Overview
The AD7873ACP from Analog Devices Inc. is a 12-bit successive approximation analog-to-digital converter (ADC) designed specifically for touch screen applications. It operates from a single supply voltage ranging from 2.2 V to 5.25 V and features a high-speed serial interface. The device includes on-chip components such as a track-and-hold, multiplexer, ADC, reference, temperature sensor, and serial interface, making it a comprehensive solution for touch screen digitization.
The AD7873ACP supports various measurement functions, including direct battery measurement, temperature measurement, and touch pressure measurement. It also has an on-board 2.5 V reference that can be used for the auxiliary input, battery monitor, and temperature measurement modes. The device is packaged in a 16-lead QSOP, TSSOP, or LFCSP, offering significant space-saving advantages.
Key Specifications
| Parameter | Value | Unit | Comments |
|---|---|---|---|
| Resolution | 12 | Bits | Programmable 8-bit or 12-bit resolution |
| Voltage Supply | 2.2 V to 5.25 V | V | Single supply operation |
| Operating Temperature | -40°C to +85°C | °C | |
| Throughput Rate | 125 kSPS | kSPS | Maximum throughput rate |
| Conversion Time | 12 DCLK cycles | DCLK cycles | Maximum conversion time |
| Track-and-Hold Acquisition Time | 3 DCLK cycles | DCLK cycles | Minimum track-and-hold acquisition time |
| Output High Voltage (VOH) | VCC – 0.2 V | V | Minimum output high voltage |
| Output Low Voltage (VOL) | 0.4 V | V | Maximum output low voltage |
| Shutdown Current | 1 µA | µA | Maximum current in shutdown mode |
| Package Type | 16-lead QSOP, TSSOP, LFCSP |
Key Features
- 4-wire touch screen interface
- On-chip temperature sensor: -40°C to +85°C
- On-board 2.5 V reference
- Direct battery measurement (0 V to 6 V)
- Touch pressure measurement
- Programmable 8-bit or 12-bit resolution
- Single supply operation: 2.2 V to 5.25 V
- Ratiometric conversion
- High-speed serial interface
- Auxiliary analog input
- Shutdown mode: 1 µA maximum current
- Low on-resistance switches for driving touch screens
Applications
- Personal digital assistants
- Smart hand-held devices
- Touch screen monitors
- Point-of-sale terminals
- Pagers
- Industrial automation systems
- Consumer electronics
- Automotive user interfaces
- Medical devices
- Aerospace and defense systems
Q & A
- Q: What is the resolution of the AD7873ACP?
A: The AD7873ACP has a programmable resolution of 8-bit or 12-bit.
- Q: What is the operating voltage range of the AD7873ACP?
A: The AD7873ACP operates from a single supply voltage ranging from 2.2 V to 5.25 V.
- Q: What is the throughput rate of the AD7873ACP?
A: The AD7873ACP has a maximum throughput rate of 125 kSPS.
- Q: Does the AD7873ACP have an on-board temperature sensor?
A: Yes, the AD7873ACP includes an on-chip temperature sensor with a range of -40°C to +85°C.
- Q: Can the AD7873ACP measure battery voltage?
A: Yes, the AD7873ACP supports direct battery measurement from 0 V to 6 V.
- Q: What is the package type of the AD7873ACP?
A: The AD7873ACP is available in 16-lead QSOP, TSSOP, and LFCSP packages.
- Q: Does the AD7873ACP have a shutdown mode?
A: Yes, the AD7873ACP has a shutdown mode that reduces the current consumption to less than 1 µA.
- Q: What are some common applications of the AD7873ACP?
A: Common applications include personal digital assistants, smart hand-held devices, touch screen monitors, point-of-sale terminals, and more.
- Q: Is the AD7873ACP RoHS compliant?
A: Yes, the AD7873ACP is RoHS compliant, ensuring reliable performance and environmental compliance.
- Q: Where can I find detailed documentation for the AD7873ACP?
A: Detailed documentation, including datasheets and application notes, can be found on the Analog Devices Inc. website or through authorized distributors.
