Part A
ADS1281IPW
德州儀器
- Lifecycle
- Active
- Stock
- 4383 件
- Package
- TSSOP-24
- Series
- 資料獲取-模數轉換器（ADC）
Replacement verdict
Not a drop-in replacement
The ADS1281IPW and ADS1202IPWRG4 are not functionally interchangeable. The ADS1281IPW is a high-resolution 31-bit delta-sigma ADC with a serial SPI interface in a TSSOP-28 package, while the ADS1202IPWRG4 is a 16-bit delta-sigma modulator with a single-bit output in a TSSOP-8 package. Their resolution, output format, channel configuration, and package footprint differ fundamentally, so the ADS1202IPWRG4 cannot serve as a direct substitute for the ADS1281IPW in existing designs.
Different resolution
Different output type
Different channel count
Different footprint
Parts at a glance
Part B
ADS1202IPWRG4
德州儀器
- Lifecycle
- Active
- Stock
- 4745 件
- Package
- TSSOP-8
- Series
- 資料獲取-ADC DAC-專用
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 | ADS1202IPWRG4 | Why it matters |
|---|---|---|---|
| Resolution (bits) | 31 | 16 | Resolution determines the smallest signal change the ADC can distinguish; a 31-bit delta-sigma converter offers far finer resolution than a 16-bit device, so they are not functionally interchangeable in high-precision applications. |
| Architecture | Delta-sigma (high-resolution) | Delta-sigma (modulator, current-shunt) | Although both are delta-sigma based, the ADS1281 is a complete high-resolution ADC while the ADS1202 is a modulator intended for isolated current sensing; the architecture and intended signal chain differ significantly. |
| Input type | Differential | Differential | Both accept differential inputs, which is important for rejecting common-mode noise; this parameter is identical and supports similar front-end topologies. |
| Data interface | SPI (serial) | Serial (modulator bitstream output) | The output format dictates how the host processor captures data; the ADS1281 provides standard SPI words while the ADS1202 outputs a 1-bit modulator stream requiring digital filtering, so firmware and interface logic are not interchangeable. |
| Supply voltage (analog) | 5 V (analog), 3.3 V (digital) | 5 V | Supply requirements affect board-level power design and level shifting; differing analog/digital rails mean the power tree and interface voltages must be re-validated when substituting. |
| Package | TSSOP-24 | TSSOP-16 | Package and pin count determine PCB footprint and layout; different footprints mean a direct drop-in replacement is not possible without a board redesign. |
| Operating temperature range | -40 °C to +85 °C | -40 °C to +85 °C | The temperature range defines the environments in which the part is guaranteed to meet specifications; identical ranges indicate comparable environmental robustness. |
| Typical application | Seismic, energy exploration, high-resolution instrumentation | Motor control, current sensing, isolated measurement | Intended application reflects the optimized signal chain and performance targets; the two parts target very different end uses, so functional substitutability is limited. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADS1281IPW | ADS1202IPWRG4 |
|---|---|---|
| Supplier | - | Texas Instruments |
| Part Status | Active | Discontinued at Digi-Key |
| Type | - | Modulator |
| Number of Channels | - | 1 |
| Resolution(Bits) | - | 16 b |
| Sampling Rate(Per Second) | 4k | 40k |
| Data Interface | SPI | Serial |
| Voltage Supply Source | - | Single Supply |
| Voltage - Supply | - | 4.75V ~ 5.25V |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
| Mounting Type | - | Surface Mount |
| Number of Bits | 31 | - |
| Number of Inputs | 1 | - |
| Input Type | Differential, Single Ended | - |
| Configuration | ADC | - |
| Number of A/D Converters | 1 | - |
| Architecture | Sigma-Delta | - |
| Reference Type | External | - |
| Voltage - Supply, Analog | 5V | - |
| Voltage - Supply, Digital | 1.65V ~ 3.6V | - |
Frequently asked questions
What are the primary functional differences between the ADS1281IPW and ADS1202IPWRG4?
The ADS1281IPW is a single-channel, 31-bit delta-sigma analog-to-digital converter designed for high-resolution seismic and energy exploration applications, featuring a programmable gain amplifier and selectable data rates up to 4 kSPS. The ADS1202IPWRG4 is a 16-bit, second-order delta-sigma modulator with a 10 MHz clock input, intended for isolated current and voltage sensing in motor control and power measurement systems. They differ fundamentally in resolution, architecture, and target application.
Are the ADS1281IPW and ADS1202IPWRG4 pin-to-pin compatible?
No. The ADS1281IPW is supplied in a 24-pin TSSOP package, while the ADS1202IPWRG4 is supplied in a 16-pin TSSOP package. The pin counts and pin functions differ, so they are not drop-in replacements for one another.
What are the resolution and output data rate specifications for each device?
The ADS1281IPW provides 31-bit resolution with programmable output data rates from 250 SPS to 4 kSPS. The ADS1202IPWRG4 is a 16-bit modulator that outputs a 1-bit delta-sigma bitstream at a rate determined by its external clock, typically 10 MHz, which the host system must decimate and filter.
Do both devices include an integrated programmable gain amplifier (PGA)?
No. The ADS1281IPW includes an integrated low-noise programmable gain amplifier with selectable gains of 1, 2, 4, 8, 16, 32, and 64. The ADS1202IPWRG4 does not include an integrated PGA; it is a modulator-only device requiring external signal conditioning.
What are the supply voltage requirements for the ADS1281IPW and ADS1202IPWRG4?
The ADS1281IPW operates from an analog supply of 5 V (AVDD) and a digital supply of 3.3 V (DVDD), with a separate 2.5 V reference input. The ADS1202IPWRG4 operates from a single 5 V supply (AVDD and DVDD both at 5 V) with a 2.5 V reference. Designers must verify exact supply tolerances against the respective manufacturer datasheets.
Which device is better suited for isolated current sensing in motor control?
The ADS1202IPWRG4 is specifically designed for isolated current and voltage sensing, as its delta-sigma modulator output can be coupled through a digital isolator, making it suitable for motor control and power measurement applications. The ADS1281IPW is optimized for high-resolution seismic and energy exploration data acquisition and is not intended for isolated current-sense architectures.
Can the ADS1202IPWRG4 be used as a direct substitute for the ADS1281IPW in a seismic acquisition design?
No. The ADS1281IPW offers 31-bit resolution and an integrated PGA required for high-dynamic-range seismic signal chains, whereas the ADS1202IPWRG4 provides only 16-bit modulator resolution without a PGA. Substitution would require redesign of the signal conditioning, digital filtering, and decimation stages, and would not meet the resolution requirements of the original application.