Part A
ADS8685IPWR
Texas Instruments
- Lifecycle
- Active
- Stock
- 3202 Stückzahl
- Series
- Datenerfassung mit Analog to Digital Converters (ADC)
Replacement verdict
Compatible functional replacement candidate
The ADS8685IPWR and ADS8665IPWR share the same TSSOP-16 package, 16-bit SAR architecture, and pin-compatible footprint, making them viable functional substitutes in many designs. However, the ADS8685IPWR offers a higher sampling rate and a wider input voltage range, so system timing margins and analog front-end scaling should be validated before substituting the ADS8665IPWR in applications requiring the higher throughput or extended input span.
Package Type
High match
Resolution
High match
Sampling Rate
Validation required
Input Voltage Range
Validation required
Parts at a glance
Part B
ADS8665IPWR
Texas Instruments
- Lifecycle
- Active
- Stock
- 6457 Stückzahl
- Package
- TSSOP-16
- Series
- Datenerfassung mit 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 | ADS8685IPWR | ADS8665IPWR | Why it matters |
|---|---|---|---|
| Resolution | 16 bit | 12 bit | Higher resolution provides finer measurement granularity and lower quantization error, which directly affects accuracy of the digitized signal. |
| Sampling Rate | 500 kSPS | 500 kSPS | Maximum throughput determines how fast input signals can be captured; identical rates mean similar timing capability for the sampling stage. |
| Number of Input Channels | 1 single-ended | 1 single-ended | Channel count defines how many analog signals can be measured; both being single-channel means they serve the same single-input use case. |
| Input Voltage Range | ±10.24 V (bipolar, programmable) | ±10.24 V (bipolar, programmable) | The supported input span must match the sensor or signal amplitude; matching ranges allow direct substitution without front-end redesign. |
| Interface Type | SPI (serial) | SPI (serial) | The digital interface must be compatible with the host controller; identical SPI interfaces simplify drop-in replacement. |
| Supply Voltage | 5 V analog supply, 1.8 V to 5 V digital I/O | 5 V analog supply, 1.8 V to 5 V digital I/O | Supply requirements determine power rail compatibility; matching rails mean the same board power design can be reused. |
| Package | TSSOP-16 | TSSOP-16 | Package and pinout must match for physical board compatibility; identical packages allow the same footprint to be used. |
| INL (Integral Nonlinearity) | ±1.0 LSB (typ) | ±0.5 LSB (typ) | INL indicates deviation from an ideal transfer function; lower INL yields better linearity and measurement fidelity. |
| Operating Temperature Range | -40 °C to +125 °C | -40 °C to +125 °C | The temperature range must cover the application environment; matching ranges ensure equivalent environmental robustness. |
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 | ADS8685IPWR | ADS8665IPWR |
|---|---|---|
| Part Status | Active | Active |
| Number of Bits | 16 | 12 |
| Sampling Rate(Per Second) | - | 500k |
| Number of Inputs | 1 | 1 |
| Input Type | Pseudo-Differential, Single Ended | Differential, Pseudo-Differential, Single Ended |
| Data Interface | SPI | SPI |
| Configuration | PGA-S/H-ADC | PGA-ADC |
| Ratio - S / H: ADC | 1:1 | 0:1 |
| Number of A/D Converters | - | 1 |
| Architecture | SAR | SAR |
| Reference Type | External, Internal | Internal |
| Voltage - Supply, Analog | 5V | 4.75V ~ 5.25V |
| Voltage - Supply, Digital | 1.65V ~ 5.25V | 1.65V ~ 5.25V |
| Features | PGA | Internal Oscillator, PGA |
| Operating Temperature | -40°C ~ 125°C (TA) | -40°C ~ 125°C |
| Base Product Number | ADS8685 | - |
| Sampling Rate (Per Second) | 500k | - |
| Number of A / D Converters | 1 | - |
| Mounting Type | Surface Mount | - |
| Packaging | Cut Tape (CT), Tape & Reel (TR) | - |
Frequently asked questions
What are the key differences between the ADS8685IPWR and ADS8665IPWR?
The ADS8685IPWR is a 16-bit, 500-kSPS SAR ADC with a ±10.24-V bipolar input range, while the ADS8665IPWR is a 12-bit, 500-kSPS SAR ADC with a ±10.24-V bipolar input range. Both share the same TSSOP-16 (PW) package, integrated analog front end, and 5-V analog supply, but differ in resolution (16-bit vs 12-bit) and related dynamic performance specifications.
Are the ADS8685IPWR and ADS8665IPWR pin-compatible?
Yes. Both devices are offered in the same 16-pin TSSOP (PW) package and share the same pinout, including the analog input, reference, SPI interface, and supply pins, per the Texas Instruments datasheets. This allows a common PCB footprint, though firmware and performance validation are still required when changing resolution.
Do both ADCs support the same input voltage range?
Yes. Both the ADS8685IPWR and ADS8665IPWR feature an integrated analog front end with a programmable bipolar input range of ±10.24 V, ±5.12 V, and ±2.56 V, along with a unipolar 0-V to 10.24-V range, as specified in the respective TI datasheets.
What is the maximum throughput of each device?
Both the ADS8685IPWR and ADS8665IPWR support a maximum sampling rate of 500 kSPS, according to the Texas Instruments datasheets. The difference lies in resolution (16-bit vs 12-bit), not in throughput.
Can the ADS8665IPWR be used as a drop-in replacement for the ADS8685IPWR?
Hardware-wise, the shared TSSOP-16 package and pinout permit a common footprint, but the ADS8665IPWR provides 12-bit resolution versus 16-bit for the ADS8685IPWR. A drop-in replacement is therefore only acceptable if the system's accuracy and noise budget tolerate the reduced resolution; otherwise, firmware scaling and performance revalidation are required.
Do both devices use the same digital interface?
Yes. Both the ADS8685IPWR and ADS8665IPWR provide an SPI-compatible serial interface for configuration and data readback, as documented in the Texas Instruments datasheets. The command set and register map are shared across the ADS868x/ADS866x family, though resolution-dependent data formatting must be considered.
What are the typical applications for these two ADCs?
Both devices target industrial data acquisition, power monitoring, test and measurement, and PLC analog input modules, where a wide bipolar input range and integrated AFE reduce external component count. The ADS8685IPWR is preferred where 16-bit accuracy is needed, while the ADS8665IPWR suits 12-bit applications with the same signal chain.