Part A
ADS1281IPWR
텍사스 인스트루먼트(주)
- Lifecycle
- Active
- Stock
- 7474 PCS
- Package
- TSSOP-24
- Series
- 데이터 수집 - 아날로그 변환기(ADC)
Replacement verdict
Not a drop-in replacement
The ADS1281IPWR and ADS1208IPWRG4 are not drop-in replacements for one another. The ADS1281IPWR is a high-resolution 31-bit delta-sigma ADC with an SPI-compatible serial interface, while the ADS1208IPWRG4 is a 16-bit delta-sigma modulator with a single-bit Manchester-encoded output. They differ in resolution, output interface, package footprint, and supply voltage requirements, so the ADS1208IPWRG4 cannot be substituted directly for the ADS1281IPWR in an existing design without significant rework.
Different output interface
Different resolution
Different package footprint
Different supply voltage
Parts at a glance
Part B
ADS1208IPWRG4
텍사스 인스트루먼트(주)
- Lifecycle
- Active
- Stock
- 4872 PCS
- Package
- TSSOP-16
- Series
- 데이터 수집 - ADC DAC- 전용
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 | ADS1208IPWRG4 | 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 quantization than a 16-bit device, directly affecting measurement precision. |
| Architecture | Delta-Sigma (2nd order) | Delta-Sigma (2nd order) | Both use delta-sigma modulation, but the ADS1281 is a high-resolution seismic-grade converter while the ADS1208 is a lower-resolution isolated-modulator-oriented part, so noise and bandwidth performance differ substantially. |
| Sample Rate (max) | 4 kSPS | 40 kSPS | Maximum sample rate sets the achievable signal bandwidth; the ADS1208 supports higher throughput for faster control loops, while the ADS1281 trades speed for resolution. |
| Input Type | Differential | Differential | Differential inputs reject common-mode noise; both are differential, but their input ranges and drive requirements differ, affecting sensor interfacing. |
| Supply Voltage | 5 V (analog), 3.3 V (digital) | 5 V | Supply requirements determine power-rail compatibility; the ADS1281 needs separate analog and digital rails, while the ADS1208 runs from a single 5 V supply. |
| Interface | SPI (serial) | Serial (modulator output) | The interface dictates how the host reads data; the ADS1281 provides a standard SPI register interface, whereas the ADS1208 outputs a raw modulator bitstream requiring external filtering. |
| Package | TSSOP-24 | TSSOP-16 | Package footprint and pin count affect PCB layout and drop-in compatibility; the two parts are not pin-compatible. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Both cover the industrial temperature range, so environmental tolerance is comparable for most applications. |
| Typical Application | Seismic and high-resolution energy exploration | Motor control and isolated current sensing | Target applications reveal the intended signal chain; the ADS1281 is optimized for ultra-low-noise precision measurement, while the ADS1208 targets isolated modulator-based control systems. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADS1281IPWR | ADS1208IPWRG4 |
|---|---|---|
| Supplier | - | Texas Instruments |
| 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 | - | Analog and Digital |
| Voltage - Supply | - | 2.7V ~ 5.5V, 4.5V ~ 5.5V |
| 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 ADS1281IPWR and ADS1208IPWRG4?
The ADS1281IPWR 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 selectable data rates up to 4 kSPS. The ADS1208IPWRG4 is a 16-bit delta-sigma modulator with a digital filter interface, intended for isolated current and voltage sensing in motor control and power conversion, offering a fixed 10 MHz master clock and a 78.1 kSPS output word rate. They differ fundamentally in resolution, architecture, and target application.
Are the ADS1281IPWR and ADS1208IPWRG4 pin-to-pin compatible?
No. The ADS1281IPWR is supplied in a 24-pin TSSOP package, while the ADS1208IPWRG4 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 specified supply voltage requirements for each device?
The ADS1281IPWR operates from an analog supply (AVDD) of 4.75 V to 5.25 V and a digital supply (DVDD) of 2.7 V to 3.6 V. The ADS1208IPWRG4 operates from a single 5 V supply (4.5 V to 5.5 V) for both analog and digital sections, with an additional isolated supply requirement depending on the application circuit.
Which device offers higher resolution and better SNR?
The ADS1281IPWR provides significantly higher resolution at 31 bits and achieves a signal-to-noise ratio (SNR) of up to 130 dB at 250 SPS. The ADS1208IPWRG4 is a 16-bit modulator with an SNR of approximately 84 dB. The ADS1281IPWR is therefore the higher-performance device for precision measurement applications.
Can the ADS1208IPWRG4 be used for seismic data acquisition like the ADS1281IPWR?
No. The ADS1281IPWR is specifically characterized for seismic and energy exploration with low noise, high resolution, and programmable gain. The ADS1208IPWRG4 is optimized for isolated current sensing in motor control and does not provide the resolution or the on-chip programmable gain amplifier required for seismic-grade signal chains.
What output interface does each converter provide?
The ADS1281IPWR provides a serial peripheral interface (SPI)-compatible output with a programmable digital filter and selectable data rates. The ADS1208IPWRG4 provides a single-bit delta-sigma modulator output stream that requires an external digital filter or a microcontroller with a suitable sinc filter to reconstruct the 16-bit data word.
Do both parts support the same operating temperature range?
Yes. Both the ADS1281IPWR and the ADS1208IPWRG4 are specified for the industrial temperature range of -40°C to +85°C, as stated in their respective manufacturer datasheets.