Dual-Current Output, Parallel Input, 16-/14-Bit
Multiplying DACs with 4-Quadrant Resistors
AD5547/AD5557
Data Sheet
FEATURES
FUNCTIONAL BLOCK DIAGRAM
R1A
Dual channel
16-bit resolution: AD5547
14-bit resolution: AD5557
2- or 4-quadrant, 6.8 MHz BW multiplying DAC
±1 LSB DNL
±1 LSB INL
Operating supply voltage: 2.7 V to 5.5 V
Low noise: 12 nV/√Hz
Low power: IDD = 10 µA max
0.5 µs settling time
Built-in RFB facilitates current-to-voltage conversion
Built-in 4-quadrant resistors allow 0 V to –10 V, 0 V to +10 V,
or ±10 V outputs
2 mA full-scale current ± 20%, with VREF = 10 V
Extended automotive operating temperature range
−40°C to +125°C
Selectable zero-scale/midscale power-on presets
Compact 38-lead TSSOP package
RCOMA
VREFA
ROFSA
RFBA
VDD
D0 TO D15
(AD5547)
D0 TO D13
(AD5557)
D0..D15
OR
D0..D13
INPUT
REGISTER
RS
DAC A
REGISTER
RS
INPUT
REGISTER
RS
DAC B
REGISTER
RS
DAC A
IOUTA
AGNDA
AGNDB
WR
A0, A1
ADDR
DECODE
POWER
ON
RESET
DGND
RS MSB
DAC B
IOUTB
RFBB
ROFSB
AD5547/AD5557
LDAC
R1B
RCOMB
VREFB
04452-013
DAC A
DAC B
Figure 1.
GENERAL DESCRIPTION
The AD5547/AD5557 are dual precision, 16-/14-bit, multiplying,
low power, current-output, parallel input, digital-to-analog
converters (DACs). They are designed to operate from single
+5 V supply with ±10 V multiplying references for 4-quadrant
outputs with 6.8 MHz bandwidth.
APPLICATIONS
The built-in, 4-quadrant resistors facilitate resistance matching
and temperature tracking, which minimize the number of
components needed for multiquadrant applications. In addition,
the feedback resistor (RFB) simplifies the I-to-V conversion with
an external buffer.
Automatic test equipment
Instrumentation
Digitally controlled calibration
Digital waveform generation
The AD5547/AD5557 are available in a compact, 38-lead TSSOP
package and operate at the extended automotive temperature
range of −40°C to +125°C.
VREF
U1
–VREF
C1
R1
16/14 DATA
VREFA
RCOMA
ROFSA
ROFS
R2
AD5547/AD5557
16-/14-BIT
DAC A
RFBA
RFB
C2
IOUTA
VOUTA
AGNDA
POWER-ON
RESET
WR LDAC RS
WR
LDAC
RS
MSB
A0, A1
U2
–VREF TO +VREF
MSB A0, A1
2
(ONE CHANNEL SHOWN ONLY)
04452-002
R1A
Figure 2. 16-/14-Bit 4-Quadrant Multiplying DAC with Minimum of External Components (Only One Channel Is Shown)
Rev. D
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Technical Support
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AD5547/AD5557
Data Sheet
TABLE OF CONTENTS
Features .............................................................................................. 1
DAC Section................................................................................ 12
Applications ....................................................................................... 1
Digital Section ............................................................................ 13
Functional Block Diagram .............................................................. 1
General Description ......................................................................... 1
PCB Layout, Power Supply Bypassing, and Ground
Connections ................................................................................ 13
Revision History ............................................................................... 2
Applications Information .............................................................. 14
Specifications..................................................................................... 3
Unipolar Mode ........................................................................... 14
Electrical Characteristics ............................................................. 3
Bipolar Mode .............................................................................. 16
Absolute Maximum Ratings ............................................................ 5
Reference Selection .................................................................... 18
ESD Caution .................................................................................. 5
Amplifier Selection .................................................................... 18
Pin Configurations and Function Descriptions ........................... 6
Outline Dimensions ....................................................................... 20
Typical Performance Characteristics ........................................... 10
Ordering Guide .......................................................................... 20
Circuit Operation ........................................................................... 12
REVISION HISTORY
11/12—Rev. C to Rev. D
Changes to Figure 22 ...................................................................... 15
11/11—Rev. B to Rev. C
Added Figure 14; Renumbered Sequentially .............................. 11
4/10—Rev. A to Rev. B
Changes to Features Section and General Description Section . 1
Changes to Table 1 ............................................................................ 3
Deleted Figure 17 and Figure 18; Renumbered Sequentially ... 10
Changes to Figure 15 and Figure 16............................................. 11
Changes to Figure 20 ...................................................................... 14
Added Reference Selection Section, Amplifier Selection Section,
Table 10, and Table 11; Renumbered Sequentially ..................... 18
Added Table 12 ............................................................................... 19
9/09—Rev. 0 to Rev. A
Changes to Features Section ............................................................1
Changes to Static Performance, Relative Accuracy,
Grade: AD5547C Parameter, Table 1 ..............................................3
Changes to Ordering Guide .......................................................... 19
1/04—Revision 0: Initial Version
Rev. D | Page 2 of 20
Data Sheet
AD5547/AD5557
SPECIFICATIONS
ELECTRICAL CHARACTERISTICS
VDD = 2.7 V to 5.5 V, IOUT = virtual GND, GND = 0 V, VREF = −10 V to +10 V, TA = −40°C to +125°C, unless otherwise noted.
Table 1.
