The DAC7612 is a dual, 12-bit digital-to-analog converter (DAC) with guaranteed 12-bit monotonicity
performance over the industrial temperature range. It
requires a single +5V supply and contains an input
shift register, latch, 2.435V reference, a dual DAC, and
high speed rail-to-rail output amplifiers. For a fullscale step, each output will settle to 1 LSB within 7µs
while only consuming 3.7mW.
The synchronous serial interface is compatible with a
wide variety of DSPs and microcontrollers. Clock
(CLK), Serial Data In (SDI), Chip Select (CS) and
Load DACs (LOADDACS) comprise the serial interface.
The DAC7612 is available in an 8-lead SOIC package
and is fully specified over the industrial temperature
range of –40°C to +85°C.
V
DD
V
12
OUTA
SBAS106
CS
CLK
SDI
DAC7612
International Airport Industrial Park • Mailing Address: PO Box 11400, Tucson, AZ 85734 • Street Address: 6730 S. Tucson Blvd., Tucson, AZ 85706 • Tel: (520) 746-1111
Output CurrentCode 800
Load RegulationR
Capacitive LoadNo Oscillation500✻pF
Short-Circuit Current±15✻mA
Short-Circuit DurationGND or V
DIGITAL INPUT
Data FormatSerial✻
Data CodingStraight Binary✻
Logic FamilyCMOS✻
Logic Levels
V
IH
V
IL
I
IH
I
IL
DYNAMIC PERFORMANCE
Settling Time
DAC Glitch2.5✻nV-s
Digital Feedthrough0.5✻nV-s
POWER SUPPLY
V
DD
I
DD
Power DissipationV
Power Supply Sensitivity∆V
TEMPERATURE RANGE
Specified Performance–40+85✻✻°C
(1)
H
H
H
H
≥ 402Ω, Code 800
LOAD
H
H
DD
–2±1/2+2–1±1/4+1LSB
–1+1+3✻✻✻ LSB
1/21/22LSB
4.0794.0954.1114.0874.0954.103V
1/21/22LSB
±5±7✻✻mA
13✻✻ LSB
Indefinite✻
0.7 • V
DD
0.3 • V
±10✻µA
✻V
DD
✻V
±10✻µA
(2)
(tS)To ±1 LSB of Final Value7✻µs
+4.75+5.0+5.25✻✻✻ V
VIH = 5V, VIL = 0V, No Load, at Code 000
= 5V, VIL = 0V, No Load3.57.5✻✻ mW
IH
= ±5%0.00250.002✻✻%/%
DD
H
0.751.5✻✻ mA
✻ Same specification as for DAC7612U.
NOTES: (1) This term is sometimes referred to as Linearity Error or Integral Nonlinearity (INL). (2) Specification does not apply to negative-going transitions where
the final output voltage will be within 3 LSBs of ground. In this region, settling time may be double the value indicated.
The information provided herein is believed to be reliable; however, BURR-BROWN assumes no responsibility for inaccuracies or omissions. BURR-BROWN assumes
no responsibility for the use of this information, and all use of such information shall be entirely at the user’s own risk. Prices and specifications are subject to change
without notice. No patent rights or licenses to any of the circuits described herein are implied or granted to any third party. BURR-BROWN does not authorize or warrant
any BURR-BROWN product for use in life support devices and/or systems.
®
DAC7612
2
PIN CONFIGURATION
PIN DESCRIPTIONS
Top ViewSO-8
1
SDI
2
CLK
LOADDACS
CS
DAC7612U
3
4
ABSOLUTE MAXIMUM RATINGS
VDD to GND .......................................................................... –0.3V to 6V
Digital Inputs to GND .............................................. –0.3V to V
to GND ...........................................................–0.3V to VDD + 0.3V
V
OUT
Power Dissipation ........................................................................ 325mW
Thermal Resistance,
Maximum Junction Temperature.................................................. +150°C
Operating Temperature Range ...................................... –40°C to +85°C
Storage Temperature Range ....................................... –65 °C to +150°C
Lead Temperature (soldering, 10s) .............................................. +300°C
NOTE: (1) Stresses above those listed under “Absolute Maximum Ratings”
may cause permanent damage to the device. Exposure to absolute maximum
conditions for extended periods may affect device reliability.
1SDISerial Data Input. Data is clocked into the internal
2CLKSynchronous Clock for the Serial Data Input.
3LOADDACS Loads the internal DAC registers. All DAC registers
4CSChip Select. Active LOW.
