Part A
ADS7870EA
Техасские инструменты
- Lifecycle
- Active
- Stock
- 3964 ПКС
- Package
- SSOP-28
- Series
- Сбор данных - ADC-DAC - Специальное назначение
Replacement verdict
Not a drop-in replacement
The ADS7870EA and ADS7841E/2K5G4 are not drop-in replacements for each other. The ADS7870EA integrates a 12-bit ADC with a programmable gain amplifier, multiplexer, and internal reference in a single package, while the ADS7841E/2K5G4 is a standalone 12-bit ADC with a fixed input configuration. Their differing architectures, channel counts, interface configurations, and package footprints require circuit redesign and validation before any substitution can be considered.
Different channel count
Different interface type
Different package footprint
Different input configuration
Parts at a glance
Part B
ADS7841E/2K5G4
Техасские инструменты
- Lifecycle
- Active
- Stock
- 5974 ПКС
- Package
- SSOP-16
- Series
- Сбор данных - аналогово-цифровые преобразователи (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 | ADS7841E/2K5G4 | 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 ADS7841E 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 (V) | 2.7 to 5.5 | 2.7 to 5.25 | Slightly different upper supply limits affect compatibility with 5 V systems and margin. |
| On-chip Programmable Gain Amplifier (PGA) | Yes (gain 1 to 20) | No | The ADS7870EA includes a PGA for small-signal amplification, which the ADS7841E lacks, affecting low-level signal measurement capability. |
| On-chip Voltage Reference | Yes (internal reference) | No (external reference required) | An internal reference simplifies design and reduces external component count; the ADS7841E requires an external reference. |
| Package / Mounting | SSOP-28 (surface mount) | SSOP-16 (surface mount) | Different package sizes and pin counts affect PCB footprint and layout compatibility. |
| Operating Temperature Range (°C) | -40 to +85 | -40 to +85 | Identical temperature ratings mean both suit the same industrial environments. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADS7870EA | ADS7841E/2K5G4 |
|---|---|---|
| Supplier | - | Texas Instruments |
| Part Status | Active | Obsolete |
| 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 the ADS7841E/2K5G4?
The ADS7870EA is a 12-bit data acquisition system that integrates a 12-bit SAR ADC, a 4-channel differential/8-channel single-ended input multiplexer, a programmable gain amplifier, and an on-chip reference, operating from a single 2.7 V to 5.5 V supply. The ADS7841E/2K5G4 is a standalone 12-bit SAR ADC with a 4-channel single-ended/2-channel differential multiplexer, operating from a single 2.7 V to 5.25 V supply, and requires an external reference voltage. The ADS7870EA integrates signal conditioning and reference functions that the ADS7841E/2K5G4 does not.
Are the ADS7870EA and ADS7841E/2K5G4 pin-compatible or package-compatible?
No. The ADS7870EA is offered in a 28-pin SSOP package, while the ADS7841E/2K5G4 is offered in a 16-pin SSOP package. The pin counts, pin functions, and package footprints differ, so they are not drop-in replacements for each other.
Do both devices support the same serial interface?
Both devices provide a serial interface, but they are not identical. The ADS7870EA uses a serial interface compatible with SPI, QSPI, and Microwire protocols for configuration and data readback. The ADS7841E/2K5G4 uses a 3-wire SPI-compatible serial interface. System firmware and timing must be validated against each device's datasheet before interchange.
How do the input configurations differ between the two parts?
The ADS7870EA supports 8 single-ended or 4 differential input channels with a programmable gain amplifier. The ADS7841E/2K5G4 supports 4 single-ended or 2 differential input channels without an integrated PGA. Designs requiring more channels or gain control should account for these differences.
Do both devices include an internal voltage reference?
The ADS7870EA includes an on-chip reference, while the ADS7841E/2K5G4 requires an external reference voltage applied to its VREF pin. Designs migrating between the two must account for the reference source and the resulting full-scale input range.
What are the supply voltage and power consumption considerations when comparing these parts?
The ADS7870EA operates from a single 2.7 V to 5.5 V supply, and the ADS7841E/2K5G4 operates from a single 2.7 V to 5.25 V supply. Because the ADS7870EA integrates a multiplexer, PGA, and reference, its power consumption profile differs from the standalone ADS7841E/2K5G4. Actual current consumption should be verified from each device's datasheet under the intended operating conditions.
Can the ADS7841E/2K5G4 be used as a direct substitute for the ADS7870EA in an existing design?
No. The devices differ in package pin count, input channel count, integrated gain and reference functions, and serial interface details. A direct substitution is not supported; any replacement requires schematic, layout, firmware, and timing validation against the target device's datasheet.