Parameter
STATIC PERFORMANCE 1
Resolution
Symbol
Test Conditions/Comments
N
AD5547, 1 LSB = VREF/216 = 153 µV at VREF = 10 V
AD5557, 1 LSB = VREF/214 = 610 µV at VREF = 10 V
Grade: AD5557C
Grade: AD5547B
Grade: AD5547C
Monotonic
Data = zero scale, TA = 25°C
Data = zero scale, TA = TA maximum
Data = full scale
Data = full scale
Data = full scale
Relative Accuracy
INL
Differential Nonlinearity
Output Leakage Current
DNL
IOUT
Full-Scale Gain Error
Bipolar Mode Gain Error
Bipolar Mode Zero-Scale Error
Full-Scale Temperature Coefficient 2
REFERENCE INPUT
VREF Range
REF Input Resistance
R1 and R2 Resistance
R1-to-R2 Mismatch
Feedback and Offset Resistance
Input Capacitance2
ANALOG OUTPUT
Output Current
Output Capacitance2
LOGIC INPUT AND OUTPUT
Logic Input Low Voltage
Logic Input High Voltage
GFSE
GE
GZSE
TCVFS
VREF
REF
R1 and R2
Δ(R1 to R2)
RFB, ROFS
CREF
VIL
VDD = 5 V
VDD = 3 V
VDD = 5 V
VDD = 3 V
Input Leakage Current
Input Capacitance2
INTERFACE TIMING2, 3
Data to WR Setup Time
tDS
Data to WR Hold Time
tDH
WR Pulse Width
tWR
LDAC Pulse Width
tLDAC
RS Pulse Width
tRS
WR to LDAC Delay Time
tLWD
±1
±1
±1
1
8
Data = full scale
Code dependent
Typ
Max
16
14
−18
4
4
IOUT
COUT
VIH
Min
5
5
±0.5
10
5
±1
±2
±1
±1
10
20
±4
±4
±3
+18
6
6
±1.5
12
2
200
Bits
Bits
LSB
LSB
LSB
LSB
nA
nA
mV
mV
mV
ppm/°C
V
kΩ
kΩ
Ω
kΩ
pF
mA
pF
0.8
0.4
2.4
2.1
IIL
CIL
Unit
10
10
V
V
V
V
µA
pF
See Figure 3
VDD = 5 V
VDD = 3 V
VDD = 5 V
VDD = 3 V
VDD = 5 V
20
35
0
0
20
ns
ns
ns
ns
ns
VDD = 3 V
VDD = 5 V
VDD = 3 V
VDD = 5 V
VDD = 3 V
VDD = 5 V
VDD = 3 V
35
20
35
20
35
0
0
ns
ns
ns
ns
ns
ns
ns
Rev. D | Page 3 of 20
AD5547/AD5557
Data Sheet
Parameter
SUPPLY CHARACTERISTICS
Power Supply Range
Positive Supply Current
Power Dissipation
Power Supply Sensitivity
AC CHARACTERISTICS4
Output Voltage Settling Time
Symbol
Test Conditions/Comments
VDD RANGE
IDD
PDISS
PSS
Logic inputs = 0 V
Logic inputs = 0 V
∆VDD = ±5%
Typ
2.7
tS
Reference Multiplying BW
DAC Glitch Impulse
Multiplying Feedthrough Error
Digital Feedthrough
Total Harmonic Distortion
Output Noise Density
Analog Crosstalk
Min
To ±0.1% of full scale, data cycles from zero scale
to full scale to zero scale
VREF = 100 mV rms, data = full scale
VREF = 0 V, midscale – 1 to midscale
VREF = 100 mV rms, f = 10 kHz
WR = 1, LDAC toggles at 1 MHz
VREF = 5 V p-p, data = full scale, f = 1 kHz
f = 1 kHz, BW = 1 Hz
Signal input at Channel A and measures the
output at Channel B, f = 1 kHz
BW
Q
VOUT/VREF
QD
THD
eN
CAT
1
Max
Unit
5.5
10
0.055
0.003
V
μA
mW
%/%
0.5
μs
6.8
−3.5
−78
7
−104
12
−95
MHz
nV-s
dB
nV-s
dB
nV/√Hz
dB
All static performance tests (except IOUT) are performed in a closed-loop system using an external precision OP97 I-to-V converter amplifier. The device RFB terminal is
tied to the amplifier output. The +IN pin of the OP97 is grounded, and the IOUT of the DAC is tied to the OP97’s −IN pin. Typical values represent average readings
measured at 25°C.
2
Guaranteed by design; not subject to production testing.
3
All input control signals are specified with tR = tF = 2.5 ns (10% to 90% of 3 V) and are timed from a voltage level of 1.5 V.
4
All ac characteristic tests are performed in a closed-loop system using an AD8038 I-to-V converter amplifier except for THD where the AD8065 was used.
Timing Diagram
tWR
WR
DATA
tDS
tDH
tLWD
LDAC
tLDAC
04452-018
tRS
RS
Figure 3. AD5547/AD5557 Timing Diagram
Rev. D | Page 4 of 20
Data Sheet
AD5547/AD5557
ABSOLUTE MAXIMUM RATINGS
Table 2.
Parameter
VDD to GND
RFB, ROFS, R1, RCOM, and VREF to GND
Logic Inputs to GND
V(IOUT) to GND
Input Current to Any Pin except Supplies
Thermal Resistance (θJA)1
Maximum Junction Temperature (TJ MAX)
Operating Temperature Range
Storage Temperature Range
Lead Temperature
Vapor Phase, 60 sec
Infrared, 15 sec
1
Rating
−0.3 V to +8 V
−18 V to +18 V
−0.3 V to +8 V
−0.3 V to VDD + 0.3 V
±50 mA
150°C
−40°C to +125°C
−65°C to +150°C
Stresses above those listed under Absolute Maximum Ratings
may cause permanent damage to the device. This is a stress
rating only; functional operation of the device at these or any
other conditions above those indicated in the operational
section of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect
device reliability.
ESD CAUTION
215°C
220°C
Package power dissipation = (TJ MAX − TA)/θJA.
Rev. D | Page 5 of 20
AD5547/AD5557
Data Sheet
D1 1
38
D2
D0 2
37
D3
ROFSA 3
36
D4
RFBA 4
35
D5
R1A 5
34
D6
RCOMA 6
33
D7
VREFA 7
32
D8
IOUTA 8
31
D9
30
D10
29
VDD
28
D11
IOUTB 12
27
D12
VREFB 13
26
D13
RCOMB 14
25
D14
R1B 15
24
D15
RFBB 16
23
RS
ROFSB 17
22
MSB
WR 18
21
LDAC
A0 19
20
A1
AGNDA 9
DGND 10
AGNDA 11
AD5547
TOP VIEW
(Not to Scale)
04452-003
PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS
Figure 4. AD5547 Pin Configuration
Table 3. AD5547 Pin Function Descriptions
Pin No.
