Product
Folder
Sample &
Buy
Technical
Documents
Support &
Community
Tools &
Software
DAC121S101, DAC121S101-Q1
SNAS265J – JUNE 2005 – REVISED SEPTEMBER 2015
DAC121S101/-Q1 12-Bit Micro Power, RRO Digital-to-Analog Converter
1 Features
3 Description
•
The DAC121S101 device is a full-featured, generalpurpose, 12-bit voltage-output digital-to-analog
converter (DAC) that can operate from a single 2.7-V
to 5.5-V supply and consumes just 177 µA of current
at 3.6 V. The on-chip output amplifier allows rail-torail output swing and the three wire serial interface
operates at clock rates up to 30 MHz over the
specified supply voltage range and is compatible with
standard SPI™, QSPI, MICROWIRE and DSP
interfaces. Competitive devices are limited to 20-MHz
clock rates at supply voltages in the 2.7 V to 3.6 V
range.
1
•
•
•
•
•
•
•
•
•
DAC121S101-Q1 is AEC-Q100 Grade 1 Qualified
and is Manufactured on an Automotive Grade
Flow.
Ensured Monotonicity
Low Power Operation
Rail-to-Rail Voltage Output
Power-on Reset to Zero Volts Output
Wide Temperature Range of −40°C to +125°C
Wide Power Supply Range of 2.7 V to 5.5 V
Small Packages
Power Down Feature
Key Specifications
– 12-Bit Resolution
– DNL -0.15, +0.25 LSB (Typical)
– 8-µs Output Settling Time (Typical)
– 4-mV Zero Code Error (Typical)
– Full-Scale Error at −0.06 %FS (Typical)
– 0.64-mW (3.6-V) / 1.43-mW (5.5-V) Normal
Mode Power Consumption (Typical)
– 0.14-µW (3.6-V) / 0.39-µW (5.5-V) PowerDown Mode (Typical)
The supply voltage for the DAC121S101 serves as its
voltage reference, providing the widest possible
output dynamic range. A power-on reset circuit
ensures that the DAC output powers up to zero volts
and remains there until there is a valid write to the
device. A power-down feature reduces power
consumption to less than a microWatt.
The low power consumption and small packages of
the DAC121S101 make it an excellent choice for use
in battery operated equipment.
Device Information(1)
PART NUMBER
2 Applications
DAC121S101
•
•
•
•
•
DAC121S101-Q1
Battery-Powered Instruments
Digital Gain and Offset Adjustment
Programmable Voltage and Current Sources
Programmable Attenuators
Automotive
BODY SIZE (NOM)
2.90 mm × 1.60 mm
VSSOP (8)
3.00 mm × 3.00 mm
SOT (6)
2.90 mm × 1.60 mm
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
Simplified Block Diagram
VA
PACKAGE
SOT (6)
DNL vs. Output Code
GND
POWER-ON
RESET
DAC121S101
REF(+) REF(-)
DAC
REGISTER
12
12-BIT DAC
BUFFER
VOUT
12
POWER-DOWN
CONTROL
LOGIC
INPUT
CONTROL
LOGIC
SYNC
SCLK
1k
100k
DIN
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.
DAC121S101, DAC121S101-Q1
SNAS265J – JUNE 2005 – REVISED SEPTEMBER 2015
www.ti.com
Table of Contents
1
2
3
4
5
6
7
Features ..................................................................
Applications ...........................................................
Description .............................................................
Revision History.....................................................
Description continued ...........................................
Pin Configuration and Functions .........................
Specifications.........................................................
7.1
7.2
7.3
7.4
7.5
7.6
7.7
8
1
1
1
2
3
3
4
Absolute Maximum Ratings ...................................... 4
ESD Ratings.............................................................. 4
Recommended Operating Conditions....................... 5
Thermal Information .................................................. 5
Electrical Characteristics.......................................... 5
AC and Timing Characteristics ................................ 7
Typical Characteristics ............................................ 10
Detailed Description ............................................ 16
8.1
8.2
8.3
8.4
Overview .................................................................
Functional Block Diagram .......................................
Feature Description.................................................
Device Functional Modes........................................
16
16
16
17
8.5 Programming........................................................... 18
9
Application and Implementation ........................ 19
9.1 Application Information............................................ 19
9.2 Typical Application ................................................. 21
10 Power Supply Recommendations ..................... 23
10.1 Using References as Power Supplies................... 23
11 Layout................................................................... 25
11.1 Layout Guidelines ................................................. 25
11.2 Layout Example .................................................... 26
12 Device and Documentation Support ................. 26
12.1
12.2
12.3
12.4
12.5
12.6
12.7
Device Support ....................................................
Documentation Support ........................................
Related Links ........................................................
Community Resources..........................................
Trademarks ...........................................................
Electrostatic Discharge Caution ............................
Glossary ................................................................
26
27
27
27
27
27
27
13 Mechanical, Packaging, and Orderable
Information ........................................................... 28
4 Revision History
NOTE: Page numbers for previous revisions may differ from page numbers in the current version.
Changes from Revision I (March 2013) to Revision J
•
Page
Added Pin Configuration and Functions section, ESD Ratings table, Feature Description section, Device Functional
Modes, Application and Implementation section, Power Supply Recommendations section, Layout section, Device
and Documentation Support section, and Mechanical, Packaging, and Orderable Information section .............................. 1
Changes from Revision H (February 2010) to Revision I
•
2
Page
Changed layout of National Data Sheet to TI format ........................................................................................................... 25
Submit Documentation Feedback
Copyright © 2005–2015, Texas Instruments Incorporated
Product Folder Links: DAC121S101 DAC121S101-Q1
DAC121S101, DAC121S101-Q1
www.ti.com
SNAS265J – JUNE 2005 – REVISED SEPTEMBER 2015
5 Description continued
The DAC121S101 is a direct replacement for the AD5320 and the DAC7512 and is one of a family of pin
compatible DACs, including the 8-bit DAC081S101 and the 10-bit DAC101S101. The DAC121S101 operates
over the extended industrial temperature range of −40°C to +105°C while the DAC121S101-Q1 operates over
the Grade 1 automotive temperature range of −40°C to +125°C. The DAC121S101 is available in a 6-lead SOT
and an 8-lead VSSOP and the DAC121S101-Q1 is available in the 6-lead SOT only.
6 Pin Configuration and Functions
DDC Package
6-Pin SOT
Top View
DAC121S101 (Only) DGK Package
8-Pin VSSOP
Top View
VOUT
1
6
SYNC
GND
2
5
SCLK
VA
3
4
DIN
VA
1
NC
NC
2
3
VOUT
4
SOT
VSSOP
8
GND
7
6
DIN
SCLK
5
SYNC
Pin Functions
PIN
SOT NO.
VSSOP
NO.
I/O
DIN
4
7
Input
GND
2
8
—
Ground reference for all on-chip circuitry.
NC
—
—
No Connect. There is no internal connection to these pins.
SCLK
5
6
Input
Serial Clock Input. Data is clocked into the input shift register on the falling edges of this
pin.
