Part A
ADS8568SPM
Texas Instruments
- Lifecycle
- Active
- Stock
- 3952 PCS
- Package
- LQFP-64
- Series
- Data Acquisition - Analog to Digital Converters (ADC)
Replacement verdict
Compatible functional replacement candidate
The ADS8568SPM is a strong functional replacement candidate for the ADS8556IPMR, sharing the same 16-bit SAR architecture, 8-channel simultaneous-sampling input structure, and comparable SPI interface, while offering a higher per-channel throughput. Designers should validate the package footprint, reference and supply configuration, and full-scale input range against the target board before committing to the substitution.
Resolution and Architecture
High match
Channel Count and Input Configuration
High match
Package and Pinout
Validation required
Supply and Reference Requirements
Validation required
Parts at a glance
Part B
ADS8556IPMR
Texas Instruments
- Lifecycle
- Active
- Stock
- 2848 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 | ADS8568SPM | Why it matters |
|---|---|---|---|
| Resolution | 16 bit | 16 bit | Both are 16-bit SAR ADCs, so nominal resolution is equivalent for substitutability. |
| Number of Input Channels | 6 single-ended / 3 differential | 8 single-ended / 4 differential | Channel count determines how many signals can be sampled; the ADS8568 offers two additional channels. |
| Sampling Rate | 630 kSPS | 510 kSPS | Maximum throughput affects achievable signal bandwidth and timing margin in the application. |
| Input Voltage Range | ±10 V (bipolar, configurable) | ±10 V (bipolar, configurable) | Matching input ranges allow direct substitution without front-end signal conditioning changes. |
| Supply Voltage | 5 V analog (AVDD), 2.7–5.5 V digital (DVDD) | 5 V analog (AVDD), 2.7–5.5 V digital (DVDD) | Compatible supply rails simplify board-level replacement and power design reuse. |
| Interface | Parallel / Serial (SPI-compatible) | Parallel / Serial (SPI-compatible) | Same interface options allow the host controller connection to remain unchanged. |
| Package | 64-pin LQFP (PM) | 64-pin LQFP (PM) | Identical package and pinout enable drop-in PCB compatibility. |
| Operating Temperature Range | -40 °C to +125 °C | -40 °C to +125 °C | Equivalent temperature ratings ensure the same environmental robustness in industrial applications. |
| INL (Integral Nonlinearity) | ±1.5 LSB (typ) | ±1.5 LSB (typ) | Matching linearity performance means comparable measurement accuracy after substitution. |
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Send your BOM and application constraints for technical and sourcing review.
Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADS8568SPM | ADS8556IPMR |
|---|---|---|
| Part Status | Active | Active |
| Number of Bits | 16 | 16 |
| Sampling Rate(Per Second) | 500k | 630k |
| Number of Inputs | 8 | 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 ~ 5.5V | 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 ADS8556IPMR and ADS8568SPM?
The ADS8556IPMR is a 16-bit, 6-channel simultaneous-sampling SAR ADC in a TQFP-64 package, while the ADS8568SPM is a 16-bit, 8-channel simultaneous-sampling SAR ADC in a TQFP-64 package. The primary differences are channel count (6 vs 8) and the specified operating temperature range (ADS8556IPMR is rated -40°C to +125°C; ADS8568SPM is rated -40°C to +125°C per the respective datasheets). Both share the same 16-bit resolution, simultaneous-sampling architecture, and parallel/serial interface family.
Are the ADS8556IPMR and ADS8568SPM pin-compatible?
No. Although both devices are offered in a 64-pin TQFP package, the ADS8556IPMR provides 6 analog input channels and the ADS8568SPM provides 8 analog input channels, so the analog input pin assignments and channel-related pins differ. A direct drop-in replacement is not supported; the PCB layout and pin connections must be reviewed against each device's datasheet.
Do both devices support simultaneous sampling of all channels?
Yes. Both the ADS8556IPMR and ADS8568SPM are simultaneous-sampling SAR ADCs, meaning all analog input channels are sampled at the same instant. This preserves phase relationships between channels, which is important for motor control, power monitoring, and multi-phase measurement applications.
What is the resolution and sample rate of these ADCs?
Both the ADS8556IPMR and ADS8568SPM are 16-bit successive-approximation register (SAR) ADCs. The ADS8556 supports up to 630 kSPS per channel, and the ADS8568 supports up to 510 kSPS per channel, per the respective Texas Instruments datasheets. Designers should confirm the exact throughput grade against the specific orderable part number.
What analog input voltage range do these devices support?
Both devices support bipolar analog input ranges of ±10 V, ±5 V, and ±2.5 V, configurable via the input range control pins. This makes them suitable for industrial signal chains that require direct interfacing with ±10 V sensors and control-loop signals without external level shifting.
What digital interfaces are available on the ADS8556IPMR and ADS8568SPM?
Both devices provide a flexible digital interface supporting parallel word/byte modes and serial SPI-compatible modes. The interface selection is configured via dedicated control pins, allowing the same device family to be used with parallel-bus host processors or serial-interface microcontrollers.
What are the typical applications for these simultaneous-sampling ADCs?
Typical applications include industrial motor control, servo drives, power quality and energy monitoring, multi-phase power measurement, and protection relays. The simultaneous sampling of 6 or 8 channels supports current and voltage sensing across multiple phases in a single conversion cycle.
What package and operating temperature range do these devices offer?
Both the ADS8556IPMR and ADS8568SPM are supplied in a 64-pin TQFP package. The ADS8556IPMR is specified over the -40°C to +125°C industrial temperature range, and the ADS8568SPM is specified over the -40°C to +125°C range per the Texas Instruments datasheets. Designers should verify the exact temperature grade for the specific orderable part number.