5V
6GNDGround
7V
8V
OUTB
OUTA
serial register on the rising edge of CLK.
are transparent latches and are transparent when
LOADDACS is LOW (regardless of the state of CS
or CLK).
DAC B Output Voltage
Positive Power Supply
DD
DAC A Output Voltage
ELECTROSTATIC
DISCHARGE SENSITIVITY
This integrated circuit can be damaged by ESD. Burr-Brown
recommends that all integrated circuits be handled with
appropriate precautions. Failure to observe proper handling
and installation procedures can cause damage.
ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits
may be more susceptible to damage because very small
parametric changes could cause the device not to meet its
published specifications.
NOTES: (1) For detailed drawing and dimension table, please see end of data sheet, or Appendix C of Burr-Brown IC Data Book. (2) Models with a slash (/) are
available only in Tape and Reel in the quantities indicated (e.g., /2K5 indicates 2500 devices per reel). Ordering 2500 pieces of “DAC7612U/2K5” will get a single
2500-piece Tape and Reel. For detailed Tape and Reel mechanical information, refer to Appendix B of Burr-Brown IC Data Book.
(1)
NUMBER
(2)
MEDIA
®
3
DAC7612
EQUIVALENT INPUT LOGIC
LOADDACS
SDI
CS
CLK
ESD protection
diodes to V
and GND
DD
DAC Switches
12
DAC B Register
12
Data
Serial Shift Register
12
DAC A Register
12
DAC Switches
®
DAC7612
4
TIMING DIAGRAMS
SDI
CLK
t
CL
t
CH
t
DH
t
DS
SDI
CLK
CS
LOADDACS
(MSB)(LSB)
A0D11D10D9D8D7D6D5D4D3D2D1D0
A1
t
CSS
t
LD1
t
CSH
t
LD2
t
LDW
LOADDACS
t
FS
V
OUT
ZS
S
±1 LSB
Error Band
LOGIC TRUTH TABLETIMING SPECIFICATIONS
A1A0
LOADDACS
REGISTERREGISTER A REGISTER B
CLK
CS
XXXHHNo ChangeNo ChangeNo Change
SERIAL SHIFTDACDAC
XX
LXXH
↑
LHShifts One BitNo ChangeNo Change
(1)
LNo ChangeLoads SerialLoads Serial
Data WordData Word
HLXHLNo ChangeLoads SerialNo Change
Data Word
HHXHLNo ChangeNo ChangeLoads Serial
Data Word
↑ Positive Logic Transition; X = Don’t Care.
NOTE: (1) A HIGH value is suggested in order to avoid to “false clock” from
advancing the shift register and changing the DAC voltage.
NOTE: All input control signals are specified with t
of +5V) and timed from a voltage level of 2.5V. These parameters are
guaranteed by design and are not subject to production testing.
= tF = 5ns (10% to 90%
R
5
DAC7612
®
TYPICAL PERFORMANCE CURVES
At TA = +25°, and VDD = 5V, unless otherwise specified.
5
OUTPUT SWING vs LOAD
4
3
RL tied to GND
Data = FFF
H
2
Output Voltage (V)
1
RL tied to V
Data = 000
DD
H
0
101001k10k100k
Load Resistance (Ω)
BROADBAND NOISE
Noise Voltage (500µV/div)
Time (2ms/div)
Code = FFF
, BW = 1MHz
H
PULL-DOWN VOLTAGE vs OUTPUT SINK CURRENT
1k
100
10
(mV)
OUT
Delta V
+25°C
1
+85°C
–40°C
0.1
Data = 000
0.01
0.0010.010.1110100
Current (mA)
SUPPLY CURRENT vs LOGIC INPUT VOLTAGE
4.0
3.5
3.0
2.5
2.0
1.5
Supply Current (mA)
1.0
0.5
0
012345
Logic Voltage (V)
H
70
POWER SUPPLY REJECTION vs FREQUENCY
60
50
Data = FFF
VDD = 5V
±200mV AC
40
30
PSR (dB)
20
10
0
101001k10k100k1M
Frequency (Hz)
®
DAC7612
5.0
MINIMUM SUPPLY VOLTAGE vs LOAD
H
4.8
4.6
Minimum (V)
4.4
DD
V
4.2
4.0
0.010.1110
Output Load Current (mA)
6
TYPICAL PERFORMANCE CURVES (CONT)
At TA = +25°, and VDD = 5V, unless otherwise specified.