SYNC
6
5
Input
Frame synchronization input for the data input. When this pin goes low, it enables the input
shift register and data is transferred on the falling edges of SCLK. The DAC is updated on
the 16th clock cycle unless SYNC is brought high before the 16th clock, in which case the
rising edge of SYNC acts as an interrupt and the write sequence is ignored by the DAC.
VA
3
1
—
VOUT
1
4
Output
NAME
2
3
DESCRIPTION
Serial Data Input. Data is clocked into the 16-bit shift register on the falling edges of SCLK
after the fall of SYNC.
Power supply and Reference input. Should be decoupled to GND.
DAC Analog Output Voltage.
Copyright © 2005–2015, Texas Instruments Incorporated
Product Folder Links: DAC121S101 DAC121S101-Q1
Submit Documentation Feedback
3
DAC121S101, DAC121S101-Q1
SNAS265J – JUNE 2005 – REVISED SEPTEMBER 2015
www.ti.com
7 Specifications
7.1 Absolute Maximum Ratings
over operating free-air temperature range (unless otherwise noted)
(1) (2)
MIN
Supply Voltage, VA
−0.3
Voltage on any Input Pin
Input Current at Any Pin
Package Input Current
See
−65
Storage Temperature, Tstg
(1)
(2)
(3)
(4)
(5)
V
V
10
mA
20
mA
235
°C
150
°C
(3)
Soldering Temperature, Infrared, 10 Seconds (5)
UNIT
6.5
(VA + 0.3)
(3)
Power Consumption at TA = 25°C
MAX
(4)
Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings
only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under Recommended
Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
All voltages are measured with respect to GND = 0 V, unless otherwise specified
When the input voltage at any pin exceeds the power supplies (that is, less than GND, or greater than VA), the current at that pin must
be limited to 10 mA. The 20-mA maximum package input current rating limits the number of pins that can safely exceed the power
supplies with an input current of 10 mA to two.
The absolute maximum junction temperature (TJMAX) for this device is 150°C. The maximum allowable power dissipation is dictated by
TJMAX, the junction-to-ambient thermal resistance (θJA), and the ambient temperature (TA), and can be calculated using the formula
PDMAX = (TJMAX − TA) / θJA. The values for maximum power dissipation will be reached only when the device is operated in a severe
fault condition (e.g., when input or output pins are driven beyond the power supply voltages, or the power supply polarity is reversed).
Obviously, such conditions must always be avoided.
See the section entitled "Surface Mount" found in any post 1986 National Semiconductor Linear Data Book for methods of soldering
surface mount devices.
7.2 ESD Ratings
VALUE
V(ESD)
(1)
4
Electrostatic discharge
Human body model (HBM), per ANSI/ESDA/JEDEC JS-001 (1)
±2500
Machine Model
±250
UNIT
V
JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.
Submit Documentation Feedback
Copyright © 2005–2015, Texas Instruments Incorporated
Product Folder Links: DAC121S101 DAC121S101-Q1
DAC121S101, DAC121S101-Q1
www.ti.com
SNAS265J – JUNE 2005 – REVISED SEPTEMBER 2015
7.3 Recommended Operating Conditions
over operating free-air temperature range (unless otherwise noted) (1)
Operating Temperature Range
(2)
MIN
NOM
MAX
UNIT
DAC121S101
−40
TA
105
°C
DAC121S101-Q1
−40
TA
125
°C
Supply Voltage, VA
2.7
5.5
V
Any Input Voltage (3)
−0.1
(VA + 0.1)
V
0
1500
Output Load
SCLK Frequency
(1)
(2)
(3)
pF
30
MHz
Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Recommended Operating Ratings indicate
conditions for which the device is functional, but do not ensure specific performance limits. For ensured specifications and test
conditions, see the Electrical Characteristics. The ensured specifications apply only for the test conditions listed. Some performance
characteristics may degrade when the device is not operated under the listed test conditions.
All voltages are measured with respect to GND = 0 V, unless otherwise specified
The analog inputs are protected as shown below. Input voltage magnitudes up to VA + 300 mV or to 300 mV below GND will not
damage this device. However, errors in the conversion result can occur if any input goes above VA or below GND by more than 100 mV.
For example, if VA is 2.7VDC, ensure that −100mV ≤ input voltages ≤2.8VDC to ensure accurate conversions.
I/O
TO INTERNAL
CIRCUITRY
GND
7.4 Thermal Information
DAC121S101, DAC121S101-Q1
THERMAL METRIC (1)
RθJA
(1)
DGK (VSSOP)
DDC (SOT)
8 PINS
6 PINS
240
250
Junction-to-ambient thermal resistance
UNIT
°C/W
For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application
report, SPRA953.
7.5
Electrical Characteristics
The following specifications apply for VA = 2.7 V to 5.5 V, RL = 2 kΩ to GND, CL = 200 pF to GND, fSCLK = 30 MHz, input code
range 48 to 4047. All limits are for TA = 25°C, unless otherwise specified.
PARAMETER
TEST CONDITIONS
MIN (1)
TYP (1)
MAX (1)
UNIT
STATIC PERFORMANCE
INL
Resolution
TMIN ≤ TA ≤ TMAX
12
Monotonicity
TMIN ≤ TA ≤ TMAX
12
Integral Non-Linearity
Over Decimal codes 48 to 4047
DNL
VA = 4.5 V to 5.5 V
ZE
Zero Code Error
(2)
+0.25
LSB
−0.7
+1
LSB
TA = 25°C
±0.11
LSB
TMIN ≤ TA ≤ TMAX
±0.5
+4
mV
+15
−0.06
TA = 25°C
IOUT = 0
GE
Gain Error
All ones Loaded to DAC register
(2)
−0.15
TMIN ≤ TA ≤ TMAX
Full-Scale Error
(1)
LSB
±8
TA = 25°C
IOUT = 0
FSE
ZCED
±2.6
TMIN ≤ TA ≤ TMAX
TMIN ≤ TA ≤ TMAX
Differential Non-Linearity
Bits
TA = 25°C
TA = 25°C
VA = 2.7 V to 5.5 V
Bits
TMIN ≤ TA ≤ TMAX
TA = 25°C
TMIN ≤ TA ≤ TMAX
−1
−0.1
%FSR
±1
−20
Zero Code Error Drift
%FSR
µV/°C
Typical figures are at TJ = 25°C, and represent most likely parametric norms. Test limits are specified to TI's AOQL (Average Outgoing
Quality Level).
This parameter is specified by design and/or characterization and is not tested in production.
Copyright © 2005–2015, Texas Instruments Incorporated
Product Folder Links: DAC121S101 DAC121S101-Q1
Submit Documentation Feedback
5
DAC121S101, DAC121S101-Q1
SNAS265J – JUNE 2005 – REVISED SEPTEMBER 2015
www.ti.com
Electrical Characteristics (continued)
The following specifications apply for VA = 2.7 V to 5.5 V, RL = 2 kΩ to GND, CL = 200 pF to GND, fSCLK = 30 MHz, input code
range 48 to 4047. All limits are for TA = 25°C, unless otherwise specified.
