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DAC7822

FEATURES DESCRIPTION

APPLICATIONS

12-Bit

R-2RDACA

12-Bit

R-2RDACB

LATCH

R A

I 1A

OUT

I 2A

OUT

I 1B

OUT

DAC /B

R/W

DB0

DATA

INPUTS

DB11

LDAC

CLR

I 2B

OUT

LATCH

INPUT

BUFFER

CONTROL

LOGIC

R A

2_3

R A

V A

REF

R A

GND

POWER-ON

RESET

R B

2_3

R B

V B

REF

R B

DAC7822

SBAS374A – JUNE 2006 – REVISED JULY 2007

Dual, 12-Bit, Parallel Input, Multiplying

Digital-to-Analog Converter

• ± 1LSB INL

The DAC7822 is a dual, CMOS, 12-bit, current

output digital-to-analog converter (DAC). This device

• 2.5V to 5.5V Supply Operation

operates from a 2.5V to 5.5V power supply, making it

• Fast Parallel Interface:

suitable for battery-powered and many other

17ns Write Cycle

applications.

• Update Rate of 20.4MSPS

The DAC7822 operates with a fast parallel interface.

• 10MHz Multiplying Bandwidth

Data readback allows the user to read the contents

• ±15V Reference Input

of the DAC register via the DB pins. On power-up,

the internal register and latches are filled with zeroes

• Extended Temperature Range:

and the DAC outputs are at zero scale.

–40 ° C to +125 ° C

The DAC7822 offers excellent 4-quadrant

• 40-Lead QFN

multiplication characteristics, with large signal

• 12-Bit Monotonic

multiplying bandwidth of 10MHz. The applied

• 4-Quadrant Multiplication

external reference input voltage (V

REF

) determines

• Power-On Reset with Brownout Detection

the full-scale output current. An integrated feedback

resistor (R

) provides temperature tracking and

• Readback Function

full-scale voltage output when combined with an

• Industry-Standard Pin Configuration

external current-to-voltage precision amplifier. The

• Pin-Compatible with the AD5405

DAC7822 also includes the resistors necessary for

4-quadrant multiplication and other configuration

modes.

• Portable Battery-Powered Instruments

The DAC7822 is available in a 40-lead QFN

• Waveform Generators

package.

• Analog Processing

• Programmable Amplifiers and Attenuators

• Digitally-Controlled Calibration

• Programmable Filters and Oscillators

• Ultrasound

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas

Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

All trademarks are the property of their respective owners.

PRODUCTION DATA information is current as of publication date.

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.

Summary of content (23 pages)

