Part A
ADS7870EA
Texas Instruments
- Lifecycle
- Active
- Stock
- 3964 PCS
- Package
- SSOP-28
- Series
- Data Acquisition - ADCs-DACs - Special Purpose
Replacement verdict
Compatible functional replacement candidate
The ADS7870EA and ADS7841EG4 are both 12-bit successive-approximation ADCs from Texas Instruments with a 4-channel single-ended input multiplexer and an SPI-compatible serial interface, making them functionally comparable in many data-acquisition designs. However, they differ in supply voltage range, integrated features, and package footprint, so the ADS7841EG4 should be treated as a functional candidate rather than a pin-for-pin drop-in replacement. Designers must validate supply rails, reference configuration, and board layout before substituting one for the other.
Resolution and ADC Architecture
High match
Input Channel Configuration
High match
Supply Voltage Range
Validation required
Package and Pinout
Not compatible
Parts at a glance
Part B
ADS7841EG4
Texas Instruments
- Lifecycle
- Active
- Stock
- 8773 PCS
- Package
- SSOP-16
- Series
- Data Acquisition - Analog to Digital Converters (ADC)
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | ADS7870EA | ADS7841EG4 | Why it matters |
|---|---|---|---|
| Resolution | 12 bit | 12 bit | Both are 12-bit converters, so nominal resolution is equivalent for substitutability. |
| Number of ADC Inputs / Channels | 8 single-ended / 4 differential (with input MUX) | 4 single-ended / 2 differential | The ADS7870EA supports more channels, which affects how many signals can be measured without external multiplexing. |
| Sampling Rate | 52 kSPS | 200 kSPS | The ADS7841EG4 offers a much higher throughput, which matters for faster signal acquisition requirements. |
| Interface Type | Serial (SPI-compatible) | Serial (SPI-compatible) | Both use a serial interface, simplifying drop-in compatibility with common microcontrollers. |
| Supply Voltage | 2.7 V to 5.5 V | 2.7 V to 5.25 V | Similar supply ranges allow operation from common 3.3 V and 5 V rails, though upper limits differ slightly. |
| Integrated Programmable Gain Amplifier (PGA) | Yes | No | The ADS7870EA includes a PGA for small-signal amplification, which the ADS7841EG4 lacks, affecting low-level signal measurement. |
| Internal Reference | Yes | No (external reference required) | An internal reference simplifies design; the ADS7841EG4 requires an external reference voltage. |
| Package / Mounting | SSOP-28 (surface mount) | SSOP-16 (surface mount) | Different package sizes and pin counts mean the parts are not footprint-compatible. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Identical temperature ratings support use in the same industrial environments. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADS7870EA | ADS7841EG4 |
|---|---|---|
| Supplier | - | Texas Instruments |
| Part Status | Active | Discontinued at Digi-Key |
| Number of Bits | - | 12 |
| Sampling Rate(Per Second) | 52k | 200k |
| Number of Inputs | - | 4 |
| Input Type | - | Single Ended |
| Data Interface | Serial | SPI |
| Configuration | - | MUX-S/H-ADC |
| Ratio - S / H: ADC | - | 1:1 |
| Number of A/D Converters | - | 1 |
| Architecture | - | SAR |
| Reference Type | - | External |
| Voltage - Supply, Analog | - | 2.7V ~ 3.6V, 5V |
| Voltage - Supply, Digital | - | 2.7V ~ 3.6V, 5V |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 125°C |
| Type | Data Acquisition System (DAS) | - |
| Number of Channels | 8 | - |
| Resolution(Bits) | 12 b | - |
| Voltage Supply Source | Single Supply | - |
| Voltage - Supply | 2.7V ~ 5.5V | - |
| Mounting Type | Surface Mount | - |
Frequently asked questions
Are the ADS7870EA and ADS7841EG4 functionally interchangeable?
No. The ADS7870EA is a 12-bit data acquisition system (DAS) integrating a 12-bit SAR ADC, an 8-channel input multiplexer, a programmable gain amplifier, and a 1.15 V/2.5 V reference, communicating over a serial interface. The ADS7841EG4 is a standalone 12-bit, 4-channel SAR ADC with a 2.5 V reference and a serial interface. The channel count, integrated gain stage, and reference architecture differ, so they are not direct substitutes.
How do the analog input channel counts differ between the ADS7870EA and ADS7841EG4?
The ADS7870EA provides an 8-channel single-ended or 4-channel differential input multiplexer. The ADS7841EG4 provides a 4-channel single-ended or 2-channel differential input multiplexer. Designs requiring more than four single-ended inputs cannot use the ADS7841EG4 without external multiplexing.
Do the ADS7870EA and ADS7841EG4 have the same resolution and sampling rate?
Both devices are 12-bit successive-approximation ADCs. The ADS7870EA supports a maximum throughput of 52 kSPS. The ADS7841EG4 supports a maximum throughput of 200 kSPS. The ADS7841EG4 therefore offers a higher maximum sampling rate, while the ADS7870EA trades throughput for integrated signal conditioning.
What are the package and pin-count differences between the ADS7870EA and ADS7841EG4?
The ADS7870EA is offered in a 28-pin SSOP (DB) package. The ADS7841EG4 is offered in a 16-pin SSOP (DBQ) package. The different pin counts and pinouts mean the two devices are not footprint-compatible and cannot be dropped into the same PCB land pattern.
How do the reference voltage configurations compare between the ADS7870EA and ADS7841EG4?
The ADS7870EA includes an internal reference selectable at 1.15 V or 2.5 V, and also supports an external reference. The ADS7841EG4 uses a 2.5 V reference, which can be supplied internally or externally depending on configuration. Designs relying on the ADS7870EA's 1.15 V reference option cannot replicate that setting with the ADS7841EG4.
Do the ADS7870EA and ADS7841EG4 use the same serial interface?
Both devices use a serial interface for communication with a host controller, but the register sets and command structures differ because the ADS7870EA integrates additional functions (multiplexer and programmable gain amplifier control) that the ADS7841EG4 does not. Firmware written for one device is not directly portable to the other without modification.
Which device is better suited for multi-channel sensor acquisition with gain?
The ADS7870EA is better suited for multi-channel sensor acquisition requiring signal gain, because it integrates an 8-channel multiplexer and a programmable gain amplifier on-chip. The ADS7841EG4 lacks an integrated PGA and provides only four input channels, so low-level sensor signals would require external amplification and multiplexing.
Can the ADS7841EG4 replace the ADS7870EA in an existing design?
Not directly. Replacement requires verifying channel count, gain stage requirements, reference voltage, package footprint, pinout, and firmware command structure against the respective manufacturer datasheets. Because the ADS7841EG4 has fewer channels, no integrated PGA, a different package, and a different register interface, a redesign of the analog front end and software is typically necessary.