Overview
The AD7156BCPZ-REEL7, produced by Analog Devices Inc., is a highly integrated capacitance-to-digital converter (CDC) designed to provide a complete signal processing solution for capacitive sensors. This ultralow power converter features fast response times and high input sensitivity, making it ideal for various capacitive sensing applications. The AD7156 uses Analog Devices' CDC technology, which includes adaptive environmental compensation, high tolerance for input parasitic ground capacitance and leakage current, and an integrated excitation source and clock generator.
Key Specifications
| Parameter | Min | Typ | Max | Unit | Test Conditions/Comments |
|---|---|---|---|---|---|
| Power Supply Voltage (VDD) | 1.8 | 3.6 | V | ||
| Operation Power Supply Current | 70 | μA | |||
| Power-Down Current | 2 | μA | |||
| Conversion Time per Channel | 10 | ms | |||
| Wake-Up Time from Serial Interface | 300 | μs | |||
| Sensor Capacitance (CSENS) Range | 0 | 13 | pF | ||
| Sensitivity | up to 3 | fF | |||
| Operating Temperature | -40 | +85 | °C | ||
| Package Type | 10-lead LFCSP (3 mm × 3 mm × 0.8 mm) |
Key Features
- Ultralow Power Consumption: Typical operation power supply current of 70 μA and power-down current of 2 μA.
- Fast Response Time: Conversion time of 10 ms per channel and wake-up time from serial interface of 300 μs.
- Adaptive Environmental Compensation: Integrated adaptive threshold algorithm to compensate for variations in sensor capacitance due to environmental factors.
- High Input Sensitivity: Sensitivity up to 3 fF and high tolerance for input parasitic ground capacitance and leakage current.
- 2-Channel Capacitance Input: Supports two capacitance input channels with a range of 0 pF to 13 pF.
- 2-Wire Serial Interface (I2C-compatible): Allows for configuration and data access through an I2C-compatible interface.
- Standalone or Microcontroller Interface: Can operate in standalone mode with fixed settings or be interfaced to a microcontroller for user-defined settings.
Applications
- Buttons and Switches: Ideal for capacitive button and switch applications.
- Proximity Sensing: Suitable for proximity sensing and contactless switching applications.
- Position Detection: Used in position detection and level detection scenarios.
- Portable Products: Suitable for use in portable products due to its low power consumption).
Q & A
- What is the power supply voltage range for the AD7156?
The power supply voltage range for the AD7156 is from 1.8 V to 3.6 V.
- What is the typical operation power supply current of the AD7156?
The typical operation power supply current is 70 μA).
- How many capacitance input channels does the AD7156 support?
The AD7156 supports two capacitance input channels).
- What is the sensitivity of the AD7156?
The sensitivity of the AD7156 is up to 3 fF).
- What is the operating temperature range of the AD7156?
The operating temperature range is from -40°C to +85°C).
- Does the AD7156 support I2C communication?
Yes, the AD7156 supports a 2-wire serial interface that is I2C-compatible).
- Can the AD7156 be used in standalone mode or with a microcontroller?
The AD7156 can operate in standalone mode with fixed settings or be interfaced to a microcontroller for user-defined settings).
- What are some common applications of the AD7156?
Common applications include buttons and switches, proximity sensing, position detection, level detection, and portable products).
- What is the package type of the AD7156?
The AD7156 comes in a 10-lead LFCSP package (3 mm × 3 mm × 0.8 mm)).
- How does the AD7156 compensate for environmental variations?
The AD7156 uses an integrated adaptive threshold algorithm to compensate for variations in sensor capacitance due to environmental factors like humidity and temperature).
