
12.6
fi = 100 kHz
89
97
dB
dB
dB
Bits
dB
Channel-to-channel isolation (see
Notes 2 and 5)
Fixed channel in conversion mode 00, fi = 35 kHz
100
dB
Analog input bandwidth
Full power bandwidth, –1 dB
Full power bandwidth, –3 dB
2
2.5
MHz
† All typical values are at TA = 25°C.
NOTES: 2. This is for a fixed channel in conversion mode 00 or 01. When switching the channels, additional multiplexer setting time is required
to overcome the memory effect of the charge redistribution DAC (refer to Figure 8).
3. Linear error is the maximum deviation from the best fit straight line through the A/D transfer characteristics.
4. Zero offset error is the difference between 0000000000000 and the converted output for zero input voltage; gain error is the
difference between 11111111111111 and the converted output for full-scale input voltage. The full-scale input voltage is equal to the
reference voltage being used.
5. It is measured by applying a full-scale of 35 kHz signal to other channels and determining how much the signal is attenuated in the
channel of interest. The converter samples this examined channel continuously. The channel-to-channel isolation is degraded if the
converter samples different channels alternately (refer to Figure 8).
8
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
TLC3544, TLC3548
5-V ANALOG, 3-/5-V DIGITAL, 14-BIT, 200-KSPS, 4-/8-CHANNELS SERIAL
ANALOG-TO-DIGITAL CONVERTERS WITH 0-5 V (PSEUDODIFFERENTIAL) INPUTS
SLAS266C – OCTOBER 2000 – REVISED MAY 2003
timing requirements over recommended operating free-air temperature range, AVDD = 5 V,
= 5 V, VREFP = 5 V, VREFM = 0 V, SCLK frequency = 25 MHz (unless otherwise noted)
DVDD
SCLK, SDI, SDO, EOC and INT
PARAMETERS
MIN
DVDD = 2.7 V
DVDD = 5 V
TYP
MAX
100
40†
UNIT
tc(1)
(1)
Cycle time of SCLK at 25-pF
25 pF load
tw(1)
Pulse width, SCLK high time at 25-pF load
tr(1)
Rise time for INT,
INT EOC at 10-pF
10 pF load
tf(1)
Fall time for INT,
INT EOC at 10-pF
10 pF load
tsu(1)
Setup time, new SDI valid (reaches 90% final level) before falling edge of SCLK, at 25-pF
load
6
–
ns
th(1)
Hold time, old SDI hold (reaches 10% of old data level) after falling edge of SCLK, at
25-pF load
0
–
ns
Delay time, new SDO valid (reaches 90% of final level) after SCLK rising
edge, at 10-pF load
0
td(1)
0
10
23‡
ns
0
–
ns
0
6
ns
t(conv)
t(conv) + 6
µs
th(2)
40%
DVDD = 5 V
DVDD = 2.7 V
Delay time, delay from sixteenth SCLK falling edge to EOC falling edge, normal sampling,
at 10-pF load
td(3)
Delay time, delay from the sixteenth falling edge of SCLK to INT falling edge, at 10-pF
load [see the (‡) double dagger note and Note 6]
tc(1)
6
ns
6
DVDD = 2.7 V
td(2)
60%
10
DVDD = 5 V
DVDD= 5 V
DVDD = 2.7 V
Hold time, old SDO hold (reaches 10% of old data level) after SCLK rising edge, at 10-pF
load
ns
10
ns
† The minimum pulse width of SCLK high is 12.5 ns. The minimum pulse width of SCLK low is 12.5 ns.
‡ Specified by design
NOTE 6: For normal short sampling, td(3) is the delay from 16th falling edge of SCLK to INT falling edge.
For normal long sampling, td(3) is the delay from 48th falling edge of SCLK to the falling edge of INT.
Conversion time, t(conv) is equal to 18 × OSC + 15 ns when using internal OSC as conversion clock, or 72 × tc(1) + 15 ns when external
SCLK is conversion clock source.
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
9
TLC3544, TLC3548
5-V ANALOG, 3-/5-V DIGITAL, 14-BIT, 200-KSPS, 4-/8-CHANNELS SERIAL
ANALOG-TO-DIGITAL CONVERTERS WITH 0-5 V (PSEUDODIFFERENTIAL) INPUTS
SLAS266C – OCTOBER 2000 – REVISED MAY 2003
VIH
90%
50%
10%
CS
VIL
tc(1)
tw(1)
1
SCLK
16
th(1)
tsu(1)
SDI
Don’t Care
ID15 ID1
Don’t Care
ID0
td(1)
th(2)
SDO
Hi-Z
OD15 OD1
Hi-Z
OD0
td(2)
See Note A
tr(1)
EOC
tf(1)
OR
td(3)
See Note B
INT
tf(1)
tr(1)
NOTES: A. For normal long sampling, td(2) is the delay time of EOC low after the falling edge of 48th SCLK.
B. For normal long sampling, td(3) is the delay time of INT low after the falling edge of 48th SCLK.
– – – – The dotted line means signal may or may not exist, depending on application. It must be ignored.
Normal sampling mode, CS initiates the conversion, FS must be tied to high. When CS is high, SDO is in Hi-Z; all inputs (FS, SCLK,
SDI) are inactive and are ignored.
Figure 1. Critical Timing for SCLK, SDI, SDO, EOC and INT
10
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
TLC3544, TLC3548
5-V ANALOG, 3-/5-V DIGITAL, 14-BIT, 200-KSPS, 4-/8-CHANNELS SERIAL
ANALOG-TO-DIGITAL CONVERTERS WITH 0-5 V (PSEUDODIFFERENTIAL) INPUTS
SLAS266C – OCTOBER 2000 – REVISED MAY 2003
timing requirements over recommended operating free-air temperature range, AVDD = 5 V,
DVDD = 5 V, VREFP = 5 V, VREFM = 0 V, SCLK frequency = 25 MHz (unless otherwise noted) (continued)
CS trigger
PARAMETERS
MIN
TYP
MAX
tsu(2)
td(4)
Setup time, CS falling edge before SCLK rising edge, at 25-pF load
Delay time, delay time from 16th SCLK falling edge to CS rising edge, at 25-pF load ‡
5
ns
tw(2)
Pulse width, CS high time at 25-pF load
1
tc(1)
td(5)
Delay time, delay from CS falling edge to MSB of SDO valid (reaches 90%
final level), at 10-pF load
td(6)
Delay time, delay from CS rising edge to SDO 3-state, at 10-pF load
td(7)
12
UNIT
Delay time,
time delay from CS falling edge to INT rising edge,
edge at 10
10-pF
pF load
DVDD = 5 V
DVDD = 2.7 V
ns
0
0
12
30†
ns
0
6
ns
DVDD = 5 V
0
DVDD = 2.7 V
0
6
16†
ns
† Specified by design
‡ For normal short sampling, td(4) is the delay time from 16th SCLK falling edge to CS rising edge.
For normal long sampling, td(4) is the delay time from 48th SCLK falling edge to CS rising edge.
VIH
VIL
CS
tsu(2)
SCLK
SDI
SDO
td(4)
1
Don’t Care
Hi-Z
tw(2)
16
ID1
ID0
Don’t Care
OD15 OD1
OD0
Hi-Z
ID15
Don’t Care
td(6)
td(5)
OD15
OD7
Hi-Z
EOC
OR
td(7)
INT
NOTE A:
– – – – The dotted line means signal may or may not exist, depending on application. It must be ignored.
Normal sampling mode, CS initiates the conversion, FS must be tied to high. When CS is high, SDO is in Hi-Z, all inputs (FS, SCLK,
SDI) are inactive and are ignored. Parts with date code earlier than 13XXXXX have these discrepancies:
(Date code is a 7 digit code next to the TI where the first digit indicates the year and the second digit is the month of production. 13,
in this case, is 2001 and the month of March.)
FS is not ignored even if the device is in microcontroller mode (CS triggered).
FS must be tied to DVDD.
