Part A
ADS7844NB/1K
Texas Instruments
- Lifecycle
- Active
- Stock
- 5039 PCS
- Package
- SSOP-20
- Series
- Acquisition de données - Convertisseur analogique - numérique (ADC)
Replacement verdict
Compatible functional replacement candidate
The ADS7841ESG4 is a functional replacement candidate for the ADS7844NB/1K, sharing the same 12-bit SAR architecture, 4-channel input multiplexer, and 200 kSPS throughput, but it is not a drop-in replacement due to differences in package, supply voltage range, and serial interface framing that require validation before substitution.
Resolution and Architecture
High match
Channel Count
High match
Package Type
Validation required
Supply Voltage Range
Validation required
Parts at a glance
Part B
ADS7841ESG4
Texas Instruments
- Lifecycle
- Active
- Stock
- 5879 PCS
- Package
- SSOP-16
- Series
- Acquisition de données - Convertisseur analogique - numérique (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 | ADS7844NB/1K | ADS7841ESG4 | Why it matters |
|---|---|---|---|
| Number of Input Channels | 8 (single-ended) / 4 (pseudo-differential) | 4 (single-ended) / 2 (pseudo-differential) | Channel count determines how many analog signals can be multiplexed into the ADC; a drop from 8 to 4 channels limits system expandability. |
| Resolution | 12 bit | 12 bit | Resolution sets the smallest measurable analog step; both are 12-bit so quantization granularity is equivalent. |
| Sampling Rate | 200 kSPS | 200 kSPS | Throughput determines the maximum signal bandwidth that can be digitized; identical rates mean comparable acquisition speed. |
| Supply Voltage | 2.7 V to 5.25 V | 2.7 V to 5.25 V | Supply range must match the host system rails; identical ranges allow drop-in use across 3 V and 5 V designs. |
| Interface Type | SPI / QSPI / Microwire compatible serial | SPI / QSPI / Microwire compatible serial | Serial interface compatibility ensures the same microcontroller bus and firmware protocol can drive either part. |
| Package / Mounting | 20-SSOP (surface mount) | 16-SSOP (surface mount) | Different package pin counts and footprints require PCB layout changes, preventing direct board-level substitution. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Temperature range defines the environments where the part is guaranteed; matching ranges suit the same industrial applications. |
| Input Type | Single-ended and pseudo-differential | Single-ended and pseudo-differential | Input configuration affects how sensor signals are wired; both support the same single-ended and pseudo-differential modes. |
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 | ADS7844NB/1K | ADS7841ESG4 |
|---|---|---|
| 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 key differences between the ADS7844NB/1K and the ADS7841ESG4?
The ADS7844NB/1K is an 8-channel, 12-bit successive-approximation ADC with a serial interface, housed in a 20-pin SSOP package (NB suffix). The ADS7841ESG4 is a 4-channel, 12-bit SAR ADC in a 16-pin QSOP package (ESG4 suffix). The ADS7844 provides twice the input channel count, while the ADS7841 offers a smaller package and fewer channels for space-constrained designs.
Are the ADS7844NB/1K and ADS7841ESG4 pin-to-pin compatible?
No. The ADS7844NB/1K uses a 20-pin SSOP package, while the ADS7841ESG4 uses a 16-pin QSOP package. The differing pin counts and package footprints mean they are not drop-in replacements and require different PCB land patterns.
Do both devices share the same resolution and sampling architecture?
Yes. Both are 12-bit successive-approximation register (SAR) ADCs. Both support serial SPI-compatible interfaces and operate from a single 2.7 V to 5.25 V supply, making them suitable for similar precision measurement applications.
How do the input channel counts compare between the two parts?
The ADS7844NB/1K provides 8 single-ended inputs (or 4 differential pairs), while the ADS7841ESG4 provides 4 single-ended inputs (or 2 differential pairs). Designs requiring more analog inputs should select the ADS7844; designs with fewer channels can use the smaller ADS7841.
Can the ADS7841ESG4 replace the ADS7844NB/1K in an existing design?
Not directly. Beyond the package and pin count differences, the channel count is halved (4 vs 8). A replacement would require PCB redesign, reduced input channel requirements, and revalidation of the serial interface timing against the respective datasheets.
What supply voltage range do both ADCs support?
Both the ADS7844NB/1K and ADS7841ESG4 operate from a single supply of 2.7 V to 5.25 V, allowing use in both 3.3 V and 5 V systems. Reference voltage and analog input range should be configured per each device's datasheet.
Which part is better suited for space-constrained designs?
The ADS7841ESG4, with its 16-pin QSOP package, occupies less board area than the 20-pin SSOP of the ADS7844NB/1K. For applications needing only 4 analog channels, the ADS7841ESG4 is the more compact choice.