Part A
ADS7844E/2K5
STマイクロエレクトロニクス
- Lifecycle
- Active
- Stock
- 3096 個数
- Package
- SSOP-20
- Series
- データ取得 - アナログ/デジタルコンバータ (ADC)
Replacement verdict
Compatible functional replacement candidate
The ADS7842E/1KG4 is a functional replacement candidate for the ADS7844E/2K5, sharing the same 12-bit SAR architecture, 4-channel input multiplexer, and 20-pin SSOP package, but it is not a drop-in replacement due to differences in serial interface protocol, sample rate, and supply voltage range that require validation against the target design.
Resolution and Architecture
High match
Serial Interface Protocol
Validation required
Sample Rate
Validation required
Supply Voltage Range
Validation required
Parts at a glance
Part B
ADS7842E/1KG4
STマイクロエレクトロニクス
- Lifecycle
- Active
- Stock
- 9177 個数
- Package
- SSOP-28
- Series
- データ取得 - アナログ/デジタルコンバータ (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 | ADS7844E/2K5 | ADS7842E/1KG4 | Why it matters |
|---|---|---|---|
| Resolution | 12 bit | 12 bit | Both are 12-bit SAR ADCs, so resolution is equivalent and not a differentiator 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 | 200 kSPS | 200 kSPS | Throughput is identical, so timing and bandwidth requirements are met by either device. |
| Supply Voltage | 2.7 V to 5.25 V | 2.7 V to 5.25 V | Both operate over the same supply range, allowing use in 3 V and 5 V systems interchangeably. |
| Interface | SPI / QSPI / Microwire compatible serial | SPI / QSPI / Microwire compatible serial | Identical serial interface simplifies drop-in replacement at the digital bus level. |
| Package | 20-pin SSOP (DBQ) | 20-pin SSOP (DBQ) | Same package and pin count support PCB footprint compatibility. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Equivalent temperature ratings mean both suit the same industrial environments. |
| Input Type | Single-ended and pseudo-differential | Single-ended and pseudo-differential | Matching input configurations allow similar analog front-end designs. |
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 | ADS7842E/1KG4 |
|---|---|---|
| Supplier | - | Texas Instruments |
| Part Status | Active | Obsolete |
| 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 ADS7842E/1KG4?
The ADS7844E/2K5 is an 8-channel, 12-bit successive-approximation ADC with a serial SPI/QSPI/Microwire interface, housed in a 20-pin SSOP package and supplied in 2,500-unit tape-and-reel. The ADS7842E/1KG4 is a 4-channel, 12-bit successive-approximation ADC with a parallel interface, housed in a 28-pin SSOP package and supplied in 1,000-unit tape-and-reel. The primary differences are channel count (8 vs 4), digital interface (serial vs parallel), and package pin count (20 vs 28).
Are the ADS7844E/2K5 and ADS7842E/1KG4 pin-compatible or footprint-compatible?
No. The ADS7844E/2K5 uses a 20-pin SSOP package, while the ADS7842E/1KG4 uses a 28-pin SSOP package. The differing pin counts and pin functions mean the PCB land patterns and pin assignments are not interchangeable, so a direct drop-in replacement is not possible without a board redesign.
Do both devices support the same analog input configuration?
Both are 12-bit successive-approximation ADCs, but their input channel configurations differ. The ADS7844E/2K5 provides 8 input channels that can be configured as single-ended or differential pairs, while the ADS7842E/1KG4 provides 4 input channels. The exact single-ended/differential configuration options should be confirmed against the respective manufacturer datasheets before design use.
How do the digital interfaces of the ADS7844E/2K5 and ADS7842E/1KG4 differ?
The ADS7844E/2K5 uses a serial interface compatible with SPI, QSPI, and Microwire, requiring fewer host pins and suited to isolated or space-constrained designs. The ADS7842E/1KG4 uses a parallel interface, which provides simultaneous multi-bit data transfer to the host but requires more I/O pins and board routing.
What are the supply voltage and reference requirements for these two ADCs?
Both devices are specified for a single +5 V analog supply with a separate digital supply, and both require an external reference voltage for ratiometric operation. Exact supply ranges, reference input ranges, and absolute maximum ratings must be verified from the official manufacturer datasheets for the ADS7844 and ADS7842, as these parameters govern accuracy and safe operating limits.
Can the ADS7844E/2K5 and ADS7842E/1KG4 be used interchangeably in an existing design?
No. Because they differ in channel count (8 vs 4), digital interface (serial vs parallel), and package pin count (20 vs 28), they are not interchangeable without redesigning the schematic, PCB layout, and host firmware. Any substitution must be validated against the manufacturer datasheets and the target system requirements.
What do the ordering suffixes /2K5 and /1KG4 indicate?
The /2K5 suffix on the ADS7844E/2K5 indicates tape-and-reel packaging in 2,500-unit reels, and the /1KG4 suffix on the ADS7842E/1KG4 indicates tape-and-reel packaging in 1,000-unit reels. These suffixes describe packaging and quantity only and do not change the electrical specifications of the devices.
Which device is better suited for multi-channel data acquisition versus high-speed parallel host interfaces?
The ADS7844E/2K5, with 8 input channels and a serial interface, is better suited to multi-channel data acquisition where host pin count is limited. The ADS7842E/1KG4, with a parallel interface, is better suited to host systems that require parallel data transfer and can accommodate the larger 28-pin package and additional I/O. Selection should be based on verified datasheet parameters for throughput, channel count, and interface timing.