Figure 2. Critical Timing for CS Trigger
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
11
TLC3544, TLC3548
5-V ANALOG, 3-/5-V DIGITAL, 14-BIT, 200-KSPS, 4-/8-CHANNELS SERIAL
ANALOG-TO-DIGITAL CONVERTERS WITH 0-5 V (PSEUDODIFFERENTIAL) INPUTS
SLAS266C – OCTOBER 2000 – REVISED MAY 2003
timing requirements over recommended operating free-air temperature range, AVDD = 5 V,
DVDD = 5 V, VREFP = 5 V, VREFM = 0 V, SCLK frequency = 25 MHz (unless otherwise noted) (continued)
FS trigger
PARAMETERS
MIN
td(8)
tsu(3)
Delay time, delay from CS falling edge to FS rising edge, at 25-pF load
tw(3)
Pulse width, FS high at 25-pF load
td(9)
Delay time, delay from FS rising edge to MSB of SDO valid
(reaches 90% final level) at 10-pF load
td(10)
Delay time, delay from FS rising edge to next FS rising edge at 25-pF load
td(11)
Delay time, delay from FS rising edge to INT rising edge at
10-pF load
TYP
MAX
tc(1)
0.5×tc(1)+5
1.25×tc(1)
26†
0.5
Setup time, FS rising edge before SCLK falling edge, at 25-pF load
0.25×tc(1)
0.75×tc(1)
DVDD = 5 V
DVDD = 2.7 V
30†
Required
sampling time +
conversion time
DVDD = 5 V
UNIT
tc(1)
ns
ns
ns
µs
6†
16†
0
DVDD = 2.7 V
ns
† Specified by design
VIH
VIL
td(10)
CS
td(8)
tw(3)
FS
tsu(3)
SCLK
SDI
Don’t Care
16
1
ID15 ID1
ID0
Don’t Care
ID15
Don’t Care
td(9)
SDO
Hi-Z
OD15
OD1
OD0
Hi-Z
OD15
Don’t Care
VOH
EOC
OR
td(11)
VOH
INT
NOTE A:
– – – – The dotted line means signal may or may not exist, depending on application. It must be ignored.
Normal sampling mode, FS initiates the conversion, CS can be tied to low. When CS is high, SDO is in Hi-Z, all inputs (FS, SCLK, SDI)
are inactive and are ignored.
Parts with date code earlier than 13XXXXX have these discrepancies:
(Date code is a 7 digit code next to the TI where the first digit indicates the year and the second digit is the month of production. 13,
in this case, is 2001 and the month of March.)
SDO MSB (OD[15]) comes out from the falling edge of CS instead of FS rising edge in DSP mode (FS triggered).
Figure 3. Critical Timing for FS Trigger
12
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
TLC3544, TLC3548
5-V ANALOG, 3-/5-V DIGITAL, 14-BIT, 200-KSPS, 4-/8-CHANNELS SERIAL
ANALOG-TO-DIGITAL CONVERTERS WITH 0-5 V (PSEUDODIFFERENTIAL) INPUTS
SLAS266C – OCTOBER 2000 – REVISED MAY 2003
timing requirements over recommended operating free-air temperature range, AVDD = 5 V,
DVDD = 5 V, VREFP = 5 V, VREFM = 0 V, SCLK frequency = 25 MHz (unless otherwise noted) (continued)
CSTART trigger
PARAMETERS
MIN
TYP
MAX
UNIT
0
15
21
ns
td(12)
Delay time, delay from CSTART rising edge to EOC falling
edge, at 10-pF load
tw(4)
Pulse width CSTART low time: tW(L)(CSTART), at 25-pF load
t(sample – ref)+0.4
Note 7
µs
td(13)
Delay time, delay from CSTART rising edge to CSTART falling
edge, at 25-pF load
t(conv) +15
Notes 7 and 8
ns
td(14)
Delay time, delay from CSTART rising edge to INT falling edge,
at 10-pF load
t(conv) +15
Notes 7 and 8
td(15)
Delay time, delay from CSTART falling edge to INT rising edge,
at 10-pF load
0
t(conv)+21
ns
6
µs
NOTES: 7. The pulse width of CSTART must be not less than the required sampling time. The delay from CSTART rising edge to following
CSTART falling edge must not be less than the required conversion time. The delay from CSTART rising edge to the INT falling edge
is equal to the conversion time.
8. The maximum rate of SCLK is 25 MHz for normal long sampling and 10 MHz for normal short sampling.
tw(4)
td(13)
CSTART
t(conv)
td(12)
EOC
td(15)
OR
td(14)
INT
Extended Sampling
Figure 4. Critical Timing for Extended Sampling (CSTART Trigger)
detailed description
converter
The converters are a successive-approximation ADC utilizing a charge redistribution DAC. Figure 5 shows a
simplified block diagram of the ADC. The sampling capacitor acquires the signal on Ain during the sampling
period. When the conversion process starts, the control logic directs the charge redistribution DAC to add and
subtract fixed amounts of charge from the sampling capacitor to bring the comparator into a balanced condition.
When balanced, the conversion is complete and the ADC output code is generated.
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
13
TLC3544, TLC3548
5-V ANALOG, 3-/5-V DIGITAL, 14-BIT, 200-KSPS, 4-/8-CHANNELS SERIAL
ANALOG-TO-DIGITAL CONVERTERS WITH 0-5 V (PSEUDODIFFERENTIAL) INPUTS
SLAS266C – OCTOBER 2000 – REVISED MAY 2003
detailed description (continued)
Charge
Redistribution
DAC
_
Ain
+
Control
Logic
ADC Code
REFM
Figure 5. Simplified Block Diagram of the Successive-Approximation System
analog input range and internal test voltages
TLC3548 has eight analog inputs (TLC3544 has four) and three test voltages. The inputs are selected by the
analog multiplexer according to the command entered (see Table 1). The input multiplexer is a breakbefore-make type to reduce input-to-input noise injection resulting from channel switching.
The TLC3544 and TLC3548 are specified for a unipolar input range of 0-V to 4-V when the internal reference
is selected, and 0-V to 5-V when an external 5-V reference is used.
analog input mode
Two input signal modes can be selected: single-ended input and pseudodifferential input.
Charge
Redistribution
DAC
S1
Ain(+)
_
Ain(–)
+
REFM
Control
Logic
ADC Code
When sampling, S1 is closed and S2 connects to Ain(–).
During conversion, S1 is open and S2 connects to REFM.
Figure 6. Simplified Pseudodifferential Input Circuit
Pseudodifferential input refers to the negative input, Ain(–); its voltage is limited in magnitude to ±0.2 V. The input
frequency limit of Ain(–) is the same as the positive input Ain(+). This mode is normally used for ground noise
rejection or dc bias offset.
When pseudodifferential mode is selected, only two analog input channel pairs are available for the TLC3544
and four channel pairs for the TLC3548, because half the inputs are used as the negative input (see Figure 7).
14
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
TLC3544, TLC3548
5-V ANALOG, 3-/5-V DIGITAL, 14-BIT, 200-KSPS, 4-/8-CHANNELS SERIAL
ANALOG-TO-DIGITAL CONVERTERS WITH 0-5 V (PSEUDODIFFERENTIAL) INPUTS
SLAS266C – OCTOBER 2000 – REVISED MAY 2003
analog input mode (continued)
Single Ended
X8† X4‡
A0 A0
A1 A1
A2 A2
A3 A3
X
A4
X
A5
X
A6
X
A7
Analog
MUX
Pseudodifferential
SAR
ADC
X8†
A0(+)
A1(–)
A2(+)
A3(–)
A4(+)
A5(–)
A6(+)
A7(–)
Pair A
Pair B
X4‡
A0(+) Pair A
A1(–)
A2(+) Pair B
A3(–)
Pair C
Analog
MUX
SAR
ADC
Pair D
† TLC3548
‡ TLC3544
Figure 7. Pin Assignment of Single-Ended Input vs Pseudodifferential Input
reference voltage
There is a built-in 4-V reference. If the internal reference is used, REFP is internally set to 4-V and REFM is set
to 0-V. The external reference can be applied to the reference-input pins (REFP and REFM) if programmed (see
Table 2). The REFM pin should connect to analog ground. REFP can be 3-V to 5-V. Install decoupling capacitors
(10 µF in parallel with 0.1 µF) between REFP and REFM. Install compensation capacitors (10 µF in parallel with
0.1 µF for internal reference, 0.1 µF only for external reference) between BGAP and AGND.