PAGE 1
DA DAC7822 C7 82 2 SBAS374A – JUNE 2006 – REVISED JULY 2007 Dual, 12-Bit, Parallel Input, Multiplying Digital-to-Analog Converter FEATURES • • • • • • • • • • • • • • ±1LSB INL 2.5V to 5.5V Supply Operation Fast Parallel Interface: 17ns Write Cycle Update Rate of 20.
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DAC7822 www.ti.com SBAS374A – JUNE 2006 – REVISED JULY 2007 This integrated circuit can be damaged by ESD. Texas Instruments 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.
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DAC7822 www.ti.com SBAS374A – JUNE 2006 – REVISED JULY 2007 ELECTRICAL CHARACTERISTICS VDD = +2.5V to +5.5V; IOUT1 = Virtual GND; IOUT2 = 0V; VREF = 10V; TA = full operating temperature. All specifications –40°C to +125°C, unless otherwise noted.
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DAC7822 www.ti.com SBAS374A – JUNE 2006 – REVISED JULY 2007 TIMING INFORMATION t8 t2 t1 t2 R/W t9 t3 CS t4 t5 t10 t11 DACA/DACB t6 t7 DATA DATA VALID t12 t13 DATA VALID TIMING REQUIREMENTS: 2.5V to 5.5V At tr = tf = 1ns (10% to 90% of VDD) and timed from a voltage level of (VIL + VIH)/2; VDD = 2.5V to 5.5V, VREF = 10V, IOUT2 = 0V. All specifications –40°C to +125°C, unless otherwise noted.
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DAC7822 www.ti.
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DAC7822 www.ti.com SBAS374A – JUNE 2006 – REVISED JULY 2007 TYPICAL CHARACTERISTICS: VDD = +5V At TA = +25°C, +VDD = +5V, unless otherwise noted. Channel A LINEARITY ERROR vs DIGITAL INPUT CODE DIFFERENTIAL LINEARITY ERROR vs DIGITAL INPUT CODE 1.0 1.0 TA = +25°C VREF = +10V 0.6 0.6 0.4 0.4 0.2 0 -0.2 0 -0.2 -0.4 -0.6 -0.6 -0.8 -0.8 -1.0 0 512 1024 1536 2048 2560 Digital Input Code 3072 3584 4096 0 512 1536 2048 2560 Digital Input Code 3072 3584 Figure 2.
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DAC7822 www.ti.com SBAS374A – JUNE 2006 – REVISED JULY 2007 TYPICAL CHARACTERISTICS: VDD = +5V (continued) At TA = +25°C, +VDD = +5V, unless otherwise noted. Channel B LINEARITY ERROR vs DIGITAL INPUT CODE DIFFERENTIAL LINEARITY ERROR vs DIGITAL INPUT CODE 1.0 1.0 TA = +25°C V = +10V 0.8 0.6 0.6 0.4 DNL (LSB) INL (LSB) 0.4 0.2 0 -0.2 0 -0.2 -0.4 -0.6 -0.6 -0.8 -0.8 -1.
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DAC7822 www.ti.com SBAS374A – JUNE 2006 – REVISED JULY 2007 TYPICAL CHARACTERISTICS: VDD = +5V (continued) At TA = +25°C, +VDD = +5V, unless otherwise noted. SUPPLY CURRENT vs LOGIC INPUT VOLTAGE REFERENCE MULTIPLYING BANDWIDTH VDD = 5.0V 1.8 Supply Current (mA) 1.6 1.4 Applied to the CS pin. R/W and LDAC held at 0V. All other digital inputs held at supply voltage. 1.2 1.0 0.8 0.6 VDD = 3.0V 0.4 VDD = 2.5V 0.2 0 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.
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DAC7822 www.ti.com SBAS374A – JUNE 2006 – REVISED JULY 2007 TYPICAL CHARACTERISTICS: VDD = +5V (continued) At TA = +25°C, +VDD = +5V, unless otherwise noted. SUPPLY CURRENT vs TEMPERATURE 2.0 2.0 VREF = +10V 1.8 VREF = +10V 1.6 1.6 Output Leakage (nA) Quiescent Current (mA) 1.8 OUTPUT LEAKAGE vs TEMPERATURE 1.4 1.2 1.0 VDD = +5.0V 0.8 0.6 0.4 1.4 1.2 1.0 0.8 0.6 0.4 VDD = +2.5V 0.2 0.
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DAC7822 www.ti.com SBAS374A – JUNE 2006 – REVISED JULY 2007 TYPICAL CHARACTERISTICS: VDD = +2.5V At TA = +25°C, +VDD = +2.5V, unless otherwise noted. Channel A LINEARITY ERROR vs DIGITAL INPUT CODE DIFFERENTIAL LINEARITY ERROR vs DIGITAL INPUT CODE 1.0 1.0 TA = +25°C VREF = +10V 0.6 0.6 0.4 0.4 0.2 0 -0.2 0 -0.2 -0.4 -0.6 -0.6 -0.8 -0.8 -1.0 0 512 1024 1536 2048 2560 Digital Input Code 3072 3584 4096 0 512 1536 2048 2560 Digital Input Code 3072 3584 Figure 22.
