Part A
ADS8568SPMR
Техасские инструменты
- Lifecycle
- Active
- Stock
- 7064 ПКС
- Package
- LQFP-64
- Series
- Сбор данных - аналогово-цифровые преобразователи (ADC)
Replacement verdict
Compatible functional replacement candidate
The ADS8568SPMR is a strong functional replacement candidate for the ADS8556IPM, sharing the same 16-bit SAR architecture, 6 simultaneous-sampling channels, and identical 64-pin LQFP footprint. Designers should validate the ±12 V input range and the 510 kSPS aggregate throughput against the original ±10 V and 630 kSPS requirements before committing to production.
Resolution and Channel Count
High match
Package and Pinout
High match
Analog Input Range
Validation required
Sampling Throughput
Validation required
Parts at a glance
Part B
ADS8556IPM
Техасские инструменты
- Lifecycle
- Active
- Stock
- 6944 ПКС
- Package
- LQFP-64
- Series
- Сбор данных - аналогово-цифровые преобразователи (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 | ADS8568SPMR | Why it matters |
|---|---|---|---|
| Resolution | 16 bit | 16 bit | Both are 16-bit SAR ADCs, so resolution is equivalent and not a differentiator 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, which affects system architecture and PCB layout. |
| Sampling Rate (max) | 630 kSPS | 500 kSPS | Maximum throughput affects achievable signal bandwidth and timing margin; the ADS8556 supports a higher sample rate. |
| Input Voltage Range | ±10 V (bipolar, configurable) | ±10 V (bipolar, configurable) | Both support wide bipolar input ranges, allowing direct connection to industrial-level signals without external conditioning. |
| 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 drop-in replacement and power supply design. |
| Interface Type | Parallel / Serial (SPI-compatible) | Parallel / Serial (SPI-compatible) | Both offer flexible parallel and serial interfaces, easing integration with a range of host processors and FPGAs. |
| Package | LQFP-64 | LQFP-64 | Identical package and pin count enable potential board-level interchangeability with minimal layout changes. |
| Operating Temperature Range | -40 °C to +125 °C | -40 °C to +125 °C | Both meet industrial temperature requirements, suitable for harsh-environment applications. |
| Internal Reference | Yes (with REFIO/REFIO- pins) | Yes (with REFIO/REFIO- pins) | On-chip reference reduces external component count and simplifies precision measurement design. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADS8568SPMR | ADS8556IPM |
|---|---|---|
| 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 ADS8556IPM and ADS8568SPMR?
The ADS8556IPM is a 16-bit, 6-channel simultaneous-sampling SAR ADC in a 64-pin LQFP package (PM suffix), while the ADS8568SPMR is a 16-bit, 8-channel simultaneous-sampling SAR ADC in a 64-pin LQFP package (PMR suffix). The primary differences are channel count (6 vs 8) and the operating temperature grade implied by the suffix ordering; both share the same ADS856x family architecture, SPI/parallel interface, and ±10 V input range capability. Designers should confirm exact temperature grade and packaging details against the respective official datasheets.
Are the ADS8556IPM and ADS8568SPMR pin-compatible?
No. Although both devices are offered in a 64-pin LQFP package, the ADS8556IPM provides 6 analog input channels and the ADS8568SPMR provides 8 analog input channels, so the pin functions and channel assignments differ. A direct drop-in replacement is not possible without verifying pinout and PCB layout against the manufacturer datasheets.
Do both devices support simultaneous sampling of all channels?
Yes. Both the ADS8556IPM and ADS8568SPMR are simultaneous-sampling SAR ADCs, meaning all analog input channels are sampled at the same instant. This makes both suitable for multi-phase power measurement, motor control, and other applications requiring phase-coherent acquisition across channels.
What is the resolution and sample rate of these ADCs?
Both the ADS8556IPM and ADS8568SPMR are 16-bit successive-approximation register (SAR) ADCs. They belong to the ADS856x family, which supports simultaneous sampling with a maximum throughput specified in the official Texas Instruments datasheet. Designers should consult the datasheet for the exact maximum sample rate under the intended interface and configuration.
What analog input range do the ADS8556IPM and ADS8568SPMR support?
The ADS856x family supports bipolar analog input ranges, including ±10 V, ±5 V, and ±2.5 V, configurable via the input range control. Both the ADS8556IPM and ADS8568SPMR share this family input structure, making them suitable for industrial signal chains that require direct connection to bipolar sensors and ±10 V industrial interfaces.
What digital interfaces are available on these devices?
Both the ADS8556IPM and ADS8568SPMR support parallel and serial (SPI-compatible) digital interfaces for reading conversion results. The interface mode is selectable, allowing flexibility in connecting to FPGAs, DSPs, or microcontrollers. Refer to the official datasheet for timing and configuration details of each mode.
Can the ADS8568SPMR replace the ADS8556IPM in an existing design?
Not directly. The ADS8568SPMR has 8 channels versus 6 channels on the ADS8556IPM, and the pinout differs despite both using a 64-pin LQFP package. A replacement requires PCB redesign, firmware updates for channel sequencing, and validation of timing, input range, and interface configuration against the manufacturer datasheet.
What applications are these simultaneous-sampling ADCs typically used in?
Both the ADS8556IPM and ADS8568SPMR are intended for industrial and instrumentation applications requiring multi-channel, phase-coherent acquisition, such as motor control, power quality monitoring, protective relays, and multi-axis data acquisition systems. The 8-channel ADS8568SPMR suits higher channel-count systems, while the 6-channel ADS8556IPM fits designs needing fewer simultaneous inputs.