Part A
ADS1210U
Texas Instruments
- Lifecycle
- Active
- Stock
- 5384 PCS
- Package
- SOIC-8
- Series
- Acquisition de données - Convertisseur analogique - numérique (ADC)
Replacement verdict
Compatible functional replacement candidate
The ADS1251U/2K5 and ADS1210U are both 24-bit delta-sigma analog-to-digital converters from Texas Instruments, but they differ in resolution architecture, interface type, and package footprint. The ADS1251U/2K5 offers a single-channel, 24-bit ADC with a serial SPI-compatible interface in an SOIC-8 package, while the ADS1210U provides a 24-bit ADC with a wider feature set including a programmable gain amplifier and a different serial interface in an SOIC-18 package. Designers should verify interface compatibility, package footprint, and channel requirements before substituting one for the other in a given application.
Resolution
Validation required
Interface Type
Not compatible
Package Type
Not compatible
Channel Count
Validation required
Parts at a glance
Part B
ADS1251U/2K5
Texas Instruments
- Lifecycle
- Active
- Stock
- 4208 PCS
- Package
- SOIC-8
- Series
- Acquisition de données - Convertisseur analogique - numérique (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 | ADS1251U/2K5 | ADS1210U | Why it matters |
|---|---|---|---|
| Resolution (bits) | 24 | 24 | Both are 24-bit delta-sigma ADCs, so resolution alone does not differentiate them for substitutability. |
| Number of input channels | 1 (single-ended) | 1 (differential) | Input configuration affects how the sensor or signal source must be connected; a differential input can reject common-mode noise that a single-ended input cannot. |
| Maximum data rate (SPS) | 20k | 19.5k | Data rate determines the maximum signal bandwidth and the trade-off between speed and noise performance in the application. |
| Interface type | SPI (serial) | SPI (serial) | Both use a serial SPI-compatible interface, so the host microcontroller connection is largely compatible. |
| Supply voltage (analog) | 5 V (single supply) | 5 V (single supply) | Matching analog supply requirements simplifies power-rail design when substituting one part for the other. |
| Package | SOIC-8 | SOIC-18 | Different package footprints and pin counts mean the PCB layout must be redesigned; they are not drop-in replacements. |
| Internal PGA | No | Yes (programmable gain) | An internal PGA allows direct amplification of small signals, reducing external components and improving low-level measurement flexibility. |
| Operating temperature range | -40°C to +85°C | -40°C to +85°C | Identical temperature ratings mean both suit the same industrial-grade environmental conditions. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADS1210U | ADS1251U/2K5 |
|---|---|---|
| Part Status | Last Time Buy | Active |
| Number of Bits | 24 | 24 |
| Sampling Rate(Per Second) | 16k | 20k |
| Number of Inputs | 1 | 1 |
| Input Type | Differential | Differential |
| Data Interface | SPI | SPI |
| Configuration | PGA-ADC | ADC |
| Number of A/D Converters | 1 | 1 |
| Architecture | Sigma-Delta | Sigma-Delta |
| Reference Type | External, Internal | External |
| Voltage - Supply, Analog | 5V | 5V |
| Voltage - Supply, Digital | 5V | 5V |
| Features | PGA | - |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
Frequently asked questions
What are the key architectural differences between the ADS1251U/2K5 and the ADS1210U?
The ADS1251U/2K5 is a 24-bit delta-sigma ADC with a fixed data rate of 20 kSPS and a single differential input, offering a simplified, low-latency signal chain. The ADS1210U is a 24-bit delta-sigma ADC featuring a programmable gain amplifier (PGA) with gains from 1 to 128, a flexible programmable data rate, and a serial interface supporting multiple modes, making it suitable for lower-level signal acquisition with configurable throughput.
Do the ADS1251U/2K5 and ADS1210U share the same package and pinout?
No. The ADS1251U/2K5 is supplied in a 16-pin SOIC package, while the ADS1210U is supplied in a 24-pin SOIC package. The pin counts and pin functions differ, so the two devices are not pin-compatible and cannot be interchanged on the same PCB land pattern without redesign.
How do the maximum data rates of the ADS1251U/2K5 and ADS1210U compare?
The ADS1251U/2K5 provides a fixed 20 kSPS output data rate. The ADS1210U offers a programmable data rate, with a maximum of approximately 15.6 kSPS depending on configuration. The ADS1251U/2K5 therefore delivers a higher fixed throughput, while the ADS1210U trades maximum rate for configurability.
Does the ADS1210U include a programmable gain amplifier while the ADS1251U/2K5 does not?
Yes. The ADS1210U integrates a PGA with selectable gains of 1, 2, 4, 8, 16, 32, 64, and 128, allowing direct amplification of low-level sensor signals. The ADS1251U/2K5 does not include an internal PGA and is intended for full-scale differential input signals, so external amplification is required for small-signal applications.
What are the supply voltage and reference requirements for each device?
Both devices operate from a single 5 V analog supply (AVDD) and a 2.7 V to 5.25 V digital supply (DVDD) per their respective datasheets. The ADS1251U/2K5 uses an external differential reference input (VREF), while the ADS1210U also requires an external reference and supports a reference range suitable for its PGA configurations. Designers should verify exact reference limits in the respective manufacturer datasheets.
Which device is better suited for low-level sensor signals such as bridge or thermocouple outputs?
The ADS1210U is generally better suited for low-level sensor signals because its integrated PGA (up to gain 128) allows small differential voltages to be amplified before conversion, improving effective resolution. The ADS1251U/2K5 lacks an internal PGA and is better suited to applications where the input signal already spans a significant portion of the reference range.
Are the digital interfaces of the ADS1251U/2K5 and ADS1210U compatible?
No, they are not directly interchangeable. The ADS1251U/2K5 uses a simple synchronous serial interface with a fixed data rate and a dedicated data-ready signal. The ADS1210U provides a more flexible serial interface with multiple modes and programmable data rates. Firmware and host interface logic must be adapted when migrating between the two devices.
Can the ADS1251U/2K5 be used as a drop-in replacement for the ADS1210U in an existing design?
No. Differences in package size (16-pin versus 24-pin SOIC), pinout, interface protocol, data rate configurability, and the presence of a PGA in the ADS1210U prevent a direct drop-in replacement. Any migration requires PCB redesign and firmware changes validated against the manufacturer datasheets.