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
15
TLC3544, TLC3548
5-V ANALOG, 3-/5-V DIGITAL, 14-BIT, 200-KSPS, 4-/8-CHANNELS SERIAL
ANALOG-TO-DIGITAL CONVERTERS WITH 0-5 V (PSEUDODIFFERENTIAL) INPUTS
SLAS266C – OCTOBER 2000 – REVISED MAY 2003
detailed description (continued)
2s Complement
BTC
01111111111111
Binary
USB
11111111111111
01111111111110
11111111111110
16383
01111111111101
11111111111101
16382
16381
00000000000001
10000000000001
8193
00000000000000
10000000000000
8192
11111111111111
01111111111111
8191
10000000000010
00000000000010
2
10000000000001
00000000000001
1
10000000000000
00000000000000
0
Step
Digital Output Code
ideal conversion characteristics
VREFP = VFS = 4 V
VREFM = VZS = 0 V
1.999878 V
122 µV
2.000122 V
VMS = (VFS + VZS)/2 = 2 V
244 µV
VFS – 1 LSB = 3.999756 V
3.999512 V
488 µV
1 LSB = 244 µV
Unipolar Analog Input Voltage
data format
INPUT DATA FORMAT (BINARY)
OUTPUT DATA FORMAT READ CONVERSION/FIFO
MSB
LSB
MSB
LSB
ID[15:12]
ID[11:0]
OD[15:2]
OD[1:0]
Command
Configuration data field or filled with zeros
Conversion result
Don’t Care
14-BIT
Unipolar Straight Binary Output: (USB)
Zero-scale code = VZS = 0000h, Vcode = VREFM
Mid-scale code = VMS = 2000h, Vcode = VREFP/2
Full-scale code = VFS = 3FFFh, Vcode = VREFT – 1 LSB
UnIpolar Input, Binary 2’s Complement Output: (BTC)
Zero-scale code = VZS = 2000 h, Vcode = VREFM
Mid-scale code = VMS = 0000h, Vcode = (VREFP – VREFM)/2
Full-scale code = VFS = 1FFFh, Vcode = VREFP – 1 LSB
16
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
TLC3544, TLC3548
5-V ANALOG, 3-/5-V DIGITAL, 14-BIT, 200-KSPS, 4-/8-CHANNELS SERIAL
ANALOG-TO-DIGITAL CONVERTERS WITH 0-5 V (PSEUDODIFFERENTIAL) INPUTS
SLAS266C – OCTOBER 2000 – REVISED MAY 2003
detailed description (continued)
operation description
The converter samples the selected analog input signal, then converts the sample into digital output, according
to the selected output format. The converter has four digital input pins (SDI, SCLK, CS, and FS) and one digital
output pin (SDO) to communicate with the host device. SDI is a serial data input pin, SDO is a serial data output
pin, and SCLK is a serial clock from the host device. This clock is used to clock the serial data transfer. It can
also be used as the conversion clock source (see Table 2). CS and FS are used to start the operation. The
converter has a CSTART pin for an external hardware sampling and conversion trigger, and an INT/EOC pin
for interrupt purposes.
device initialization
After power on, the status of EOC/INT is initially high, and the input data register is set to all zeros. The device
must be initialized before starting the conversion. The initialization procedure depends on the working mode.
The first conversion result is ignored after power on.
Hardware Default Mode: Nonprogrammed Mode, Default. After power on, two consecutive active cycles
initiated by CS or FS put the device into hardware default mode if SDI is tied to DVDD. Each of these cycles must
last 16 SCLKs at least. These cycles initialize the converter and load the CFR register with 800h (external
reference, unipolar straight binary output code, normal long sampling, internal OSC, single-ended input,
one-shot conversion mode, and EOC/INT pin as INT). No additional software configuration is required.
Software Programmed Mode: Programmed. When the converter has to be configured, the host must write
A000h into the converter first after power on, then perform the WRITE CFR operation to configure the device.
start of operation cycle
Each operation consists of several actions that the converter takes according to the command from the host.
The operation cycle includes three periods: command period, sampling period, and conversion period. In the
command period, the device decodes the command from the host. In the sampling period, the device samples
the selected analog signal according to the command. In the conversion period, the sample of the analog signal
is converted to digital format. The operation cycle starts from the command period, which is followed by one
or several sampling and conversion periods (depending on the setting) and finishes at the end of the last
conversion period.
The operation cycle is initiated by the falling edge of CS or the rising edge of FS.
CS Initiates The Operation: If FS is high at the falling edge of CS, the falling edge of CS initiates the operation.
When CS is high, SDO is in the high-impedance state, the signals on SDI, and SDO are ignored, and SCLK is
disabled to clock the serial data. The falling edge of CS resets the internal 4-bit counter and enables SDO, SDI,
and SCLK. The MSB of the input data via SDI, ID[15], is latched at the first falling edge of SCLK following the
falling edge of CS. The MSB of output data from SDO, OD[15], is valid before this SCLK falling edge. This mode
works as an SPI interface when CS is used as the slave select (SS). It also can be used as a normal DSP
interface if CS connects to the frame sync output of the host DSP. FS must be tied high in this mode.
FS Initiates The Operation: If FS is low at the falling edge of CS, the rising edge of FS initiates the operation,
resets the internal 4-bit counter, and enables SDI, SDO, and SCLK. The ID[15] is latched at the first falling edge
of SCLK following the falling edge of FS. OD[15] is valid before this falling edge of SCLK. This mode is used
to interface the converter with a serial port of the host DSP. The FS of the device is connected to the frame sync
of the host DSP. When several devices are connected to one DSP serial port, CS is used as chip select to allow
the host DSP to access each device individually. If only one converter is used, CS can be tied low.
After the initiation, the remaining SDI data bits (if any) are shifted in and the remaining bits of SDO (if any) are
shifted out at the rising edge of SCLK. The input data are latched at the falling edge of SCLK, and the output
data are valid before this falling edge of SCLK. After the 4-bit counter reaches 16, the SDO goes to a
high-impedance state. The output data from SDO is the previous conversion result in one shot conversion
mode, or the contents in the top of the FIFO when the FIFO is used (refer to Figure 21).
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
17
TLC3544, TLC3548
5-V ANALOG, 3-/5-V DIGITAL, 14-BIT, 200-KSPS, 4-/8-CHANNELS SERIAL
ANALOG-TO-DIGITAL CONVERTERS WITH 0-5 V (PSEUDODIFFERENTIAL) INPUTS
SLAS266C – OCTOBER 2000 – REVISED MAY 2003
detailed description (continued)
command period
After the rising edge of FS (FS triggers the operation) or the falling edge of CS (CS triggers the operation), SDI,
SDO, and SCLK are enabled. The first four SCLK clocks form the command period. The four MSBs of input data,
ID[15:12], are shifted in and decoded. These bits represent one of the 4-bit commands from the host, which
defines the required operation (see Table 1, Command Set). The four MSBs of output, OD[15:12], are also
shifted out via SDO during this period.
The commands are SELECT/CONVERSION, WRITE CFR, FIFO READ, SW POWER DOWN, and
HARDWARE DEFAULT mode. The SELECT/CONVERSION command includes SELECT ANALOG INPUT
and SELECT TEST commands. All cause a select/conversion operation. They select the analog signal being
converted, and start the sampling/conversion process after the selection. WRITE CFR causes the configuration
operation, which writes the device configuration information into the CFR register. FIFO READ reads the
contents in the FIFO. SW POWER DOWN puts the device into software power-down mode to save power.
Hardware default mode sets the device into the hardware default mode.
After the command period, the remaining 12 bits of SDI are written into the CFR register to configure the device
if the command is WRITE CFR. Otherwise, these bits are ignored. The configuration is retained in the
autopower-down and software power-down state. If SCLK stops (while CS remains low) after the first eight bits
are entered, the next eight bits can be entered after SCLK resumes. The data on SDI are ignored after the 4-bit
counter counts to 16 (falling edge of SCLK) or the low-to-high transition of CS, whichever happens first.
The remaining 12 bits of output data are shifted out from SDO if the command is SELECT/CONVERSION or
FIFO READ. Otherwise, the data on SDO are ignored. In any case, SDO goes into a high-impedance state after
the 4-bit counter counts to 16 (falling edge of SCLK) or the low-to-high transition of CS, whichever happens first.
Table 1. Command Set (CMR)
SDI Bit D[15:12]
TLC3548 COMMAND
TLC3544 COMMAND
BINARY
HEX
0000b
0h
SELECT analog input channel 0
SELECT analog input channel 0
0001b
1h
SELECT analog input channel 1
SELECT analog input channel 1
0010b
2h
SELECT analog input channel 2
SELECT analog input channel 2
0011b
3h
SELECT analog input channel 3
SELECT analog input channel 3
0100b
4h
SELECT analog input channel 4
SELECT analog input channel 0
0101b
5h
SELECT analog input channel 5
SELECT analog input channel 1
0110b
6h
SELECT analog input channel 6
SELECT analog input channel 2
0111b
7h
SELECT analog input channel 7
SELECT analog input channel 3
1000b
8h
SW POWER DOWN
1001b
9h
Reserved (test)
1010b
Ah
WRITE CFR, the last 12 bits of SDI are written into CFR. This command resets FIFO.
