Part A
ADS1251U
德州儀器
- Lifecycle
- Active
- Stock
- 2748 件
- Package
- SOIC-8
- Series
- 資料獲取-模數轉換器（ADC）
Replacement verdict
Compatible functional replacement candidate
The ADS1251U/2K5 and ADS1251U are functionally identical 24-bit delta-sigma ADCs from Texas Instruments; the only distinction is packaging format, with the /2K5 suffix denoting tape-and-reel delivery versus the standard tube or tray option. Both parts share the same die, electrical specifications, and SOIC-8 footprint, making them interchangeable for design and production purposes, with the selection driven solely by assembly and inventory handling requirements.
Resolution and Architecture
High match
Package and Footprint
High match
Supply Voltage and Interface
High match
Packaging Format
Validation required
Parts at a glance
Part B
ADS1251U/2K5
德州儀器
- Lifecycle
- Active
- Stock
- 4208 件
- Package
- SOIC-8
- Series
- 資料獲取-模數轉換器（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 | ADS1251U | Why it matters |
|---|---|---|---|
| Resolution | 24 bit | 24 bit | Both parts provide identical 24-bit resolution, so measurement precision is unchanged when substituting. |
| Number of Input Channels | 1 (differential) | 1 (differential) | Identical single differential input configuration means the same sensor/signal wiring can be reused. |
| Sampling Rate | Up to 20 kSPS | Up to 20 kSPS | Same maximum data rate ensures equivalent throughput for the target application. |
| Interface Type | Serial (SPI-compatible) | Serial (SPI-compatible) | Identical serial interface allows the same microcontroller firmware and bus connections to be used. |
| Supply Voltage | 5 V (analog and digital) | 5 V (analog and digital) | Same supply requirement means no power-rail redesign is needed for substitution. |
| Package / Mounting | SOIC-8, surface mount | SOIC-8, surface mount | Identical package and footprint allow drop-in board replacement without layout changes. |
| Packaging / Reel Quantity | Tape and reel (2,500 units per reel) | Tube / bulk | Different packaging affects automated assembly handling and minimum order quantities, though the die and function are the same. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Same temperature range confirms equivalent environmental robustness for the application. |
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 | ADS1251U | ADS1251U/2K5 |
|---|---|---|
| Part Status | Active | Active |
| Number of Bits | 24 | 24 |
| Sampling Rate(Per Second) | 20k | 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 is the difference between ADS1251U and ADS1251U/2K5?
The ADS1251U is the base part number for Texas Instruments' 24-bit delta-sigma analog-to-digital converter in an SOIC-8 package. The ADS1251U/2K5 is the same device supplied on a 2,500-unit tape-and-reel carrier for automated assembly. Both share identical electrical specifications, die, and package; the suffix only denotes packaging and shipping quantity.
Are the ADS1251U and ADS1251U/2K5 electrically and functionally identical?
Yes. Both variants use the same silicon die and are specified with the same datasheet parameters, including 24-bit resolution, a data rate of up to 20 kSPS, a single 5 V analog supply, and an SPI-compatible serial interface. The /2K5 suffix affects only the delivery format, not device performance.
What package do the ADS1251U and ADS1251U/2K5 use?
Both devices are offered in an 8-pin SOIC (D) package. The package outline, pinout, and PCB land pattern are identical between the two orderable part numbers.
Can ADS1251U/2K5 be used as a drop-in replacement for ADS1251U?
Yes, from an electrical and mechanical standpoint the devices are interchangeable because they are the same converter in the same package. The only practical difference is that ADS1251U/2K5 is supplied on tape-and-reel, which may suit high-volume automated placement, while ADS1251U is typically supplied in tube or smaller quantities.
Which variant should be selected for production versus prototyping?
For engineering prototypes and low-volume builds, ADS1251U in tube or small-quantity packaging is typically convenient. For automated SMT production lines, ADS1251U/2K5 tape-and-reel packaging is generally preferred because it is compatible with pick-and-place feeders. Selection should be based on assembly method and order quantity rather than electrical differences.
Do ADS1251U and ADS1251U/2K5 differ in resolution or data rate?
No. Both are 24-bit delta-sigma ADCs with a maximum data rate of 20 kSPS, as specified in the Texas Instruments ADS1251 datasheet. Resolution and throughput are identical across both orderable part numbers.
What supply voltage and interface do ADS1251U and ADS1251U/2K5 require?
Both devices operate from a single 5 V analog supply and provide a serial peripheral interface (SPI) compatible output for communication with a host microcontroller or DSP. These parameters are common to both orderable variants per the manufacturer datasheet.
Is the moisture sensitivity level (MSL) the same for ADS1251U and ADS1251U/2K5?
Because both part numbers use the same 8-pin SOIC package and the same TI assembly and test flow, the moisture sensitivity level and reflow classification are the same for both variants. Designers should confirm the MSL rating on the specific reel or tube label and in the current TI datasheet before setting reflow profiles.