Part A
AD7656YSTZ
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 7772 PCS
- Package
- LQFP-64
- Series
- Acquisição de dados - Analogo para Convertedores Digitais (ADC)
Replacement verdict
Compatible functional replacement candidate
The AD7656BSTZ and AD7656YSTZ are functionally equivalent 16-bit, 6-channel simultaneous-sampling bipolar SAR ADCs in the same 64-lead LQFP package, differing only in specified temperature grade and correspondingly in some dynamic performance limits. The AD7656YSTZ is a valid functional replacement candidate for the AD7656BSTZ, provided the target application's operating temperature range and AC performance requirements are validated against the Y-grade specifications.
Package Type
High match
Resolution and Channel Count
High match
Operating Temperature Range
Validation required
Dynamic Performance
Validation required
Parts at a glance
Part B
AD7656BSTZ
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 3438 PCS
- Package
- LQFP-64
- 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 | AD7656BSTZ | AD7656YSTZ | Why it matters |
|---|---|---|---|
| Operating Temperature Range | -40°C to +85°C | -40°C to +125°C | The YSTZ grade supports a wider industrial temperature range, making it suitable for harsher environments where the BSTZ grade may not be rated. |
| Resolution | 16 bits | 16 bits | Both parts provide identical 16-bit resolution, so conversion accuracy and dynamic range are equivalent. |
| Number of ADC Channels | 6 (simultaneous sampling) | 6 (simultaneous sampling) | Identical channel count and simultaneous sampling architecture allow direct functional substitution in multi-phase measurement systems. |
| Sampling Rate | 250 kSPS | 250 kSPS | Matching throughput ensures the same signal bandwidth and timing performance in the target application. |
| Supply Voltage | 5 V analog (AVCC), 5 V digital (DVCC) | 5 V analog (AVCC), 5 V digital (DVCC) | Identical supply requirements mean the same power design and decoupling can be reused without modification. |
| Package / Mounting | 64-lead LQFP | 64-lead LQFP | Same package and footprint allow drop-in board replacement without layout changes. |
| Interface Type | Parallel / Serial (SPI-compatible) | Parallel / Serial (SPI-compatible) | Identical digital interface options ensure firmware and host-controller connections remain compatible. |
| Input Type | Bipolar, true differential | Bipolar, true differential | Same input configuration preserves signal conditioning design and measurement accuracy for bipolar signals. |
| Internal Reference | Yes (2.5 V) | Yes (2.5 V) | Both include an on-chip 2.5 V reference, so external reference circuitry is not required for either part. |
Need help validating a replacement?
Send your BOM and application constraints for technical and sourcing review.
Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD7656YSTZ | AD7656BSTZ |
|---|---|---|
| Series | iCMOS® | iCMOS® |
| Part Status | Active | Active |
| Number of Bits | 16 | 16 |
| Sampling Rate(Per Second) | 250k | 250k |
| Number of Inputs | 6 | 6 |
| Input Type | Single Ended | Single Ended |
| Data Interface | SPI, Parallel, DSP | SPI, Parallel, DSP |
| Configuration | S/H-ADC | S/H-ADC |
| Ratio - S / H: ADC | 1:1 | 1:1 |
| Number of A/D Converters | 6 | 6 |
| Architecture | SAR | SAR |
| Reference Type | External, Internal | External, Internal |
| Voltage - Supply, Analog | 5V | 5V |
| Voltage - Supply, Digital | 5V | 5V |
| Features | Simultaneous Sampling, True Bipolar | Simultaneous Sampling, True Bipolar |
| Operating Temperature | -40°C ~ 125°C | -40°C ~ 85°C |
Frequently asked questions
What are the key differences between the AD7656BSTZ and AD7656YSTZ?
Both are 6-channel, 16-bit, 250 kSPS bipolar SAR ADCs from Analog Devices in a 64-lead LQFP package. The primary difference is the operating temperature range: the AD7656BSTZ is specified for 0°C to +70°C, while the AD7656YSTZ is specified for −40°C to +125°C. The YSTZ is the extended-temperature grade suitable for industrial and automotive environments.
Are the AD7656BSTZ and AD7656YSTZ pin-compatible?
Yes. Both devices are offered in the same 64-lead LQFP (ST-64-2) package with identical pin assignments, so they are pin-compatible and share the same PCB footprint and land pattern.
Can the AD7656BSTZ be used as a drop-in replacement for the AD7656YSTZ?
Electrically and mechanically they are interchangeable, but the AD7656BSTZ is only rated for 0°C to +70°C. It should not be substituted for the YSTZ in applications that require operation below 0°C or above +70°C. Substitution is acceptable only when the system's ambient and junction temperatures remain within the BSTZ's specified range.
What are the resolution and throughput specifications of these ADCs?
Both the AD7656BSTZ and AD7656YSTZ are 16-bit successive-approximation ADCs with six independent simultaneous-sampling channels and a maximum throughput of 250 kSPS per channel. They feature true bipolar input ranges of ±10 V, ±5 V, and ±2.5 V.
What supply voltages and interfaces do the AD7656BSTZ and AD7656YSTZ require?
Both devices operate from a 5 V analog supply (AVCC), a 5 V digital supply (DVCC), and dual ±5 V to ±16.5 V supplies (VDD/VSS) for the bipolar input range. They provide a parallel interface and a serial (SPI/QSPI/MICROWIRE/DSP-compatible) interface, plus a high-speed parallel interface option.
Do the AD7656BSTZ and AD7656YSTZ differ in power consumption or accuracy?
No. Both grades share the same datasheet electrical characteristics, including typical power dissipation of approximately 160 mW at 250 kSPS and the same linearity, offset, and gain specifications. The only specified difference between the B and Y grades is the operating temperature range.
Which grade should be selected for industrial or outdoor applications?
The AD7656YSTZ should be selected for industrial, outdoor, or automotive applications because its −40°C to +125°C temperature range covers harsh environments. The AD7656BSTZ is intended for commercial 0°C to +70°C environments such as benchtop instrumentation and consumer equipment.