Part A
AD7689ACPZ
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 2964 PCS
- Package
- WFQFN-20
- Series
- Acquisição de dados - Analogo para Convertedores Digitais (ADC)
Replacement verdict
Compatible functional replacement candidate
The AD7689ACPZ is a strong functional replacement candidate for the AD7682BCPZRL7, as both are 16-bit, 4-channel/8-channel PulSAR ADCs in the same LFCSP package with identical supply and interface characteristics. The primary distinction is channel count, so designers must confirm the required multiplexer configuration before substituting.
Resolution
High match
Package Type
High match
Channel Count
Validation required
Supply Voltage
High match
Parts at a glance
Part B
AD7682BCPZRL7
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 4566 PCS
- Package
- WFQFN-20
- Series
- Acquisição de dados - Analogo para Convertedores Digitais (ADC)
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | AD7682BCPZRL7 | AD7689ACPZ | Why it matters |
|---|---|---|---|
| Number of Input Channels | 4 channels | 8 channels | Channel count determines how many analog signals can be multiplexed into the ADC; a 4-channel part cannot directly replace an 8-channel part in multi-sensor designs. |
| Resolution | 16 bits | 16 bits | Resolution sets the smallest detectable signal change; identical 16-bit resolution means comparable measurement precision. |
| Sampling Rate | 250 kSPS | 250 kSPS | Maximum throughput must meet the system's signal bandwidth requirements; matching rates allow equivalent timing performance. |
| Architecture | SAR | SAR | Successive-approximation architecture affects latency and power behavior; identical architecture supports similar system-level timing. |
| Supply Voltage | 2.3 V to 5.5 V | 2.3 V to 5.5 V | Compatible supply range allows the parts to operate from the same rails without level shifting or regulator changes. |
| Interface | SPI / QSPI / MICROWIRE / DSP | SPI / QSPI / MICROWIRE / DSP | Matching serial interfaces ensure the same host controller and firmware can drive either device. |
| Package | 20-Lead LFCSP | 20-Lead LFCSP | Identical package and footprint enable drop-in board replacement without layout changes. |
| Input Type | Single-ended / Differential / Pseudo-differential | Single-ended / Differential / Pseudo-differential | Input configuration flexibility affects how sensors connect; both support the same modes, but channel count differs. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Matching temperature ratings ensure both parts suit the same industrial environments. |
Need help validating a replacement?
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD7689ACPZ | AD7682BCPZRL7 |
|---|---|---|
| Series | PulSAR® | PulSAR® |
| Part Status | Active | Active |
| Number of Bits | 16 | 16 |
| Sampling Rate(Per Second) | 250k | 250k |
| Number of Inputs | 8 | 4 |
| Input Type | Differential, Pseudo-Differential, Single Ended | Differential, Pseudo-Differential, Single Ended |
| Data Interface | SPI, DSP | SPI, DSP |
| Configuration | MUX-S/H-ADC | MUX-S/H-ADC |
| Ratio - S / H: ADC | 1:1 | 1:1 |
| Number of A/D Converters | 1 | 1 |
| Architecture | SAR | SAR |
| Reference Type | External, Internal | External, Internal |
| Voltage - Supply, Analog | 2.3V ~ 5.5V | 2.3V ~ 5.5V |
| Voltage - Supply, Digital | 2.3V ~ 5.5V | 2.3V ~ 5.5V |
| Features | Temperature Sensor | Temperature Sensor |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
Frequently asked questions
What are the key differences between the AD7682BCPZRL7 and the AD7689ACPZ?
The AD7682BCPZRL7 is a 16-bit, 4-channel, 250 kSPS PulSAR ADC in a 20-lead LFCSP package supplied in tape and reel. The AD7689ACPZ is an 8-channel, 16-bit, 250 kSPS PulSAR ADC in a 20-lead LFCSP. The primary differences are channel count (4 vs. 8) and the ordering format (tape-and-reel vs. tray). Both share the same 16-bit resolution, 250 kSPS throughput, and LFCSP footprint family.
Are the AD7682BCPZRL7 and AD7689ACPZ pin-compatible?
Both devices are offered in a 20-lead LFCSP package, but the AD7689 provides 8 input channels while the AD7682 provides 4. Pin functions and channel assignments differ, so a direct drop-in substitution should not be assumed. Designers must verify pinout and channel mapping against the respective manufacturer datasheets before replacing one with the other.
Do both ADCs support the same serial interface?
Yes. Both the AD7682 and AD7689 use a SPI-compatible serial interface (with CS and SCLK) for configuration and data readback, supporting daisy-chain and busy-indicator modes. The interface timing and register structure are consistent across the family, allowing similar host-side firmware with appropriate channel configuration.
What is the resolution and throughput of each device?
Both the AD7682BCPZRL7 and AD7689ACPZ are 16-bit successive-approximation (SAR) ADCs with a maximum throughput of 250 kSPS. Resolution and sample rate are identical; the selection between them is driven primarily by channel count and packaging/ordering requirements.
What input voltage range and reference options do these ADCs support?
Both devices support a pseudo-differential input with a selectable unipolar or bipolar range and an external reference (REF) input, along with an internal reference buffer option. The analog input range is set by the reference voltage and configuration register settings. Consult the manufacturer datasheet for the exact reference voltage limits and configuration options.
Can the AD7689ACPZ be used as a replacement for the AD7682BCPZRL7 in an existing design?
Replacement is possible only after validating channel count, pinout, configuration register settings, and PCB land pattern against both datasheets. Because the AD7689 offers 8 channels versus 4 on the AD7682, firmware and channel sequencing must be updated. Package and footprint compatibility should be confirmed, and the design should be re-verified for timing and reference configuration.
What are the typical applications for these PulSAR ADCs?
Both the AD7682 and AD7689 are suited to multichannel data acquisition, industrial process control, medical instrumentation, and battery-powered systems where 16-bit resolution at 250 kSPS is required. The AD7689's 8 channels suit higher-channel-count multiplexed systems, while the AD7682's 4 channels fit more compact signal chains.