Part A
ADS8556IPMR
Texas Instruments
- Lifecycle
- Active
- Stock
- 2848 PCS
- Package
- LQFP-64
- Series
- Data Acquisition - Analog to Digital Converters (ADC)
Replacement verdict
Compatible functional replacement candidate
The ADS8556IPMR and ADS8555SPM are both 16-bit, 6-channel, simultaneous-sampling SAR ADCs from Texas Instruments with matching resolution, channel count, and serial interface architecture, making the ADS8555SPM a viable functional replacement candidate for the ADS8556IPMR. Designers should validate the reduced maximum sampling rate, narrower analog input range, and the extended temperature grade before committing to substitution in the target application.
Resolution and Channel Count
High match
Maximum Sampling Rate
Validation required
Analog Input Range
Validation required
Package and Pin Configuration
High match
Parts at a glance
Part B
ADS8555SPM
Texas Instruments
- Lifecycle
- Active
- Stock
- 8068 PCS
- Package
- LQFP-64
- Series
- Data Acquisition - 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 | ADS8556IPMR | ADS8555SPM | Why it matters |
|---|---|---|---|
| Resolution | 16 bit | 16 bit | Both converters provide the same 16-bit resolution, so measurement precision is equivalent. |
| Number of ADC Inputs / Channels | 6 single-ended (or 3 differential) | 6 single-ended (or 3 differential) | Identical channel count and configuration allow the same sensor front-end to be reused. |
| Sampling Rate (Max) | 630 kSPS | 630 kSPS | Same maximum throughput means timing and bandwidth budgets remain unchanged. |
| Input Type | Single-ended / Differential (pseudo-differential) | Single-ended / Differential (pseudo-differential) | Matching input topologies ensure the same signal conditioning and wiring can be used. |
| Supply Voltage (Analog) | 5 V (4.5 V to 5.5 V) | 5 V (4.5 V to 5.5 V) | Same analog supply range allows the existing power rail design to be retained. |
| Interface | Parallel / Serial (SPI-compatible) | Parallel / Serial (SPI-compatible) | Identical digital interfaces permit drop-in replacement without firmware or layout changes. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +125 °C | The wider temperature range of the ADS8555SPM suits harsher environments, while the ADS8556IPMR is limited to industrial-grade conditions. |
| Package / Mounting | 64-LQFP (10x10), Surface Mount | 64-LQFP (10x10), Surface Mount | Both use the same 64-pin LQFP footprint, so PCB layout is compatible; the difference is in the qualified grade/ordering variant. |
| Product Grade / Qualification | Industrial grade (I) | Enhanced/automotive-grade (S) | The grade suffix indicates different qualification and reliability levels, affecting suitability for automotive or high-reliability applications. |
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 | ADS8556IPMR | ADS8555SPM |
|---|---|---|
| Supplier | - | Rochester Electronics, LLC,Texas Instruments |
| Part Status | Active | Active |
| Number of Bits | 16 | 16 |
| Sampling Rate(Per Second) | 630k | 630k |
| Number of Inputs | 6 | 6 |
| Input Type | Single Ended | Single Ended |
| Data Interface | SPI, Parallel | SPI, Parallel |
| Configuration | S/H-ADC | S/H-ADC |
| Ratio - S / H: ADC | 1:1 | 1:1 |
| Number of A/D Converters | 1 | 1 |
| Architecture | SAR | SAR |
| Reference Type | External, Internal | External, Internal |
| Voltage - Supply, Analog | 5V | 5V |
| Voltage - Supply, Digital | 2.7V ~ 3.6V, 5V | 2.7V ~ 3.6V, 5V |
| Features | Simultaneous Sampling | Simultaneous Sampling |
| Operating Temperature | -40°C ~ 125°C | -40°C ~ 125°C |
Frequently asked questions
What are the primary differences between the ADS8556IPMR and the ADS8555SPM?
The ADS8556IPMR is a 16-bit, 6-channel simultaneous-sampling SAR ADC specified for operation from -40°C to +125°C and supplied in a 64-pin LQFP (PM) package. The ADS8555SPM is a 16-bit, 6-channel simultaneous-sampling SAR ADC specified for operation from -40°C to +125°C and supplied in a 64-pin LQFP (PM) package, with the "S" designation indicating an enhanced automotive-qualified variant per the datasheet ordering information. Both share the same 6-channel simultaneous-sampling architecture and 16-bit resolution, but the ADS8555SPM is the automotive-qualified grade.
Are the ADS8556IPMR and ADS8555SPM pin-compatible?
Yes. Both devices are offered in the same 64-pin LQFP (PM) package with the same pinout as defined in the respective Texas Instruments datasheets, so they are pin-compatible when both are in the PM package option.
Do the ADS8556IPMR and ADS8555SPM have the same resolution and channel count?
Yes. Both are 16-bit successive-approximation register (SAR) ADCs with six simultaneously sampled input channels, as specified in the Texas Instruments datasheets for both devices.
What is the maximum sample rate of these ADCs?
Both the ADS8556IPMR and ADS8555SPM support a maximum throughput of 500 kSPS per channel in parallel interface mode, per the Texas Instruments datasheet specifications.
What analog input voltage range do the ADS8556IPMR and ADS8555SPM support?
Both devices support software-selectable analog input ranges of ±10 V, ±5 V, and ±2.5 V (with a 0 to 5 V range also available depending on configuration), as defined in the Texas Instruments datasheets.
What supply voltages do the ADS8556IPMR and ADS8555SPM require?
Both devices operate from an analog supply (AVDD) of 5 V and a digital supply (DVDD) of 2.7 V to 5.25 V, with a separate buffer supply (BVDD) of 5 V for the analog input range, per the Texas Instruments datasheet electrical characteristics.
What is the operating temperature range for each device?
The ADS8556IPMR is specified over the -40°C to +125°C industrial temperature range. The ADS8555SPM is specified over the -40°C to +125°C range as an automotive-qualified device per the Texas Instruments ordering information.
Can the ADS8555SPM be used as a drop-in replacement for the ADS8556IPMR in an existing design?
Because both devices share the same 64-pin LQFP (PM) package, pinout, resolution, channel count, and core specifications, the ADS8555SPM can generally serve as a drop-in replacement for the ADS8556IPMR provided the design's qualification requirements accept the automotive-qualified grade. Final validation against the specific datasheet and application requirements is recommended.