Part A
ADS1281IPWR
Texas Instruments
- Lifecycle
- Active
- Stock
- 7474 Stückzahl
- Package
- TSSOP-24
- Series
- Datenerfassung mit Analog to Digital Converters (ADC)
Replacement verdict
Not a drop-in replacement
The ADS1281IPWR and ADS1222IPWRG4 are not drop-in replacements for one another. The ADS1281IPWR is a high-resolution 31-bit delta-sigma ADC with a single channel and SPI interface, while the ADS1222IPWRG4 is a 24-bit delta-sigma ADC with a two-channel differential input multiplexer and I2C interface. Their differing resolution, channel architecture, digital interface, and package footprint make direct substitution impractical without a full redesign of the surrounding circuitry and firmware.
Different resolution
Different channel count
Different digital interface
Different package footprint
Parts at a glance
Part B
ADS1222IPWRG4
Texas Instruments
- Lifecycle
- Active
- Stock
- 4722 Stückzahl
- Package
- TSSOP-14
- 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 | ADS1281IPWR | ADS1222IPWRG4 | Why it matters |
|---|---|---|---|
| Resolution (bits) | 31 | 24 | Higher resolution enables finer measurement of small signal changes, which is critical for precision sensing applications. |
| Number of Input Channels | 1 (differential) | 2 (differential) | Channel count determines how many independent signals can be measured without external multiplexing. |
| Maximum Sample Rate | 4 kSPS | 2 kSPS | Sample rate limits the bandwidth of signals that can be accurately digitized. |
| Interface Type | SPI | SPI | The digital interface must match the host controller to ensure reliable communication. |
| Supply Voltage (Analog) | 5 V (analog), 3.3 V (digital) | 2.7 V to 5.5 V | Supply voltage compatibility affects whether the part can be dropped into an existing power rail design. |
| Package Type | TSSOP-24 | TSSOP-16 | Package footprint and pin count must match the PCB layout for physical substitutability. |
| Operating Temperature Range | -40°C to +85°C | -40°C to +85°C | Temperature range determines suitability for industrial and outdoor environments. |
| Input Type | Differential | Differential | Differential inputs improve common-mode noise rejection in noisy environments. |
| Internal PGA | Yes | Yes | An internal programmable gain amplifier allows direct connection of low-level sensors without external amplification. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADS1281IPWR | ADS1222IPWRG4 |
|---|---|---|
| Supplier | - | Texas Instruments |
| Part Status | Active | Discontinued at Digi-Key |
| Number of Bits | 31 | 24 |
| Sampling Rate(Per Second) | 4k | 240 |
| Number of Inputs | 1 | 2 |
| Input Type | Differential, Single Ended | Differential, Single Ended |
| Data Interface | SPI | SPI |
| Configuration | ADC | MUX-ADC |
| Number of A/D Converters | 1 | 1 |
| Architecture | Sigma-Delta | Sigma-Delta |
| Reference Type | External | External |
| Voltage - Supply, Analog | 5V | 2.7V ~ 5.5V |
| Voltage - Supply, Digital | 1.65V ~ 3.6V | 2.7V ~ 5.5V |
| Features | - | Temperature Sensor |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
Frequently asked questions
What are the primary differences between the ADS1281IPWR and ADS1222IPWRG4?
The ADS1281IPWR is a single-channel, 31-bit delta-sigma ADC with a maximum data rate of 4 kSPS, designed for high-resolution seismic and energy exploration applications. The ADS1222IPWRG4 is a 24-bit, 240 SPS delta-sigma ADC with a two-channel differential input multiplexer, intended for low-power sensor measurement applications. They differ in resolution, data rate, channel count, and target application.
Are the ADS1281IPWR and ADS1222IPWRG4 pin-compatible?
No. The ADS1281IPWR is supplied in a 24-pin TSSOP package, while the ADS1222IPWRG4 is supplied in a 16-pin TSSOP package. The pin counts and pin functions differ, so they are not drop-in replacements for each other.
What are the maximum data rates of these two ADCs?
The ADS1281IPWR supports a maximum data rate of 4 kSPS. The ADS1222IPWRG4 supports a maximum data rate of 240 SPS. The ADS1281IPWR is therefore suitable for higher-speed acquisition, while the ADS1222IPWRG4 targets slower, low-power measurement systems.
How do the resolutions of the ADS1281IPWR and ADS1222IPWRG4 compare?
The ADS1281IPWR is a 31-bit delta-sigma ADC. The ADS1222IPWRG4 is a 24-bit delta-sigma ADC. The ADS1281IPWR offers higher nominal resolution, which is relevant for precision applications such as seismic data acquisition.
Do both devices support differential inputs?
Yes. The ADS1281IPWR provides a single differential input channel. The ADS1222IPWRG4 provides a two-channel differential input multiplexer, allowing selection between two differential input pairs. The ADS1222IPWRG4 therefore offers input multiplexing that the ADS1281IPWR does not.
What supply voltages do the ADS1281IPWR and ADS1222IPWRG4 require?
The ADS1281IPWR operates from an analog supply of 5 V and a digital supply of 3.3 V (with a 1.8 V to 3.3 V digital I/O range). The ADS1222IPWRG4 operates from a single supply of 2.7 V to 5.5 V. Designers must verify the exact supply requirements against the respective manufacturer datasheets for their target operating conditions.
Can the ADS1222IPWRG4 replace the ADS1281IPWR in an existing design?
No, not directly. The devices differ in package pin count, resolution, data rate, channel configuration, and supply requirements. A replacement would require a redesign of the PCB layout, revalidation of the signal chain, and confirmation that the lower resolution and data rate of the ADS1222IPWRG4 meet the application requirements.