1, 2, 24 to
28, 30 to
38
3
Mnemonic
D0 to D15
Function
Digital Input Data Bits D0 to D15. Signal level must be ≤ VDD + 0.3 V.
ROFSA
4
5
RFBA
R1A
6
RCOMA
7
VREFA
8
9
10
11
12
13
IOUTA
AGNDA
DGND
AGNDB
IOUTB
VREFB
14
RCOMB
15
R1B
16
17
RFBB
ROFSB
18
WR
Bipolar Offset Resistor A. Accepts up to ±18 V. In 2-quadrant mode, ROFSA ties to RFBA. In 4-quadrant mode, ROFSA
ties to R1A and the external reference.
Internal Matching Feedback Resistor A. Connects to the external op amp for I-to-V conversion.
4-Quandrant Resistor. In 2-quadrant mode, R1A shorts to the VREFA pin. In 4-quadrant mode, R1A ties to ROFSA. Do
not connect when operating in unipolar mode.
Center Tap Point of the Two 4-Quadrant Resistors, R1A and R2A. In 4-quadrant mode, RCOMA ties to the inverting
node of the reference amplifier. In 2-quadrant mode, RCOMA shorts to the associated VREFA pin. Do not connect if
operating in unipolar mode.
DAC A Reference Input in 2-Quadrant Mode, R2 Terminal in 4-Quadrant Mode. In 2-quadrant mode, VREFA is the
reference input with constant input resistance vs. code. In 4-quadrant mode, VREFA is driven by the external
reference amplifier.
DAC A Current Output. Connects to the inverting terminal of external precision I-to-V op amp for voltage output.
DAC A Analog Ground.
Digital Ground.
DAC B Analog Ground.
DAC B Current Output. Connects to inverting terminal of external precision I-to-V op amp for voltage output.
DAC B Reference Input Pin. Establishes DAC full-scale voltage. Constant input resistance vs. code. If configured
with an external op amp for 4-quadrant multiplying, VREFB becomes –VREF.
Center Tap Point of the Two 4-Quadrant Resistors, R1B and R2B. In 4-quadrant mode, RCOMB ties to the inverting
node of the reference amplifier. In 2-quadrant mode, RCOMB shorts to the VREFB pin. Do not connect if operating in
unipolar mode.
4-Quandrant Resistor. In 2-quadrant mode, R1B shorts to the VREFB pin. In 4-quadrant mode, R1B ties to ROFSB. Do not
connect if operating in unipolar mode.
Internal Matching Feedback Resistor B. Connects to external op amp for I-to-V conversion.
Bipolar Offset Resistor B. Accepts up to ±18 V. In 2-quadrant mode, ROFSB ties to RFBB. In 4-quadrant mode, ROFSB
ties to R1B and an external reference.
Write Control Digital Input In, Active Low. WR transfers shift register data to the DAC register on the rising edge.
Signal level must be ≤VDD + 0.3 V.
Rev. D | Page 6 of 20
Data Sheet
Pin No.
19
20
21
22
Mnemonic
A0
A1
LDAC
MSB
23
RS
29
VDD
AD5547/AD5557
Function
Address Pin 0. Signal level must be ≤VDD + 0.3 V.
Address Pin 1. Signal level must be ≤VDD + 0.3 V.
Digital Input Load DAC Control. Signal level must be ≤VDD + 0.3 V.
Power-On Reset State. MSB = 0 corresponds to zero-scale reset; MSB = 1 corresponds to midscale reset. The
signal level must be ≤VDD + 0.3 V.
Active low resets both input and DAC registers. Resets to zero-scale if MSB = 0 and resets to midscale if MSB = 1.
Signal level must be ≤VDD + 0.3 V.
Positive Power Supply Input. The specified range of operation is 2.7 V to 5.5 V.
Rev. D | Page 7 of 20
Data Sheet
NC 1
38
D0
NC 2
37
D1
ROFSA 3
36
D2
RFBA 4
35
D3
R1A 5
34
D4
RCOMA 6
33
D5
VREFA 7
32
D6
IOUTA 8
31
D7
AD5557
30
D8
TOP VIEW
(Not to Scale)
29
VDD
28
D9
IOUTB 12
27
D10
VREFB 13
26
D11
RCOMB 14
25
D12
R1B 15
24
D13
RFBB 16
23
RS
ROFSB 17
22
MSB
WR 18
21
LDAC
A0 19
20
A1
AGNDA 9
DGND 10
AGNDB 11
NC = NO CONNECT
04452-004
AD5547/AD5557
Figure 5. AD5557 Pin Configuration
Table 4. AD5557 Pin Function Descriptions
Pin No.
1, 2
3
Mnemonic
NC
ROFSA
4
5
RFBA
R1A
6
RCOMA
7
VREFA
8
IOUTA
9
10
11
12
13
AGNDA
DGND
AGNDB
IOUTB
VREFB
14
RCOMB
15
R1B
16
17
RFBB
ROFSB
18
WR
19
20
21
22
A0
A1
LDAC
MSB
Function
No Connection. Do not connect anything other than the dummy pads to these pins.
Bipolar Offset Resistor A. Accepts up to ±18 V. In 2-quadrant mode, ROFSA ties to RFBA. In 4-quadrant mode, ROFSA
ties to R1A and the external reference.
Internal Matching Feedback Resistor A. Connects to the external op amp for I-to-V conversion.
4-Quandrant Resistor. In 2-quadrant mode, R1A shorts to the VREFA pin. In 4-quadrant mode, R1A ties to ROFSA. Do
not connect when operating in unipolar mode.
Center Tap Point of the Two 4-Quadrant Resistors, R1A and R2A. In 4-quadrant mode, RCOMA ties to the inverting
node of the reference amplifier. In 2-quadrant mode, RCOMA shorts to the VREFA pin. Do not connect if operating
in unipolar mode.
DAC A Reference Input in 2-Quadrant Mode, R2 Terminal in 4-Quadrant Mode. In 2-quadrant mode, VREFA is the
reference input with constant input resistance vs. code. In 4-quadrant mode, VREFA is driven by the external
reference amplifier.