PARAMETER
TC GE
TEST CONDITIONS
Gain Error Tempco
MIN (1)
TYP (1)
MAX (1)
UNIT
VA = 3 V
−0.7
ppm/°C
VA = 5 V
−1
ppm/°C
OUTPUT CHARACTERISTICS
Output Voltage Range (2)
TMIN ≤ TA ≤ TMAX
0
VA = 3 V, IOUT = 10 µA
ZCO
FSO
VA = 3 V, IOUT = 100 µA
Zero Code Output
Full Scale Output
Maximum Load Capacitance
V
mV
5
mV
VA = 5 V, IOUT = 10 µA
3.7
mV
VA = 5 V, IOUT = 100 µA
5.4
mV
VA = 3 V, IOUT = 10 µA
2.997
V
VA = 3 V, IOUT = 100 µA
2.99
V
VA = 5 V, IOUT = 10 µA
4.995
V
VA = 5 V, IOUT = 100 µA
4.992
V
RL = ∞
1500
pF
RL = 2 kΩ
1500
DC Output Impedance
IOS
VA
1.8
pF
1.3
Ohm
VA = 5 V, VOUT = 0 V,
Input code = FFFh
−63
mA
VA = 3 V, VOUT = 0 V,
Input code = FFFh
−50
mA
VA = 5 V, VOUT = 5 V,
Input code = 000h
74
mA
VA = 3 V, VOUT = 3 V,
Input code = 000h
53
mA
TMIN ≤ TA ≤ TMAX
±1
µA
VA = 5 V
TMIN ≤ TA ≤ TMAX
0.8
V
VA = 3 V
TMIN ≤ TA ≤ TMAX
0.5
V
Output Short Circuit Current
LOGIC INPUT
IIN
VIL
Input Current
(2)
Input Low Voltage
VIH
Input High Voltage
CIN
Input Capacitance
(2)
(2)
(2)
VA = 5 V
TMIN ≤ TA ≤ TMAX
2.4
VA = 3 V
TMIN ≤ TA ≤ TMAX
2.1
TMIN ≤ TA ≤ TMAX
V
V
3
pF
POWER REQUIREMENTS
VA = 5.5 V
Normal Mode
fSCLK = 30 MHz
VA = 3.6 V
VA = 5.5 V
Normal Mode
fSCLK = 20 MHz
VA = 3.6 V
IA
Supply Current (output
unloaded)
260
TMIN ≤ TA ≤ TMAX
312
TA = 25°C
177
TMIN ≤ TA ≤ TMAX
217
TA = 25°C
224
TMIN ≤ TA ≤ TMAX
279
TA = 25°C
158
TMIN ≤ TA ≤ TMAX
197
µA
µA
µA
µA
Normal Mode
fSCLK = 0
VA = 5.5 V
153
µA
VA = 3.6 V
118
µA
All PD Modes,
fSCLK = 30 MHz
VA = 5 V
84
µA
VA = 3 V
42
µA
All PD Modes,
fSCLK = 20 MHz
VA = 5 V
56
µA
VA = 3 V
28
µA
VA = 5.5 V
All PD Modes,
fSCLK = 0 (2)
VA = 3.6 V
6
TA = 25°C
Submit Documentation Feedback
TA = 25°C
0.07
µA
TMIN ≤ TA ≤ TMAX
1
TA = 25°C
0.04
µA
TMIN ≤ TA ≤ TMAX
1
Copyright © 2005–2015, Texas Instruments Incorporated
Product Folder Links: DAC121S101 DAC121S101-Q1
DAC121S101, DAC121S101-Q1
www.ti.com
SNAS265J – JUNE 2005 – REVISED SEPTEMBER 2015
Electrical Characteristics (continued)
The following specifications apply for VA = 2.7 V to 5.5 V, RL = 2 kΩ to GND, CL = 200 pF to GND, fSCLK = 30 MHz, input code
range 48 to 4047. All limits are for TA = 25°C, unless otherwise specified.
PARAMETER
TEST CONDITIONS
VA = 5.5 V
Normal Mode
fSCLK = 30 MHz
VA = 3.6 V
VA = 5.5 V
Normal Mode
fSCLK = 20 MHz
VA = 3.6 V
Power Consumption (output
unloaded)
PC
UNIT
1.43
TMIN ≤ TA ≤ TMAX
1.72
TA = 25°C
0.64
TMIN ≤ TA ≤ TMAX
0.78
TA = 25°C
1.23
TMIN ≤ TA ≤ TMAX
1.53
TA = 25°C
0.57
TMIN ≤ TA ≤ TMAX
0.71
mW
mW
mW
mW
0.84
µW
VA = 3.6 V
0.42
µW
All PD Modes,
fSCLK = 30 MHz
VA = 5 V
0.42
µW
VA = 3 V
0.13
µW
All PD Modes,
fSCLK = 20 MHz
VA = 5 V
0.28
µW
VA = 3 V
0.08
µW
VA = 3.6 V
7.6
MAX (1)
VA = 5.5 V
VA = 5.5 V
Power Efficiency
TYP (1)
Normal Mode
fSCLK = 0
All PD Modes,
fSCLK = 0 (2)
IOUT / IA
MIN (1)
TA = 25°C
ILOAD = 2 mA
TA = 25°C
0.39
µW
TMIN ≤ TA ≤ TMAX
5.5
TA = 25°C
0.14
µW
TMIN ≤ TA ≤ TMAX
3.6
VA = 5 V
91%
VA = 3 V
94%
AC and Timing Characteristics
The following specifications apply for VA = 2.7 V to 5.5 V, RL = 2 kΩ to GND, CL = 200 pF to GND, fSCLK = 30 MHz, input code
range 48 to 4047. All limits are for TA = 25°C, unless otherwise specified.
PARAMETER
fSCLK SCLK Frequency
Output Voltage Settling
Time (1)
ts
TEST CONDITIONS
400h to C00h
code change,
RL = 2 kΩ
00Fh to FF0h
code change,
RL = 2 kΩ
SR
MIN
CL ≤
200 pF
Wake-Up Time
1/fSC
SCLK Cycle Time
LK
tH
SCLK High time
tL
SCLK Low Time
tSUCL
Set-up Time SYNC to
SCLK Rising Edge
tSUD
Data Set-up Time
(1)
UNIT
30
MHz
8
TMIN ≤ TA ≤
TMAX
10
µs
CL = 500 pF
12
µs
CL ≤ 200 pF
8
µs
CL = 500 pF
12
µs
1
V/µs
12
nV-s
0.5
nV-s
Code change from 800h to 7FFh
Digital Feedthrough
tWU
MAX
TA = 25°C
Output Slew Rate
Glitch Impulse
TYP
TMIN ≤ TA ≤ TMAX
VA = 5 V
6
µs
VA = 3 V
39
µs
TMIN ≤ TA ≤ TMAX
TA = 25°C
TMIN ≤ TA ≤ TMAX
TA = 25°C
TMIN ≤ TA ≤ TMAX
TA = 25°C
TMIN ≤ TA ≤ TMAX
TA = 25°C
TMIN ≤ TA ≤ TMAX
33
ns
5
ns
13
5
ns
13
−15
ns
0
2.5
ns
5
This parameter is specified by design and/or characterization and is not tested in production.
