Part A
ADS7844E/2K5
德州儀器
- Lifecycle
- Active
- Stock
- 3096 件
- Package
- SSOP-20
- Series
- 資料獲取-模數轉換器（ADC）
Replacement verdict
Compatible functional replacement candidate
The ADS7842EB can serve as a functional replacement candidate for the ADS7844E/2K5 in many 12-bit SAR ADC applications, but the design must be validated against the differing channel configuration, package footprint, and interface timing before production adoption.
Channel Configuration
Validation required
Resolution and Architecture
High match
Package Type
Validation required
Interface Timing
Validation required
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | ADS7844E/2K5 | ADS7842EB | Why it matters |
|---|---|---|---|
| Resolution (bits) | 12 | 12 | Both are 12-bit ADCs, so nominal conversion resolution is equivalent for substitutability. |
| Number of input channels | 8 (single-ended) / 4 (differential) | 4 (single-ended) / 2 (differential) | Channel count determines how many signals can be multiplexed into one ADC; the ADS7844 supports twice as many inputs. |
| Sampling rate (max) | 200 kSPS | 200 kSPS | Maximum throughput affects achievable acquisition speed; both parts offer the same 200 kSPS ceiling. |
| Interface type | SPI / serial (4-wire) | Parallel (byte-wide) | The digital interface differs fundamentally (serial vs parallel), which affects host MCU pin count and firmware compatibility. |
| Supply voltage (analog) | 2.7 V to 5.25 V | 5 V (single supply) | Operating supply range determines compatibility with low-voltage or 5 V systems; the ADS7844 is more flexible across rails. |
| Package | SSOP-20 | SSOP-28 | Different package footprints and pin counts prevent direct board-level drop-in replacement without layout changes. |
| Input type | Single-ended / differential (software selectable) | Single-ended / differential (software selectable) | Both support pseudo-differential and single-ended modes, preserving measurement flexibility. |
| Operating temperature range | -40 °C to +85 °C | -40 °C to +85 °C | Industrial temperature range compatibility ensures both parts suit the same environmental conditions. |
Need help validating a replacement?
Send your BOM and application constraints for technical and sourcing review.
Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADS7844E/2K5 | ADS7842EB |
|---|---|---|
| Supplier | - | Rochester Electronics, LLC |
| Part Status | Active | Active |
| Number of Bits | 12 | 12 |
| Sampling Rate(Per Second) | 200k | 200k |
| Number of Inputs | 4, 8 | 4 |
| Input Type | Differential, Single Ended | Single Ended |
| Data Interface | SPI | Parallel |
| Configuration | MUX-S/H-ADC | MUX-S/H-ADC |
| Ratio - S / H: ADC | 1:1 | 1:1 |
| Number of A/D Converters | 1 | 1 |
| Architecture | SAR | SAR |
| Reference Type | External | External |
| Voltage - Supply, Analog | 2.7V ~ 3.6V, 5V | 2.7V ~ 3.6V, 5V |
| Voltage - Supply, Digital | 2.7V ~ 3.6V, 5V | 2.7V ~ 3.6V, 5V |
| Features | - | Selectable Address |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
Frequently asked questions
What are the key architectural differences between the ADS7844E/2K5 and the ADS7842EB?
The ADS7844E/2K5 is an 8-channel, 12-bit successive-approximation register (SAR) analog-to-digital converter with a serial SPI/QSPI/Microwire interface, housed in a 20-pin SSOP package. The ADS7842EB is a 4-channel, 12-bit SAR ADC with a parallel interface, housed in a 28-pin SSOP package. The ADS7844E/2K5 provides twice the input channel count and a serial interface, while the ADS7842EB offers a parallel interface for faster host-side data reads.
Are the ADS7844E/2K5 and ADS7842EB pin-to-pin or package compatible?
No. The ADS7844E/2K5 uses a 20-pin SSOP package, while the ADS7842EB uses a 28-pin SSOP package. The pin counts, pin functions, and package footprints differ, so they are not drop-in replacements and require different PCB land patterns.
Do the ADS7844E/2K5 and ADS7842EB support the same digital host interface?
No. The ADS7844E/2K5 uses a serial interface compatible with SPI, QSPI, and Microwire protocols. The ADS7842EB uses a parallel microprocessor interface. System designers must select the device that matches the host controller's available interface.
How do the input channel counts of the ADS7844E/2K5 and ADS7842EB compare?
The ADS7844E/2K5 provides 8 analog input channels, configurable as single-ended or differential pairs. The ADS7842EB provides 4 analog input channels. The ADS7844E/2K5 is therefore suited to applications requiring more sensor or signal inputs per converter.
What is the resolution and converter architecture of both devices?
Both the ADS7844E/2K5 and the ADS7842EB are 12-bit successive-approximation register (SAR) analog-to-digital converters. Both provide 12-bit resolution, but they differ in channel count, package, and digital interface as noted above.
Can the ADS7844E/2K5 and ADS7842EB operate from the same supply voltage?
Both devices are specified for single-supply operation in the 2.7 V to 5.25 V range, per their respective manufacturer datasheets. Designers should still verify the exact supply and reference requirements for each device against the latest official datasheet before finalizing a design.
Which device should be selected for a design requiring a parallel host interface?
The ADS7842EB should be selected when a parallel microprocessor interface is required, since it provides a parallel data bus. The ADS7844E/2K5 provides only a serial interface and would not meet a parallel-interface requirement without additional glue logic or a different host configuration.
Are the ADS7844E/2K5 and ADS7842EB interchangeable in an existing PCB design?
No. Because the two devices differ in package pin count (20-pin vs 28-pin SSOP), pin functions, and digital interface type (serial vs parallel), they cannot be interchanged on the same PCB without a redesign of the footprint and host interface. Any substitution must be validated against the official manufacturer datasheets for both parts.