DAC A Current Output. Connects to the inverting terminal of external precision I-to-V op amp for voltage
output.
DAC A Analog Ground.
Digital Ground.
DAC B Analog Ground.
DAC B Current Output. Connects to inverting terminal of external precision I-to-V op amp for voltage output.
DAC B Reference Input Pin. Establishes DAC full-scale voltage. Constant input resistance vs. code. If configured
with an external op amp for 4-quadrant multiplying, VREFB becomes –VREF.
Center Tap Point of the Two 4-Quadrant Resistors, R1B and R2B. In 4-quadrant mode, RCOMB ties to the inverting
node of the reference amplifier. In 2-quadrant mode, RCOMB shorts to the VREFB pin. Do not connect if operating
in unipolar mode.
4-Quandrant Resistor. In 2-quadrant mode, R1B shorts to the VREFB pin. In 4-quadrant mode, R1B ties to ROFSB. Do
not connect if operating in unipolar mode.
Internal Matching Feedback Resistor B. Connects to external op amp for I-to-V conversion.
Bipolar Offset Resistor B. Accepts up to ±18 V. In 2-quadrant mode, ROFSB ties to RFBB. In 4-quadrant mode, ROFSB
ties to R1B and an external reference.
Write Control Digital Input In, Active Low. Transfers shift register data to the DAC register on the rising edge.
Signal level must be ≤VDD + 0.3 V.
Address Pin 0. Signal level must be ≤VDD + 0.3 V.
Address Pin 1. Signal level must be ≤VDD + 0.3 V.
Digital Input Load DAC Control. Signal level must be ≤VDD + 0.3 V.
Power-On Reset State. MSB = 0 corresponds to zero-scale reset; MSB = 1 corresponds to midscale reset. The
signal level must be ≤VDD + 0.3 V.
Rev. D | Page 8 of 20
Data Sheet
AD5547/AD5557
Pin No.
23
Mnemonic
RS
24 to 28,
30 to 38
29
D13 to D0
Function
Active low resets both input and DAC registers. Resets to zero-scale if MSB = 0 and resets to midscale if MSB = 1.
Signal level must be ≤VDD + 0.3 V.
Digital Input Data Bits D13 to D0. Signal level must be ≤VDD + 0.3 V.
VDD
Positive Power Supply Input. The specified range of operation is 2.7 V to 5.5 V.
Table 5. Address Decoder Pins
A1
0
0
1
1
A0
0
1
0
1
Output Update
DAC A
None
DAC A and DAC B
DAC B
Table 6. Control Inputs
RS
0
1
1
1
1
WR
X
0
1
0
LDAC
Register Operation
X
0
1
1
1
1
0
Reset the output to 0 with MSB = 0; reset the output to midscale with MSB = 1.
Load the input register with data bits.
Load the DAC register with the contents of the input register.
The input and DAC registers are transparent.
When LDAC and WR are tied together and programmed as a pulse, the data bits are loaded into the input register
on the falling edge of the pulse and are then loaded into the DAC register on the rising edge of the pulse.
No register operation.
Rev. D | Page 9 of 20
AD5547/AD5557
Data Sheet
TYPICAL PERFORMANCE CHARACTERISTICS
1.0
0.8
0.6
0.6
0.4
0.4
0.2
0.2
0
–0.2
0
–0.2
–0.4
–0.4
–0.6
–0.6
–0.8
–0.8
–1.0
0
8192
16,384 24,576 32,768 40,960 49,152 57,344 65,536
CODE (Decimal)
–1.0
0
2048
4096
6144
8192 10,240 12,288 14,336 16,384
CODE (Decimal)
04452-010
DNL (LSB)
0.8
04452-019
INL (LSB)
1.0
Figure 9. AD5557 Differential Nonlinearity Error
Figure 6. AD5547 Integral Nonlinearity Error
1.5
1.0
VREF = 2.5V
TA = 25°C
0.8
1.0
LINEARITY ERROR (LSB)
0.6
0.2
0
–0.2
–0.4
–0.6
0.5
INL
0
DNL
–0.5
–1.0
0
8192
16,384 24,576 32,768 40,960 49,152 57,344 65,536
CODE (Decimal)
–1.5
04452-020
–1.0
2
6
8
SUPPLY VOLTAGE VDD (V)
10
Figure 10. Linearity Error vs. Supply Voltage, VDD
Figure 7. AD5547 Differential Nonlinearity Error
1.0
5
VDD = 5V
TA = 25°C
0.8
SUPPLY CURRENT IDD (LSB)
0.6
0.4
0.2
0
–0.2
–0.4
–0.6
4
3
2
1
–0.8
–1.0
0
2048
4096
6144
8192 10,240 12,288 14,336 16,384
CODE (Decimal)
04452-021
INL (LSB)
4
04452-022
GE
–0.8
Figure 8. AD5557 Integral Nonlinearity Error
0
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
LOGIC INPUT VOLTAGE VIH (V)
Figure 11. Supply Current vs. Logic Input Voltage
Rev. D | Page 10 of 20
5.0
04452-023
DNL (LSB)
0.4
Data Sheet
AD5547/AD5557
3.0
SUPPLY CURRENT (mA)
2.5
LDAC
1
2.0
0x5555
1.5
2
0x8000
1.0
0xFFFF
0x0000
VOUT
0
10k
100k
1M
10M
100M
CLOCK FREQUENCY (Hz)
M 200ns
A CH1 2.70V
B CH1 –6.20V
400.00ns
04452-024
CH1 5.00V CH2 2.00V
04452-025
0.5
Figure 15. Settling Time from Full Scale to Zero Scale
Figure 12. AD5547 Supply Current vs. Clock Frequency
–3.85
90
VDD = 5V ± 10%
VREF = 10V
80
–3.90
70
–3.95
VOUT (V)
PSRR (–dB)
60
50
40
–4.00
–4.05
30
–4.10
20
100
1k
10k
FREQUENCY (Hz)
100k
1M
04452-014
0
10
–4.20
–20
0
10
20
30
40
TIME (ns)
Figure 13. Power Supply Rejection Ratio (PSRR) vs. Frequency
Figure 16. AD5547 Midscale Transition and Digital Feedthrough
20
2
0
0
–20
–2
–4
–40
GSIN (dB)
–60
–80
–6
–8
–10
–100
–12
–120
–14
–140
0
5
10
15
FREQUENCY (kHz)
20
25
04452-114
–16
–160
Figure 14. AD5547/AD5557 Analog Total Harmonic Distortion (THD)
Rev. D | Page 11 of 20
–18
10k
100k
1M
10M
100M
FREQUENCY (Hz)
Figure 17. AD5547 Unipolar Reference Multiplying Bandwidth
04452-017
POWER SPECTRUM (dB)
–10
04452-0016
–4.15
10
AD5547/AD5557
Data Sheet
CIRCUIT OPERATION
The reference voltage inputs exhibit a constant input resistance
of 5 kΩ ± 20%. The impedance of IOUT, the DAC output, is code
dependent. External amplifier choice should take into account
the variation of the AD5547/AD5557 output impedance. The
feedback resistance in parallel with the DAC ladder resistance
dominates output voltage noise. To maintain good analog
performance, it is recommended that the power supply is
bypassed with a 0.01 µF to 0.1 µF ceramic or chip capacitor in
parallel with a 1 µF tantalum capacitor. Also, to minimize gain
error, PCB metal traces between VREF and RFB should match.
