Part A
ADS8555SPMR
Texas Instruments
- Lifecycle
- Active
- Stock
- 2733 PCS
- Package
- LQFP-64
- Series
- Data Acquisition - Analog to Digital Converters (ADC)
Replacement verdict
Compatible functional replacement candidate
The ADS8555SPMR is a strong functional replacement candidate for the ADS8556IPM, sharing the same 16-bit SAR architecture, six simultaneous-sampling channels, and ±10 V input range. The primary distinction is the serial interface configuration, which requires validation against the host controller before substitution. Package footprint and channel count align, supporting a straightforward board-level swap once the interface compatibility is confirmed.
Channel Count
High match
Package Type
High match
Input Voltage Range
High match
Serial Interface
Validation required
Parts at a glance
Part B
ADS8556IPM
Texas Instruments
- Lifecycle
- Active
- Stock
- 6944 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 | ADS8556IPM | ADS8555SPMR | Why it matters |
|---|---|---|---|
| Resolution | 16 bit | 16 bit | Both are 16-bit SAR ADCs, so nominal resolution is identical and not a differentiator for substitutability. |
| Number of Input Channels | 6 single-ended / 3 differential | 6 single-ended / 3 differential | Channel count and configuration determine how many signals can be sampled simultaneously, which is critical for multi-axis or multi-phase applications. |
| Sampling Rate (max) | 630 kSPS | 630 kSPS | Maximum throughput affects achievable signal bandwidth and control-loop update rate; identical rates mean equivalent timing performance. |
| Supply Voltage (Analog) | 5 V (4.5 V to 5.5 V) | 5 V (4.5 V to 5.5 V) | Analog supply range must match the system rail; identical ranges allow drop-in replacement without power redesign. |
| Digital Interface Supply | 2.7 V to 5.5 V | 2.7 V to 5.5 V | Flexible digital I/O voltage enables direct connection to 3.3 V or 5 V logic; matching ranges preserve host compatibility. |
| Interface Type | Parallel / Serial (SPI) | Parallel / Serial (SPI) | Interface options determine how the ADC connects to the host processor; identical options mean the same firmware and PCB routing can be reused. |
| Package | 64-pin LQFP (PM) | 64-pin LQFP (PM) | Package and pinout must match for physical board compatibility; identical LQFP-64 packages allow the same footprint. |
| Operating Temperature Range | -40 °C to +125 °C | -40 °C to +125 °C | Temperature range determines suitability for industrial and automotive environments; matching ranges preserve application scope. |
| INL (Integral Nonlinearity) | ±1.5 LSB (typ) | ±1.5 LSB (typ) | INL defines DC accuracy; identical typical values indicate comparable measurement precision for control and instrumentation use. |
| Power Consumption | ~250 mW (typ, 5 V) | ~250 mW (typ, 5 V) | Power draw affects thermal design and supply sizing; comparable consumption means no change to power budget when substituting. |
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 | ADS8555SPMR | ADS8556IPM |
|---|---|---|
| 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 key differences between the ADS8556IPM and ADS8555SPMR?
The ADS8556IPM is a 16-bit, 6-channel simultaneous-sampling SAR ADC in a 64-pin LQFP package (PM suffix), specified over the industrial temperature range of –40°C to +125°C. The ADS8555SPMR is a 16-bit, 6-channel simultaneous-sampling SAR ADC in a 64-pin LQFP package (PM suffix) specified over the –40°C to +125°C range as well, but the "S" designator denotes the enhanced automotive-qualified version per the datasheet ordering options. Both share the same 6-channel simultaneous-sampling architecture, ±10 V input range capability, and parallel/serial interface, but the ADS8555SPMR carries automotive qualification while the ADS8556IPM is the industrial-grade variant.
Are the ADS8556IPM and ADS8555SPMR pin-compatible?
Yes. Both devices are offered in the same 64-pin LQFP (PM) package with identical pin functions as defined in the respective Texas Instruments datasheets, so they are pin-compatible when the package suffix matches.
Do both parts offer the same resolution and channel count?
Yes. Both the ADS8556IPM and ADS8555SPMR are 16-bit, 6-channel simultaneous-sampling SAR analog-to-digital converters, providing six independent sample-and-hold circuits that sample all channels at the same instant.
What is the maximum sampling rate of these ADCs?
Both devices support a maximum throughput of 630 kSPS per channel in parallel interface mode, as specified in the Texas Instruments datasheet for the ADS8556/ADS8555 family.
What input voltage range do the ADS8556IPM and ADS8555SPMR support?
Both parts support bipolar input ranges of ±10 V, ±5 V, and 0 V to 10 V (with the appropriate reference and configuration), making them suitable for industrial and automotive signal acquisition.
What supply voltages are required for these converters?
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 an additional 5 V supply for the input buffer/driver stage, per the Texas Instruments datasheet.
Can the ADS8555SPMR be used as a drop-in replacement for the ADS8556IPM in an existing design?
Because both share the same 64-pin LQFP package, pinout, resolution, channel count, and interface, the ADS8555SPMR can generally serve as a drop-in replacement for the ADS8556IPM provided the design's qualification requirements accept the automotive-grade variant and all timing and supply conditions are verified against the datasheet.
What interface options do these ADCs provide?
Both the ADS8556IPM and ADS8555SPMR provide a flexible parallel interface (16-bit or 8-bit) and a serial interface (SPI-compatible) for connection to host processors and FPGAs, as documented in the Texas Instruments datasheet.