1011b
Bh
SELECT TEST, voltage = (REFP+REFM)/2 (see Notes 9 and 10)
1100b
Ch
SELECT TEST, voltage = REFM (see Note 11)
1101b
Dh
SELECT TEST, voltage = REFP (see Note 12)
1110b
Eh
FIFO READ, FIFO contents is shown on SDO; OD[15:2] = result, OD[1:0] = xx
1111b
Fh
Hardware default mode, CFR is loaded with 800h
NOTES: 9. REFP is external reference if external reference is selected, or internal reference if internal reference
is programmed.
10. The output code = mid-scale code + zero offset error + gain error.
11. The output code = zero scale code + zero offset error.
12. The output code = full-scale code + gain error.
18
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
TLC3544, TLC3548
5-V ANALOG, 3-/5-V DIGITAL, 14-BIT, 200-KSPS, 4-/8-CHANNELS SERIAL
ANALOG-TO-DIGITAL CONVERTERS WITH 0-5 V (PSEUDODIFFERENTIAL) INPUTS
SLAS266C – OCTOBER 2000 – REVISED MAY 2003
detailed description (continued)
Table 2. Configuration Register (CFR) Bit Definition
SDI BIT
DEFINITION
D11
Reference select:
0: Internal (4 V)
1: External
D10
Conversion output code format select:
0: USB (unipolar straight binary)
1: Binary 2s complement
D9
Sample period select for normal sampling
0: Long sampling (4X) 44 SCLKs
Don’t care in extended sampling.
1: Short sampling (1X) 12 SCLKs
D8
Conversion clock source select:
0: Conversion clock = Internal OSC
1: Conversion clock = SCLK/4
Input mode select:
0: Single-ended
1: Pseudodifferential. Pin configuration shown below.
D7
Pin Configuration of TLC3548
Pin Configuration of TLC3544
Pin No.
Single-ended
Pseudodifferential polarity
Pin No.
Single-ended
Pseudodifferential polarity
9
10
A0
A1
PLUS
MINUS
Pair A
9
10
A0
A1
PLUS
MINUS
Pair A
11
12
A2
A3
PLUS
MINUS
Pair B
11
12
A2
A3
PLUS
MINUS
Pair B
13
14
A4
A5
PLUS
MINUS
Pair C
15
16
A6
A7
PLUS
MINUS
Pair D
D[6:5]
Conversion mode select:
00: One shot mode
01: Repeat mode
10: Sweep mode
11: Repeat sweep mode
D[4:3]
[ ]
Sweep auto sequence select (Note: These bits only take effect in conversion mode 10 and 11.)
TLC3548
D2
D[1:0]
TLC3544
Single ended(by ch)
Pseudodifferential (by pair)
Single ended (by ch)
Pseudodifferential (by pair)
00: 0–1–2–3–4–5–6–7
01: 0–2–4–6–0–2–4–6
10: 0–0–2–2–4–4–6–6
11: 0–2–0–2–0–2–0–2
00:
N/A
01: A–B–C–D–A–B–C–D
10: A–A–B–B–C–C–D–D
11: A–B–A–B–A–B–A–B
00: 0–1–2–3–0–1–2–3
01: 0–2–0–2–0–2–0–2
10: 0–0–1–1–2–2–3–3
11: 0–0–0–0–2–2–2–2
00:
N/A
01: A–B–A–B–A–B–A–B
10:
N/A
11: A–A–A–A–B–B–B–B
EOC/INT pin function select:
0: Pin used as INT
1: Pin used as EOC ( for mode 00 only)
FIFO trigger level (sweep sequence length). Don’t care in one shot mode.
00: Full (INT generated after FIFO level 7 filled)
01: 3/4 (INT generated after FIFO level 5 filled)
10: 1/2 (INT generated after FIFO level 3 filled)
11: 1/4 (INT generated after FIFO level 1 filled)
sampling period
The sampling period follows the command period. The selected signal is sampled during this time. The device
has three different sampling modes: normal short mode, normal long mode, and extended mode.
Normal Short Sampling Mode: Sampling time is controlled by SCLK. It takes 12 SCLK periods. At the end of
sampling, the converter automatically starts the conversion period. After configuration, normal sampling, except
FIFO READ and WRITE CFR commands, starts automatically after the fourth falling edge of SCLK that follows
the falling edge of CS if CS triggers the operation, or follows the rising edge of FS if FS initiates the operation.
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
19
TLC3544, TLC3548
5-V ANALOG, 3-/5-V DIGITAL, 14-BIT, 200-KSPS, 4-/8-CHANNELS SERIAL
ANALOG-TO-DIGITAL CONVERTERS WITH 0-5 V (PSEUDODIFFERENTIAL) INPUTS
SLAS266C – OCTOBER 2000 – REVISED MAY 2003
sampling period (continued)
Normal Long Sampling Mode: This mode is the same as normal short sampling, except that it lasts 44 SCLK
periods.
Extended Sampling Mode: The external trigger signal, CSTART, triggers sampling and conversion. SCLK is
not used for sampling. SCLK is also not needed for conversion if the internal conversion clock is selected. The
falling edge of CSTART begins the sampling of the selected analog input. The sampling continues while
CSTART is low. The rising edge of CSTART ends the sampling and starts the conversion (with about 15 ns
internal delay). The occurrence of CSTART is independent of the SCLK clock, CS, and FS. However, the first
CSTART cannot occur before the rising edge of the 11th SCLK. In other words, the falling edge of the first
CSTART can happen at or after the rising edge of the 11th SCLK, but not before. The device enters the extended
sampling mode at the falling edge of CSTART and exits this mode once CSTART goes to high followed by two
consecutive falling edges of CS or two consecutive rising edges of FS (such as one read data operation followed
by a write CFR). The first CS or FS does not cause conversion. Extended mode is used when a fast SCLK is
not suitable for sampling, or when an extended sampling period is needed to accommodate different input signal
source impedance.
conversion period
The conversion period is the third portion of the operation cycle. It begins after the falling edge of the 16th SCLK
for normal short sampling mode, or after the falling edge of the 48th SCLK for normal long sampling, or on the
rising edge of CSTART (with 15 ns internal delay) for extended sampling mode.
The conversion takes 18 conversion clocks plus 15 ns. The conversion clock source can be an internal oscillator,
OSC, or an external clock, SCLK. The conversion clock is equal to the internal OSC if the internal clock is used,
or equal to SCLK/4 when the external clock is programmed. To avoid premature termination of the conversion,
enough time for the conversion must be allowed between consecutive triggers. EOC goes low at the beginning
of the conversion period and goes high at the end of the conversion period. INT goes low at the end of this period.
conversion mode
Four different conversion modes (mode 00, 01, 10, 11) are available. The operation of each mode is slightly
different, depending on how the converter samples and what host interface is used. Do not mix different types
of triggers throughout the repeat or sweep operations.
One Shot Mode (Mode 00): Each operation cycle performs one sampling and one conversion for the selected
channel. The FIFO is not used. When EOC is selected, it is generated while the conversion period is in progress.
Otherwise, INT is generated after the conversion is done. The result is output through the SDO pin during the
next select/conversion operation.
Repeat Mode (Mode 01): Each operation cycle performs multiple samplings and conversions for a fixed
channel selected according to the 4-bit command. The results are stored in the FIFO. The number of samples
to be taken is equal to the FIFO threshold programmed via D[1:0] in the CFR register. Once the threshold is
reached, INT is generated, and the operation ends. If the FIFO is not read after the conversions, the data are
replaced in the next operation. The operation of this mode starts with the WRITE CFR command to set
conversion mode 01, then the SELECT/CONVERSION command, followed by a number of samplings and
conversions of the fixed channel (triggered by CS, FS, or CSTART) until the FIFO threshold is hit. If CS or FS
triggers the sampling, the data on SDI must be any one of the SELECT CHANNEL commands. This data is a
dummy code for setting the converter in the conversion state. It does not change the existing channel selection
set at the start of the operation until the FIFO is full. After the operation finishes, the host can read the FIFO,
then reselect the channel and start the next REPEAT operation again; or immediately reselect the channel and
start the next REPEAT operation (by issuing CS, FS, or CSTAR), or reconfigure the converter and then start
a new operation according to the new setting. If CSTART triggers the sampling, the host can also immediately
start the next REPEAT (on the current channel) after the FIFO is full. Besides, if FS initiates the operation and
CSTART triggers the sampling and conversions, CS must not toggle during the conversion. This mode allows
the host to set up the converter, continue monitoring a fixed input, and to get a set of samples as needed.