DAC SECTION
The AD5547/AD5557 are 16-/14-bit, multiplying, currentoutput, parallel input DACs. The devices operate from a single
2.7 V to 5.5 V supply and provide both unipolar (0 V to –VREF
or 0 V to +VREF) and bipolar (±VREF) output ranges from –18 V
to +18 V references. In addition to the precision conversion RFB
commonly found in current output DACs, there are three additional precision resistors for 4-quadrant bipolar applications.
The AD5547/AD5557 consist of two groups of precision R-2R
ladders, which make up the 12/10 LSBs, respectively. Furthermore,
the 4 MSBs are decoded into 15 segments of resistor value 2R.
Figure 18 shows the architecture of the 16-bit AD5547. Each of
the 16 segments and the R-2R ladder carries an equally weighted
current of one-sixteenth of full scale. The feedback resistor RFB
and 4-quadrant resistor ROFS have values of 10 kΩ. Each 4-quadrant
resistor, R1 and R2, equals 5 kΩ. In 4-quadrant operation, R1,
R2, and an external op amp work together to invert the reference
voltage and apply it to the VREF input. With ROFS and RFB
connected as shown in Figure 2, the output can swing from
−VREF to +VREF.
VREF
2R
80kΩ
2R
80kΩ
R2
5kΩ
Every code change of the DAC corresponds to a step function;
gain peaking at each output step may occur if the op amp has
limited GBP and excessive parasitic capacitance present at the
inverting node of the op amp. A compensation capacitor, therefore,
may be needed between the I-to-V op amp inverting and output
nodes to smooth the step transition. Such a compensation capacitor
should be found empirically, but a 20 pF capacitor is generally
adequate for the compensation.
The VDD power is used primarily by the internal logic to drive
the DAC switches. Note that the output precision degrades if
the operating voltage falls below the specified voltage. Users
should also avoid using switching regulators because device
power supply rejection degrades at higher frequencies.
2R
80kΩ
2R
80kΩ
RCOM
R1
5kΩ
4 MSB
15 SEGMENTS
R1
R
40kΩ
R
40kΩ
R
40kΩ
R
40kΩ
R
40kΩ
R
40kΩ
R
40kΩ
R
40kΩ
2R
80kΩ
2R
80kΩ
2R
80kΩ
2R
80kΩ
2R
80kΩ
2R
80kΩ
2R
80kΩ
2R
80kΩ
2R
80kΩ
8-BIT R2R
ROFS
RA
R
R
R
R
RB
2R
80kΩ
2R
80kΩ
2R
80kΩ
2R
80kΩ
RFB
2R
80kΩ
10kΩ
10kΩ
4-BIT R2R
IOUT
AGND
15
8
4
ADDRESS DECODER
WR
LDAC
WR
D15
DAC REGISTER
RS
INPUT REGISTER
RS
D14
RS
D0
Figure 18. 16-Bit AD5547 Equivalent R-2R DAC Circuit with Digital Section, One Channel Shown
Rev. D | Page 12 of 20
04452-011
LDAC
Data Sheet
AD5547/AD5557
The AD5547/AD5557 have 16-/14-bit parallel inputs. The devices
are double buffered with 16-/14-bit registers. The double buffered
feature allows the simultaneous update of several AD5547s/
AD5557s. For the AD5547, the input register is loaded directly
from a 16-bit controller bus when WR is brought low. The DAC
register is updated with data from the input register when LDAC
is brought high. Updating the DAC register updates the DAC
output with the new data (see Figure 18). To make both registers
transparent, tie WR low and LDAC high. The asynchronous RS
pin resets the part to zero scale if MSB = 0 and to midscale if
MSB = 1.
ESD Protection Circuits
All logic input pins contain back-biased ESD protection Zeners
connected to ground (DGND) and VDD, as shown in Figure 19.
As a result, the voltage level of the logic input should not be
greater than the supply voltage.
VDD
5kΩ
DGND
04452-026
DIGITAL
INPUTS
Figure 19. Equivalent ESD Protection Circuits
Amplifier Selection
In addition to offset voltage, the bias current is important in
op amp selection for precision current output DACs. A 30 nA
input bias current in the op amp contributes to 1 LSB in the
full-scale error of the AD5547. The OP1177 and AD8628 op
amps are good candidates for the I-to-V conversion.
The voltage reference temperature coefficient (TC) and longterm drift are primary considerations. For example, a 5 V
reference with a TC of 5 ppm/°C means the output changes by
25 µV/°C. As a result, a reference operating at 55°C contributes
an additional 750 µV full-scale error.
Similarly, the same 5 V reference with a ±50 ppm long-term
drift means the output may change by ±250 µV over time.
Therefore, it is practical to calibrate a system periodically to
maintain its optimum precision.
