Part A
ADS1220IPW
Texas Instruments
- Lifecycle
- Active
- Stock
- 4062 Stückzahl
- Package
- TSSOP-16
- Series
- Datenerfassung mit Analog to Digital Converters (ADC)
Replacement verdict
Not a drop-in replacement
The ADS1281IPW and ADS1220IPW are both 24-bit delta-sigma ADCs in a TSSOP-16 package, but they differ fundamentally in resolution architecture, input channel configuration, interface protocol, and reference/supply requirements. The ADS1281IPW is a single-channel, high-resolution seismic-grade converter with a serial SPI-compatible interface and external reference, while the ADS1220IPW is a 4-channel multiplexed, low-power converter with an integrated PGA, internal reference, and SPI interface. Because the channel count, input architecture, reference scheme, and target application profiles diverge, the ADS1220IPW cannot be treated as a direct drop-in substitute for the ADS1281IPW without significant redesign and validation.
Different channel count
Different input architecture
Different reference scheme
Different application profile
Parts at a glance
Part B
ADS1281IPW
Texas Instruments
- Lifecycle
- Active
- Stock
- 4383 Stückzahl
- Package
- TSSOP-24
- 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 | ADS1281IPW | ADS1220IPW | 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) | 4 (2 differential / 4 single-ended) | More channels allow a single device to monitor multiple sensors, reducing component count and board space. |
| Maximum sample rate | 4 kSPS | 2 kSPS | Sample rate determines the bandwidth of signals that can be captured; higher rates suit faster-changing inputs. |
| Interface type | SPI (serial) | SPI (serial) | Both use SPI, so the host microcontroller interface is compatible, easing drop-in substitution. |
| Supply voltage (analog) | 5 V (analog), 3.3 V (digital) | 2.7 V to 5.5 V (analog), 2.7 V to 5.5 V (digital) | Supply requirements affect power rail design and compatibility with the rest of the system. |
| Integrated PGA | No | Yes (gain 1 to 128) | An integrated PGA allows direct amplification of low-level sensor signals without external gain stages. |
| Package | TSSOP-24 | TSSOP-16 | Different pin counts and footprints affect PCB layout and whether a direct board swap is possible. |
| Operating temperature range | -40 °C to +85 °C | -40 °C to +125 °C | Wider temperature range supports use in harsher environments and industrial applications. |
| Input type | Differential | Differential / single-ended | Flexible input configurations allow the device to interface with a broader range of sensor topologies. |
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 | ADS1220IPW | ADS1281IPW |
|---|---|---|
| Part Status | Active | Active |
| Number of Bits | 24 | 31 |
| Sampling Rate(Per Second) | 2k | 4k |
| Number of Inputs | 2, 4 | 1 |
| Input Type | Differential, Single Ended | Differential, Single Ended |
| Data Interface | SPI | SPI |
| Configuration | MUX-PGA-ADC | ADC |
| Number of A/D Converters | 1 | 1 |
| Architecture | Sigma-Delta | Sigma-Delta |
| Reference Type | External, Internal, Supply | External |
| Voltage - Supply, Analog | 2.3V ~ 5.5V, ±2.5 | 5V |
| Voltage - Supply, Digital | 2.3V ~ 5.5V | 1.65V ~ 3.6V |
| Features | PGA, Temperature Sensor | - |
| Operating Temperature | -40°C ~ 125°C | -40°C ~ 85°C |
Frequently asked questions
What are the primary differences between the ADS1281IPW and ADS1220IPW?
The ADS1281IPW is a single-channel, 31-bit delta-sigma ADC designed for high-resolution seismic and energy exploration applications, featuring a maximum data rate of 4 kSPS and an SNR of 130 dB. The ADS1220IPW is a 24-bit, 4-channel delta-sigma ADC with an integrated PGA, offering data rates up to 2 kSPS and an SNR of 105 dB, intended for small-signal sensor applications such as temperature and bridge measurements.
Do the ADS1281IPW and ADS1220IPW share the same package and pinout?
Both devices are offered in a 24-pin TSSOP (PW) package, but their pinouts and internal architectures differ. The ADS1281IPW provides a single differential input with dedicated synchronization and clock pins, while the ADS1220IPW provides four analog inputs, an internal PGA, and an SPI-compatible interface with different pin functions. They are not pin-for-pin compatible.
Which device offers a higher resolution and better noise performance?
The ADS1281IPW provides 31-bit resolution with an SNR of 130 dB, while the ADS1220IPW provides 24-bit resolution with an SNR of 105 dB. The ADS1281IPW therefore delivers higher resolution and lower noise, making it better suited for precision seismic and high-dynamic-range measurements.
Can the ADS1220IPW be used as a direct replacement for the ADS1281IPW?
No. The ADS1220IPW is not a drop-in replacement for the ADS1281IPW. They differ in resolution (24-bit vs 31-bit), channel count (4 vs 1), SNR (105 dB vs 130 dB), maximum data rate (2 kSPS vs 4 kSPS), and pinout. A redesign and validation against the manufacturer datasheets would be required.
What are the typical applications for each device?
The ADS1281IPW is typically used in seismic data acquisition, energy exploration, and high-resolution industrial measurement systems requiring low noise and high dynamic range. The ADS1220IPW is typically used in temperature sensing, pressure and bridge sensor measurements, portable instrumentation, and PLC analog input modules where multiple channels and an integrated PGA are beneficial.
Do both devices support an SPI interface?
The ADS1220IPW includes an SPI-compatible serial interface for configuration and data readout. The ADS1281IPW uses a dedicated serial interface with separate data output and synchronization signals rather than a standard SPI bus. Designers should consult the respective datasheets for exact interface timing and protocol requirements.
How do the supply voltage requirements compare?
The ADS1281IPW operates from an analog supply of 5 V with a digital supply of 3.3 V (per the manufacturer datasheet). The ADS1220IPW operates from a single analog supply of 2.7 V to 5.5 V and a digital supply of 2.7 V to 5.5 V. The ADS1220IPW offers greater flexibility for low-voltage systems, while the ADS1281IPW is intended for higher-performance 5 V analog designs.