Part A
ADS1251U/2K5
Texas Instruments
- Lifecycle
- Active
- Stock
- 4208 PCS
- Package
- SOIC-8
- Series
- Acquisição de dados - Analogo para Convertedores Digitais (ADC)
Replacement verdict
Compatible functional replacement candidate
The ADS1251U/2K5 and ADS1252UG4 are both 24-bit delta-sigma analog-to-digital converters from Texas Instruments sharing the same SOIC-8 footprint and single-channel architecture, making the ADS1252UG4 a viable functional substitute for the ADS1251U/2K5 in many designs. However, engineers must validate the higher full-scale input range and increased power consumption of the ADS1252UG4 against the system's analog front-end and thermal budget before committing to a drop-in replacement.
Resolution and Architecture
High match
Package and Pinout
High match
Input Voltage Range
Validation required
Power Consumption
Validation required
Parts at a glance
Part B
ADS1252UG4
Texas Instruments
- Lifecycle
- Active
- Stock
- 6755 PCS
- Package
- SOIC-8
- Series
- Acquisição de dados - Analogo para Convertedores Digitais (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 | ADS1252UG4 | Why it matters |
|---|---|---|---|
| Resolution (bits) | 24 | 24 | Both are 24-bit delta-sigma ADCs, so resolution is equivalent for precision measurement applications. |
| Sample Rate (SPS) | 20k | 40k | The ADS1252 offers twice the maximum data rate, which matters for higher-bandwidth signal acquisition. |
| Number of Input Channels | 1 (differential) | 1 (differential) | Both provide a single differential input, so channel count is not a differentiator. |
| Input Type | Differential | Differential | Differential inputs improve common-mode noise rejection in both parts equally. |
| Supply Voltage (V) | 5 | 5 | Both operate from a single 5 V supply, simplifying power design and interchangeability. |
| Interface | Serial (SPI-compatible) | Serial (SPI-compatible) | Both use a serial interface, allowing similar microcontroller connectivity. |
| Package / Mounting | SOIC-8, Surface Mount | SOIC-8, Surface Mount | Identical package and mounting allow drop-in PCB compatibility. |
| Operating Temperature Range (°C) | -40 to +85 | -40 to +85 | Matching temperature ranges ensure equivalent environmental robustness. |
| Power Consumption (mW, typ) | 25 | 35 | The ADS1252 draws more power due to its higher sample rate, which matters for low-power designs. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADS1251U/2K5 | ADS1252UG4 |
|---|---|---|
| Part Status | Active | Discontinued at Digi-Key |
| Number of Bits | 24 | 24 |
| Sampling Rate(Per Second) | 20k | 40k |
| 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/2K5 and the ADS1252UG4?
Both are 24-bit delta-sigma analog-to-digital converters from Texas Instruments in an SOIC-8 package, but they differ in maximum data rate and input configuration. The ADS1251U/2K5 supports a maximum data rate of 20 kSPS, while the ADS1252UG4 supports up to 40 kSPS. The ADS1251U/2K5 is specified for a single differential input with a fixed gain of 1, whereas the ADS1252UG4 offers a programmable gain amplifier (PGA) with gain settings of 1, 2, 4, 8, 16, 32, and 64.
Are the ADS1251U/2K5 and ADS1252UG4 pin-compatible?
Yes. Both devices are offered in the same 8-pin SOIC (D) package and share the same pinout, including the serial interface pins (SCLK, DOUT, DRDY/DOUT), analog inputs, reference inputs, and power supply pins. This allows a common PCB footprint, but firmware and timing must be revalidated because the register maps and control interfaces differ.
Do the ADS1251U/2K5 and ADS1252UG4 use the same digital interface?
No. The ADS1251U/2K5 uses a simple 2-wire serial interface with a dedicated DRDY/DOUT line and SCLK, and it has no internal registers to configure. The ADS1252UG4 uses a 3-wire SPI-compatible interface with separate DIN, DOUT, SCLK, and DRDY/CS lines, and it includes internal registers for configuring the PGA, data rate, and other settings. Firmware written for one device is not directly portable to the other.
Can the ADS1251U/2K5 and ADS1252UG4 operate from the same supply voltage?
Yes. Both devices operate from a single 5 V analog supply (AVDD) and a 1.8 V to 3.6 V digital supply (DVDD) for the serial interface, per the respective Texas Instruments datasheets. The reference input range and analog input range are also similar, but the PGA on the ADS1252UG4 changes the effective full-scale input range at gains greater than 1.
Which device should be selected for higher-throughput applications?
The ADS1252UG4 should be selected when higher throughput is required, because it supports data rates up to 40 kSPS versus 20 kSPS for the ADS1251U/2K5. The ADS1252UG4 also provides a programmable gain amplifier, which can improve resolution for low-level signals without an external amplifier, at the cost of a more complex register-based interface.
Are the ADS1251U/2K5 and ADS1252UG4 available in the same operating temperature range?
Both devices are specified for the industrial temperature range of -40°C to +85°C, as stated in the Texas Instruments datasheets. The "U" suffix in both part numbers denotes the SOIC-8 package, and the "G4" suffix on the ADS1252UG4 indicates a green (RoHS-compliant) molding compound.
What is the difference in packaging and ordering quantity between the two part numbers?
The ADS1251U/2K5 is supplied in tape-and-reel packaging with a quantity of 2,500 units per reel, as indicated by the "2K5" suffix. The ADS1252UG4 is supplied in tube or tape-and-reel depending on the specific orderable part number, and the "G4" suffix denotes the green/RoHS-compliant version. Buyers should confirm the exact packaging and quantity from the distributor or the Texas Instruments ordering information.
Can the ADS1251U/2K5 be replaced by the ADS1252UG4 without hardware changes?
Hardware replacement is possible because both devices share the same SOIC-8 package and pinout, but it is not a drop-in replacement at the system level. The ADS1252UG4 requires a different serial interface (SPI with DIN) and register configuration, and its maximum data rate and PGA settings differ. The replacement must be validated against the Texas Instruments datasheets and the target design's timing and firmware requirements.