PCB LAYOUT, POWER SUPPLY BYPASSING, AND
GROUND CONNECTIONS
It is a good practice to employ a compact, minimum lead length,
PCB layout design. The leads to the input should be as short as
possible to minimize IR drop and stray inductance.
The PCB metal traces between VREF and RFB should also be
matched to minimize gain error.
It is also essential to bypass the power supply with quality
capacitors for optimum stability. Supply leads to the device
should be bypassed with 0.01 µF to 0.1 µF disc or chip ceramic
capacitors. Low ESR 1 µF to 10 µF tantalum or electrolytic
capacitors should also be applied at the supply in parallel with
the ceramic capacitor to minimize transient disturbance and
filter out low frequency ripple.
To minimize the digital ground bounce, the AD5547/AD5557
DGND terminal should be joined with the AGND terminal at
a single point. Figure 20 illustrates the basic supply bypassing
configuration and AGND/DGND connection for the
AD5547/AD5557.
Reference Selection
The initial accuracy and rated output of the voltage reference
determine the full-span adjustment. The initial accuracy of
the reference is usually a secondary concern because it can be
trimmed. Figure 25 shows an example of a trimming circuit.
The zero-scale error can also be minimized by standard op amp
nulling techniques.
Rev. D | Page 13 of 20
+ C2
5V
–
VDD
C1
1µF
0.1µF
AD5547/AD5557
AGND
DGND
04452-015
DIGITAL SECTION
Figure 20. Power Supply Bypassing
AD5547/AD5557
Data Sheet
APPLICATIONS INFORMATION
UNIPOLAR MODE
In this case, the output voltage polarity is opposite the VREF
polarity (see Figure 21). Table 7 shows the negative output vs.
code for the AD5547.
2-Quadrant Multiplying Mode, VOUT = 0 V to –VREF
The AD5547/AD5557 DAC architecture uses a current-steering
R-2R ladder design that requires an external reference and op
amp to convert the unipolar mode of the output voltage to
VOUT = −VREF × D/65,536 (AD5547)
(1)
VOUT = −VREF × D/16,384 (AD5557)
(2)
Table 7. AD5547 Unipolar Mode Negative Output vs. Code
D in Binary
1111 1111 1111 1111
1000 0000 0000 0000
0000 0000 0000 0001
0000 0000 0000 0000
where D is the decimal equivalent of the input code.
+5V
2
U3 ADR03
C2
0.1µF VIN
TRIM
VOUT
5
6
+2.5V
GND
VREFA
4
R1A
VDD
C3
0.1µF
ROFSA
RCOMA
R1
ROFS
R2
RFBA
2.5V
AD5547/AD5557
C6
6.8pF
RFB
16-/14-BIT
U1
IOUTA
AGNDA
VOUTA
+V
AD8628
–V
–2.5V TO 0V
16/14 DATA
WR LDAC RS
WR
LDAC
RS
MSB
A0, A1
MSB A0, A1
C4
C5
2
1µF
–5V
Figure 21. Unipolar 2-Quadrant Multiplying Mode, VOUT = 0 to –VREF
Rev. D | Page 14 of 20
0.1µF
04452-007
C1
1µF
VOUT (V)
–VREF (65,535/65,536)
–VREF/2
–VREF (1/65,536)
0
Data Sheet
AD5547/AD5557
2-Quadrant Multiplying Mode, VOUT = 0 V to +VREF
Table 8 shows the positive output vs. code for the AD5547.
The AD5547/AD5557 are designed to operate with either
positive or negative reference voltages. As a result, a positive
output can be achieved with an additional op amp, (see
Figure 22); the output becomes
Table 8. AD5547 Unipolar Mode Positive Output vs. Code
VOUT = +VREF × D/65,536 (AD5547)
(3)
VOUT = +VREF × D/16,384 (AD5557)
(4)
D in Binary
1111 1111 1111 1111
1000 0000 0000 0000
0000 0000 0000 0001
0000 0000 0000 0000
VOUT (V)
+VREF(65,535/65,536)
+VREF/2
+VREF(1/65,536)
0
U2
+5V
C8
0.1µF
U3
C2
1µF
VIN
TRIM
VOUT
5
6
GND
4
C9
1µF
–5V
–2.5V
C7
ADR03
+5V
+2.5V
C4
R1A
VDD
C3
0.1µF
R1
RCOMA
VREFA
R2
ROFSA
RFBA
ROFS
RFB
C6
IOUTA
AD5547/AD5557
C5 0.1µF
U2B
16-/14-BIT
AGNDA
1µF
+V
VOUTA
AD8628
–V
16/14 DATA
WR LDAC RS
WR
LDAC
RS
MSB
A0, A1
MSB A0, A1
2
Figure 22. Unipolar 2-Quadrant Multiplying Mode, VOUT = 0 to +VREF
Rev. D | Page 15 of 20
0V TO +2.5V
04452-005
C1
1µF
AD8628
2
AD5547/AD5557
Data Sheet
BIPOLAR MODE
4-Quadrant Multiplying Mode, VOUT = –VREF to +VREF
Table 9 shows some of the results for the 16-bit AD5547.
The AD5547/AD5557 contain on-chip all the 4-quadrant
resistors necessary for precision bipolar multiplying operation.
Such a feature minimizes the number of exponent components
to only a voltage reference, dual op amp, and compensation
capacitor (see Figure 23). For example, with a +10 V reference,
the circuit yields a precision, bipolar –10 V to +10 V output.
