Part A
ADS7844EB
Texas Instruments
- Lifecycle
- Active
- Stock
- 3681 PCS
- Package
- SSOP-20
- Series
- Data Acquisition - Analog to Digital Converters (ADC)
Replacement verdict
Compatible functional replacement candidate
The ADS7844EB and ADS7841EG4 are both 12-bit successive-approximation ADCs from Texas Instruments with a serial SPI/QSPI/MICROWIRE interface, making them functionally interchangeable in many designs. However, the ADS7844EB provides 8 input channels versus 4 on the ADS7841EG4, and the two devices differ in package and pinout, so the replacement is viable only when the reduced channel count and layout changes are acceptable.
Resolution
High match
Interface Type
High match
Channel Count
Validation required
Package Type
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 | ADS7844EB | ADS7841EG4 | Why it matters |
|---|---|---|---|
| Number of Input Channels | 8 single-ended / 4 differential | 4 single-ended / 2 differential | Determines how many analog signals can be measured; a direct functional substitutability constraint. |
| Resolution | 12 bit | 12 bit | Both provide 12-bit conversion, so measurement precision is equivalent. |
| Sampling Rate | 200 kSPS | 200 kSPS | Maximum throughput must meet the system's signal bandwidth requirements. |
| Supply Voltage | 2.7 V to 5.25 V | 2.7 V to 5.25 V | Operating voltage range must match the host system's power rails. |
| Interface Type | SPI / Serial | SPI / Serial | Digital interface compatibility is required for direct drop-in replacement. |
| Package / Case | 20-SSOP | 16-SSOP | Different package pin counts and footprints affect PCB layout and mechanical fit. |
| Pin Count | 20 | 16 | Pin count differences prevent direct footprint compatibility between the two parts. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Both support industrial temperature ranges, suitable for the same environments. |
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 | ADS7844EB | ADS7841EG4 |
|---|---|---|
| Supplier | - | Texas Instruments |
| Part Status | Active | Discontinued at Digi-Key |
| 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 | SPI |
| 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 |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 125°C |
Frequently asked questions
What are the primary differences between the ADS7844EB and ADS7841EG4?
The ADS7844EB is an 8-channel, 12-bit successive-approximation ADC, while the ADS7841EG4 is a 4-channel, 12-bit SAR ADC. Both operate from a 2.7 V to 5 V single supply and offer a serial SPI/QSPI/Microwire-compatible interface, but the ADS7844EB provides twice the input channel count of the ADS7841EG4.
Are the ADS7844EB and ADS7841EG4 pin-compatible?
No. The ADS7844EB is offered in a 20-pin SSOP package, whereas the ADS7841EG4 is offered in a 16-pin SSOP package. The differing pin counts and pinouts mean they are not drop-in replacements for one another.
Do both devices support the same analog input configuration?
Both ADCs support single-ended and differential input configurations. The ADS7844EB provides 8 input channels (4 differential pairs), while the ADS7841EG4 provides 4 input channels (2 differential pairs), so the ADS7844EB accommodates more analog signal sources per device.
What is the maximum sampling rate of each device?
Both the ADS7844EB and ADS7841EG4 are specified for a 200 kHz throughput rate at a 5 V supply, using a 12-bit successive-approximation architecture with an external reference.
Do the ADS7844EB and ADS7841EG4 use the same external reference requirements?
Yes. Both devices require an external voltage reference applied to the VREF pin, and the reference voltage sets the full-scale input range. The reference input range and the analog input span scale accordingly for both parts.
Can the ADS7841EG4 replace the ADS7844EB in an existing design?
Not directly. Because the ADS7841EG4 has fewer channels (4 versus 8) and a different package and pinout (16-pin versus 20-pin SSOP), a redesign of the analog input multiplexing and PCB layout would be required. The replacement is only appropriate when 4 channels are sufficient and the layout is revised.
What supply voltage range do both devices support?
Both the ADS7844EB and ADS7841EG4 operate from a single supply voltage of 2.7 V to 5 V, making them suitable for low-power, battery-operated and portable instrumentation applications.