Part A
ADS7844NB/1K
德州儀器
- Lifecycle
- Active
- Stock
- 5039 件
- Package
- SSOP-20
- Series
- 資料獲取-模數轉換器（ADC）
Replacement verdict
Compatible functional replacement candidate
The ADS7841EG4 is a functionally compatible replacement candidate for the ADS7844NB/1K in many 12-bit, 4-channel SAR ADC applications, sharing the same resolution, channel count, and serial interface family. However, the two devices differ in package footprint and analog input configuration, so validation of the board layout and input drive circuitry is required before substitution.
Resolution
High match
Channel Count
High match
Package Type
Validation required
Analog Input Configuration
Validation required
Parts at a glance
Part B
ADS7841EG4
德州儀器
- Lifecycle
- Active
- Stock
- 8773 件
- Package
- SSOP-16
- Series
- 資料獲取-模數轉換器（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 | ADS7841EG4 | Why it matters |
|---|---|---|---|
| Resolution | 12 bit | 12 bit | Both are 12-bit ADCs, so conversion resolution is equivalent for substitutability. |
| Number of Input Channels | 8 single-ended / 4 differential | 4 single-ended / 2 differential | The ADS7844 supports twice as many input channels, which affects how many signals can be multiplexed without external circuitry. |
| Sampling Rate | 200 kSPS | 200 kSPS | Identical throughput means timing and bandwidth requirements are met by either device. |
| Supply Voltage (Analog) | 2.7 V to 5.25 V | 2.7 V to 5.25 V | Same analog supply range allows operation from common 3 V or 5 V rails. |
| Interface | SPI / QSPI / Microwire compatible serial | SPI / QSPI / Microwire compatible serial | Matching serial interfaces simplify drop-in replacement in existing digital designs. |
| Package | 20-pin SSOP (DBQ) | 16-pin SSOP (DBQ) | Different pin counts and footprints mean the PCB layout must be redesigned; they are not footprint-compatible. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Same industrial temperature range supports use in identical environmental conditions. |
| Power Consumption (Typical) | Low power CMOS design | Low power CMOS design | Both are low-power CMOS converters suitable for battery-powered and portable applications. |
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 | 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 key differences between the ADS7844NB/1K and the ADS7841EG4?
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 ADS7841EG4 is a 4-channel, 12-bit SAR ADC with a serial interface, supplied in a 16-pin SSOP package (E suffix, G4 indicates lead-free/RoHS-compliant construction). The primary differences are channel count (8 vs. 4), package pin count (20 vs. 16), and the lead-free G4 designation on the ADS7841EG4.
Are the ADS7844NB/1K and ADS7841EG4 pin-compatible?
No. The ADS7844NB/1K uses a 20-pin SSOP package, while the ADS7841EG4 uses a 16-pin SSOP package. The differing pin counts and pin assignments prevent direct pin-to-pin substitution on the same PCB footprint.
Do both devices share the same resolution and sampling architecture?
Yes. Both are 12-bit successive-approximation register (SAR) analog-to-digital converters with a serial digital interface, as specified in their respective Texas Instruments datasheets. Both operate from a single supply and support similar serial timing conventions, but they differ in input channel count and package.
What is the difference in analog input channel count between the two parts?
The ADS7844NB/1K provides 8 analog input channels, configurable as single-ended or differential pairs. The ADS7841EG4 provides 4 analog input channels, also configurable as single-ended or differential inputs. Designs requiring more than four input channels must use the ADS7844NB/1K or an external multiplexer.
Does the G4 suffix on the ADS7841EG4 indicate a functional difference?
No. The G4 suffix denotes lead-free (Pb-free) and RoHS-compliant packaging and construction per Texas Instruments nomenclature. It does not change the electrical function or parametric performance of the ADS7841 device itself; the base ADS7841 and ADS7841EG4 are functionally equivalent converters.
Can the ADS7841EG4 be used as a drop-in replacement for the ADS7844NB/1K in an existing design?
No. Because the two devices differ in package pin count (16 vs. 20 pins), pinout, and analog channel count (4 vs. 8), the ADS7841EG4 cannot be dropped into a PCB designed for the ADS7844NB/1K. Any substitution requires a redesign of the footprint and verification of channel requirements against the system specification.
Which device should be selected for an application needing more analog input channels?
The ADS7844NB/1K should be selected when up to 8 analog input channels are required, since it provides 8 channels in a single 20-pin SSOP package. The ADS7841EG4 is limited to 4 channels and is appropriate only when four or fewer inputs are needed.