Part A
AD7654ASTZ
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 2675 Stückzahl
- Package
- LQFP-48
- Series
- Datenerfassung mit Analog to Digital Converters (ADC)
Replacement verdict
Compatible functional replacement candidate
The AD7654ASTZ and AD7652AST are both 16-bit successive-approximation ADCs from Analog Devices in the same 48-lead LQFP package, sharing a compatible digital interface and reference architecture. The AD7654ASTZ offers a dual simultaneous-sampling front end, while the AD7652AST is a single-channel device, so the AD7654ASTZ can serve as a functional substitute for the AD7652AST in most designs provided the additional channel is unused or beneficial and the slightly higher power consumption is acceptable. Designers should validate the timing and power budget before committing to the replacement.
Resolution and Accuracy
High match
Package Type
High match
Channel Count
Validation required
Power Consumption
Validation required
Parts at a glance
Part B
AD7652AST
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 5054 Stückzahl
- Package
- LQFP-48
- Series
- Datenerfassung mit 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 | AD7654ASTZ | AD7652AST | Why it matters |
|---|---|---|---|
| Number of ADC Inputs / Channels | 2 (dual simultaneous-sampling) | 1 (single channel) | Determines how many signals can be digitized; a dual-channel part cannot be directly substituted where two simultaneous channels are required. |
| Sampling Architecture | Dual SAR, simultaneous sampling | Single SAR | Simultaneous sampling preserves phase relationships between two inputs, which a single-channel sequential converter cannot do. |
| Resolution | 16 bits | 16 bits | Both provide 16-bit resolution, so accuracy class is comparable; resolution alone does not differentiate them. |
| Maximum Throughput (per channel) | 500 kSPS | 500 kSPS | Identical per-channel speed means timing budgets are preserved when swapping, provided channel count matches the application. |
| Input Configuration | Dual pseudo-differential / unipolar or bipolar | Single pseudo-differential / unipolar or bipolar | Input topology must match the sensor or signal chain; a single-input device cannot serve a two-input simultaneous requirement. |
| Package | 48-lead LQFP | 48-lead LQFP | Matching package and footprint simplifies board-level substitution, though pin functions may still differ. |
| Supply Voltage | 5 V analog supply with 2.7 V to 5.25 V digital interface | 5 V analog supply with 2.7 V to 5.25 V digital interface | Compatible supply rails allow reuse of the same power design when substituting. |
| Interface | Parallel and serial (SPI/QSPI/MICROWIRE/DSP) | Parallel and serial (SPI/QSPI/MICROWIRE/DSP) | Identical digital interface options ease host-processor integration and firmware reuse. |
| Internal Reference | Yes, on-chip reference | Yes, on-chip reference | Both include an internal reference, so no external reference redesign is needed for a swap. |
| Functional Role | Dual simultaneous-sampling ADC | Single-channel ADC | The core functional difference: the dual-channel device supports two synchronized inputs, while the single-channel device supports only one, so they are not drop-in substitutes in multi-channel designs. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD7654ASTZ | AD7652AST |
|---|---|---|
| Supplier | - | Rochester Electronics, LLC |
| Series | PulSAR® | PulSAR® |
| Part Status | Active | Obsolete |
| Number of Bits | 16 | 16 |
| Sampling Rate(Per Second) | 500k | 500k |
| Number of A/D Converters | 1 | 1 |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
| Number of Inputs | 2, 4 | - |
| Input Type | Pseudo-Differential, Single Ended | - |
| Data Interface | SPI, Parallel, DSP | - |
| Configuration | MUX-S/H-MUX-ADC | - |
| Ratio - S / H: ADC | 2:1 | - |
| Architecture | SAR | - |
| Reference Type | External | - |
| Voltage - Supply, Analog | 5V | - |
| Voltage - Supply, Digital | 5V | - |
| Features | Simultaneous Sampling | - |
Frequently asked questions
What are the key differences between the AD7654ASTZ and the AD7652AST?
The AD7654ASTZ is a dual, simultaneous-sampling 16-bit SAR ADC with two independent ADCs that sample at the same instant, making it suited to applications requiring phase-coherent acquisition of two channels. The AD7652AST is a single-channel 16-bit SAR ADC. Both are successive-approximation converters, but the AD7654ASTZ provides two simultaneous channels while the AD7652AST provides one channel per package.
Do the AD7654ASTZ and AD7652AST have the same resolution and converter architecture?
Yes. Both devices are 16-bit successive-approximation register (SAR) analog-to-digital converters. The primary architectural distinction is channel count and simultaneous-sampling capability, not resolution or conversion method.
Are the AD7654ASTZ and AD7652AST pin-compatible or package-compatible?
No. The AD7654ASTZ is supplied in a 48-lead LQFP package, while the AD7652AST is supplied in a 48-lead LQFP package as well, but the pin functions differ because the AD7654ASTZ implements two simultaneous-sampling channels and the AD7652AST implements a single channel. Pin assignments and external connections are therefore not interchangeable, and a direct drop-in substitution should not be assumed without verifying pin functions against the respective datasheets.
Can the AD7652AST be used as a substitute for the AD7654ASTZ in an existing design?
Not directly. The AD7654ASTZ provides two simultaneous-sampling channels, whereas the AD7652AST provides a single channel. A design that relies on simultaneous acquisition of two signals cannot be satisfied by a single-channel converter without additional external circuitry and revalidation. Substitution requires confirming channel count, pin functions, timing, and interface compatibility against the manufacturer datasheets.
What is the role of the simultaneous-sampling feature in the AD7654ASTZ?
The AD7654ASTZ contains two independent SAR ADCs that sample their respective inputs at the same instant. This simultaneous sampling preserves the relative phase and timing relationship between two analog signals, which is important in applications such as motor control, power monitoring, and multi-axis sensing where channel-to-channel skew must be minimized.
Do both devices use the same digital interface?
Both the AD7654ASTZ and the AD7652AST provide a parallel digital interface for output data. Because the AD7654ASTZ outputs two channels of conversion results and the AD7652AST outputs one, the data-bus behavior and conversion-result sequencing differ. Interface timing and bus-width details should be confirmed against the respective manufacturer datasheets before designing a common interface.
Are the AD7654ASTZ and AD7652AST available in the same package type?
Both devices are offered in a 48-lead LQFP package. However, identical package outlines do not imply identical pin functions or interchangeable footprints, because the internal channel architecture differs between the two parts. PCB layout and pin connections must follow each device's own datasheet.
Which part should be selected for a single-channel 16-bit acquisition system?
For a single-channel 16-bit SAR acquisition requirement, the AD7652AST is the appropriate choice because it provides one conversion channel. The AD7654ASTZ is intended for applications requiring two simultaneously sampled channels. Selection should be based on channel count, simultaneous-sampling needs, and interface requirements verified from the manufacturer datasheets.