Part A
ADS1242IPWR
德州儀器
- Lifecycle
- Active
- Stock
- 5745 件
- Package
- TSSOP-16
- Series
- 資料獲取-模數轉換器（ADC）
Replacement verdict
Not a drop-in replacement
The ADS1242IPWR and ADS1208IPWR are not functionally interchangeable. The ADS1242IPWR is a 24-bit delta-sigma ADC with an integrated PGA and SPI interface, while the ADS1208IPWR is a 16-bit delta-sigma modulator with a single-bit output and no integrated digital filter or serial register interface. Their resolution, output format, and interface architecture differ fundamentally, so the ADS1208IPWR cannot directly replace the ADS1242IPWR in existing designs without significant redesign.
Different output type
Different resolution
Different interface
Different functional architecture
Parts at a glance
Part B
ADS1208IPWR
德州儀器
- Lifecycle
- Active
- Stock
- 7626 件
- Package
- TSSOP-16
- 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 | ADS1242IPWR | ADS1208IPWR | Why it matters |
|---|---|---|---|
| Resolution (bits) | 24 | 16 | Higher resolution enables finer measurement of small signal changes; a 24-bit ADC resolves much smaller steps than a 16-bit ADC. |
| Architecture | Delta-Sigma (low-speed, high-resolution) | Delta-Sigma modulator (current-shunt oriented) | The converter architecture determines noise shaping, bandwidth, and the type of signal chain the device is suited for. |
| Input type / channels | 4-channel differential/single-ended (PGA input) | Single-channel differential modulator input | Channel count and input configuration dictate how many signals can be measured and whether multiplexing is required. |
| Output interface | SPI-compatible serial (digital output) | 1-bit delta-sigma bitstream | The output format determines the required host interface and whether an external digital filter/decimator is needed. |
| Programmable gain amplifier (PGA) | Yes (on-chip PGA) | No (external gain/filtering required) | An integrated PGA allows direct connection of low-level sensors without external amplification, simplifying the signal chain. |
| Supply voltage | 2.7 V to 5.25 V (analog and digital) | 5 V (single supply) | Supply range affects compatibility with system rails and low-power operation. |
| Package | TSSOP-16 | TSSOP-16 | Package footprint and pinout determine board layout compatibility and whether a drop-in replacement is possible. |
| Typical application focus | Precision sensor/industrial measurement | Motor control / current-shunt measurement | Application focus indicates whether the device is optimized for precision DC sensing or for isolated current-sense signal chains. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADS1242IPWR | ADS1208IPWR |
|---|---|---|
| Supplier | - | Texas Instruments,Rochester Electronics, LLC |
| Part Status | Active | Obsolete |
| Type | - | Modulator |
| Number of Channels | - | 1 |
| Resolution(Bits) | - | 16 b |
| Sampling Rate(Per Second) | 15 | 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 | 24 | - |
| Number of Inputs | 4 | - |
| Input Type | Differential, Single Ended | - |
| Configuration | MUX-PGA-ADC | - |
| Number of A/D Converters | 1 | - |
| Architecture | Sigma-Delta | - |
| Reference Type | External | - |
| Voltage - Supply, Analog | 2.7V ~ 3.3V, 5V | - |
| Voltage - Supply, Digital | 2.7V ~ 5.25V | - |
| Features | PGA | - |
Frequently asked questions
What are the primary functional differences between the ADS1242IPWR and ADS1208IPWR?
The ADS1242IPWR is a 24-bit delta-sigma analog-to-digital converter (ADC) with a low-noise programmable gain amplifier (PGA) and an SPI-compatible serial interface, designed for precision low-frequency measurement. The ADS1208IPWR is a 16-bit delta-sigma modulator with a ±2.5 V input range and a digital filter interface, intended for isolated signal conditioning and current-sensing applications. They differ in resolution, output format, and intended signal chain role.
Are the ADS1242IPWR and ADS1208IPWR pin-to-pin compatible?
No. Both devices are offered in a TSSOP-16 package (PW suffix), but their pin functions and internal architectures differ. The ADS1242IPWR provides a complete ADC with PGA, reference input, and SPI interface, while the ADS1208IPWR provides a modulator output requiring an external digital filter. Pin assignments and functions must be verified against the respective manufacturer datasheets before any layout substitution.
What is the resolution and output format of each device?
The ADS1242IPWR provides 24-bit resolution with a serial SPI output word. The ADS1208IPWR is a 16-bit delta-sigma modulator that outputs a 1-bit serial bitstream (modulator output) at a high oversampling rate, which must be processed by an external digital filter to obtain a 16-bit result. The two devices are therefore not interchangeable in terms of output data format.
Can the ADS1208IPWR be used as a direct replacement for the ADS1242IPWR in an existing design?
No. The ADS1242IPWR integrates a PGA, reference, and SPI interface that deliver a complete ADC function, whereas the ADS1208IPWR requires an external digital filter and different clocking and interface circuitry. A direct replacement would require redesign of the signal chain, clocking, and digital filtering, and is not supported by pin or functional compatibility.
What are the typical applications for each device?
The ADS1242IPWR is typically used in precision instrumentation, weigh scales, temperature and pressure sensing, and industrial process control where high resolution and low noise are required. The ADS1208IPWR is typically used in isolated current sensing, motor control, power measurement, and other applications requiring a modulator output for galvanic isolation and digital filtering.
Do both devices support the same supply voltage range?
Both devices are specified for a single 5 V analog supply in their respective datasheets, but the ADS1242IPWR also requires a digital supply and provides an internal PGA and reference, while the ADS1208IPWR is designed for a 5 V supply with a ±2.5 V input range. Exact supply and reference requirements must be confirmed from the manufacturer datasheets for each part before design use.
Which device is better suited for isolated signal measurement?
The ADS1208IPWR is better suited for isolated signal measurement because its modulator output bitstream can be transmitted across an isolation barrier and processed by a digital filter on the isolated or non-isolated side. The ADS1242IPWR provides a complete ADC with SPI output and is not specifically intended for isolated modulator-based signal chains.