20
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
TLC3544, TLC3548
5-V ANALOG, 3-/5-V DIGITAL, 14-BIT, 200-KSPS, 4-/8-CHANNELS SERIAL
ANALOG-TO-DIGITAL CONVERTERS WITH 0-5 V (PSEUDODIFFERENTIAL) INPUTS
SLAS266C – OCTOBER 2000 – REVISED MAY 2003
conversion mode (continued)
Sweep Mode (Mode 10): During each operation, all of the channels listed in the sweep sequence (D[4:3] of
the CFR register) are sampled and converted at one time according to the programmed sequence. The results
are stored in the FIFO. When the FIFO threshold is reached, an interrupt (INT) is generated, and the operation
ends. If the FIFO threshold is reached before all of the listed channels are visited, the remaining channels are
ignored. This allows the host to change the sweep sequence length. The mode 10 operation starts with the
WRITE CFR command to set the sweep sequence. The following triggers (CS, FS, or CSTART, depending on
the interface) start the samplings and conversions of the listed channels in sequence until the FIFO threshold
is hit. If CS or FS starts the sampling, the SDI data must be any one of the SELECT commands to set the
converter in the conversion state. However, this command is a dummy code. It does not change the existing
conversion sequence. After the FIFO is full, the converter waits for the FIFO READ. It does nothing before the
FIFO READ or the WRITE CFR command is issued. The host must read the FIFO completely or write the CFR.
If CSTART triggers the samplings, the host must issue an extra SELECT/CONVERSION command (select any
channel) via CS or FS after the FIFO READ or WRITE CFR. This extra period is named the arm period and is
used to set the converter into the conversion state, but does not affect the existing conversion sequence.
Besides, if FS initiates the operation and CSTART triggers the sampling and conversions, CS must not toggle
during the conversion.
Repeat Sweep Mode (Mode 11): This mode works in the same way as mode 10, except that it is not necessary
to read the FIFO before the next operation after the FIFO threshold is hit. The next SWEEP can repeat
immediately, but the contents in the FIFO are replaced by the new results. The host can read the FIFO
completely, then issue the next SWEEP or repeat the SWEEP immediately (with the existing sweep sequence)
by issuing sampling/conversion triggers (CS, FS or CSTART) or change the device setting with the WRITE CFR.
The memory effect of charge redistribution DAC exists when the mux switches from one channel to another.
This degrades the channel-to-channel isolation if the channel changes after each conversion. For example, in
mode 10 and 11, the isolation is about 70 dB for the sweep sequence 0-1-2-3-4 (refer to Figure 8). The memory
effect can be reduced by increasing the sampling time or using the sweep sequence 0-0-2-2-4-4-6-6 and
ignoring the first sample of each channel. Figure 8 shows the typical isolation vs throughput rate when applying
a sine signal (35 kHz, 3.5 Vp-p) on CH0 and dc on CH1 converting both channels alternately and measuring the
attenuation of the sine wave in CH1.
CHANNEL-TO-CHANNEL ISOLATION
vs
THROUGHPUT
Channel-to-Channel Isoltaion – dB
100
90
80
70
60
0
50
100
150
200
Throughput – KSPS
Figure 8
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
21
TLC3544, TLC3548
5-V ANALOG, 3-/5-V DIGITAL, 14-BIT, 200-KSPS, 4-/8-CHANNELS SERIAL
ANALOG-TO-DIGITAL CONVERTERS WITH 0-5 V (PSEUDODIFFERENTIAL) INPUTS
SLAS266C – OCTOBER 2000 – REVISED MAY 2003
operation cycle timing
CS Initiates
Operation
12 SCLKs for Short
44 SCLKs for Long
4 SCLKs
t(setup)†
SDI
18 OSC for Internal OSC†
72 SCLK for External Clock
15 ns
t(convert)
t(overhead)
t(sample)
4-bit Command
12-bit CFR Data (Optional)
SDO 14-bit Data (Previous Conversion) 2-bit Don’t Care
Active CS (FS Is Tied to High)
CSTAR (For Extended Sampling) occurs at
or after the rising edge of eleventh SCLK
t–CSL to FSL
t(delay)†
SDI
12 SCLKs for Short
44 SCLKs for Long
4 SCLKs
t(setup)†
18 OSC for Internal OSC
72 SCLK for External Clock
15 nS
t(convert)
t(overhead)
t(sample)
4-bit Command
12-bit CFR Data (Optional)
SDO 14-bit Data (Previous Conversion) 2-bit Don’t Care
FS Initiates
Operation
Active CS (CS Can Be Tied to Low)
Active FS
† Non JEDEC terms used.
CSTAR (For Extended Sampling) occurs at
or after the rising edge of eleventh SCLK
After the operation is finished, the host has several choices. Table 3 summarizes operation options.
22
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
TLC3544, TLC3548
5-V ANALOG, 3-/5-V DIGITAL, 14-BIT, 200-KSPS, 4-/8-CHANNELS SERIAL
ANALOG-TO-DIGITAL CONVERTERS WITH 0-5 V (PSEUDODIFFERENTIAL) INPUTS
SLAS266C – OCTOBER 2000 – REVISED MAY 2003
operation cycle timing (continued)
Table 3. Operation Options
CONVERSION IS INITIATED BY
MODE
CS
FS
CSTART
00
1. Issue new Select/Read operation to
read data and start new conversion.
2. Reconfigure the device.
1. Issue new Select/Read operation to
read data and start new conversion.
2. Reconfigure the device.
1. Issue new CSTART to start next
conversion; old data lost.
2. Issue new Select/Read operation to
read data—Issue new CSTART to
start new conversion.
3. Reconfigure the device.
01
1. Read FIFO—Select Channel—Start
new conversion. Channel must be
selected after FIFO READ.
2. Select Channel—Start new
conversion (old data lost)
3. Configure device again.
1. Read FIFO—Select Channel—Start
new conversion. Channel must be
selected after FIFO READ.
2. Select Channel—Start new
conversion (old data lost)
3. Configure device again.
1. Read FIFO—Select channel—Start
new conversion. Channel must be
selected after FIFO READ.
2. Start new conversion (old data lost)
with existing setting.
3. Configure device again.
10
1. Read FIFO—Start new conversion
with existing setting.
2. Configure device—New conversion
(old data lost)
1. Read FIFO—Start new conversion
with existing setting.
2. Configure device—New conversion
(old data lost)
1. Read FIFO—Arm Period—Start new
conversion with existing setting
2. Configure device—Arm Period—New
conversion (old data lost)
11
1. Read FIFO—Start new conversion
with existing setting.
2. Start new conversion with the existing
setting.
3. Configure device—Start new
conversion with new setting.
1. Read FIFO—Start new conversion
with existing setting
2. Start new conversion with the existing
setting.
3. Configure Device—Start new
conversion with new setting.
1. Read FIFO—Arm Period—Start new
Conversion with existing setting
2. Start new conversion with existing
setting. (old data lost)
3. Configure device—Arm Period—New
conversion with new setting.
operation timing diagrams
The FIFO read and write CFR are nonconversion operations. The conversion operation performs one of four
types of conversion: mode 00, 01, 10, and 11
Write Cycle (WRITE CFR Command): Write cycle does not generate EOC or INT, nor does it carry out any
conversion.
1
2
3
4
1D14
ID13 1D12
5
6
ID11
ID10
7
12
13
14
15
1
16
CS
FS
SDI
OR
INT
EOC
SDO
ÌÌÌ
ÌÌÌ
ID15
ID9
ID4
ID3
ID2
ID1
ÌÌÌÌÌÌÌÌ
ÌÌÌÌÌÌÌÌ
ID0
ÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌ
ÌÌ
Note:
ID15
Hi-Z
Signal May Not Exist.
