AD7738: 8-Channel, 8.5 kHz, 24-Bit Sigma-Delta A/D Converter
The AD7738 is a high precision, high throughput analog front end. True 16-bit peak-to-peak resolution is achievable with a total conversion time of 117 µs (8.5 kHz channel switching) making it ideally ...More
AD7738: 8-Channel, 8.5 kHz, 24-Bit Sigma-Delta A/D Converter
Product Description
The AD7738 is a high precision, high throughput analog front end. True 16-bit peak-to-peak resolution is achievable with a total conversion time of 117 µs (8.5 kHz channel switching) making it ideally suitable for high resolution multiplexing applications.
The AD7738 is based on a sigma-delta architecture and features up to 24 bits of no missing codes performance. The part can be configured via a simple digital interface, which allows users to balance the noise performance against data throughput up to a 15.4 kHz conversion rate. The analog front end features 8 single-ended or 4 fully differential input channels with unipolar or bipolar 625 mV, 1.25 V and 2.5V input ranges and accepts a common mode input voltage from 200 mV above AGND to AVDD-300 mV. The multiplexer output is pinned out externally allowing the user to implement programmable gain or signal conditioning before applying the input signal to the ADC. The differential reference input features “No Reference” detect capability. The ADC also supports per channel system calibration options.
The digital serial interface can be configured for three-wire operation and is compatible with microcontrollers and digital signal processors. All interface inputs are Schmitt triggered.
The part is specified for operation over the extended industrial temperature range of -40ºC to +105ºC and is available in 28-lead TSSOP package.
Design Tools
AD7732/34/38/39 Codeword Tool
A tool to calculate codewords from voltages in the AD7732/34/38/39 Sigma-De...
AD7732, AD7734, AD7738, AD7739 Voltage to Code Converter
This tool generates the output code that the ADC will produce, based on the...
Features
- High resolution ADC
- 24 bits no missing codes
- ±0.0015% Nonlinearity - Optimized for Fast Channel Switching
- 18-Bits p-p Resolution (21 Bits Effective) at 500 Hz
- 16-Bits p-p Resolution (19 Bits Effective) at 8.5 kHz
- 15-Bits p-p Resolution (18 Bits Effective) at 15 kHz
- On-Chip Per Channel System Calibration - Configurable Inputs
- 8 Single-Ended or 4 Fully Differential
- Input Ranges
- +625 mV, +1.25 V, +2.5 V, ±625 mV, ±1.25 V, ±2.5 V - 3-Wire Serial Interface
- SPI®, QSPI™, MICROWIRE™ and DSP Compatible
- Schmitt Trigger on Logic Inputs - Single-Supply Operation
- 5 V Analog Supply
- 3 V or 5 V Digital Supply - Package: 28-Lead TSSOP
Diagrams
- Enlarge
- Symbols and Footprints
Functional Block Diagram for AD7738
8-Channel, 8.5 kHz, 24-Bit Sigma-Delta A/D Converter
Functional Block Diagram for AD7738
AD7401A - Isolated Sigma-Delta Modulator
EVAL-CED - Converter Evaluation and Development (CED) Board
AD7949 - 14-Bit, 8-Channel, 250 kSPS PulSAR® ADC
AD7682 - 16-Bit, 4-Channel, 250 kSPS PulSAR® ADC
| Part# | Res | Throughput Rate | # of Inputs | Operating Pwr Diss |
|---|---|---|---|---|
| AD7738 | 24 | 15.4KSPS | 8 | 100mW |
| AD7734 | 24 | 15.4KSPS | 4 | 100mW |
| AD1555 | 24 | 16KSPS | 2 | 96mW |
| AD7732 | 24 | 15.4KSPS | 2 | 100mW |
| AD7766 | 24 | 128KSPS | 1 | 18mW |
| AD9874 | 24 | 541.5KSPS | 1 | 79.5mW |
| AD7767 | 24 | 128KSPS | 1 | 18mW |
| AD7856 | 14 | 285KSPS | 8 | 89.25mW |
| AD7739 | 24 | 15.1KSPS | 8 | 100mW |
| AD7858B | 12 | 200KSPS | 8 | 33mW |
| AD7888 | 12 | 125KSPS | 8 | 3.5mW |
AD7738 Model Options
| Model | Status | Package | Pins | Temp. Range |
Price* (1000 pcs.) |
Available | ROHS Compilant | Samples Cart | Purchase Cart |
|---|---|---|---|---|---|---|---|---|---|
| AD7738BRU | Prodn | 28 ld TSSOP | 28 | Ind | $8.55 | 07/11/2008 |
N
Material Declaration |
Contact ADI | Add To Cart |
| AD7738BRU-REEL7 | Prodn | 28 ld TSSOP | 28 | Ind | $8.55 | - |
N
Material Declaration |
Contact ADI | Add To Cart |
| AD7738BRUZ | Prodn | 28 ld TSSOP | 28 | Ind | $7.77 | 08/01/2008 |
Y
Material Declaration |
Add To Cart | Add To Cart |
| AD7738BRUZ-REEL | Prodn | 28 ld TSSOP | 28 | Ind | $7.77 | - |
Y
Material Declaration |
Contact ADI | Add To Cart |
| AD7738BRUZ-REEL7 | Prodn | 28 ld TSSOP | 28 | Ind | $7.77 | 09/26/2008 |
Y
Material Declaration |
Contact ADI | Add To Cart |
| EVAL-AD7738EB-U2 | Obs | EVALUATION BOARDS | - | TBD | - | - | Y | Contact ADI | Contact ADI |
| EVAL-AD7738EBZ | Prodn | EVALUATION BOARDS | - | TBD | $169.00 | 09/05/2008 | Y | Contact ADI | Add To Cart |
Help
- Pre-Release: The model has not been released to general production, but samples may be available.
- Production: The model is currently being produced, and generally available for purchase and sampling.
- Last Time Buy: The model has been scheduled for obsolescence, but may still be purchased for a limited time.
- Obsolete: The specific part is obsolete and no longer available. Other models listed in the table may still be available (if they have a status that is not obsolete).
For detailed drawings and chemical composition please consult our Package Site
- Commercial: 0 to +70 degrees Celsius
- Military : -55 to +125 degrees Celsius
- Industrial: Temperature ranges may vary by model. Please consult the datasheet for more information.
- Automotive: -40 to +125 degrees Celsius
The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.

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