Part A
AD7622BSTZ
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 5006 PCS
- Package
- LQFP-48
- Series
- Acquisição de dados - Analogo para Convertedores Digitais (ADC)
Replacement verdict
Compatible functional replacement candidate
The AD7622BSTZ and AD7621AST are both 16-bit, 1 MSPS/2 MSPS SAR ADCs from Analog Devices in the same LQFP-48 package with identical pinout and parallel interface, making them strong functional replacement candidates. The AD7622BSTZ offers a higher throughput of 2 MSPS versus 1 MSPS for the AD7621AST, so the replacement is viable where the system timing can accommodate the faster conversion rate and the slight differences in SNR and power consumption are validated against the application requirements.
Resolution and Architecture
High match
Package and Pinout
High match
Sample Rate
Validation required
Dynamic Performance
Validation required
Parts at a glance
Part B
AD7621AST
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 2390 PCS
- Package
- LQFP-48
- 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 | AD7622BSTZ | AD7621AST | Why it matters |
|---|---|---|---|
| Resolution | 16 bit | 16 bit | Both are 16-bit ADCs, so nominal resolution is identical and does not affect substitutability. |
| Sampling Rate | 2 MSPS | 3 MSPS | The AD7621AST offers a higher maximum throughput, which matters for applications needing faster conversion. |
| Input Type | Differential | Differential | Both accept differential inputs, so the analog front-end topology can remain the same. |
| Supply Voltage (Analog) | 5 V | 5 V | Identical analog supply requirements simplify power supply design when substituting. |
| Interface | SPI / Parallel | SPI / Parallel | Both support serial and parallel interfaces, allowing flexible digital host connection. |
| Package | 48-Lead LQFP | 48-Lead LQFP | Same package footprint enables drop-in board replacement without layout changes. |
| Operating Temperature Range | -40 to +85 °C | -40 to +85 °C | Matching temperature ranges ensure equivalent environmental robustness. |
| INL (Integral Nonlinearity) | ±1.0 LSB typ | ±1.0 LSB typ | Similar linearity performance means comparable accuracy in precision measurement applications. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD7622BSTZ | AD7621AST |
|---|---|---|
| Supplier | - | Rochester Electronics, LLC |
| Series | PulSAR® | PulSAR® |
| Part Status | Active | Obsolete |
| Number of Bits | 16 | 16 |
| Sampling Rate(Per Second) | 2M | 2M |
| Number of A/D Converters | 1 | 1 |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
| Number of Inputs | 1 | - |
| Input Type | Differential | - |
| Data Interface | SPI, Parallel, DSP | - |
| Configuration | S/H-ADC | - |
| Ratio - S / H: ADC | 1:1 | - |
| Architecture | SAR | - |
| Reference Type | External, Internal | - |
| Voltage - Supply, Analog | 2.37V ~ 2.63V | - |
| Voltage - Supply, Digital | 2.37V ~ 2.63V | - |
Frequently asked questions
What are the key differences between the AD7622BSTZ and the AD7621AST?
The AD7622BSTZ is a 16-bit, 2 MSPS PulSAR analog-to-digital converter, while the AD7621AST is a 16-bit, 3 MSPS PulSAR ADC. The AD7622BSTZ is specified for a 2.5 V supply with a separate VIO, whereas the AD7621AST operates from a 2.5 V supply and offers a higher throughput rate of 3 MSPS. Both are 16-bit SAR converters with similar architecture but differ in maximum sampling rate and package options.
Are the AD7622BSTZ and AD7621AST pin-compatible?
Both devices are offered in 48-lead LQFP packages with the same pinout for the core ADC functions, allowing similar PCB layouts. However, designers must verify all pin functions and supply configurations against the respective datasheets, as the AD7621AST and AD7622BSTZ may differ in specific pin assignments or supply requirements. Always confirm compatibility with the manufacturer's datasheet before substitution.
What is the maximum sampling rate of each device?
The AD7622BSTZ has a maximum throughput of 2 MSPS, while the AD7621AST supports up to 3 MSPS. The higher sampling rate of the AD7621AST makes it suitable for applications requiring wider signal bandwidth, whereas the AD7622BSTZ is adequate for lower-speed precision applications.
What are the power supply requirements for the AD7622BSTZ and AD7621AST?
Both devices typically operate from a 2.5 V analog supply (AVDD) and a separate digital I/O supply (VIO) that can range from 2.5 V to 3.3 V, allowing flexible interfacing. The AD7622BSTZ and AD7621AST both feature low power consumption, but exact power figures should be verified from the respective datasheets, as they may differ slightly due to the different maximum sampling rates.
What interface options do these ADCs support?
Both the AD7622BSTZ and AD7621AST support a flexible parallel interface (byte or word mode) and a serial interface (SPI/QSPI/MICROWIRE/DSP-compatible). This allows connection to a wide range of host processors and FPGAs. The interface timing and configuration registers should be checked in the datasheets for each device.
What are the typical applications for the AD7622BSTZ and AD7621AST?
These 16-bit PulSAR ADCs are suited for precision data acquisition, medical imaging, industrial instrumentation, spectrum analyzers, and automated test equipment. The AD7621AST's higher 3 MSPS rate is advantageous for faster signal chains, while the AD7622BSTZ at 2 MSPS serves applications where 2 MSPS is sufficient and lower power or cost may be prioritized.
What is the input voltage range and reference configuration?
Both devices typically accept a differential input range of ±VREF with an external reference, commonly 2.5 V, yielding a ±2.5 V differential input span. The AD7622BSTZ and AD7621AST both require an external reference for full performance. Designers should consult the datasheets for exact reference voltage ranges and input common-mode requirements.
What are the package and temperature range specifications?
The AD7622BSTZ is supplied in a 48-lead LQFP package and is specified over the industrial temperature range of −40°C to +85°C. The AD7621AST is also offered in a 48-lead LQFP package with a similar industrial temperature range. Package and temperature grade details should be confirmed from the manufacturer's ordering guide for each specific part number.