Part A
AD7655ASTZRL
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 1730 PCS
- Package
- LQFP-48
- Series
- Acquisição de dados - Analogo para Convertedores Digitais (ADC)
Replacement verdict
Compatible functional replacement candidate
The AD7655ASTZRL and AD7653ASTZRL share the same LQFP-48 footprint, 16-bit SAR architecture, and serial/parallel interface family, making them viable functional replacement candidates in many designs. However, the AD7655 provides four simultaneous-sampling channels versus a single channel on the AD7653, and the two devices differ in throughput rate and analog input configuration. Engineers should validate channel-count requirements, sampling rate headroom, and input range compatibility before substituting one for the other in a given application.
Package Type
High match
Resolution
High match
Channel Count
Validation required
Sampling Rate
Validation required
Parts at a glance
Part B
AD7653ASTZRL
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 7144 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 | AD7655ASTZRL | AD7653ASTZRL | Why it matters |
|---|---|---|---|
| Number of ADC Channels | 2 (simultaneous sampling) | 1 | Determines how many analog signals can be digitized; the AD7655 supports two simultaneous channels while the AD7653 is single-channel, affecting system architecture and channel count. |
| Resolution | 16 bits | 16 bits | Both provide 16-bit resolution, so dynamic range and quantization granularity are equivalent for precision measurement applications. |
| Sampling Rate | 1 MSPS | 1 MSPS | Identical throughput of 1 MSPS means both can handle the same signal bandwidth and update rates in the target application. |
| Input Configuration | 4-channel, 2 simultaneous SAR | Single-channel SAR | The AD7655 offers multi-channel simultaneous sampling, enabling phase-coherent acquisition, whereas the AD7653 is limited to one channel at a time. |
| Interface Type | Parallel / Serial (SPI/QSPI/MICROWIRE/DSP) | Parallel / Serial (SPI/QSPI/MICROWIRE/DSP) | Both support flexible parallel and serial interfaces, allowing drop-in compatibility with common microcontrollers and DSPs. |
| Supply Voltage | 5 V analog, 2.7–5.25 V digital | 5 V analog, 2.7–5.25 V digital | Matching supply requirements simplify power supply design and allow the parts to share the same rail configuration. |
| Package | 48-lead LQFP | 48-lead LQFP | Identical package and pin count support the same PCB footprint, though pinout differences must be verified before substitution. |
| Power Consumption | ~120 mW typical | ~120 mW typical | Comparable power draw means thermal and supply budgeting remain similar between the two devices. |
| Operating Temperature Range | -40°C to +85°C | -40°C to +85°C | Same industrial temperature range ensures both parts suit the same environmental conditions. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD7655ASTZRL | AD7653ASTZRL |
|---|---|---|
| Supplier | - | Analog Devices Inc. |
| Series | PulSAR® | PulSAR® |
| Part Status | Active | Obsolete |
| Number of Bits | 16 | 16 |
| Sampling Rate(Per Second) | 1M | 1M |
| Number of Inputs | 2, 4 | 1 |
| Input Type | Pseudo-Differential, Single Ended | Pseudo-Differential |
| Data Interface | SPI, Parallel, DSP | SPI, Parallel, DSP |
| Configuration | MUX-S/H-MUX-ADC | S/H-ADC |
| Ratio - S / H: ADC | 2:1 | 1:1 |
| Number of A/D Converters | 1 | 1 |
| Architecture | SAR | SAR |
| Reference Type | External | External, Internal |
| Voltage - Supply, Analog | 5V | 5V |
| Voltage - Supply, Digital | 5V | 5V |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
| Features | Simultaneous Sampling | - |
Frequently asked questions
What are the key architectural differences between the AD7655ASTZRL and the AD7653ASTZRL?
The AD7655ASTZRL is a 16-bit, 1 MSPS, dual-channel simultaneous-sampling successive-approximation (SAR) ADC with two independent track-and-hold amplifiers, while the AD7653ASTZRL is a 16-bit, 1 MSPS, single-channel SAR ADC with one track-and-hold amplifier. The AD7655 provides two simultaneous conversion results per conversion cycle, whereas the AD7653 provides a single conversion result per cycle.
Are the AD7655ASTZRL and AD7653ASTZRL pin-compatible?
No. Although both devices are offered in a 48-lead LQFP package, their pin functions differ because the AD7655 provides two analog input channels and two track-and-hold circuits, while the AD7653 provides a single analog input channel. The pinouts are not interchangeable, and each device must be laid out according to its own datasheet pin configuration.
Do both devices support the same digital interface?
Both the AD7655ASTZRL and AD7653ASTZRL provide a parallel digital interface for reading conversion results and support serial interface operation via the SER/PAR configuration. The AD7655 outputs two 16-bit conversion results per cycle (one per channel), while the AD7653 outputs a single 16-bit result per conversion. Interface timing and data-word framing should be verified against each device's respective datasheet.
Can the AD7653ASTZRL be used as a drop-in replacement for the AD7655ASTZRL in an existing design?
No. The AD7653ASTZRL is a single-channel ADC, whereas the AD7655ASTZRL is a dual-channel simultaneous-sampling ADC. A design requiring two simultaneously sampled channels cannot use the AD7653 without adding an external multiplexer or second ADC, and the differing pinouts and channel architecture prevent a direct drop-in replacement.
What are the analog input voltage ranges for these two ADCs?
Both the AD7655ASTZRL and AD7653ASTZRL support a 0 V to 5 V unipolar analog input range and a ±10 V bipolar analog input range, configurable via the device's input range selection. The AD7655 applies this range to each of its two input channels, while the AD7653 applies it to its single input channel. Refer to the respective datasheets for the exact configuration pin settings.
Do both parts operate from the same supply voltages?
Yes. Both the AD7655ASTZRL and AD7653ASTZRL operate from a 5 V analog supply (AVDD) and a 5 V digital supply (DVDD), with a separate VDRIVE supply for the digital I/O interface. Both devices also require an external reference voltage. Designers should confirm the exact supply and reference requirements in each device's datasheet.
Which device should be selected for applications requiring simultaneous sampling of two signals?
The AD7655ASTZRL should be selected when two channels must be sampled simultaneously, since it integrates two independent track-and-hold amplifiers and performs simultaneous conversions on both channels. The AD7653ASTZRL, being a single-channel ADC, cannot sample two channels simultaneously without external signal conditioning or additional conversion stages.
Are both devices specified for the same operating temperature range?
Both the AD7655ASTZRL and AD7653ASTZRL are specified for the industrial temperature range of −40°C to +85°C. The "ASTZ" suffix in both part numbers denotes the industrial temperature grade in the 48-lead LQFP package. Confirm the exact grade and package designation in the manufacturer's ordering guide before finalizing a design.