Table 9. AD5547 Output vs. Code
VOUT = (D/32768 − 1) × VREF (AD5547)
(5)
VOUT = (D/16384 − 1) × VREF (AD5557)
(6)
+15V
VOUT
+VREF (32,767/32,768)
+VREF (1/32,768)
0
–VREF (1/32,768)
–VREF
2
C2
0.1µF
U3
VIN
TRIM
VOUT
5
6
GND
U2A
4
ADR01
AD8512
C8
R1A
–10V
VREFA
RCOMA
+10V
ROFSA
RFBA
+5V
VDD
R1
ROFS
R2
RFB
C4 1µF
+15V
C9
U2B
C3
0.1µF
AD5547/AD5557
U1
16/14 DATA
WR LDAC RS
WR
LDAC
RS
MSB
A0, A1
16-/14-BIT
DAC A
C5 0.1µF
IOUTA
AGNDA
+V
VOUT
AD8512
–V
C6 0.1µF –10V TO +10V
C7 1µF
MSB A0, A1
2
–15V
04452-006
C1
1µF
D in Binary
1111 1111 1111 1111
1000 0000 0000 0001
1000 0000 0000 0000
0111 1111 1111 1111
0000 0000 0000 0000
Figure 23. 4-Quadrant Multiplying Mode, VOUT = –VREF to +VREF
Rev. D | Page 16 of 20
Data Sheet
AD5547/AD5557
AC Reference Signal Attenuator
System Calibration
Besides handling the digital waveform decoded from the
parallel input data, the AD5547/AD5557 can also handle low
frequency ac reference signals for signal attenuation, channel
equalization, and waveform generation applications. The
maximum signal range can be up to ±18 V (see Figure 24).
The initial accuracy of the system can be adjusted by trimming
the voltage reference ADR0x with a digital potentiometer (see
Figure 25). The AD5170 provides a one-time programmable
(OTP), 8-bit adjustment that is ideal and reliable for such
calibration. Analog Devices, Inc., OTP digital potentiometer
comes with programmable software that simplifies factory
calibration.
U2A
OP2177
C7
+10V
–10V
+15V
R1A
RCOMA
+5V
R1
VDD
C1
1µF
C2
0.1µF
ROFSA
VREFA
R2
C4
RFBA
ROFS
C6
IOUTA
16-/14-BIT
AD5547/AD5557
C5 0.1µF
U2B
RFB
VOUTA
+V
OP2177
–V
AGNDA
U1
1µF
16/14 DATA
WR LDAC RS
C8
MSB A0, A1
1µF
C9 0.1µF
WR
LDAC
RS
MSB
A0, A1
04452-008
2
–15V
Figure 24. Signal Attenuator with AC Reference
+5V
2
C2
0.1µF
AD5170
U3
VIN
TRIM
VOUT
R3
5
470kΩ B
6
GND
4
U4
10kΩ
R7
U2
1kΩ
AD8628
ADR03
–2.5V
C7
+2.5V
+5V
R1A
VDD
C3
0.1µF
RCOMA
R1
VREFA
R2
ROFSA
ROFS
AD5547/AD5557
C4
RFBA
16-/14-BIT
C6
U2B
RFB
IOUTA
AGNDA
U1
16/14 DATA
WR LDAC RS
WR
LDAC
REF 01/AD
RS
MSB
A0, A1
1µF
C5 0.1µF
+V
VOUTA
AD8628
–V
0V TO +2.5V
MSB A0, A1
2
04452-009
C1
1µF
Figure 25. Full-Span Calibration
Rev. D | Page 17 of 20
AD5547/AD5557
Data Sheet
REFERENCE SELECTION
When selecting a reference for use with the AD55xx series of
current output DACs, pay attention to the output voltage,
temperature coefficient specification of the reference. Choosing
a precision reference with a low output temperature coefficient
minimizes error sources. Table 10 lists some of the references
available from Analog Devices, Inc., that are suitable for use
with this range of current output DACs.
AMPLIFIER SELECTION
The primary requirement for the current-steering mode is an
amplifier with low input bias currents and low input offset voltage.
Because of the code-dependent output resistance of the DAC,
the input offset voltage of an op amp is multiplied by the variable
gain of the circuit. A change in this noise gain between two
adjacent digital fractions produces a step change in the output
voltage due to the amplifier’s input offset voltage. This output
voltage change is superimposed upon the desired change in output
between the two codes and gives rise to a differential linearity error,
which, if large enough, can cause the DAC to be nonmonotonic.
The input bias current of an op amp also generates an offset at
the voltage output because of the bias current flowing in the
feedback resistor, RFB.
Common-mode rejection of the op amp is important in voltageswitching circuits because it produces a code-dependent error
at the voltage output of the circuit.
Provided that the DAC switches are driven from true wideband
low impedance sources (VIN and AGND), they settle quickly.
Consequently, the slew rate and settling time of a voltage-switching
DAC circuit is determined largely by the output op amp. To obtain
minimum settling time in this configuration, minimize capacitance
at the VREF node (the voltage output node in this application) of
the DAC. This is done by using low input capacitance buffer
amplifiers and careful board design.
Analog Devices offers a wide range of amplifiers for both precision
dc and ac applications, as listed in Table 11 and Table 12.
Table 10. Suitable Analog Devices Precision References
Part No.
ADR01
ADR01
ADR02
ADR02
ADR03
ADR03
ADR06
ADR06
ADR420
ADR421
ADR423
ADR425
ADR431
ADR435
ADR391
ADR395
Output Voltage (V)
10
10
5.0
5.0
2.5
2.5
3.0
3.0
2.048
2.50
3.00
5.00
2.500
5.000
2.5
5.0
Initial Tolerance (%)
0.05
0.05
0.06
0.06
0.1
0.1
0.1
0.1
0.05
0.04
0.04
0.04
0.04
0.04
0.16
0.10
Maximum Temperature
Drift (ppm/°C)
3
9
3
9
3
9
3
9
3
3
3
3
3
3
9
9
ISS (mA)
1
1
1
1
1
1
1
1
0.5
0.5
0.5
0.5
0.8
0.8
0.12
0.12
Output Noise (µV p-p)
20
20
10
10
6
6
10
10
1.75
1.75
2
3.4
3.5
8
5
8
Package(s)
SOIC-8
TSOT-5, SC70-5
SOIC-8
TSOT-5, SC70-5
SOIC-8
TSOT-5, SC70-5
SOIC-8
TSOT-5, SC70-5
SOIC-8, MSOP-8
SOIC-8, MSOP-8
SOIC-8, MSOP-8
SOIC-8, MSOP-8
SOIC-8, MSOP-8
SOIC-8, MSOP-8
TSOT-5
TSOT-5
Table 11. Suitable Analog Devices Precision Op Amps
Part No.