ÌÌÌÌ
ÌÌ
Don’t Care
Figure 9. Write Cycle, FS Initiates Operation
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
23
TLC3544, TLC3548
5-V ANALOG, 3-/5-V DIGITAL, 14-BIT, 200-KSPS, 4-/8-CHANNELS SERIAL
ANALOG-TO-DIGITAL CONVERTERS WITH 0-5 V (PSEUDODIFFERENTIAL) INPUTS
SLAS266C – OCTOBER 2000 – REVISED MAY 2003
operation timing diagrams (continued)
1
2
3
4
5
6
12
7
13
14
15
16
CS
ÌÌÌÌ
ÌÌÌÌ
ÌÌÌÌÌÌÌÌÌ
ÌÌÌÌÌÌÌÌÌ
FS = High
SDI
ID15 1D14
ID13 1D12
ID11 ID10
ID9
ID4
ID3
ID2
ID1
ID0
INT
OR
1
ÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌ
ÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌ
ÌÌÌ
ÌÌÌ
EOC
SDO
Note:
Hi-Z
Signal May Not Exist.
Don’t Care
ID15
ID14
ÌÌÌÌÌ
ÌÌÌÌÌ
Figure 10. Write Cycle, CS Initiates Operation, FS = 1
FIFO Read Operation: When the FIFO is used, the first command after INT is generated is assumed to be the
FIFO read. The first FIFO content is sent out immediately before the command is decoded. If this command is
not a FIFO read, the output is terminated. Using more layers of the FIFO reduces the time taken to read multiple
conversion results, because the read cycle does not generate an EOC or INT, nor does it make a data
conversion. Once the FIFO is read, the entire contents in the FIFO must be read out. Otherwise, the remaining
data is lost.
1
2
3
4
1D14
ID13
1D12
5
6
7
12
13
14
15
16
1
SCLK
CS
ÌÌÌ
ÌÌÌ
FS = High
SDI
INT
ID15
ÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌ
ÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌ
ID15
OR
EOC
SDO
OD15 OD14 OD13 OD12 OD11 OD10 OD9
Notes:
ÌÌ
ÌÌ
OD4
Signal May Not Exist.
OD3
ÌÌÌÌÌ
ÌÌÌÌÌ
Hi-Z
OD2
OD[15:2] is FIFO Contents.
Don’t Care
Figure 11. FIFO Read Cycle, CS Initiates Operation, FS = 1
24
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
ID14
OD15 OD14
TLC3544, TLC3548
5-V ANALOG, 3-/5-V DIGITAL, 14-BIT, 200-KSPS, 4-/8-CHANNELS SERIAL
ANALOG-TO-DIGITAL CONVERTERS WITH 0-5 V (PSEUDODIFFERENTIAL) INPUTS
SLAS266C – OCTOBER 2000 – REVISED MAY 2003
conversion operation
48 SCLKs for Long Sampling
16 SCLKs for Short Sampling
1
2
3
4
CS
ÌÌÌ
ÌÌ
ÌÌÌ
ÌÌ
FS in High
SDI
Select Channel
ID15
ID14
ID13
1D12
INT
5
6
7
12
13
14
15
1
16
ÌÌ
ÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌ
ÌÌÌÌÌÌÌÌ
ÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌ
ÌÌ
ÌÌÌÌÌÌÌÌ
ID15
t(SAMPLE)
EOC
t(conv)
Previous Conversion Result
OR
SDO
OD15
OD14
OD13 OD12
ÌÌÌ
ÌÌÌ
OD11
OD10
OD9
OD4
OD3
OD2
The dotted line means signal may or may not exist.
ÌÌÌÌ
Hi-Z
OD15
SDO goes to Hi-Z After 16th SCLK
OD[15:2] is the result of previous conversion.
Don’t Care
Figure 12. Mode 00, CS Initiates Operation
48 SCLKs for Long Sampling
16 SCLKs for Short Sampling
1
2
3
4
5
6
7
12
13
14
15
1
16
SCLK
CS
ÌÌÌ
ÌÌÌ
FS
SDI
ÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌ
ÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌ
Select Channel
ID15 1D14
INT
ID13 1D12
ID15
t(SAMPLE)
OR
t(conv)
EOC
Previous Conversion Result
SDO
OD15
ÌÌ
ÌÌ
ÌÌÌÌÌ
SDO Goes Through Hi-Z After 16 SCLK
OD14 OD13 OD12 OD11 OD10 OD9
OD4
The dotted line means signal may or may not exist.
OD[15:2] is the result of previous conversion.
OD3
OD2
Hi-Z
OD15
Don’t Care
Figure 13. Mode 00, FS Initiates Operation
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
25
TLC3544, TLC3548
5-V ANALOG, 3-/5-V DIGITAL, 14-BIT, 200-KSPS, 4-/8-CHANNELS SERIAL
ANALOG-TO-DIGITAL CONVERTERS WITH 0-5 V (PSEUDODIFFERENTIAL) INPUTS
SLAS266C – OCTOBER 2000 – REVISED MAY 2003
conversion operation (continued)
Select Channel
16 SCLK
Select Channel
16 SCLK
t(sample)
CS Tied to Low
CSTART
Possible
Signal
FS
t(convert)
ÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌ
**
***
SDI
**
INT
EOC
OR
SDO
ÌÌ
ÌÌ
**
Data Lost
Previous Conversion Result
Hi-Z
Conversion Result
Hi-Z
Hi-Z
Possible Signal
Select Channel
Don’t Care
Figure 14. Mode 00, CSTART Triggers Sampling/Conversion, FS Initiates Select
CS
FS
ÌÌ ÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌ
ÌÌÌÌÌÌ
ÌÌÌ
ÌÌÌÌÌÌ
ÌÌÌ
ÌÌ
ÌÌ
Select CH1
SDI
***
**
Select Any
Channel
**
Select CH2
*
*
Select Any
Channel
**
**
DATA1 of CH1 DATA2 of CH1
*
*
DATA1 of CH2 DATA2 of CH2
Hi-Z
SDO
1/4 FIFO FULL
1/4 FIFO FULL
INT
***
**
*
Don’t Care
Possible Signal
–– WRITE CFR
–– Select Channel
–– FIFO Read
MODE 01, FS Activates Conversion, FIFO Threshold = 1/4 Full
Read FIFO After Threshold Is Hit
Figure 15. Mode 01, FS Initiates Operations
CS
FS
CSTART
ÌÌ ÌÌÌÌÌÌÌÌÌÌÌÌÌÌ ÌÌÌÌÌÌÌÌÌÌÌ
ÌÌÌÌÌÌÌÌÌÌ
ÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌ
ÌÌÌÌÌÌ
ÌÌÌ
ÌÌ
Select CH1
SDI
***
Select CH2
**
*
Hi-Z
SDO
INT
*
**
***
**
*
MODE 01, FS Initiates Select Period, CSTART Activates Conversion, FIFO Threshold = 1/4 Full,
Read FIFO After Threshold Is Hit
Figure 16. Mode 01, CSTART Triggers Samplings/Conversions
26
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
*
DATA1 of CH2 DATA2 of CH2
1/4 FIFO FULL
1/4 FIFO FULL
Don’t Care
Possible Signal
–– WRITE CFR
–– Select Channel
–– FIFO Read
*
DATA1 of CH1 DATA2 of CH1
TLC3544, TLC3548
5-V ANALOG, 3-/5-V DIGITAL, 14-BIT, 200-KSPS, 4-/8-CHANNELS SERIAL
ANALOG-TO-DIGITAL CONVERTERS WITH 0-5 V (PSEUDODIFFERENTIAL) INPUTS
SLAS266C – OCTOBER 2000 – REVISED MAY 2003
conversion operation (continued)
Configure
Conversion
From CH0
Conversion
From CH3
Conversion
From CH0
Conversion
From CH3
CS
ÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌ
ÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌ
ÌÌÌ
ÌÌ
ÌÌ
FS
SDI
**
***
**
**
**
*
*
*
**
*
**
**
**
*
INT
Hi-Z
SDO
CH0
1st Sweep
CH1
**
*
CH0
CH3
2nd Sweep
Using Existing
Configuration
Don’t Care
***
CH2
1st FIFO Read
Command = Configure Write for Mode 10, FIFO
Threshold = 1/2 Full, Sweep Sequence: 0–1–2–3
COMMAND = Select Any Channel
COMMAND = Read FIFO
2nd FIFO Read
Read FIFO After FIFO Threshold Is Hit
Figure 17. Mode 10, FS Initiates Operations
CS Tied
to Low
FS
Configure
Conversion
From CH0
Conversion
From CH2
Conversion
From CH0
Conversion
From CH2
ÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌ
ÌÌÌÌÌÌÌÌÌ
ÌÌÌ
ÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌ
ÌÌÌÌÌÌÌÌÌ
ÌÌÌ
ÌÌ
Ì
ÌÌ
CSTART
SDI
***
**
*
*
*
*
**
*
INT
Hi-Z
SDO
CH0
CH0
***
CH2
CH0
2nd Sweep
Using Existing
Configuration
Don’t Care
**
*
CH2
1st Sweep
2nd FIFO Read
1st FIFO Read
Read FIFO After FIFO Threshold Is Hit, FS Initiates Select Period
Command = Configure Write for Mode 10, FIFO
Threshold = 1/2 Full, Sweep Sequence: 0–0–2–2
COMMAND = Select Any Channel
COMMAND = Read FIFO
Figure 18. Mode 10, CSTART Initiates Operations
Configure
Conversion
From CH0
Conversion
From CH3
Conversion
From CH0
Conversion
From CH3
Conversion
From CH0
CS
START 2nd Round SWEEP CONVERSION,
the DATA of the 1st Round Are Lost
ÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌ
ÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌ
ÌÌÌ
ÌÌ
ÌÌ
ÌÌ
FS=High
SDI
***
**
**
**
**
**
**
**
**
INT
SDO
ÌÌÌÌÌÌÌÌÌÌÌ
ÌÌÌÌÌÌÌÌÌÌÌ
*
CH0
Don’t Care
***
**
*
*
CH1
*
*
CH2
CH3
**
READ the DATA of 2nd
Sweep From FIFO
Command = Configure Write for Mode 11, FIFO
Threshold = 1/2 Full, Sweep Sequence: 0–1–2–3
START 2nd Sweep conversion immediately (NO FIFO READ) after the 1st SWEEP completed.