SHORT-CIRCUIT CURRENT vs OUTPUT VOLTAGE
20
15
10
5
Positive
Current
Limit
Data = 800
Output tied to I
SOURCE
0
–5
Output Current (mA)
–10
–15
Negative
Current
Limit
–20
0142356
Output Voltage (V)
MIDSCALE GLITCH PERFORMANCE
LOADDACS
2.0
SUPPLY CURRENT vs TEMPERATURE
V
= 3.5V
LOGIC
1.8
Data = FFF
1.6
No Load
H
1.4
1.2
1.0
0.8
0.6
Supply Current (mA)
0.4
At worst-case digital inputs.
0.2
H
VDD = 5.25V
VDD = 4.75V
VDD = 5.0V
0
–50 –30 –101030507090110 130
Temperature (°C)
MIDSCALE GLITCH PERFORMANCE
LOADDACS
(5mV/div)
OUT
V
(1V/div)
OUT
V
7FFH to 800
Time (500ns/div)
LARGE-SIGNAL SETTLING TIME
CL = 100pF
R
LOADDACS
Time (20µs/div)
H
= No Load
L
(5mV/div)
OUT
V
LOADDACS
(1mV/div)
OUT
V
Time (500ns/div)
RISE TIME DETAIL
Time (10µs/div)
800H to 7FF
CL = 100pF
R
= No Load
L
H
®
7
DAC7612
TYPICAL PERFORMANCE CURVES (CONT)
At TA = +25°, and VDD = 5V, unless otherwise specified.
FALL TIME DETAIL
CL = 100pF
R
(1mV/div)
OUT
V
LOADDACS
Time (10µs/div)
LONG-TERM DRIFT ACCELERATED BY BURN-IN
5
4
3
2
1
0
–1
–2
–3
–4
Output Voltage Change at FS (mV)
–5
01683365046728401008
Hours of Operation at +150°C
Max
Avg
Min
= No Load
L
10.000
1.000
0.100
Noise (µV/√Hz)
0.010
35
30
25
20
15
Number of Units
10
OUTPUT VOLTAGE NOISE vs FREQUENCY
Data = FFF
101001k10k100k
Frequency (Hz)
TOTAL UNADJUSTED ERROR HISTOGRAM
T.U.E = Σ (INL + ZSE + FSE)
Sample Size = 200 Units
T
= +25°C
A
5
0
–12
–10 –8 –6–4 –20284610 12
H
4.111
4.103
4.095
Full-Scale Output (V)
4.087
4.079
FULL-SCALE VOLTAGE vs TEMPERATURE
Avg + 3σ
Avg
Avg – 3σ
–40–1510356085
Temperature (°C)
®
DAC7612
Zero-Scale Output (mV)
–1
8
3
ZERO-SCALE VOLTAGE vs TEMPERATURE
Avg + 3σ
2
Avg
1
Avg – 3σ
0
–40–1510356085
Temperature (°C)
TYPICAL PERFORMANCE CURVES (CONT)
At TA = +25°, and VDD = 5V, unless otherwise specified.
LINEARITY ERROR vs DIGITAL CODE
2.0
1.5
1.0
0.5
0
–0.5
Linearity Error (LSBs)
–1.0
–1.5
–2.0
05121024 153620482560307235844096
LINEARITY ERROR vs DIGITAL CODE
2.0
1.5
1.0
0.5
0
–0.5
Linearity Error (LSBs)
–1.0
–1.5
–2.0
05121024 153620482560307235844096
(DAC A at +85°C)
Code
(DAC A at +25°C)
Code
LINEARITY ERROR vs DIGITAL CODE
2.0
1.5
1.0
0.5
0
–0.5
Linearity Error (LSBs)
–1.0
–1.5
–2.0
05121024 153620482560307235844096
LINEARITY ERROR vs DIGITAL CODE
2.0
1.5
1.0
0.5
0
–0.5
Linearity Error (LSBs)
–1.0
–1.5
–2.0
05121024 153620482560307235844096
(DAC B at +85°C)
Code
(DAC B at +25°C)
Code
LINEARITY ERROR vs DIGITAL CODE
2.0
1.5
1.0
0.5
0
–0.5
Linearity Error (LSBs)
–1.0
–1.5
–2.0
05121024 153620482560307235844096
(DAC A at –40°C)
Code
LINEARITY ERROR vs DIGITAL CODE
2.0
1.5
1.0
0.5
0
–0.5
Linearity Error (LSBs)
–1.0
–1.5
–2.0
05121024 153620482560307235844096
9
(DAC B at –40°C)
Code
®
DAC7612
OPERATION
The DAC7612 is a dual, 12-bit digital-to-analog converter
(DAC) complete with a serial-to-parallel shift register, DAC
registers, laser-trimmed 12-bit DACs, on-board reference,
and rail-to-rail output amplifiers. Figure 1 shows the basic
operation of the DAC7612.
