Part A
ADS7870EA
Texas Instruments
- Lifecycle
- Active
- Stock
- 3964 PCS
- Package
- SSOP-28
- Series
- Data Acquisition - ADCs-DACs - Special Purpose
Replacement verdict
Not a drop-in replacement
The ADS7870EA and ADS7841ESG4 are not drop-in replacements for one another. Although both are 12-bit successive-approximation ADCs, they differ fundamentally in serial interface protocol, analog input architecture, package footprint, and integrated feature set, so a direct board-level substitution is not possible without redesign.
Different serial interface
Different input architecture
Different package footprint
Different integrated features
Parts at a glance
Part B
ADS7841ESG4
Texas Instruments
- Lifecycle
- Active
- Stock
- 5879 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 | ADS7841ESG4 | Why it matters |
|---|---|---|---|
| Resolution (bits) | 12 | 12 | Both are 12-bit ADCs, so resolution is equivalent for substitutability. |
| Number of ADC Input Channels | 8 (single-ended) / 4 (differential) | 4 (single-ended) / 2 (differential) | The ADS7870EA supports twice as many input channels, which affects how many signals can be multiplexed without external circuitry. |
| Sampling Rate (max) | 52 kSPS | 200 kSPS | The ADS7841ESG4 offers a much higher throughput, which matters for faster signal acquisition requirements. |
| Interface Type | SPI / QSPI / Microwire / DSP (serial) | SPI / QSPI / Microwire / DSP (serial) | Both use a compatible serial interface, easing drop-in replacement from a bus standpoint. |
| Supply Voltage (analog) | 2.7 V to 5.5 V | 2.7 V to 5.25 V | Slightly different maximum analog supply voltage; the ADS7870EA tolerates a marginally higher rail. |
| Integrated Programmable Gain Amplifier (PGA) | Yes (gain 1 to 20) | No | The ADS7870EA includes a PGA for small-signal amplification, which the ADS7841ESG4 lacks, affecting low-level signal handling. |
| Integrated Voltage Reference | Yes (internal 2.5 V) | No (external reference required) | The ADS7870EA has an on-chip reference, reducing external component count versus the ADS7841ESG4. |
| Package / Mounting | 28-SSOP (surface mount) | 16-SSOP (surface mount) | Different package footprints and pin counts mean the boards are not physically interchangeable without redesign. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Identical industrial temperature range, so environmental suitability is equivalent. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADS7870EA | ADS7841ESG4 |
|---|---|---|
| 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
What are the key architectural differences between the ADS7870EA and ADS7841ESG4?
The ADS7870EA is a 12-bit data acquisition system (DAS) integrating a 4-channel differential input multiplexer, a programmable gain amplifier (PGA), a 12-bit successive-approximation ADC, and a serial interface in a 28-pin SSOP package. The ADS7841ESG4 is a standalone 12-bit, 4-channel (single-ended or 2-channel differential) successive-approximation ADC with a serial interface, offered in a 16-pin SSOP package. The ADS7870EA integrates signal conditioning (PGA and MUX) that the ADS7841ESG4 does not include.
Do the ADS7870EA and ADS7841ESG4 have the same resolution and sampling rate?
Both devices provide 12-bit resolution. The ADS7870EA supports a maximum throughput of 52 kSPS, while the ADS7841ESG4 supports a maximum throughput of 200 kSPS. The ADS7841ESG4 therefore offers a higher maximum sampling rate than the ADS7870EA.
Are the ADS7870EA and ADS7841ESG4 pin-compatible or package-compatible?
No. The ADS7870EA is supplied in a 28-pin SSOP package, and the ADS7841ESG4 is supplied in a 16-pin SSOP package. The pin counts, pin functions, and package footprints differ, so they are not drop-in replacements for one another.
What input channel configurations do the ADS7870EA and ADS7841ESG4 support?
The ADS7870EA provides a 4-channel differential input multiplexer with programmable gain, allowing differential or single-ended configurations through its integrated MUX and PGA. The ADS7841ESG4 provides 4 single-ended inputs or 2 differential input pairs, selectable via its input configuration, without an integrated PGA.
How do the supply voltage and reference requirements compare between the ADS7870EA and ADS7841ESG4?
The ADS7870EA operates from a single 5 V supply (with an on-chip reference and reference buffer). The ADS7841ESG4 operates from a single 2.7 V to 5 V supply and requires an external reference voltage applied to its VREF pin. Designers must account for these differences in supply and reference architecture when comparing the two devices.
What serial interface do the ADS7870EA and ADS7841ESG4 use?
Both devices use a serial interface for communication with a host controller. The ADS7870EA provides a serial interface compatible with SPI/QSPI/MICROWIRE protocols. The ADS7841ESG4 also provides an SPI-compatible serial interface. Exact timing and protocol details should be verified against the respective manufacturer datasheets before design integration.
Can the ADS7870EA and ADS7841ESG4 be used interchangeably in an existing design?
No. Due to differences in package pinout, pin count, integrated functionality (the ADS7870EA includes a PGA and MUX), sampling rate, and reference architecture, the two devices are not interchangeable without a redesign of the circuit, footprint, and firmware. Each part should be evaluated against its own datasheet for the target application.