MCP3202-BI/SN 12-Bit Dual-Channel ADC: Datasheet, Pinout, and Application Circuit Guide
The MCP3202-BI/SN from Microchip Technology is a successive approximation 12-bit Analog-to-Digital Converter (ADC) renowned for its exceptional price-to-performance ratio and ease of integration into various embedded systems. This versatile IC is an ideal solution for applications requiring precise digital conversion of two analog signals, such as sensor interfaces, data acquisition systems, and industrial control modules.
This guide provides a detailed overview of the MCP3202's key specifications, pin configuration, and a fundamental application circuit to ensure a successful design implementation.
Datasheet Overview and Key Specifications
The MCP3202 operates on a 2.7V to 5.5V single supply, making it compatible with a wide range of microcontroller platforms, from 3.3V to 5V logic. Its core functionality is centered around a 12-bit SAR architecture, providing 4096 (2^12) discrete digital output codes.
Key electrical characteristics from the datasheet include:
Resolution: 12 Bits
Number of Channels: 2 (Differential or Pseudo-Differential)
Maximum Sampling Rate: Up to 100 kSPS at 5V
Interface: SPI (Serial Peripheral Interface) compatible
Integral Nonlinearity (INL): ±1 LSB (max)
Signal-to-Noise and Distortion (SINAD): Typically 72 dB
Operating Temperature Range (BI grade): -40°C to +85°C
The SPI interface is straightforward, requiring only four wires (CS, CLK, DIN, DOUT) for communication with a host microcontroller. The device features a single differential input that can be configured as two single-ended inputs via software control, offering significant flexibility in signal conditioning.
Pinout Configuration and Functions
The MCP3202-BI/SN is available in an 8-pin SOIC (SN) package. Understanding the pinout is critical for proper PCB layout and connection.
1. CH0 / IN+: Analog Input Channel 0 (Positive Differential Input).
2. CH1 / IN-: Analog Input Channel 1 (Negative Differential Input).
3. AGND: Analog Ground. This is the ground reference for the internal analog circuitry.
4. VREF: Reference Voltage Input. This pin sets the analog input range. The converted digital output is proportional to VREF.
5. CS /SHDN: Chip Select/Shutdown Input. Initiates communication and can be used to put the device in low-power shutdown mode.
6. DIN: Serial Data Input. Receives control bits from the microcontroller to configure the conversion (channel selection, mode).
7. DOUT: Serial Data Output. Transmits the conversion result (MSB or LSB first) back to the microcontroller.
8. CLK: Serial Clock Input. Driven by the microcontroller to synchronize data shifting.
9. VDD: Positive Supply Voltage (2.7V - 5.5V).
Typical Application Circuit Guide
A basic application circuit for interfacing the MCP3202 with a microcontroller (MCU) is shown below. This setup is common for reading a single-ended analog voltage from a sensor like a potentiometer or thermistor.
Components Required:
Microcontroller (e.g., Arduino, PIC, STM32)
MCP3202-BI/SN ADC
Power supply decoupling capacitor (0.1µF ceramic)
A stable reference voltage source (can be VDD or a dedicated IC like REF3030)
Analog signal source (e.g., potentiometer)
Circuit Connections:
1. Power: Connect VDD to the positive supply rail (3.3V or 5V). Decouple this pin to AGND with a 0.1µF ceramic capacitor placed as close to the IC as possible.
2. Ground: Connect AGND directly to the system's analog ground plane.
3. Reference Voltage: Connect VREF to a clean, stable voltage source. For maximum accuracy, use a dedicated voltage reference IC. For less critical applications, VREF can be tied to VDD.
4. SPI Interface:
Connect the MCU's CS pin to the ADC's CS/SHDN.
Connect the MCU's SCK output to the ADC's CLK.
Connect the MCU's MOSI output to the ADC's DIN.
Connect the MCU's MISO input to the ADC's DOUT.
5. Analog Input: For a single-ended measurement on CH0, connect the analog signal to CH0 and the signal ground to CH1.
Software Operation:
The MCU initiates a conversion by pulling the CS pin low. It then clocks out a start bit, a configuration bit (to select single-ended/differential mode and the channel), and receives the 12-bit result over the next 13 clock cycles. The process is highly efficient and requires minimal MCU processing overhead.
ICGOODFIND: The MCP3202-BI/SN stands out as a robust and cost-effective solution for adding dual-channel 12-bit ADC capability to any embedded design. Its simple SPI interface, low power consumption, and flexible input configuration make it an excellent choice for engineers and hobbyists tackling projects involving analog sensor data acquisition.
Keywords:
1. 12-Bit ADC
2. SPI Interface
3. Dual-Channel
4. Analog-to-Digital Converter
5. Application Circuit
