Part A
ADS7844EB
Texas Instruments
- Lifecycle
- Active
- Stock
- 3681 PCS
- Package
- SSOP-20
- Series
- Acquisition de données - Convertisseur analogique - numérique (ADC)
Replacement verdict
Not a drop-in replacement
The ADS7844EB and ADS7842E/1KG4 are not drop-in replacements for one another. Although both are 12-bit successive-approximation ADCs from Texas Instruments, they differ in channel configuration, analog input architecture, package footprint, and serial interface framing, so a direct board-level substitution is not possible without redesign.
Different channel configuration
Different input architecture
Different package footprint
Different interface framing
Parts at a glance
Part B
ADS7842E/1KG4
Texas Instruments
- Lifecycle
- Active
- Stock
- 9177 PCS
- Package
- SSOP-28
- 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 | ADS7844EB | ADS7842E/1KG4 | 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 | Channel count determines how many analog signals can be multiplexed into the ADC; the ADS7844EB supports twice as many inputs. |
| Sampling Rate | 200 kSPS | 200 kSPS | Throughput must meet the system's acquisition speed; both devices offer the same maximum sampling rate. |
| Interface Type | SPI / QSPI / Microwire (serial) | Parallel | The digital interface must match the host controller; serial vs parallel interfaces are not directly interchangeable without redesign. |
| Supply Voltage | 2.7 V to 5.25 V | 5 V (single supply) | Supply range affects compatibility with the system power rail; the ADS7844EB supports lower-voltage operation. |
| Package / Mounting | 20-pin SSOP (surface mount) | 28-pin SSOP (surface mount) | Different pin counts and footprints require board layout changes; they are not drop-in replacements. |
| Input Type | Single-ended / differential | Single-ended / differential | Both support single-ended and differential inputs, allowing similar signal conditioning approaches. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Industrial temperature range compatibility ensures operation in the same environmental conditions. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADS7844EB | 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 differences between the ADS7844EB and the ADS7842E/1KG4?
The ADS7844EB is an 8-channel, 12-bit successive-approximation ADC with a serial interface, housed in a 20-lead SSOP package. The ADS7842E/1KG4 is a 4-channel, 12-bit successive-approximation ADC with a parallel interface, supplied in a 28-lead SSOP package in tape-and-reel form. They differ in channel count, digital interface type, and package pin count.
Are the ADS7844EB and ADS7842E/1KG4 pin-compatible?
No. The ADS7844EB uses a 20-lead SSOP package, while the ADS7842E/1KG4 uses a 28-lead SSOP package. The different pin counts and pin functions prevent direct PCB footprint compatibility.
Do both devices support the same analog input configuration?
No. The ADS7844EB provides 8 input channels that can be configured as single-ended or differential pairs. The ADS7842E/1KG4 provides 4 input channels. The channel count and multiplexer configuration differ between the two devices.
What digital interface does each device use?
The ADS7844EB uses a serial SPI-compatible interface. The ADS7842E/1KG4 uses a parallel microprocessor interface. System designers must account for this difference in host controller requirements and PCB routing.
Do the ADS7844EB and ADS7842E/1KG4 have the same resolution and sampling architecture?
Yes. Both are 12-bit successive-approximation register (SAR) ADCs. Their resolution and conversion architecture are equivalent, but they differ in channel count, interface, and package.
Can the ADS7842E/1KG4 be used as a drop-in replacement for the ADS7844EB?
No. Because of differences in package pin count, digital interface type (parallel versus serial), and channel count, the ADS7842E/1KG4 is not a drop-in replacement for the ADS7844EB. A redesign of the PCB and host interface would be required.
What supply voltage range do these ADCs support?
Both the ADS7844EB and ADS7842E/1KG4 are specified for a single-supply operation of 2.7 V to 5.25 V, per their respective manufacturer datasheets. Designers should confirm the exact supply and reference conditions in the official datasheets for their target application.