INTERFACE
Figure 1 shows the basic connection between a
microcontroller and the DAC7612. The interface consists of
a Serial Clock (CLK), Serial Data (SDI), and a Load DAC
signal (LOADDACS). In addition, a chip select (CS) input is
available to enable serial communication when there are
multiple serial devices. Loading either DAC A or DAC B is
done by shifting 14 serial bits in via the SDI input. The first
2 bits represent the address of the DAC to be updated and the
DAC7612 Full-Scale Range = 4.095V
Least Significant Bit = 1mV
DIGITAL INPUT CODEANALOG OUTPUT
STRAIGHT OFFSETBINARY(V)DESCRIPTION
FFF
H
801
H
800
H
7FF
H
000
H
TABLE I. Digital Input Code and Corresponding Ideal
next 12 bits are the code (MSB-first) sent to the DAC. The
data format is Straight Binary and is loaded MSB-first into
the shift registers after loading the address bits. Table I shows
the relationship between input code and output voltage.
The digital data into the DAC7612 is double-buffered. This
means that new data can be entered into the chosen DAC
without disturbing the old data and the analog output of the
converter. At some point after the data has been entered into
the serial shift register, this data can be transferred into the
DAC registers. This transfer is accomplished with a HIGH
to LOW transition of the LOADDACS pin. The LOADDACS
pin makes the DAC registers transparent. If new data is
shifted into the shift register while LOADDACS is LOW,
the DAC output voltages will change as each new bit is
entered. To prevent this, LOADDACS must be returned
HIGH prior to shifting in new serial data.
DIGITAL-TO-ANALOG CONVERTER
The internal DAC section is a 12-bit voltage output
device that swings between ground and the internal reference voltage. The DAC is realized by a laser-trimmed
R-2R ladder network which is switched by N-channel
MOSFETs. Each DAC output is internally connected to a
rail-to-rail output operational amplifier.
OUTPUT AMPLIFIER
A precision, low-power amplifier buffers the output of each
DAC section and provides additional gain to achieve a 0V to
4.095V range. Each amplifier has low offset voltage, low
Serial Data
Serial Clock
Load DACs
Chip Select
FIGURE 1. Basic Operation of the DAC7612.
SDI
1
CLK
2
LOADDACS
3
CS
4
DAC7612U
V
GND
V
OUTA
V
OUTB
8
7
DD
6
5
0V to +4.095V
+
0.1µF
0V to +4.095V
10µF
®
DAC7612
10
noise, and a set gain of 1.682V/V (4.095/2.435). See Figure
2 for an equivalent circuit schematic of the analog portion of
the DAC7612.
The output amplifier has a 7µs typical settling time to ±1
LSB of the final value. Note that there are differences in the
settling time for negative-going signals versus positivegoing signals.
The rail-to-rail output stage of the amplifier provides the fullscale range of 0V to 4.095V while operating on a supply voltage
as low as 4.75V. In addition to its ability to drive resistive loads,
the amplifier will remain stable while driving capacitive loads
of up to 500pF. See Figure 3 for an equivalent circuit schematic
of the amplifier’s output driver and the Typical Performance
Curves section for more information regarding settling time,
load driving capability, and output noise.
POWER SUPPLY
A BiCMOS process and careful design of the bipolar and
CMOS sections of the DAC7612 result in a very low power
device. Bipolar transistors are used where tight matching
and low noise are needed to achieve analog accuracy, and
CMOS transistors are used for logic, switching functions
and for other low power stages.
If power consumption is critical, it is important to keep the
logic levels on the digital inputs (SDI, CLK, CS,
LOADDACS) as close as possible to either VDD or ground.
This will keep the CMOS inputs (see “Supply Current vs
Logic Input Voltages” in the Typical Performance Curves)
from shunting current between VDD and ground.
The DAC7612 power supply should be bypassed as shown
in Figure 1. The bypass capacitors should be placed as close
to the device as possible, with the 0.1µF capacitor taking
priority in this regard. The “Power Supply Rejection vs
Frequency” graph in the Typical Performance Curves section shows the PSRR performance of the DAC7612. This
should be taken into account when using switching power
supplies or DC/DC converters.
In addition to offering guaranteed performance with VDD in
the 4.75V to 5.25V range, the DAC7612 will operate with
reduced performance down to 4.5V. Operation between
4.5V and 4.75V will result in longer settling time, reduced
performance, and current sourcing capability. Consult the
“VDD vs Load Current” graph in the Typical Performance
Curves section for more information.
