Part A
AD7667ASTZ
Công ty Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 6318 PCS
- Package
- LQFP-48
- Series
- Data Acquisition - Analog to Digital Converters (ADC)
Replacement verdict
Compatible functional replacement candidate
The AD7667ASTZ and AD7661AST are both 16-bit successive-approximation ADCs from Analog Devices in the same 48-lead LQFP package, sharing a parallel interface and comparable analog input architecture, making the AD7667ASTZ a viable functional replacement candidate for the AD7661AST in many designs. However, the two devices differ in sample rate, analog input range, and reference configuration, so the replacement should be validated against the specific timing, signal-chain, and accuracy requirements of the target application before adoption.
Resolution and ADC Architecture
High match
Sample Rate
Validation required
Analog Input Range
Validation required
Package and Pin Configuration
High match
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | AD7667ASTZ | AD7661AST | Why it matters |
|---|---|---|---|
| Resolution | 16 bits | 16 bits | Both are 16-bit SAR ADCs, so nominal resolution is equivalent for substitutability. |
| Sampling Rate | 1 MSPS | 100 kSPS | The AD7667 supports much higher throughput, which is critical for fast-sampling applications. |
| Number of Input Channels | 1 (single-ended) | 1 (single-ended) | Both provide a single analog input channel, so channel count is not a differentiator. |
| Input Type | Single-ended | Single-ended | Matching input configuration simplifies direct replacement in single-ended signal chains. |
| Interface | Parallel / Serial (SPI/QSPI/MICROWIRE/DSP) | Parallel / Serial (SPI/QSPI/MICROWIRE/DSP) | Identical digital interface options allow reuse of the same host controller connections. |
| Supply Voltage (Analog) | 5 V | 5 V | Same analog supply simplifies power rail design when swapping parts. |
| Supply Voltage (Digital) | 5 V | 5 V | Matching digital supply ensures logic-level compatibility with the same host interface. |
| Package / Case | 48-LQFP | 48-LQFP | Same package footprint enables drop-in board replacement without layout changes. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Equivalent temperature ratings mean both suit the same industrial environments. |
| Power Consumption | ~87 mW (typical at 1 MSPS) | ~25 mW (typical at 100 kSPS) | The faster AD7667 dissipates more power, which affects thermal and energy budgets. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD7667ASTZ | AD7661AST |
|---|---|---|
| Supplier | - | Rochester Electronics, LLC |
| Series | PulSAR® | PulSAR® |
| Part Status | Active | Obsolete |
| Number of Bits | 16 | 16 |
| Sampling Rate(Per Second) | 1M | 100k |
| Number of A/D Converters | 1 | 1 |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
| Number of Inputs | 1 | - |
| Input Type | Pseudo-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 | 5V | - |
| Voltage - Supply, Digital | 5V | - |
Frequently asked questions
What are the key differences between the AD7667ASTZ and the AD7661AST?
The AD7667ASTZ is a 16-bit, 1 MSPS PulSAR analog-to-digital converter, while the AD7661AST is a 16-bit, 100 kSPS PulSAR ADC. The AD7667ASTZ offers a significantly higher sampling rate (1 MSPS vs. 100 kSPS) and is specified for a different speed grade, making the two devices suited to different throughput requirements rather than being direct drop-in equivalents.
Are the AD7667ASTZ and AD7661AST pin-compatible?
Both devices are offered in a 48-lead LQFP package, and Analog Devices documents them within the same PulSAR family with a common pinout for many pins. However, because the AD7667ASTZ supports a higher sampling rate and different timing specifications, designers must verify the full pin function and timing compatibility against the respective datasheets before considering a board-level substitution.
What is the resolution and architecture of both converters?
Both the AD7667ASTZ and the AD7661AST are 16-bit successive-approximation (SAR) analog-to-digital converters based on Analog Devices' PulSAR architecture, providing no missing codes and high accuracy for precision data acquisition applications.
What are the maximum sampling rates of the AD7667ASTZ and AD7661AST?
The AD7667ASTZ is specified for a maximum throughput of 1 MSPS, whereas the AD7661AST is specified for a maximum throughput of 100 kSPS. The higher throughput of the AD7667ASTZ makes it suitable for faster signal chains, while the AD7661AST targets lower-speed, lower-power precision applications.
Do both parts support the same analog input range and reference configuration?
Both devices are 16-bit PulSAR converters that support a pseudo-differential analog input and an external reference. Because the AD7667ASTZ and AD7661AST are separate speed grades with their own datasheet specifications, the exact input voltage range, reference requirements, and AC/DC performance figures should be confirmed individually from each device's official datasheet before design reuse.
Can the AD7661AST be used as a lower-speed substitute for the AD7667ASTZ?
Substitution is only possible if the system's sampling rate requirement is 100 kSPS or less and all timing, interface, and performance specifications are validated against the AD7661AST datasheet. Because the AD7667ASTZ supports 1 MSPS, replacing it with the 100 kSPS AD7661AST would reduce maximum throughput and must be evaluated against the application's timing budget.
What digital interface do these converters provide?
Both the AD7667ASTZ and AD7661AST are PulSAR-family ADCs that provide a parallel digital output interface with conversion control signals, allowing direct connection to DSPs, FPGAs, and microcontrollers. Designers should confirm the exact interface timing and control signal definitions in each device's datasheet, since the two speed grades have different timing specifications.