Part A
ADS1252U
Texas Instruments
- Lifecycle
- Active
- Stock
- 5583 Stückzahl
- Package
- SOIC-8
- Series
- Datenerfassung mit Analog to Digital Converters (ADC)
Replacement verdict
Compatible functional replacement candidate
The ADS1251U and ADS1252U are functionally interchangeable 24-bit delta-sigma ADCs sharing the same SOIC-8 footprint, supply range, and serial interface, with the ADS1252U offering a higher programmable data rate. Both are viable substitutes when the system timing budget accommodates the selected output rate, though the differing maximum sample rate should be validated against the target application.
Resolution
High match
Package Type
High match
Supply Voltage
High match
Data Rate
Validation required
Parts at a glance
Part B
ADS1251U
Texas Instruments
- Lifecycle
- Active
- Stock
- 2748 Stückzahl
- Package
- SOIC-8
- 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 | ADS1251U | ADS1252U | Why it matters |
|---|---|---|---|
| Resolution (bits) | 24 | 24 | Both are 24-bit delta-sigma ADCs, so resolution alone does not distinguish them for substitutability. |
| Data Rate (SPS) | 20k | 40k | The ADS1252U offers twice the maximum output data rate, which matters for higher-bandwidth signal acquisition. |
| Interface Type | Serial (SPI-compatible) | Serial (SPI-compatible) | Both use a serial interface, but the exact protocol timing differs, affecting drop-in compatibility with existing firmware. |
| Number of Input Channels | 1 (differential) | 1 (differential) | Both are single-channel differential devices, so channel count is not a differentiator. |
| Supply Voltage (V) | 4.75 to 5.25 | 4.75 to 5.25 | Identical analog supply range means the same power rail can be reused in either design. |
| Package / Case | SOIC-8 | SOIC-8 | Same package footprint allows board-level interchangeability without layout changes. |
| Operating Temperature Range (°C) | -40 to +85 | -40 to +85 | Matching temperature ratings ensure equivalent environmental robustness for industrial applications. |
| Input Type | Differential | Differential | Both accept differential inputs, preserving common-mode rejection characteristics when substituting. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADS1252U | ADS1251U |
|---|---|---|
| Part Status | Active | Active |
| Number of Bits | 24 | 24 |
| Sampling Rate(Per Second) | 40k | 20k |
| Number of Inputs | 1 | 1 |
| Input Type | Differential | Differential |
| Data Interface | SPI | SPI |
| Configuration | ADC | ADC |
| Number of A/D Converters | 1 | 1 |
| Architecture | Sigma-Delta | Sigma-Delta |
| Reference Type | External | External |
| Voltage - Supply, Analog | 5V | 5V |
| Voltage - Supply, Digital | 5V | 5V |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
Frequently asked questions
What are the key differences between the ADS1251U and ADS1252U?
The ADS1251U and ADS1252U are both 24-bit delta-sigma analog-to-digital converters from Texas Instruments in an SOIC-8 package, but they differ in maximum data rate and resolution performance. The ADS1251U supports a fixed 20kHz data output rate, while the ADS1252U supports a higher 40kHz data output rate. The ADS1252U also specifies a lower noise level, making it better suited for higher-speed precision measurement applications.
Are the ADS1251U and ADS1252U pin-compatible?
Yes. Both devices are offered in the same 8-pin SOIC (D) package with identical pin functions, including VREF, AIN, VDD, and the serial interface pins (SCLK, DOUT/DRDY). This allows the ADS1252U to be used as a drop-in replacement for the ADS1251U in existing PCB layouts, provided the system timing and data rate requirements are validated.
What is the maximum data rate of each device?
The ADS1251U provides a fixed 20kHz output data rate, while the ADS1252U provides a fixed 40kHz output data rate. Both devices use a delta-sigma architecture with a fixed oversampling ratio and do not offer programmable data rate settings.
What is the resolution and noise performance of the ADS1251U versus the ADS1252U?
Both converters provide 24-bit resolution. The ADS1251U achieves approximately 19.5 bits of effective resolution (noise-free) at its 20kHz data rate, while the ADS1252U achieves approximately 19 bits of effective resolution at its higher 40kHz data rate. The ADS1252U is optimized for lower noise at the higher speed, making it preferable when faster sampling is required without significant loss of precision.
Do the ADS1251U and ADS1252U use the same reference voltage and analog input configuration?
Yes. Both devices use a differential analog input and require an external reference voltage applied to the VREF pin. The reference input range and analog input range specifications are the same for both parts, so the same external reference and input signal conditioning circuitry can generally be used for either device.
What is the supply voltage and power consumption of the ADS1251U and ADS1252U?
Both devices operate from a single 5V analog supply (AVDD) and a 2.7V to 5.25V digital supply (DVDD). Power consumption is similar between the two parts, with the ADS1252U drawing slightly more current due to its higher data rate. Typical power dissipation is in the range of 25mW to 30mW for both devices under nominal conditions.
Can the ADS1252U be used in an existing ADS1251U design without firmware changes?
In most cases, yes, because both devices share the same serial interface protocol and pinout. However, the host firmware must be able to accommodate the higher 40kHz output data rate of the ADS1252U, including the corresponding DRDY timing and SCLK frequency requirements. The system clock and read timing should be verified against the ADS1252U datasheet before substitution.
Which device is better for high-speed precision measurement applications?
The ADS1252U is better suited for applications requiring higher throughput, since it offers a 40kHz data rate versus 20kHz for the ADS1251U, while maintaining comparable 24-bit resolution and low noise. The ADS1251U remains appropriate for lower-speed, lower-power precision measurement where 20kHz is sufficient.