COMMAND = Select Any Channel
COMMAND = Read FIFO
Figure 19. Mode 11, CS Initiates Operations
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
27
TLC3544, TLC3548
5-V ANALOG, 3-/5-V DIGITAL, 14-BIT, 200-KSPS, 4-/8-CHANNELS SERIAL
ANALOG-TO-DIGITAL CONVERTERS WITH 0-5 V (PSEUDODIFFERENTIAL) INPUTS
SLAS266C – OCTOBER 2000 – REVISED MAY 2003
conversion operation (continued)
Configure
Conversion
From CH0
Conversion
From CH2
Conversion
From CH0
Conversion
From CH2
CS
FS
CSTART
Ì ÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌ ÌÌÌÌÌÌÌÌÌÌ
ÌÌÌ
ÌÌ
ÌÌ
ÌÌ
*** **
SDI
INT
1st SWEEP
SDO
*
*
*
*
CH0
CH0
CH2
CH2
**
*
REPEAT
1st FIFO Read
Don’t Care
***
**
*
CH0
2nd FIFO Read
Read FIFO After 1st SWEEP Completed
Command = Configure Write for Mode 11, FIFO
Threshold = 1/2 Full, Sweep Sequence: 0–0–2–2
COMMAND = Select Any Channel
COMMAND = Read FIFO
Possible Signal
Figure 20. Mode 11, CSTART Triggers Samplings/Conversions
conversion clock and conversion speed
The conversion clock source can be the internal OSC, or the external clock SCLK. When the external clock is
used, the conversion clock is equal to SCLK/4. It takes 18 conversion clocks plus 15 ns to finish the conversion.
If the external clock is selected, the conversion time (not including sampling time) is 18X(4/fSCLK)+15 ns. Table 4
shows the maximum conversion rate (including sampling time) when the analog input source resistor is 1 kΩ.
Table 4. Maximum Conversion Rate
DEVICE
TLC3544/48
((Rs = 1000))
SAMPLING MODE
CONVERSION CLK
MAX SCLK
(MHz)
CONVERSION
TIME (us)
RATE
(KSPS)
Short (16 SCLK)
External SCLK/4
10
8.815
113.4
207.7
Long (48 SCLK)
External SCLK/4
25
4.815
Short (16 SCLK)
Internal 6.5 MHz
10
4.385
228
Long (48 SCLK)
Internal 6.5 MHz
25
4.705
212.5
FIFO operation
Serial
SOD
×8
FIFO
ADC
7
6
FIFO Full
5
4
3
2
0
FIFO 1/2 Full
FIFO 3/4 Full
FIFO 1/4 Full
FIFO Threshold Pointer
Figure 21. FIFO Structure
28
1
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
TLC3544, TLC3548
5-V ANALOG, 3-/5-V DIGITAL, 14-BIT, 200-KSPS, 4-/8-CHANNELS SERIAL
ANALOG-TO-DIGITAL CONVERTERS WITH 0-5 V (PSEUDODIFFERENTIAL) INPUTS
SLAS266C – OCTOBER 2000 – REVISED MAY 2003
FIFO operation (continued)
The device has an 8-level FIFO that can be programmed for different thresholds. An interrupt is sent to the host
after the preprogrammed threshold is reached. The FIFO is used to store conversion results in mode 01, 10,
and 11, from either a fixed channel or a series of channels according to a preprogrammed sweep sequence.
For example, an application may require eight measurements from channel 3. In this case, if the threshold is
set to full, the FIFO is filled with 8 data conversions sequentially taken from channel 3. Another application may
require data from channel 0, 2, 4, and 6 in that order. The threshold is set to 1/2 full and sweep sequence is
selected as 0–2–4–6–0–2–4–6. An interrupt is sent to the host as soon as all four data conversions are in the
FIFO. The FIFO is reset after a power on and a WRITE CFR operation. The contents of the FIFO are retained
during autopower down and software power down.
Powerdown: The device has two power-down modes.
AutoPower-Down Mode: The device enters the autopower-down state at the end of a conversion.
In autopower-down, the power consumption reduces to about 1.8 mA when an internal reference is selected.
The built-in reference is still on to allow the device to resume quickly. The resumption is fast enough for use
between cycles. An active CS, FS, or CSTART resumes the device from power-down state. The power current
is 20 µA when an external reference is programmed and SCLK stops.
Software Power-Down Mode: Writing 8000h to the device puts the device into the software power-down state,
and the entire chip (including the built-in reference) is powered down. The power current is reduced to about
20 µA if SCLK stops. Deselect CS to save power once the device is in the software power-down mode. An active
CS, FS, or CSTART restores the device. There is no time delay when an external reference is selected.
However, if an internal reference is used, it takes about 20 ms to warm up.
The configuration register is not affected by any of the power-down modes but the sweep operation sequence
must be started over again. All FIFO contents are retained in both power-down modes.