Copyright © 2005–2015, Texas Instruments Incorporated
Product Folder Links: DAC121S101 DAC121S101-Q1
Submit Documentation Feedback
7
DAC121S101, DAC121S101-Q1
SNAS265J – JUNE 2005 – REVISED SEPTEMBER 2015
www.ti.com
AC and Timing Characteristics (continued)
The following specifications apply for VA = 2.7 V to 5.5 V, RL = 2 kΩ to GND, CL = 200 pF to GND, fSCLK = 30 MHz, input code
range 48 to 4047. All limits are for TA = 25°C, unless otherwise specified.
PARAMETER
tDHD
Data Hold Time
TEST CONDITIONS
2.5
TMIN ≤ TA ≤ TMAX
4.5
VA = 5 V
tCS
MIN
TA = 25°C
SCLK fall to rise of
SYNC
VA = 3 V
2.7 ≤ VA ≤ 3.6
tSYNC SYNC High Time
3.6 ≤ VA ≤ 5.5
TA = 25°C
0
TMIN ≤ TA ≤
TMAX
3
TA = 25°C
–2
TMIN ≤ TA ≤
TMAX
1
TA = 25°C
9
TMIN ≤ TA ≤
TMAX
20
TA = 25°C
5
TMIN ≤ TA ≤
TMAX
10
TYP
MAX
UNIT
ns
ns
ns
ns
ns
FSE
4095 x VA
4096
GE = FSE - ZE
FSE = GE + ZE
OUTPUT
VOLTAGE
ZE
0
0
4095
DIGITAL INPUT CODE
Figure 1. Input / Output Transfer Characteristic
8
Submit Documentation Feedback
Copyright © 2005–2015, Texas Instruments Incorporated
Product Folder Links: DAC121S101 DAC121S101-Q1
DAC121S101, DAC121S101-Q1
www.ti.com
SNAS265J – JUNE 2005 – REVISED SEPTEMBER 2015
SCLK
1
13
14
15
16
tL
tSUCL
tH
tCS
|
tSYNC
2
|
|
1 / fSCLK
|
SYNC
DB15
DB0
|
DIN
| |
tDHD
tSUD
Figure 2. DAC121S101 Timing
Copyright © 2005–2015, Texas Instruments Incorporated
Product Folder Links: DAC121S101 DAC121S101-Q1
Submit Documentation Feedback
9
DAC121S101, DAC121S101-Q1
SNAS265J – JUNE 2005 – REVISED SEPTEMBER 2015
www.ti.com
7.7 Typical Characteristics
fSCLK = 30 MHz, TA = 25C, Input Code Range 48 to 4047, unless otherwise stated
10
Figure 3. DNL at VA = 3 V
Figure 4. DNL at VA = 5 V
Figure 5. INL at VA = 3 V
Figure 6. INL at VA = 5 V
Figure 7. TUE at VA = 3 V
Figure 8. TUE at VA = 5 V
Submit Documentation Feedback
Copyright © 2005–2015, Texas Instruments Incorporated
Product Folder Links: DAC121S101 DAC121S101-Q1
DAC121S101, DAC121S101-Q1
www.ti.com
SNAS265J – JUNE 2005 – REVISED SEPTEMBER 2015
Typical Characteristics (continued)
fSCLK = 30 MHz, TA = 25C, Input Code Range 48 to 4047, unless otherwise stated
Figure 9. DNL vs. VA
Figure 10. INL vs. VA
Figure 11. 3-V DNL vs. fSCLK
Figure 12. 5-V DNL vs. fSCLK
Figure 13. 3-V DNL vs. Clock Duty Cycle
Figure 14. 5-V DNL vs. Clock Duty Cycle
Copyright © 2005–2015, Texas Instruments Incorporated
Product Folder Links: DAC121S101 DAC121S101-Q1
Submit Documentation Feedback
11
DAC121S101, DAC121S101-Q1
SNAS265J – JUNE 2005 – REVISED SEPTEMBER 2015
www.ti.com
Typical Characteristics (continued)
fSCLK = 30 MHz, TA = 25C, Input Code Range 48 to 4047, unless otherwise stated
12
Figure 15. 3-V DNL vs. Temperature
Figure 16. 3-V INL vs. fSCLK
Figure 17. 5-V INL vs. fSCLK
Figure 18. 3-V INL vs. Clock Duty Cycle
Figure 19. 5-V INL vs. Clock Duty Cycle
Figure 20. 3-V INL vs. Temperature
Submit Documentation Feedback
Copyright © 2005–2015, Texas Instruments Incorporated
Product Folder Links: DAC121S101 DAC121S101-Q1
DAC121S101, DAC121S101-Q1
www.ti.com
SNAS265J – JUNE 2005 – REVISED SEPTEMBER 2015
Typical Characteristics (continued)
fSCLK = 30 MHz, TA = 25C, Input Code Range 48 to 4047, unless otherwise stated
Figure 21. 5-V INL vs. Temperature
Figure 22. Zero Code Error vs. fSCLK
Figure 23. Zero Code Error vs. Clock Duty Cycle
Figure 24. Zero Code Error vs. Temperature
Figure 25. Full-Scale Error vs. fSCLK
Figure 26. Full-Scale Error vs. Clock Duty Cycle
Copyright © 2005–2015, Texas Instruments Incorporated
Product Folder Links: DAC121S101 DAC121S101-Q1
Submit Documentation Feedback
13
DAC121S101, DAC121S101-Q1
SNAS265J – JUNE 2005 – REVISED SEPTEMBER 2015
www.ti.com
Typical Characteristics (continued)
fSCLK = 30 MHz, TA = 25C, Input Code Range 48 to 4047, unless otherwise stated
14
Figure 27. Full-Scale Error vs. Temperature
Figure 28. Supply Current vs. VA
Figure 29. Supply Current vs. Temperature
Figure 30. 5-V Glitch Response
Figure 31. Power-On Reset
Figure 32. 3-V Wake-Up Time
Submit Documentation Feedback
Copyright © 2005–2015, Texas Instruments Incorporated
Product Folder Links: DAC121S101 DAC121S101-Q1
DAC121S101, DAC121S101-Q1
www.ti.com
SNAS265J – JUNE 2005 – REVISED SEPTEMBER 2015
Typical Characteristics (continued)
fSCLK = 30 MHz, TA = 25C, Input Code Range 48 to 4047, unless otherwise stated
Figure 33. 5-V Wake-Up Time
Copyright © 2005–2015, Texas Instruments Incorporated
Product Folder Links: DAC121S101 DAC121S101-Q1
Submit Documentation Feedback
15
DAC121S101, DAC121S101-Q1
SNAS265J – JUNE 2005 – REVISED SEPTEMBER 2015
www.ti.com
8 Detailed Description
8.1 Overview
The DAC121S101 device is a full-featured, general purpose 12-bit voltage-output digital-to-analog converter
(DAC) with 10-µs settling time. Control of the output of the DAC is achieved over a 3-wire SPI interface. Once
the DAC output has been set, additional communication with the DAC is not required unless the output condition
needs to be changed. Likewise, the DAC121S101 power on state is 0 V. The DAC output will remain at 0 V until
a valid write sequence is made.
