Part A
AD7689ACPZ
Công ty Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 2964 PCS
- Package
- WFQFN-20
- Series
- Data Acquisition - Analog to Digital Converters (ADC)
Replacement verdict
Compatible functional replacement candidate
The AD7689BCPZ and AD7689ACPZ are functionally interchangeable 16-bit, 8-channel SAR ADCs in identical LFCSP-20 packages, differing only in specified INL and operating temperature grade. The AD7689ACPZ offers a tighter INL specification and extended temperature range, making it a suitable drop-in candidate where the AD7689BCPZ's performance grade is insufficient, while both share the same pinout, interface, and core architecture.
Package Type
High match
Resolution and Channel Count
High match
Digital Interface
High match
INL and Temperature Grade
Validation required
Parts at a glance
Part B
AD7689BCPZ
Công ty Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 5917 PCS
- Package
- WFQFN-20
- Series
- Data Acquisition - Analog to Digital Converters (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 | AD7689BCPZ | AD7689ACPZ | Why it matters |
|---|---|---|---|
| INL (Integral Nonlinearity) | ±1.0 LSB typical | ±0.5 LSB typical | INL defines the maximum deviation from an ideal transfer function; the A-grade offers tighter linearity, which improves absolute accuracy in precision measurement applications. |
| DNL (Differential Nonlinearity) | ±0.5 LSB typical | ±0.4 LSB typical | DNL indicates guaranteed monotonicity and code transition accuracy; tighter DNL reduces missing codes and improves resolution performance. |
| Offset Error | ±0.5 LSB typical | ±0.25 LSB typical | Offset error shifts the entire transfer curve; a lower offset improves DC accuracy and reduces the need for system-level calibration. |
| Gain Error | ±1.0 LSB typical | ±0.5 LSB typical | Gain error affects full-scale accuracy; the A-grade's tighter gain specification improves end-point accuracy across the input range. |
| Resolution | 16 bits | 16 bits | Resolution determines the smallest detectable signal change; both parts provide identical 16-bit conversion, so no difference in quantization granularity. |
| Number of Input Channels | 8 (multiplexed) | 8 (multiplexed) | Channel count determines how many analog signals can be sampled; identical channel count means the same system-level multiplexing architecture can be used. |
| Sampling Rate | 250 kSPS | 250 kSPS | Throughput sets the maximum conversion rate; identical sampling rate ensures the same timing and bandwidth budget in the application. |
| Supply Voltage | 2.3 V to 5.5 V | 2.3 V to 5.5 V | Supply range determines compatibility with system rails; identical range allows the same power supply design for either part. |
| Package | 20-Lead LFCSP (4 mm × 4 mm) | 20-Lead LFCSP (4 mm × 4 mm) | Package footprint and thermal characteristics must match for drop-in substitution; identical package enables direct PCB replacement. |
| Operating Temperature Range | −40 °C to +85 °C | −40 °C to +85 °C | Temperature range defines environmental limits; identical ratings mean both parts are suitable for the same operating conditions. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD7689ACPZ | AD7689BCPZ |
|---|---|---|
| Series | PulSAR® | PulSAR® |
| Part Status | Active | Active |
| Number of Bits | 16 | 16 |
| Sampling Rate(Per Second) | 250k | 250k |
| Number of Inputs | 8 | 8 |
| 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 is the difference between the AD7689BCPZ and the AD7689ACPZ?
The AD7689BCPZ and AD7689ACPZ are both 16-bit, 8-channel, 250 kSPS PulSAR analog-to-digital converters in a 20-lead LFCSP package. The primary difference is the grade/performance class designation: the B-grade (AD7689BCPZ) and A-grade (AD7689ACPZ) differ in specified accuracy and linearity parameters per the Analog Devices datasheet. Designers should consult the official AD7689 datasheet for the exact grade-specific specifications before selecting between them.
Are the AD7689BCPZ and AD7689ACPZ pin-compatible?
Yes. Both devices are offered in the same 20-lead LFCSP (CP-20) package with the same pinout, so they are pin-compatible and share the same PCB land pattern. This allows a board designed for one grade to accept the other without layout changes.
Do the AD7689BCPZ and AD7689ACPZ share the same resolution and throughput?
Yes. Both are 16-bit successive-approximation (SAR) ADCs with 8 input channels and a maximum throughput of 250 kSPS, and both support a flexible input configuration (single-ended, differential, and pseudo-differential) as documented in the Analog Devices AD7689 datasheet.
What supply and interface requirements do the AD7689BCPZ and AD7689ACPZ have?
Both devices operate from a single analog supply (typically 5 V, with a separate VIO logic supply) and use a SPI-compatible serial interface for communication with a host controller. Refer to the AD7689 datasheet for the exact supply voltage ranges and timing specifications.
Can the AD7689ACPZ be used as a drop-in replacement for the AD7689BCPZ?
Because both parts are pin-compatible and functionally equivalent 16-bit, 8-channel, 250 kSPS SAR ADCs, the A-grade can generally be substituted for the B-grade on the same board. However, the substitution should be validated against the grade-specific accuracy and linearity specifications in the AD7689 datasheet to confirm the design's performance requirements are met.
Which grade should be selected for a design requiring tighter accuracy?
The grade designation (A vs. B) corresponds to different specified performance levels in the AD7689 datasheet. For applications requiring tighter accuracy or linearity, the designer should compare the grade-specific specifications (such as INL, offset, and gain error) in the official datasheet and select the grade that meets the required error budget.
Are the AD7689BCPZ and AD7689ACPZ RoHS compliant?
Both the AD7689BCPZ and AD7689ACPZ are supplied in the LFCSP package with the "Z" suffix indicating RoHS-compliant, lead-free construction per Analog Devices ordering information. Designers should confirm the compliance status on the official Analog Devices product page or an authorized distributor listing for the specific orderable part number.