Buffer
Bandgap
Reference
2.435V
FIGURE 2. Simplified Schematic of Analog Portion.
R-2R DAC
2R
2R
2R
2R
P-Channel
R
R
R
2R
Output Amplifier
R
2
R
1
Typical of DAC A or DAC B
V
DD
FIGURE 3. Simplified Driver Section of Output Amplifier.
N-Channel
11
V
OUT
GND
®
DAC7612
APPLICATIONS
POWER AND GROUNDING
The DAC7612 can be used in a wide variety of situations—
from low power, battery operated systems to large-scale
industrial process control systems. In addition, some applications require better performance than others, or are particularly sensitive to one or two specific parameters. This
diversity makes it difficult to define definite rules to follow
concerning the power supply, bypassing, and grounding.
The following discussion must be considered in relation to
the desired performance and needs of the particular system.
A precision analog component requires careful layout, adequate bypassing, and a clean, well-regulated power supply.
As the DAC7612 is a single-supply, +5V component, it will
often be used in conjunction with digital logic,
microcontrollers, microprocessors, and digital signal processors. The more digital logic present in the design and the
higher the switching speed, the more difficult it will be to
achieve good performance.
Because the DAC7612 has a single ground pin, all return
currents, including digital and analog return currents, must
flow through this pin. The GND pin is also the ground
reference point for the internal bandgap reference. Ideally,
GND would be connected directly to an analog ground
plane. This plane would be separate from the ground connection for the digital components until they are connected
at the power entry point of the system (see Figure 4).
The power applied to VDD should be well regulated and lownoise. 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 VDD and V
OUT
.
As with the GND connection, VDD should be connected to
a +5V power supply plane or trace that is separate from the
connection for digital logic until they are connected at the
power entry point. In addition, the 10µF and 0.1µF capacitors shown in Figure 4 are strongly recommended and
should be installed as close to VDD and ground as possible.
In some situations, additional bypassing may be required
such as a 100µF electrolytic capacitor or even a “Pi” filter
made up of inductors and capacitors—all designed to essentially lowpass filter the +5V supply, removing the high
frequency noise (see Figure 4).
+5V
Power
Supply
+5V
GND
100µF
Optional
Digital Circuits
+5V
GND
+
+
10µF
Analog
Components
Other
0.1µF
DAC7612
V
DD
GND
FIGURE 4. Suggested Power and Ground Connections for a DAC7612 Sharing a +5V Supply with a Digital System.
®
DAC7612
12
PACKAGE OPTION ADDENDUM
www.ti.com
8-Jan-2007
PACKAGING INFORMATION
Orderable DeviceStatus
(1)
Package
Type
Package
Drawing
Pins Package
Qty
Eco Plan
DAC7612UACTIVESOICD8100 Green (RoHS &
no Sb/Br)
DAC7612U/2K5ACTIVESOICD82500 Green(RoHS &
no Sb/Br)
DAC7612U/2K5G4ACTIVESOICD82500 Green (RoHS &
no Sb/Br)
DAC7612UBACTIVESOICD8100 Green (RoHS &
no Sb/Br)
DAC7612UB/2K5ACTIVESOICD82500 Green (RoHS &
no Sb/Br)
DAC7612UB/2K5G4ACTIVESOICD82500 Green (RoHS &
no Sb/Br)
DAC7612UBG4ACTIVESOICD8100 Green (RoHS &
no Sb/Br)
DAC7612UG4ACTIVESOICD8100 Green (RoHS &
no Sb/Br)
(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)
Lead/Ball Finish MSL Peak Temp
CU NIPDAULevel-3-260C-168 HR
CU NIPDAULevel-3-260C-168 HR
CU NIPDAULevel-3-260C-168 HR
CU NIPDAULevel-3-260C-168 HR
CU NIPDAULevel-3-260C-168 HR
CU NIPDAULevel-3-260C-168 HR
CU NIPDAULevel-3-260C-168 HR
CU NIPDAULevel-3-260C-168 HR
(3)
(2)
Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check
http://www.ti.com/productcontent for the latest availability information and additional product content details.
TBD: The Pb-Free/Green conversion plan has not been defined.
Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements
for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered
at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes.
Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and
package, or 2) lead-based die adhesive used between the die and leadframe. The component is otherwise considered Pb-Free (RoHS
compatible) as defined above.
Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame
retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material)
(3)
MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder
temperature.
Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is
provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the
accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take
reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on
incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited
information may not be available for release.
In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI
to Customer on an annual basis.