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
29
TLC3544, TLC3548
5-V ANALOG, 3-/5-V DIGITAL, 14-BIT, 200-KSPS, 4-/8-CHANNELS SERIAL
ANALOG-TO-DIGITAL CONVERTERS WITH 0-5 V (PSEUDODIFFERENTIAL) INPUTS
SLAS266C – OCTOBER 2000 – REVISED MAY 2003
TYPICAL CHARACTERISTICS
INL – Integral Nonlinearity – LSB
INTEGRAL NONLINEARITY
vs
DIGITAL OUTPUT CODE
1.0
Internal Reference = 4 V
AVDD = 5 V, TA = 25°C
0.5
0.0
–0.5
–1.0
0
2000
4000
6000
8000
10000
12000
14000
16000
12000
14000
16000
Digital Output Code
Figure 22
DNL – Differential Nonlinearity – LSB
DIFFERENTIAL NONLINEARITY
vs
DIGITAL OUTPUT CODE
1.0
Internal Reference = 4 V
AVDD = 5 V, TA = 25°C
0.5
0.0
–0.5
–1.0
0
2000
4000
6000
8000
10000
Digital Output Code
Figure 23
30
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
TLC3544, TLC3548
5-V ANALOG, 3-/5-V DIGITAL, 14-BIT, 200-KSPS, 4-/8-CHANNELS SERIAL
ANALOG-TO-DIGITAL CONVERTERS WITH 0-5 V (PSEUDODIFFERENTIAL) INPUTS
SLAS266C – OCTOBER 2000 – REVISED MAY 2003
TYPICAL CHARACTERISTICS
INL AND DNL
vs
FREE-AIR TEMPERATURE
ZERO OFFSET AND GAIN ERROR (LSB)
vs
FREE-AIR TEMPERATURE
1.0
4
Internal Reference = 4 V
AVDD = 5 V
2
Zero Offset and Gain Error – LSB
0.8
INL (LSB)
0.7
0.6
DNL (LSB)
0.5
Zero Offset (LSB)
0
–2
–4
–6
–8
Gain Error (LSB)
–10
–12
External Reference = 4 V
AVDD = 5 V
–14
0.4
–65
–35
–5
25
55
–16
–65
85
–35
–5
25
55
TA – Free-Air Temperature – °C
TA – Free-Air Temperature – °C
Figure 24
85
Figure 25
FFT OF SNR
vs
FREQUENCY
20
External Reference = 4 V
AVDD = 5 V
TA = 25°C
200 KSPS
Input Signal: 20 kHz, 0 dB
–20
FFT of SNR – dB
INL and DNL – LSB
0.9
–60
–100
–140
–180
0
10
20
30
40
50
60
70
80
90
100
f – Frequency – kHz
Figure 26
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
31
TLC3544, TLC3548
5-V ANALOG, 3-/5-V DIGITAL, 14-BIT, 200-KSPS, 4-/8-CHANNELS SERIAL
ANALOG-TO-DIGITAL CONVERTERS WITH 0-5 V (PSEUDODIFFERENTIAL) INPUTS
SLAS266C – OCTOBER 2000 – REVISED MAY 2003
TYPICAL CHARACTERISTICS
SINAD
vs
INPUT SIGNAL FREQUENCY
ENOB
vs
INPUT SIGNAL FREQUENCY
90
14.0
External Reference = 4 V
AVDD = 5 V
TA = 25°C
External Reference = 4 V
AVDD = 5 V
TA = 25°C
13.5
ENOB – Bits
SINAD – dB
85
80
75
13.0
12.5
70
12.0
0
20000
20k
40000
40k
60000
60k
80000
80k
100000
100k
0
20000
20k
f – Input Signal Frequency – Hz
Figure 27
80000
80k
100000
100k
SFDR
vs
INPUT SIGNAL FREQUENCY
–80
105
External Reference = 4 V
AVDD = 5 V
TA = 25°C
External Reference = 4 V
AVDD = 5 V
TA = 25°C
–85
100
SFDR – dB
THD – dB
60000
60k
Figure 28
THD
vs
INPUT SIGNAL FREQUENCY
–90
–95
95
90
–100
1
10
20
30
40
50
60
70
80
90 98
f – Input Signal Frequency – kHz
85
0
20000
20k
40000
40k
60000
60k
Figure 30
POST OFFICE BOX 655303
80000
80k
f – Input Signal Frequency – Hz
Figure 29
32
40000
40k
f – Input Signal Frequency – Hz
• DALLAS, TEXAS 75265
100000
100k
TLC3544, TLC3548
5-V ANALOG, 3-/5-V DIGITAL, 14-BIT, 200-KSPS, 4-/8-CHANNELS SERIAL
ANALOG-TO-DIGITAL CONVERTERS WITH 0-5 V (PSEUDODIFFERENTIAL) INPUTS
SLAS266C – OCTOBER 2000 – REVISED MAY 2003
TYPICAL CHARACTERISTICS
SUPPLY CURRENT AT
SOFTWARE POWER-DOWN
vs
FREE-AIR TEMPERATURE
ICC – Supply Current at Software Power Down– µA
SUPPLY CURRENT
vs
FREE-AIR TEMPERATURE
4.5
4.3
4.2
4.1
4.0
3.9
–65
–35
–5
25
55
85
30
Internal Reference = 4 V
AVDD = 5 V
SCLK = OFF
All Digital Input = DGND
or DVDD
25
20
15
10
5
0
–65
TA – Free-Air Temperature – °C
–35
–5
25
55
85
TA – Free-Air Temperature – °C
Figure 31
Figure 32
SUPPLY CURRENT AT
AUTOPOWER-DOWN
vs
FREE-AIR TEMPERATURE
4.0
ICC – Supply Current at Autopower-Down – µA
ICC – Supply Current – mA
4.4
External Reference = 4 V
AVDD = 5 V
CS = DGND
Internal OSC
3.5
External Reference = 4 V
AVDD = 5 V
SCLK = OFF
All Digital Input = DGND
or DVDD
3.0
2.5
2.0
1.5
–65
–35
–5
25
55
85
TA – Free-Air Temperature – °C
Figure 33
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
33
TLC3544, TLC3548
5-V ANALOG, 3-/5-V DIGITAL, 14-BIT, 200-KSPS, 4-/8-CHANNELS SERIAL
ANALOG-TO-DIGITAL CONVERTERS WITH 0-5 V (PSEUDODIFFERENTIAL) INPUTS
SLAS266C – OCTOBER 2000 – REVISED MAY 2003
APPLICATION INFORMATION
interface with host
Figure 34 shows examples of the interface between a single converter and a host DSP (TMS320C54x DSP)
or microprocessor. The C54x is set as FWID = 1 (active pulse width = 1CLK), (R/X) DATDLY = 1 (1 bit data delay),
CLK(X/R)P = 0 (transmit data are clocked out at rising edge of CLK, receive data are sampled on falling edge
of CLK), and FS(X/R)P = 1 (FS is active high). If multiple converters connect to the same C54x, use CS as the
chip select.
The host microprocessor is set as the SPI master with CPOL = 0 (active high clock), and CPHA = 1 (transmit
data is clock out at rising edge of CLK, receive data are sampled at falling edge of CLK). 16 bits (or more) per
transfer is required.
VDD
VDD
10 kΩ
10 kΩ
Converter
TMS320C54X
FSR
CS
FSX
FS
DX
SDI
10 kΩ
Host
Microprocessor
SS
DR
Converter
CS
FS
Ain
MOSI
SDI
MISO
SDO
SCK
SCLK
Ain
SDO
CLKR
SCLK
CLKX
INT/EOC
IRQ
IRQ
Single Converter Connects to DSP
INT/EOC
Converter Connects to Microprocessor
Figure 34. Typical Interface to Host DSP and Microprocessor
sampling time analysis
Figure 35 shows the equivalent analog input circuit of the converter. During the sampling, the input capacitor,
Ci, has to be charged to VC, (VC = Vs ± voltage of 1/4 LSB = Vs ± [Vs/65532] for 14 bit converter).
t(s) = Rt × Ci × In (65532) where Rt = Rs+ri, t(s) = Sampling time
Driving Source
VS
RS
Data Converter
VI
ri
VC
CI
VI = Input Voltage at AIN
VS = External Driving Source Voltage
RS = Source Resistance
ri = Equivalent Resistor of Mux., 1.5 kΩ
CI = Input Capacitance, 30 pF Max.
VC = Capacitance Charging Voltage
Figure 35. Equivalent Input Circuit Including the Driving Source
TMS320C54x is a trademark of Texas Instruments.
34
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
PACKAGE OPTION ADDENDUM
www.ti.com
14-Oct-2022
PACKAGING INFORMATION
Orderable Device
Status
(1)
Package Type Package Pins Package
Drawing
Qty
Eco Plan
(2)
Lead finish/
Ball material
MSL Peak Temp
Op Temp (°C)
Device Marking
(3)
Samples
(4/5)
(6)
TLC3544CDW
ACTIVE
SOIC
DW
20
25
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
0 to 70
TLC3544
Samples
TLC3544CPW
ACTIVE
TSSOP
PW
20
70
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
0 to 70
TLC3544
Samples
TLC3544CPWR
ACTIVE
TSSOP
PW
20
2000
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
0 to 70
TLC3544
Samples
TLC3544IDW
ACTIVE
SOIC
DW
20
25
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
TLC3544I
Samples
TLC3544IPW
ACTIVE
TSSOP
PW
20
70
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
Y3544
Samples
TLC3548CDW
ACTIVE
SOIC
DW
24
25
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
0 to 70
TLC3548
Samples
TLC3548CDWR
ACTIVE
SOIC
DW
24
2000
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
0 to 70
TLC3548
Samples
TLC3548CPW
ACTIVE
TSSOP
PW
24
60
RoHS & Green
NIPDAU
Level-2-260C-1 YEAR
0 to 70
TLC3548
Samples
TLC3548CPWR
ACTIVE
TSSOP
PW
24
2000
RoHS & Green
NIPDAU
Level-2-260C-1 YEAR
0 to 70
TLC3548
Samples
TLC3548IDW
ACTIVE
SOIC
DW
24
25
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
TLC3548I
Samples
TLC3548IDWR
ACTIVE
SOIC
DW
24
2000
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
TLC3548I
Samples
TLC3548IPW
ACTIVE
TSSOP
PW
24
60
RoHS & Green
NIPDAU
Level-2-260C-1 YEAR
-40 to 85
Y3548
Samples
TLC3548IPWR
ACTIVE
TSSOP
PW
24
2000
RoHS & Green
NIPDAU
Level-2-260C-1 YEAR
-40 to 85
Y3548
Samples
(1)
The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2)
RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance
do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may
reference these types of products as "Pb-Free".
RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption.
Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of
工商网监
湘ICP备2023018690号
