Part A
ADS1281IPW
Texas Instruments
- Lifecycle
- Active
- Stock
- 4383 PCS
- Package
- TSSOP-24
- Series
- Acquisição de dados - Analogo para Convertedores Digitais (ADC)
Replacement verdict
Not a drop-in replacement
The ADS1281IPW and ADS1203IPWR 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 ADS1203IPWR is a 16-bit isolated delta-sigma modulator with a single-bit output in a TSSOP-16 package. Their resolution, output format, channel architecture, and package footprint differ fundamentally, so the ADS1203IPWR cannot serve as a drop-in substitute for the ADS1281IPW in existing designs.
Different resolution
Different output type
Different channel count
Different footprint
Parts at a glance
Part B
ADS1203IPWR
Texas Instruments
- Lifecycle
- Active
- Stock
- 3345 PCS
- Package
- TSSOP-8
- Series
- Acquisição de dados - ADCs-DACs - Objetivo Especial
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 | ADS1203IPWR | 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 measurement granularity than a 16-bit device. |
| Architecture | Delta-sigma (high-resolution) | Delta-sigma (modulator) | The ADS1281 is a complete high-resolution ADC, while the ADS1203 is a modulator-only device requiring external digital filtering, so they are not drop-in substitutes. |
| Output Interface | SPI (serial) | Serial bit-stream modulator output | Interface compatibility dictates whether the part can connect directly to a host controller or needs additional signal-processing circuitry. |
| Sample Rate (max) | 4 kSPS | 40 kSPS (modulator clock dependent) | Maximum sample rate defines the bandwidth of signals the converter can capture and affects achievable noise performance. |
| Input Type | Differential | Differential | Differential inputs improve common-mode noise rejection; both parts share this trait, aiding similar front-end design. |
| Supply Voltage | 5 V analog, 3.3 V digital (dual supply) | 5 V (single supply) | Supply requirements affect power-rail design and whether the part can be used in an existing single- or dual-supply system. |
| Package | TSSOP-24 | TSSOP-16 | Package footprint and pin count determine PCB layout compatibility and whether a board redesign is required. |
| Operating Temperature Range | -40°C to +85°C | -40°C to +105°C | Temperature range affects suitability for industrial and harsh-environment applications. |
| Typical Application | Seismic and energy exploration, high-resolution instrumentation | Motor control, current sensing, isolated measurement | Intended application areas indicate whether the part's performance profile matches the target system requirements. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADS1281IPW | ADS1203IPWR |
|---|---|---|
| Supplier | - | Texas Instruments,Rochester Electronics, LLC |
| Part Status | Active | Obsolete |
| 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 ~ 125°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 ADS1203IPWR?
The ADS1281IPW is a high-resolution, 31-bit delta-sigma analog-to-digital converter designed for seismic and energy exploration applications, featuring a programmable gain amplifier and operating from a 5 V analog supply. The ADS1203IPWR is a 16-bit, second-order delta-sigma modulator with a digital output, intended for isolated current and voltage sensing in motor control and power measurement applications, operating from a 5 V supply with a separate digital I/O supply.
Do the ADS1281IPW and ADS1203IPWR have compatible package footprints?
No. The ADS1281IPW is supplied in a 24-pin TSSOP (PW) package, while the ADS1203IPWR is supplied in an 8-pin SOIC (D) package. The pin counts, pin functions, and PCB land patterns differ, so they are not footprint-compatible.
What are the resolution and output data rate specifications for each device?
The ADS1281IPW provides up to 31-bit resolution with programmable data rates from 250 SPS to 4 kSPS. The ADS1203IPWR is a 16-bit modulator with a clock input up to 20 MHz, producing a 1-bit digital output stream whose effective resolution depends on the external digital filter and decimation ratio.
Can the ADS1203IPWR be used as a direct replacement for the ADS1281IPW in an existing design?
No. The two devices differ in resolution, output format (the ADS1281IPW provides a parallel/serial interface with on-chip digital filter, while the ADS1203IPWR provides a 1-bit modulator output requiring external filtering), package, and pinout. A direct substitution is not possible without redesigning the signal chain, digital interface, and PCB layout.
What are the typical application areas for the ADS1281IPW versus the ADS1203IPWR?
The ADS1281IPW is typically used in seismic data acquisition, energy exploration, and high-accuracy industrial measurement systems. The ADS1203IPWR is typically used in isolated current sensing, motor control, power inverters, and industrial process control where a modulator output is processed by an external digital filter or microcontroller.
What supply voltage requirements apply to each device?
The ADS1281IPW operates from a 5 V analog supply (AVDD) and a 3.3 V or 5 V digital supply (DVDD), with an additional 2.5 V reference requirement. The ADS1203IPWR operates from a 5 V analog supply (AVDD) and a 3.3 V or 5 V digital I/O supply (DVDD), with an external reference input.
How do the digital interfaces of the ADS1281IPW and ADS1203IPWR differ?
The ADS1281IPW provides a serial peripheral interface (SPI-compatible) with on-chip digital filtering and decimation, outputting fully processed conversion results. The ADS1203IPWR outputs a 1-bit delta-sigma modulated data stream that must be processed by an external digital filter or FPGA/MCU to obtain a multi-bit conversion result.