A unique benefit of the DAC121S101 is the logic levels of the SPI™ input pins. The logic levels of SCLK, DIN,
and SYNCB are independent of VA. As a result, the DAC121S101 can operate at a supply voltage (VA) that is
higher than the microcontroller that is controlling the DAC. This feature is advantageous in applications where the
analog circuitry is being run at 5 V in order to maximize signal-to-noise ratio and digital logic is running at 3 V in
order to conserve power.
8.2 Functional Block Diagram
VA
GND
POWER-ON
RESET
DAC121S101
REF(+) REF(-)
DAC
REGISTER
12
12-BIT DAC
BUFFER
VOUT
12
POWER-DOWN
CONTROL
LOGIC
INPUT
CONTROL
LOGIC
SYNC
SCLK
1k
100k
DIN
8.3 Feature Description
8.3.1 DAC Section
The DAC121S101 is fabricated on a CMOS process with an architecture that consists of switches and a resistor
string that are followed by an output buffer. The power supply serves as the reference voltage. The input coding
is straight binary with an ideal output voltage of:
VOUT = VA × (D / 4096)
where
•
D is the decimal equivalent of the binary code that is loaded into the DAC register and can take on any value
between 0 and 4095.
(1)
8.3.2 Resistor String
The resistor string is shown in Figure 34. This string consists of 4096 equal valued resistors with a switch at each
junction of two resistors, plus a switch to ground. The code loaded into the DAC register determines which switch
is closed, connecting the proper node to the amplifier. This configuration ensures that the DAC is monotonic.
16
Submit Documentation Feedback
Copyright © 2005–2015, Texas Instruments Incorporated
Product Folder Links: DAC121S101 DAC121S101-Q1
DAC121S101, DAC121S101-Q1
www.ti.com
SNAS265J – JUNE 2005 – REVISED SEPTEMBER 2015
Feature Description (continued)
VA
R
R
R
To Output Amplifier
R
R
Figure 34. DAC Resistor String
8.3.3 Output Amplifier
The output buffer amplifier is a rail-to-rail type, providing an output voltage range of 0 V to VA. All amplifiers, even
rail-to-rail types, exhibit a loss of linearity as the output approaches the supply rails (0 V and VA, in this case). For
this reason, linearity is specified over less than the full output range of the DAC. The output capabilities of the
amplifier are described in the Electrical Characteristics.
8.4 Device Functional Modes
8.4.1 Power-On Reset
The power-on reset circuit controls the output voltage during power-up. Upon application of power the DAC
register is filled with zeros and the output voltage is 0 V and remains there until a valid write sequence is made to
the DAC.
8.4.2 Power-Down Modes
The DAC121S101 has four modes of operation. These modes are set with two bits (DB13 and DB12) in the
control register.
Table 1. Modes of Operation
DB13
DB12
0
0
OPERATING MODE
Normal Operation
0
1
Power-Down with 1kΩ to GND
1
0
Power-Down with 100kΩ to GND
1
1
Power-Down with Hi-Z
Copyright © 2005–2015, Texas Instruments Incorporated
Product Folder Links: DAC121S101 DAC121S101-Q1
Submit Documentation Feedback
17
DAC121S101, DAC121S101-Q1
SNAS265J – JUNE 2005 – REVISED SEPTEMBER 2015
www.ti.com
When both DB13 and DB12 are 0, the device operates normally. For the other three possible combinations of
these bits the supply current drops to its power-down level and the output is pulled down with either a 1-kΩ or a
100-KΩ resistor, or is in a high-impedance state, as described in Table 1.
The bias generator, output amplifier, the resistor string and other linear circuitry are all shut down in any of the
power-down modes. However, the contents of the DAC register are unaffected when in power-down, so when
coming out of power down the output voltage returns to the same voltage it was before entering power down.
Minimum power consumption is achieved in the power-down mode with SCLK disabled and SYNC and DIN idled
low. The time to exit power-down (Wake-Up Time) is typically tWU µsec as stated in the A.C. and Timing
Characteristics Table.
8.5 Programming
8.5.1 Serial Interface
The three-wire interface is compatible with SPI, QSPI and MICROWIRE, as well as most DSPs. See the Timing
Diagram for information on a write sequence.
A write sequence begins by bringing the SYNC line low. Once SYNC is low, the data on the DIN line is clocked
into the 16-bit serial input register on the falling edges of SCLK. On the 16th falling clock edge, the last data bit is
clocked in and the programmed function (a change in the mode of operation and/or a change in the DAC register
contents) is executed. At this point the SYNC line may be kept low or brought high. In either case, it must be
brought high for the minimum specified time before the next write sequence as a falling edge of SYNC can
initiate the next write cycle.
Since the SYNC and DIN buffers draw more current when they are high, they must be idled low between write
sequences to minimize power consumption.
8.5.2 Input Shift Register
The input shift register, , has sixteen bits. The first two bits are don't cares and are followed by two bits that
determine the mode of operation (normal mode or one of three power-down modes). The contents of the serial
input register are transferred to the DAC register on the sixteenth falling edge of SCLK. See Figure 2.
DB15 (MSB)
X
X
DB0 (LSB)
PD1 PD0 D11 D10 D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
DATA BITS
0
0
1
1
0 Normal Operation
1 1 k:to GND
0 100 k:
to GND
1 High Impedance
Power-Down Modes
Input Register Contents
Normally, the SYNC line is kept low for at least 16 falling edges of SCLK and the DAC is updated on the 16th
SCLK falling edge. However, if SYNC is brought high before the 16th falling edge, the shift register is reset and
the write sequence is invalid. The DAC register is not updated and there is no change in the mode of operation
or in the output voltage.
18
Submit Documentation Feedback
Copyright © 2005–2015, Texas Instruments Incorporated
Product Folder Links: DAC121S101 DAC121S101-Q1
DAC121S101, DAC121S101-Q1
www.ti.com
SNAS265J – JUNE 2005 – REVISED SEPTEMBER 2015
9 Application and Implementation
NOTE
Information in the following applications sections is not part of the TI component
specification, and TI does not warrant its accuracy or completeness. TI’s customers are
responsible for determining suitability of components for their purposes. Customers should
validate and test their design implementation to confirm system functionality.
9.1 Application Information
9.1.1 DSP and Microprocessor Interfacing
The simplicity of the DAC121S101 implies ease of use. However, it is important to recognize that any data
converter that uses its supply voltage as its reference voltage will have essentially zero PSRR (power supply
rejection ratio). Therefore, it is necessary to provide a noise-free supply voltage to the device.
Interfacing the DAC121S101 to microprocessors and DSPs is quite simple. The following guidelines are offered
to hasten the design process.
9.1.1.1 ADSP-2101/ADSP2103 Interfacing
Figure 35 shows a serial interface between the DAC121S101 and the ADSP-2101/ADSP2103. The DSP must be
set to operate in the SPORT Transmit Alternate Framing Mode. It is programmed through the SPORT control
register and must be configured for Internal Clock Operation, Active Low Framing and 16-bit Word Length.