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DAC7822 www.ti.com SBAS374A – JUNE 2006 – REVISED JULY 2007 TYPICAL CHARACTERISTICS: VDD = +2.5V (continued) At TA = +25°C, +VDD = +2.5V, unless otherwise noted. Channel B LINEARITY ERROR vs DIGITAL INPUT CODE DIFFERENTIAL LINEARITY ERROR vs DIGITAL INPUT CODE 1.0 1.0 TA = +25°C VREF = +10V 0.6 0.6 0.4 0.4 0.2 0 -0.2 0 -0.2 -0.4 -0.6 -0.6 -0.8 -0.8 -1.0 0 512 1024 1536 2048 2560 Digital Input Code 3072 3584 4096 0 512 1024 1536 2048 2560 Digital Input Code 3072 3584 Figure 27.
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DAC7822 www.ti.com SBAS374A – JUNE 2006 – REVISED JULY 2007 TYPICAL CHARACTERISTICS: VDD = +2.5V (continued) At TA = +25°C, +VDD = +2.5V, unless otherwise noted. MIDSCALE DAC GLITCH Output Voltage (50mV/div) Output Voltage (50mV/div) MIDSCALE DAC GLITCH Code 2048 to 2047 Code 2047 to 2048 DAC Update DAC Update 10 8 Time (50ns/div) Time (50ns/div) Figure 33. Figure 34. GAIN ERROR vs TEMPERATURE OUTPUT LEAKAGE vs TEMPERATURE 2.0 VREF = +10V 1.8 1.
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DAC7822 www.ti.com SBAS374A – JUNE 2006 – REVISED JULY 2007 THEORY OF OPERATION The DAC7822 is a dual channel, current output, 12-bit, digital-to-analog converter (DAC). The architecture, illustrated in Figure 37, is an R-2R ladder configuration with the three MSBs segmented. Each 2R leg of the ladder is either switched to IOUT1 or the IOUT2 terminal. The IOUT1 terminal of the DAC is held at a virtual GND potential by the use of an external I/V converter op amp.
PAGE 14
DAC7822 www.ti.com SBAS374A – JUNE 2006 – REVISED JULY 2007 APPLICATION INFORMATION Stability Circuit For a current-to-voltage design (see Figure 39), the DAC7822 current output (IOUT) and the connection with the inverting node of the op amp should be as short as possible and according to correct printed circuit board (PCB) layout design practices. For each code change, there is a step function.
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DAC7822 www.ti.com SBAS374A – JUNE 2006 – REVISED JULY 2007 Table 2. Suitable High Speed Operational Amplifiers from Texas Instruments (Multiple Channel Options) SUPPLY VOLTAGE (V) GBW PRODUCT (MHz) VOLTAGE NOISE nV/√Hz GBW (typ) (MHz) SLEW RATE (V/μs) VOS (typ) (μV) VOS (max) (μV) CMRR (min) (dB) THS4281 ±2.7 to ±15 38 12.5 35 500 3500 500 1000 SOT5-23, MSOP-8, SOIC-8 Very Low-Power High Speed Rail-To-Rail Input/Output Voltage Feedback Operational Amplifier THS4031 ±4.5 to ±16.
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DAC7822 www.ti.com SBAS374A – JUNE 2006 – REVISED JULY 2007 External resistance mismatching is the significant error in Figure 41. VDD R 1A R1 2R RFB 2R RFBA C1 R2A VIN R2_3A R3A U1 (2) IOUT1A R2 2R DAC7822 (1) VOUT = -VIN to +VIN U2 IOUT2A R3 2R AGND AGND GND VREFA AGND NOTES: (1) Similar configuration for DAC B. (2) C1 phase compensation (1pF to 5pF) may be required if U2 is a high-speed amplifier. Figure 41.
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PACKAGE OPTION ADDENDUM www.ti.
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PACKAGE MATERIALS INFORMATION www.ti.com 16-Feb-2012 TAPE AND REEL INFORMATION *All dimensions are nominal Device Package Package Pins Type Drawing SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant DAC7822IRTAR WQFN RTA 40 2000 330.0 16.4 6.3 6.3 1.5 12.0 16.0 Q2 DAC7822IRTAT WQFN RTA 40 250 330.0 16.4 6.3 6.3 1.5 12.0 16.
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PACKAGE MATERIALS INFORMATION www.ti.com 16-Feb-2012 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) DAC7822IRTAR WQFN RTA 40 2000 336.6 336.6 28.6 DAC7822IRTAT WQFN RTA 40 250 336.6 336.6 28.
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IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications, enhancements, improvements, and other changes to its products and services at any time and to discontinue any product or service without notice. Customers should obtain the latest relevant information before placing orders and should verify that such information is current and complete.