Part A
ADS1220IPWR
Texas Dụng cụ
- Lifecycle
- Active
- Stock
- 6260 PCS
- Package
- TSSOP-16
- Series
- Data Acquisition - Analog to Digital Converters (ADC)
Replacement verdict
Compatible functional replacement candidate
The ADS1220IPWR and ADS1256IDBRG4 are both 24-bit delta-sigma ADCs suitable for precision sensor measurement, but they differ in resolution architecture, channel count, interface speed, and package footprint. The ADS1220IPWR offers a compact 4-channel PGA input with integrated features for low-power sensor applications, while the ADS1256IDBRG4 provides 8-channel high-resolution conversion with faster data rates for higher-throughput systems. Designers should validate channel requirements, interface timing, and board layout before substituting one for the other.
Resolution and Data Rate
Validation required
Channel Count
Not compatible
Interface Type
Validation required
Package Type
Not compatible
Parts at a glance
Part B
ADS1256IDBRG4
Texas Dụng cụ
- Lifecycle
- Active
- Stock
- 7726 PCS
- Package
- SSOP-28
- Series
- Data Acquisition - 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 | ADS1220IPWR | ADS1256IDBRG4 | Why it matters |
|---|---|---|---|
| Resolution (bits) | 24 | 24 | Both are 24-bit delta-sigma ADCs, so resolution alone does not distinguish them for substitutability. |
| Number of input channels | 4 (2 differential / 4 single-ended) | 8 (4 differential / 8 single-ended) | Channel count determines how many sensors can be multiplexed; the ADS1256 supports twice the input count. |
| Maximum sample rate (SPS) | 2000 | 30000 | Higher sample rate enables faster signal acquisition and wider bandwidth applications; the ADS1256 is significantly faster. |
| PGA gain range | 1 to 128 | 1 to 64 | PGA gain sets the smallest resolvable input signal; the ADS1220 offers higher gain for low-level sensors. |
| Interface | SPI | SPI | Both use SPI, so the host microcontroller interface is compatible between the two parts. |
| Supply voltage (analog) | 2.3 V to 5.5 V | 5 V (4.75 V to 5.25 V) | The ADS1220 supports lower and wider supply rails, while the ADS1256 requires a regulated 5 V analog supply. |
| Package | TSSOP-16 | SSOP-28 | Different footprints and pin counts mean the boards are not drop-in compatible and require layout changes. |
| Internal oscillator | Yes | No (external crystal required) | The ADS1220 can operate standalone, while the ADS1256 needs an external clock source, affecting BOM and design complexity. |
| Operating temperature range | -40 °C to +125 °C | -40 °C to +85 °C | The wider temperature range of the ADS1220 suits harsher environments than the ADS1256. |
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Send your BOM and application constraints for technical and sourcing review.
Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADS1220IPWR | ADS1256IDBRG4 |
|---|---|---|
| Supplier | - | Texas Instruments |
| Part Status | Active | Discontinued at Digi-Key |
| Number of Bits | 24 | 24 |
| Sampling Rate(Per Second) | 2k | 30k |
| Number of Inputs | 2, 4 | 4, 8 |
| Input Type | Differential, Single Ended | Differential, Single Ended |
| Data Interface | SPI | SPI |
| Configuration | MUX-PGA-ADC | MUX-PGA-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 | 1.8V ~ 3.6V |
| Features | PGA, Temperature Sensor | PGA |
| Operating Temperature | -40°C ~ 125°C | -40°C ~ 85°C |
Frequently asked questions
What are the key architectural differences between the ADS1220IPWR and ADS1256IDBRG4?
The ADS1220IPWR is a 24-bit, 4-channel delta-sigma ADC with an integrated PGA, VREF, and SPI interface in a TSSOP-16 package. The ADS1256IDBRG4 is a 24-bit, 8-channel (4 differential) delta-sigma ADC with a PGA, input buffer, and SPI interface in a SSOP-28 package. The ADS1256 offers more input channels and a higher programmable data rate (up to 30 kSPS) compared to the ADS1220 (up to 2 kSPS in normal mode).
Can the ADS1220IPWR and ADS1256IDBRG4 be used interchangeably in an existing design?
No, they are not pin-compatible or footprint-compatible. The ADS1220IPWR uses a 16-pin TSSOP package, while the ADS1256IDBRG4 uses a 28-pin SSOP package. Pin functions, supply requirements, and external component connections differ, so a direct substitution without PCB redesign is not possible.
How do the input channel configurations compare between the two devices?
The ADS1220IPWR provides 4 single-ended or 2 differential input channels, configurable through an internal multiplexer. The ADS1256IDBRG4 provides 8 single-ended or 4 differential input channels. Designs requiring more than 4 single-ended inputs should select the ADS1256, while the ADS1220 suits lower-channel-count applications.
What are the maximum data rates for the ADS1220IPWR and ADS1256IDBRG4?
The ADS1220IPWR supports programmable data rates up to 2 kSPS in normal mode (with higher rates available in turbo mode per datasheet). The ADS1256IDBRG4 supports programmable data rates up to 30 kSPS. For high-speed acquisition, the ADS1256 provides a significant advantage.
Do both ADCs include an integrated programmable gain amplifier (PGA)?
Yes, both the ADS1220IPWR and ADS1256IDBRG4 integrate a programmable gain amplifier. The ADS1220 PGA supports gains from 1 to 128, and the ADS1256 PGA also supports gains from 1 to 64. This allows both devices to interface directly with low-level sensor signals without external amplification.
How do the power supply requirements differ between the ADS1220IPWR and ADS1256IDBRG4?
The ADS1220IPWR operates from an analog supply (AVDD) of 2.3 V to 5.5 V and a digital supply (DVDD) of 2.3 V to 5.5 V. The ADS1256IDBRG4 requires an analog supply of 5 V (AVDD) and a digital supply of 1.8 V to 3.6 V (DVDD), with an additional 5 V for the input buffer. The ADS1220 offers greater flexibility for low-voltage systems.
Which device is better suited for low-power portable applications?
The ADS1220IPWR is generally better suited for low-power portable applications. It offers low current consumption (as low as 120 µA in duty-cycle mode) and operates from a single 2.3 V to 5.5 V supply. The ADS1256IDBRG4 typically consumes more power due to its higher channel count and faster data rate, making it more suitable for benchtop or line-powered systems.
Are the communication interfaces of the ADS1220IPWR and ADS1256IDBRG4 compatible?
Both devices use a SPI-compatible serial interface for communication with a host microcontroller. However, the command sets, register maps, and timing specifications differ between the two devices. Firmware written for one device cannot be directly reused for the other without modification according to the respective datasheets.