Transmission is started by writing a word to the Tx register after the SPORT mode has been enabled.
ADSP-2101/
ADSP2103
TFS
DT
SCLK
DAC121S101
SYNC
DIN
SCLK
Figure 35. ADSP-2101/2103 Interface
9.1.1.1.1 80C51/80L51 Interface
A serial interface between the DAC121S101 and the 80C51/80L51 microcontroller is shown in Figure 36. The
SYNC signal comes from a bit-programmable pin on the microcontroller. The example shown here uses port line
P3.3. This line is taken low when data is to transmitted to the DAC121S101. Because the 80C51/80L51 transmits
8-bit bytes, only eight falling clock edges occur in the transmit cycle. To load data into the DAC, the P3.3 line
must be left low after the first eight bits are transmitted. A second write cycle is initiated to transmit the second
byte of data, after which port line P3.3 is brought high. The 80C51/80L51 transmit routine must recognize that
the 80C51/80L51 transmits data with the LSB first while the DAC121S101 requires data with the MSB first.
80C51/80L51
P3.3
DAC121S101
SYNC
TXD
SCLK
RXD
DIN
Figure 36. 80C51/80L51 Interface
9.1.1.1.2 68HC11 Interface
A serial interface between the DAC121S101 and the 68HC11 microcontroller is shown in Figure 37. The SYNC
line of the DAC121S101 is driven from a port line (PC7 in the figure), similar to the 80C51/80L51.
Copyright © 2005–2015, Texas Instruments Incorporated
Product Folder Links: DAC121S101 DAC121S101-Q1
Submit Documentation Feedback
19
DAC121S101, DAC121S101-Q1
SNAS265J – JUNE 2005 – REVISED SEPTEMBER 2015
www.ti.com
Application Information (continued)
The 68HC11 must be configured with its CPOL bit as a zero and its CPHA bit as a one. This configuration
causes data on the MOSI output to be valid on the falling edge of SCLK. PC7 is taken low to transmit data to the
DAC. The 68HC11 transmits data in 8-bit bytes with eight falling clock edges. Data is transmitted with the MSB
first. PC7 must remain low after the first eight bits are transferred. A second write cycle is initiated to transmit the
second byte of data to the DAC, after which PC7 must be raised to end the write sequence.
68HC11
DAC121S101
PC7
SYNC
SCK
SCLK
MOSI
DIN
Figure 37. 68HC11 Interface
9.1.1.1.3 Microwire Interface
Figure 38 shows an interface between a Microwire compatible device and the DAC121S101. Data is clocked out
on the rising edges of the SCLK signal.
MICROWIRE
DEVICE
DAC121S101
CS
SYNC
SK
SCLK
SO
DIN
Figure 38. Microwire Interface
9.1.2 Bipolar Operation
The DAC121S101 is designed for single supply operation and thus has a unipolar output. However, a bipolar
output may be obtained with the circuit in Figure 39. This circuit will provide an output voltage range of ±5 V. A
rail-to-rail amplifier must be used if the amplifier supplies are limited to ±5 V.
10 pF
R2
+5V
+5V
10 PF
+
R1
-
0.1 PF
±5V
+
DAC121S101
-5V
SYNC
VOUT
DIN
SCLK
Figure 39. Bipolar Operation
The output voltage of this circuit for any code is found to be
VO = (VA × (D / 4096) × ((R1 + R2) / R1) – VA × R2 / R
where
•
D is the input code in decimal form.
(2)
With VA = 5 V and R1 = R2,
VO = (10 × D / 4096) – 5 V
(3)
A list of rail-to-rail amplifiers suitable for this application are indicated in Table 2.
20
Submit Documentation Feedback
Copyright © 2005–2015, Texas Instruments Incorporated
Product Folder Links: DAC121S101 DAC121S101-Q1
DAC121S101, DAC121S101-Q1
www.ti.com
SNAS265J – JUNE 2005 – REVISED SEPTEMBER 2015
Application Information (continued)
Table 2. Some Rail-to-Rail Amplifiers
AMP
PKGS
LMC7111
PDIP
SOT-23
Typ VOS
Typ ISUPPLY
0.9 mV
25 µA
LM7301
SOIC
SOT-23
0.03 mV
620 µA
LM8261
SOT-23
0.7 mV
1 mA
9.2 Typical Application
3
VA
1
VOUT
+5
120pF
+5
3
+
/SYNC
5
SCLK
4
DIN
8
SCLK
7
DOUT
6
/CS
2
1uF
5
1
A2
4
LM4132-3.3
4
5
3
2 .1uF
DAC121S101
6
-
.2uF
2
180
+5
+3.3
10
VA
9
VIO
100K
2
470pF
+IN
1
VREF
ADC161S626
AV = 100
2.02K
3
-IN
4,
5
+5
.2uF
100K
3
-
5
1
A1
Pressure
Sensor
0.2mV/Volt/PSI
4
+
180
470pF
2
A1 and A2 = LMP7701
Figure 40. Pressure Sensor Gain Adjust
9.2.1 Design Requirements
A positive supply only data acquisition system capable of digitizing a pressure sensor output. In addition to
digitizing the pressure sensor output, the system designer can use the DAC121S101 to correct for gain errors in
the pressure sensor output by adjusting the bias voltage to the bridge pressure sensor.
Copyright © 2005–2015, Texas Instruments Incorporated
Product Folder Links: DAC121S101 DAC121S101-Q1
Submit Documentation Feedback
21
DAC121S101, DAC121S101-Q1
SNAS265J – JUNE 2005 – REVISED SEPTEMBER 2015
www.ti.com
Typical Application (continued)
9.2.2 Detailed Design Procedure
As shown in Equation 4, the output of the pressure sensor is relative to the imbalance of the resistive bridge
times the output of the DAC121S101, thus providing the desired gain correction.
Pressure Sensor Output = (DAC_Output × [(R2 / (R1 + R2) – (R4 / (R3 + R4)]
(4)
Likewise for the ADC161S626, Equation 5 shows that the ADC output is function of the Pressure Sensor Output
times relative to the ratio of the ADC input divided by the DAC121S101 output voltage.
ADC161S626 Output = (Pressure Sensor Output × 100 /(2 × VREF) ) × 216
(5)
9.2.3 Application Curve
Figure 41. Total Unadjusted Error vs. Output Code
22
Submit Documentation Feedback
Copyright © 2005–2015, Texas Instruments Incorporated
Product Folder Links: DAC121S101 DAC121S101-Q1
DAC121S101, DAC121S101-Q1
www.ti.com
SNAS265J – JUNE 2005 – REVISED SEPTEMBER 2015
10 Power Supply Recommendations
NOTE
Information in the following power supply recommendations section is not part of the TI
component specification, and TI does not warrant its accuracy or completeness. TI’s
customers are responsible for determining suitability of components for their purposes.
Customers should validate and test their design implementation to confirm system
functionality.
10.1 Using References as Power Supplies
Recall the need for a quiet supply source for devices that use their power supply voltage as a reference voltage.
