Part A
ADS1242IPWR
STマイクロエレクトロニクス
- Lifecycle
- Active
- Stock
- 5745 個数
- Package
- TSSOP-16
- Series
- データ取得 - アナログ/デジタルコンバータ (ADC)
Replacement verdict
Not a drop-in replacement
The ADS1242IPWR and ADS1208IPWRG4 are not drop-in replacements for one another. The ADS1242IPWR is a 24-bit delta-sigma ADC with an SPI-compatible serial interface and integrated PGA, while the ADS1208IPWRG4 is a 16-bit second-order delta-sigma modulator with a single-bit output stream. They differ in resolution, output interface, channel configuration, and package pinout, so direct substitution is not feasible without redesign of the surrounding signal chain and digital interface.
Different output interface
Different resolution
Different channel configuration
Different package pinout
Parts at a glance
Part B
ADS1208IPWRG4
STマイクロエレクトロニクス
- Lifecycle
- Active
- Stock
- 4872 個数
- Package
- TSSOP-16
- Series
- データ取得 - ADC/DAC - 特殊用途向け
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 | ADS1208IPWRG4 | 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 device. |
| Architecture | Delta-Sigma (with PGA) | Delta-Sigma modulator | The ADS1242 integrates a programmable gain amplifier and digital filter for direct sensor interfacing, while the ADS1208 is a modulator-only device requiring external digital filtering. |
| Number of input channels | 4 (differential) | 1 (differential) | More channels allow multiple sensors to be measured by one device; the single-channel ADS1208 suits isolated single-signal paths. |
| Interface type | SPI (serial) | Serial bit-stream output | The ADS1242 provides a standard SPI interface with on-chip filtering, whereas the ADS1208 outputs a raw modulator bit-stream that must be processed by an external digital filter. |
| Supply voltage (analog) | 2.7 V to 5.25 V | 4.5 V to 5.5 V | Wider supply range offers flexibility for low-voltage systems; the ADS1208 requires a nominal 5 V supply. |
| Package | TSSOP-16 | TSSOP-16 | Package footprint affects PCB layout and drop-in compatibility; both share the same TSSOP-16 footprint. |
| Operating temperature range | -40 °C to +85 °C | -40 °C to +85 °C | Industrial temperature range ensures reliable operation across harsh environments; both devices meet the same range. |
| Typical application focus | Precision sensor measurement (temperature, pressure, weigh scales) | Isolated current/voltage sensing, motor control | The integrated PGA and digital filter of the ADS1242 target direct precision sensing, while the modulator-only ADS1208 is optimized for isolated signal chains. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADS1242IPWR | ADS1208IPWRG4 |
|---|---|---|
| Supplier | - | Texas Instruments |
| 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 ADS1208IPWRG4?
The ADS1242IPWR is a 24-bit delta-sigma analog-to-digital converter (ADC) with a built-in PGA and SPI interface, designed for low-frequency precision measurement. The ADS1208IPWRG4 is a 16-bit delta-sigma modulator with a ±2.5 V input range and a digital filter interface, intended for isolated current sensing and industrial applications. They differ in resolution, output format, and typical application focus.
Are the ADS1242IPWR and ADS1208IPWRG4 pin-compatible?
No. The ADS1242IPWR is supplied in a 20-pin TSSOP package, while the ADS1208IPWRG4 is supplied in a 16-pin TSSOP package. Pin counts and pin functions differ, so they are not drop-in replacements.
What are the supply voltage requirements for each device?
The ADS1242IPWR operates from a single 2.7 V to 5.25 V analog supply and a 2.7 V to 5.25 V digital supply. The ADS1208IPWRG4 operates from a 4.5 V to 5.5 V analog supply and a 2.7 V to 5.5 V digital supply. Designs must verify that the available rails meet these ranges.
Which device offers higher resolution and why does it matter?
The ADS1242IPWR provides 24-bit resolution, whereas the ADS1208IPWRG4 provides 16-bit resolution. Higher resolution in the ADS1242IPWR supports finer measurement of low-level signals, while the ADS1208IPWRG4 is optimized for modulator-based isolated sensing where 16-bit resolution is sufficient.
Can the ADS1208IPWRG4 directly replace the ADS1242IPWR in an existing SPI-based design?
No. The ADS1242IPWR uses an SPI-compatible serial interface for reading conversion results, while the ADS1208IPWRG4 outputs a single-bit delta-sigma modulator stream that requires an external digital filter or FPGA to reconstruct the data. The interface and data format are not interchangeable.
What are the typical input configurations for these two converters?
The ADS1242IPWR supports differential and single-ended inputs with an integrated programmable gain amplifier. The ADS1208IPWRG4 has a fixed ±2.5 V input range and is typically used with a shunt resistor for current sensing. Input conditioning and gain settings must be designed accordingly.
Do both parts support the same operating temperature range?
Both the ADS1242IPWR and ADS1208IPWRG4 are specified for the industrial temperature range of −40 °C to +85 °C. System-level thermal design should still be validated for the target application.
Which device is better suited for isolated current sensing applications?
The ADS1208IPWRG4 is specifically intended for isolated current sensing because its modulator output can be passed through a digital isolator and reconstructed by a digital filter. The ADS1242IPWR is a complete ADC with SPI output and is more suited to direct precision voltage or sensor measurements rather than isolated current-sense chains.