OP97
OP1177
AD8675
AD8671
ADA4004-1
AD8603
AD8607
AD8605
AD8615
AD8616
Supply Voltage (V)
±2 to ±20
±2.5 to ±15
±5 to ±18
±5 to ±15
±5 to ±15
1.8 to 5
1.8 to 5
2.7 to 5
2.7 to 5
2.7 to 5
VOS Maximum
(µV)
25
60
75
75
125
50
50
65
65
65
IB Maximum
(nA)
0.1
2
2
12
90
0.001
0.001
0.001
0.001
0.001
0.1 Hz to 10 Hz
Noise (µV p-p)
0.5
0.4
0.1
0.077
0.1
2.3
2.3
2.3
2.4
2.4
Rev. D | Page 18 of 20
Supply Current (µA)
600
500
2300
3000
2000
40
40
1000
2000
2000
Package(s)
SOIC-8 , PDIP-8
MSOP-8, SOIC-8
MSOP-8, SOIC-8
MSOP-8, SOIC-8
SOIC-8, SOT-23-5
TSOT-5
MSOP-8, SOIC-8
WLCSP-5, SOT-23-5
TSOT-5
MSOP-8, SOIC-8
Data Sheet
AD5547/AD5557
Table 12. Suitable Analog Devices High Speed Op Amps
Part No.
AD8065
AD8066
AD8021
AD8038
ADA4899
AD8057
AD8058
AD8061
AD8062
AD9631
Supply Voltage (V)
5 to 24
5 to 24
5 to 24
3 to 12
5 to 12
3 to 12
3 to 12
2.7 to 8
2.7 to 8
±3 to ±6
BW @ ACL (MHz)
145
145
490
350
600
325
325
320
320
320
Slew Rate (V/µs)
180
180
120
425
310
1000
850
650
650
1300
VOS (Max) (µV)
1500
1500
1000
3000
35
5000
5000
6000
6000
10,000
IB (Max) (nA)
0.006
0.006
10,500
750
100
500
500
350
350
7000
Package(s)
SOIC-8, SOT-23-5
SOIC-8, MSOP-8
SOIC-8, MSOP-8
SOIC-8, SC70-5
LFCSP-8, SOIC-8
SOT-23-5, SOIC-8
SOIC-8, MSOP-8
SOT-23-5, SOIC-8
SOIC-8, MSOP-8
SOIC-8, PDIP-8
Table 13 lists the latest DACS available from Analog Devices.
Table 13. ADI Current Output DACs
Model
AD5425
AD5426
AD5450
AD5424
AD5429
AD5428
AD5432
AD5451
AD5433
AD5439
AD5440
AD5443
AD5452
AD5445
AD5444
AD5449
AD5415
AD5447
AD5405
AD5453
AD5553
AD5556
AD5446
AD5555
AD5557
AD5543
AD5546
AD5545
AD5547
Bits
8
8
8
8
8
8
10
10
10
10
10
12
12
12
12
12
12
12
12
14
14
14
14
14
14
16
16
16
16
Outputs
1
1
1
1
2
2
1
1
1
2
2
1
1
1
1
2
2
2
2
1
1
1
1
2
2
1
1
2
2
Interface
SPI, 8-Bit Load
SPI
SPI
Parallel
SPI
Parallel
SPI
SPI
Parallel
SPI
Parallel
SPI
SPI
Parallel
SPI
SPI
SPI
Parallel
Parallel
SPI
SPI
Parallel
SPI
SPI
Parallel
SPI
Parallel
SPI
Parallel
Package
MSOP-10
MSOP-10
TSOT-8
TSSOP-16
TSSOP-16
TSSOP-20
MSOP-10
TSOT-8
TSSOP-20
TSSOP-16
TSSOP-24
MSOP-10
TSOT-8
TSSOP-20
MSOP-10
TSSOP-16
TSSOP-24
TSSOP-24
LFCSP-40
TSOT-8
MSOP-8
TSSOP-28
MSOP-10
TSSOP-16
TSSOP-38
MSOP-8
TSSOP-28
TSSOP-16
TSSOP-38
Comments
Fast 8-bit load; see also AD5426
See also AD5425 fast load
See also AD5425 fast load
See also AD5452 and AD5444
Higher accuracy version of AD5443; see also AD5444
Higher accuracy version of AD5443; see also AD5452
Uncommitted resistors
Uncommitted resistors
MSOP version of AD5453; compatible with AD5443, AD5432, and AD5426
Rev. D | Page 19 of 20
AD5547/AD5557
Data Sheet
OUTLINE DIMENSIONS
9.80
9.70
9.60
20
38
4.50
4.40
4.30
6.40 BSC
1
19
PIN 1
1.20
MAX
0.15
0.05
COPLANARITY
0.10
0.50
BSC
0.27
0.17
SEATING
PLANE
0.20
0.09
8°
0°
0.70
0.60
0.45
COMPLIANT TO JEDEC STANDARDS MO-153-BD-1
Figure 26. 38-Lead Thin Shrink Small Outline Package [TSSOP]
(RU-38)
Dimension s shown in millimeters
ORDERING GUIDE
Model 1
AD5547BRU
AD5547BRU-REEL7
AD5547BRUZ
AD5547CRUZ
AD5547CRUZ-REEL7
AD5557CRU
AD5557CRU-REEL7
AD5557CRUZ
1
Resolution (Bits)
16
16
16
16
16
14
14
14
DNL
(LSB)
±1
±1
±1
±1
±1
±1
±1
±1
INL
(LSB)
±2
±2
±2
±1
±1
±1
±1
±1
Temperature Range
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
Z = RoHS Compliant Part.
©2004–2012 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
D04452-0-11/12(D)
Rev. D | Page 20 of 20
Package Description
38-Lead TSSOP
38-Lead TSSOP
38-Lead TSSOP
38-Lead TSSOP
38-Lead TSSOP
38-Lead TSSOP
38-Lead TSSOP
38-Lead TSSOP
Package
Option
RU-38
RU-38
RU-38
RU-38
RU-38
RU-38
RU-38
RU-38
Ordering
Quantity
50
1,000
50
50
1,000
50
1,000
50
工商网监
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