Part A
ADS7843E/2K5
Texas Instruments
- Lifecycle
- Active
- Stock
- 2859 PCS
- Package
- SSOP-16
- Series
- Acquisition de données - Contrôleur à écran tactile
Replacement verdict
Not a drop-in replacement
The ADS7843E/2K5 and ADS7842E/1KG4 are not drop-in replacements for one another. Although both are 12-bit touch screen controller ADCs from Texas Instruments in SSOP-16 packages, they differ in channel configuration, interface protocol, and reference architecture, requiring design changes and validation before any substitution.
Different channel configuration
Different interface protocol
Different reference architecture
Different conversion architecture
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 | ADS7843E/2K5 | ADS7842E/1KG4 | Why it matters |
|---|---|---|---|
| Resolution | 12 bit | 12 bit | Both provide 12-bit conversion, so resolution is not a differentiator for substitutability. |
| Number of Input Channels | 4 (single-ended) / 2 (differential) | 4 (single-ended) / 2 (differential) | Channel count determines how many touch or analog signals can be measured simultaneously. |
| Interface Type | SPI (serial) | Parallel | The host interface must match the microcontroller or processor bus; SPI vs parallel is a major functional difference. |
| Supply Voltage Range | 2.7 V to 5.25 V | 2.7 V to 5.25 V | Compatible supply range allows operation from the same system rails. |
| Package / Mounting | 16-pin SSOP (surface mount) | 16-pin SSOP (surface mount) | Identical package and footprint enable drop-in board replacement without layout changes. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Matching temperature ratings ensure equivalent environmental robustness. |
| Typical Application | Touch screen controller (resistive) | General-purpose ADC | The intended use differs; the ADS7843 includes touch-screen drive logic while the ADS7842 is a general ADC, affecting direct substitutability. |
| Conversion Architecture | Successive approximation (SAR) | Successive approximation (SAR) | Same SAR architecture gives comparable conversion speed and accuracy behavior. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADS7843E/2K5 | ADS7842E/1KG4 |
|---|---|---|
| Supplier | - | Texas Instruments |
| Part Status | Active | Obsolete |
| Number of Bits | - | 12 |
| Sampling Rate(Per Second) | - | 200k |
| Number of Inputs | - | 4 |
| Input Type | - | Single Ended |
| Data Interface | - | Parallel |
| Configuration | - | MUX-S/H-ADC |
| Ratio - S / H: ADC | - | 1:1 |
| Number of A/D Converters | - | 1 |
| Architecture | - | SAR |
| Reference Type | - | External |
| Voltage - Supply, Analog | - | 2.7V ~ 3.6V, 5V |
| Voltage - Supply, Digital | - | 2.7V ~ 3.6V, 5V |
| Features | - | Selectable Address |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
| Touchscreen | 4 Wire Resistive | - |
| Resolution(Bits) | 12 b | - |
| Interface | Serial | - |
| Voltage Reference | External | - |
| Voltage - Supply | 2.7V ~ 5V | - |
| Supply Current | 2.5 µA | - |
| Mounting Type | Surface Mount | - |
Frequently asked questions
Are the ADS7843E/2K5 and ADS7842E/1KG4 interchangeable in a design?
No. The ADS7843E/2K5 is a 4-wire resistive touch screen controller with an SPI-compatible serial interface, while the ADS7842E/1KG4 is a 4-channel 12-bit parallel-output sampling analog-to-digital converter. They differ in function, interface, and package, so they are not direct substitutes.
What is the resolution and architecture of each device?
The ADS7843E/2K5 is a 12-bit successive-approximation ADC optimized for 4-wire resistive touch screen digitizing. The ADS7842E/1KG4 is a 12-bit, 4-channel sampling ADC with a parallel digital output interface.
How do the digital interfaces of the two parts differ?
The ADS7843E/2K5 uses an SPI-compatible 3-wire serial interface for communication with a host controller. The ADS7842E/1KG4 provides a parallel output bus, which requires more host I/O pins and a different interface design.
Do the two devices use the same package and pinout?
No. The ADS7843E/2K5 is supplied in a 16-pin SSOP package, while the ADS7842E/1KG4 is supplied in a 28-pin SSOP package. The pin counts and pin functions differ, so PCB footprints are not compatible.
What are the typical supply voltage requirements for these devices?
Both devices operate from a single supply in the 2.7 V to 5.25 V range, making them suitable for low-power and mixed 3 V/5 V system designs. Refer to the respective datasheets for exact operating conditions and timing specifications.
What are the typical applications for each device?
The ADS7843E/2K5 is intended for 4-wire resistive touch screen digitizing in portable instruments, PDAs, and handheld terminals. The ADS7842E/1KG4 is a general-purpose 4-channel sampling ADC suited to data acquisition and multi-channel signal monitoring where a parallel interface is acceptable.
What do the orderable suffixes /2K5 and /1KG4 indicate?
The suffixes denote tape-and-reel packaging quantities as defined by the manufacturer. The /2K5 suffix on the ADS7843E indicates a 2500-unit reel, and the /1KG4 suffix on the ADS7842E indicates a 1000-unit reel. Package type and device function are unchanged by these suffixes.