Because the DAC121S101 consumes very little power, a reference source may be used as the supply voltage.
The advantages of using a reference source over a voltage regulator are accuracy and stability. Some low noise
regulators can also be used for the power supply of the DAC121S101. Listed below are a few power supply
options for the DAC121S101.
10.1.1 LM4130
The LM4130 reference, with its 0.05% accuracy over temperature, is a good choice as a power source for the
DAC121S101. Its primary disadvantage is the lack of 3-V and 5-V versions. However, the 4.096-V version is
useful if a 0 to 4.095-V output range is desirable or acceptable. Bypassing the LM4130 VIN pin with a 0.1-µF
capacitor and the VOUT pin with a 2.2-µF capacitor will improve stability and reduce output noise. The LM4130
comes in a space-saving 5-pin SOT23.
Input
Voltage
LM4130-4.1
C2
2.2 PF
C1
0.1 PF
DAC121S101
SYNC
VOUT = 0V to 4.095V
DIN
SCLK
Figure 42. The LM4130 as a Power Supply
10.1.2 LM4050
Available with accuracy of 0.44%, the LM4050 shunt reference is also a good choice as a power regulator for the
DAC121S101. It does not come in a 3-V version, but 4.096-V and 5-V versions are available. It comes in a
space-saving 3-pin SOT23.
Input
Voltage
R
VZ
LM4050-4.1
or
LM4050-5.0
0.47 PF
DAC121S101
SYNC
VOUT = 0V to 5V
DIN
SCLK
Figure 43. The LM4050 as a Power Supply
Copyright © 2005–2015, Texas Instruments Incorporated
Product Folder Links: DAC121S101 DAC121S101-Q1
Submit Documentation Feedback
23
DAC121S101, DAC121S101-Q1
SNAS265J – JUNE 2005 – REVISED SEPTEMBER 2015
www.ti.com
Using References as Power Supplies (continued)
The minimum resistor value in the circuit of Figure 43 must be chosen such that the maximum current through
the LM4050 does not exceed its 15-mA rating. The conditions for maximum current include the input voltage at
its maximum, the LM4050 voltage at its minimum, the resistor value at its minimum due to tolerance, and the
DAC121S101 draws zero current. The maximum resistor value must allow the LM4050 to draw more than its
minimum current for regulation plus the maximum DAC121S101 current in full operation. The conditions for
minimum current include the input voltage at its minimum, the LM4050 voltage at its maximum, the resistor value
at its maximum due to tolerance, and the DAC121S101 draws its maximum current. These conditions can be
summarized as
R(min) = ( VIN(max) − VZ(min) / (IA(min) + IZ(max))
(6)
and
R(max) = ( VIN(min) − VZ(max) / (IA(max) + IZ(min) )
where
•
•
•
•
•
VZ(min) and VZ(max) are the nominal LM4050 output voltages ± the LM4050 output tolerance over
temperature,
IZ(max) is the maximum allowable current through the LM4050,
IZ(min) is the minimum current required by the LM4050 for proper regulation,
IA(max) is the maximum DAC121S101 supply current,
and IA(min) is the minimum DAC121S101 supply current.
(7)
10.1.3 LP3985
The LP3985 is a low noise, ultra-low dropout voltage regulator with a 3% accuracy over temperature. It is a good
choice for applications that do not require a precision reference for the DAC121S101. It comes in 3-V, 3.3-V and
5-V versions, among others, and sports a low 30-µV noise specification at low frequencies. Because lowfrequency noise is relatively difficult to filter, this specification could be important for some applications. The
LP3985 comes in a space-saving 5-pin SOT-23 and 5-bump DSBGA packages.
Input
Voltage
LP3985
1 PF
0.1 PF
0.01 PF
DAC121S101
SYNC
VOUT = 0V to 5V
DIN
SCLK
Figure 44. Using the LP3985 Regulator
An input capacitance of 1 µF without any ESR requirement is required at the LP3985 input, while a 1-µF ceramic
capacitor with an ESR requirement of 5 mΩ to 500 mΩ is required at the output. Careful interpretation and
understanding of the capacitor specification is required to ensure correct device operation.
24
Submit Documentation Feedback
Copyright © 2005–2015, Texas Instruments Incorporated
Product Folder Links: DAC121S101 DAC121S101-Q1
DAC121S101, DAC121S101-Q1
www.ti.com
SNAS265J – JUNE 2005 – REVISED SEPTEMBER 2015
Using References as Power Supplies (continued)
10.1.4 LP2980
The LP2980 is an ultra-low dropout regulator with a 0.5% or 1.0% accuracy over temperature, depending upon
grade. It is available in 3-V, 3.3-V and 5-V versions, among others.
Input
Voltage
VIN
ON / OFF
LP2980
VOUT
1 PF
DAC121S101
SYNC
VOUT = 0V to 5V
DIN
SCLK
Figure 45. Using the LP2980 Regulator
Like any low dropout regulator, the LP2980 requires an output capacitor for loop stability. This output capacitor
must be at least 1-µF over temperature, but values of 2.2 µF or more will provide even better performance. The
ESR of this capacitor must be within the range specified in the LP2980 data sheet. Surface-mount solid tantalum
capacitors offer a good combination of small size and ESR. Ceramic capacitors are attractive due to their small
size but generally have ESR values that are too low for use with the LP2980. Aluminum electrolytic capacitors
are typically not a good choice due to their large size and have ESR values that may be too high at low
temperatures.
11 Layout
11.1 Layout Guidelines
A precision analog component requires careful layout, adequate bypassing, and clean, well-regulated power
supplies. The power applied to VA must be well regulated and low noise. Switching power supplies and DC/DC
converters will often have high-frequency glitches or spikes riding on the output voltage. In addition, digital
components can create similar high-frequency spikes as their internal logic switches states. This noise can easily
couple into the DAC output voltage through various paths between the power connections and analog output. As
with the GND connection, VA must be connected to a power supply plane or trace that is separate from the
connection for digital logic until they are connected at the power entry point.
The DAC121S101 power supply must be bypassed with a 10-µF and a 0.1-µF capacitor as close as possible to
the device with the 0.1 µF right at the device supply pin. The 10-µF capacitor must be a tantalum type and the
0.1-µF capacitor must be a low ESL, low ESR type. The power supply for the DAC121S101 must only be used
for analog circuits.
For best accuracy and minimum noise, the printed-circuit-board containing the DAC121S101 must have separate
analog and digital areas. The areas are defined by the locations of the analog and digital power planes. Both of
these planes must be located in the same board layer. There must be a single ground plane. A single ground
plane is preferred if digital return current does not flow through the analog ground area. Frequently a single
ground plane design will use a fencing technique to prevent the mixing of analog and digital ground current.
Separate ground planes must only be used when the fencing technique is inadequate. The separate ground
planes must be connected in one place, preferably near the DAC121S101. Take special care to ensure that
digital signals with fast edge rates do not pass over split ground planes. They must always have a continuous
return path below their traces.
Avoid crossover of analog and digital signals and keep the clock and data lines on the component side of the
board. The clock and data lines must have controlled impedances.
Copyright © 2005–2015, Texas Instruments Incorporated
Product Folder Links: DAC121S101 DAC121S101-Q1
Submit Documentation Feedback
25
DAC121S101, DAC121S101-Q1
SNAS265J – JUNE 2005 – REVISED SEPTEMBER 2015
www.ti.com
11.2 Layout Example
VOUT
SYNCB
SOT
GND
C1
SCLK
DIN
VA
Figure 46. Typical Layout
12 Device and Documentation Support
12.1 Device Support
12.1.1 Device Nomenclature
12.1.1.1 Specification Definitions
DIFFERENTIAL NON-LINEARITY (DNL) is the measure of the maximum deviation from the ideal step size of 1
LSB, which is VREF / 4096 = VA / 4096.
DIGITAL FEEDTHROUGH is a measure of the energy injected into the analog output of the DAC from the digital
inputs when the DAC outputs are not updated. It is measured with a full-scale code change on the data bus.
FULL-SCALE ERROR is the difference between the actual output voltage with a full scale code (FFFh) loaded
into the DAC and the value of VA x 4095 / 4096.
GAIN ERROR is the deviation from the ideal slope of the transfer function. It can be calculated from Zero and
Full-Scale Errors as GE = FSE - ZE, where GE is Gain error, FSE is Full-Scale Error and ZE is Zero Error.
GLITCH IMPULSE is the energy injected into the analog output when the input code to the DAC register
changes. It is specified as the area of the glitch in nanovolt-seconds.
INTEGRAL NON-LINEARITY (INL) is a measure of the deviation of each individual code from a straight line
through the input to output transfer function. The deviation of any given code from this straight line is measured
from the center of that code value. The end point method is used. INL for this product is specified over a limited
range, per the Electrical Characteristics.
LEAST SIGNIFICANT BIT (LSB) is the bit that has the smallest value or weight of all bits in a word. This value is
LSB = VREF / 2n
(8)
where VREF is the supply voltage for this product, and "n" is the DAC resolution in bits, which is 12 for the
DAC121S101.
MAXIMUM LOAD CAPACITANCE is the maximum capacitance that can be driven by the DAC with output
stability maintained.
MONOTONICITY is the condition of being monotonic, where the DAC has an output that never decreases when
the input code increases.
MOST SIGNIFICANT BIT (MSB) is the bit that has the largest value or weight of all bits in a word. Its value is
1/2 of VA.
POWER EFFICIENCY is the ratio of the output current to the total supply current. The output current comes from
the power supply. The difference between the supply and output currents is the power consumed by the device
without a load.
26
Submit Documentation Feedback
Copyright © 2005–2015, Texas Instruments Incorporated
Product Folder Links: DAC121S101 DAC121S101-Q1
DAC121S101, DAC121S101-Q1
www.ti.com
SNAS265J – JUNE 2005 – REVISED SEPTEMBER 2015
SETTLING TIME is the time for the output to settle to within 1/2 LSB of the final value after the input code is
updated.
WAKE-UP TIME is the time for the output to settle to within 1/2 LSB of the final value after the device is
commanded to the active mode from any of the power down modes.
ZERO CODE ERROR is the output error, or voltage, present at the DAC output after a code of 000h has been
entered.
12.2 Documentation Support
12.2.1 Related Documentation
For related documentation see the following:
• LM4130 Precision Micropower Low Dropout Voltage Reference, SNVS048
• LM4050 Precision Micropower Shunt Voltage Reference, SNOS455
• LP3985 Micropower, 150mA Low-Noise Ultra Low-Dropout CMOS Voltage Regulator, SNVS087
• LP2980 Micropower 50-mA Ultralow-Dropout Voltage Regulator, SLVS715
• LMC7111 Tiny CMOS Operational Amplifier with Rail-to-Rail Input and Output, SNOS753
• LM7301 Low Power, 4 MHz GBW, Rail-to-Rail Input-Output Operational Amplifier in TinyP, SNOS879
• LM8261 Single RRIO, High Output Current & Unlimited Cap Load Op Amp in SOT23-5, SNOS469
12.3 Related Links
The table below lists quick access links. Categories include technical documents, support and community
resources, tools and software, and quick access to sample or buy.
12.4 Community Resources
The following links connect to TI community resources. Linked contents are provided "AS IS" by the respective
contributors. They do not constitute TI specifications and do not necessarily reflect TI's views; see TI's Terms of
Use.
TI E2E™ Online Community TI's Engineer-to-Engineer (E2E) Community. Created to foster collaboration
among engineers. At e2e.ti.com, you can ask questions, share knowledge, explore ideas and help
solve problems with fellow engineers.
Design Support TI's Design Support Quickly find helpful E2E forums along with design support tools and
contact information for technical support.
12.5 Trademarks
E2E is a trademark of Texas Instruments.
SPI is a trademark of Motorola, Inc..
All other trademarks are the property of their respective owners.
12.6 Electrostatic Discharge Caution
These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam
during storage or handling to prevent electrostatic damage to the MOS gates.
12.7 Glossary
SLYZ022 — TI Glossary.
This glossary lists and explains terms, acronyms, and definitions.
Copyright © 2005–2015, Texas Instruments Incorporated
Product Folder Links: DAC121S101 DAC121S101-Q1
Submit Documentation Feedback
27
DAC121S101, DAC121S101-Q1
SNAS265J – JUNE 2005 – REVISED SEPTEMBER 2015
www.ti.com
13 Mechanical, Packaging, and Orderable Information
The following pages include mechanical, packaging, and orderable information. This information is the most
current data available for the designated devices. This data is subject to change without notice and revision of
this document. For browser-based versions of this data sheet, refer to the left-hand navigation.
28
Submit Documentation Feedback
Copyright © 2005–2015, Texas Instruments Incorporated
Product Folder Links: DAC121S101 DAC121S101-Q1
PACKAGE OPTION ADDENDUM
www.ti.com
30-Sep-2021
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)
(4/5)
(6)
DAC121S101CIMK
NRND
SOT-23-THIN
DDC
6
1000
Non-RoHS
& Green
Call TI
Level-1-260C-UNLIM
-40 to 105
X61C
DAC121S101CIMK/NOPB
ACTIVE
SOT-23-THIN
DDC
6
1000
RoHS & Green
SN
Level-1-260C-UNLIM
-40 to 105
X61C
DAC121S101CIMKX/NOPB
ACTIVE
SOT-23-THIN
DDC
6
3000
RoHS & Green
SN
Level-1-260C-UNLIM
-40 to 105
X61C
DAC121S101CIMM/NOPB
ACTIVE
VSSOP
DGK
8
1000
RoHS & Green
SN
Level-1-260C-UNLIM
-40 to 105
X60C
DAC121S101QCMK/NOPB
ACTIVE
SOT-23-THIN
DDC
6
1000
RoHS & Green
SN
Level-1-260C-UNLIM
-40 to 125
X61Q
DAC121S101QCMKX/NOPB
ACTIVE
SOT-23-THIN
DDC
6
3000
RoHS & Green
SN
Level-1-260C-UNLIM
-40 to 125
X61Q
(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
