Microchip MCP3004-I/ST 10-Bit 4-Channel ADC: Datasheet, Pinout, and Application Circuit Guide

The MCP3004-I/ST from Microchip Technology is a versatile 10-bit resolution analog-to-digital converter (ADC) that provides a simple and cost-effective solution for adding sensor measurement capabilities to embedded systems. This integrated circuit communicates via the ubiquitous SPI serial interface, making it easy to connect to a wide range of microcontrollers (MCUs), including popular platforms like Arduino, Raspberry Pi, and PIC microcontrollers. Its 4 single-ended input channels allow a single chip to monitor multiple analog sensors, such as temperature sensors, potentiometers, light-dependent resistors (LDRs), and more.

Datasheet Overview and Key Specifications

The datasheet for the MCP3004 is the primary source for all electrical and operational characteristics. Key specifications include:

Resolution: 10-bit, providing 2^10 (1024) discrete digital values.

Input Channels: 4 single-ended or 2 pseudo-differential channels.

Supply Voltage: Operates from 2.7V to 5.5V, compatible with both 3.3V and 5V logic systems.

Conversion Rate: Up to 200 kilosamples per second (ksps) at 5V.

Interface: SPI serial interface (modes 0,0 and 1,1).

Package: The "ST" suffix denotes a 14-lead TSSOP package.

Pinout Configuration

Understanding the pinout is crucial for correct circuit design. The MCP3004-I/ST in the TSSOP package has 14 pins:

1. CH0 (Pin 1): Analog Input Channel 0.

2. CH1 (Pin 2): Analog Input Channel 1.

3. CH2 (Pin 3): Analog Input Channel 2.

4. CH3 (Pin 4): Analog Input Channel 3.

5. VREF (Pin 5): Voltage Reference Input. Sets the analog input range.

6. AGND (Pin 6): Analog Ground.

7. VDD (Pin 7): Positive Power Supply (2.7V - 5.5V).

8. DGND (Pin 8): Digital Ground.

9. CS/SHDN (Pin 9): Chip Select/Shutdown Input.

10. DIN (Pin 10): Serial Data Input (from MCU).

11. DOUT (Pin 11): Serial Data Output (to MCU).

12. CLK (Pin 12): Serial Clock Input.

13. DGND (Pin 13): Digital Ground.

14. VDD (Pin 14): Positive Power Supply.

Typical Application Circuit Guide

A basic connection diagram for interfacing the MCP3004 with an MCU is straightforward:

1. Power: Connect VDD to the system's positive rail (e.g., 3.3V or 5V). Decouple this pin to AGND with a 0.1µF ceramic capacitor placed close to the IC.

2. Ground: Tie all AGND and DGND pins directly to the system's common ground plane.

3. Reference Voltage: Connect VREF to the same voltage as VDD for the full-scale range (0V to VDD). For more precise measurements, use a stable external reference voltage.

4. SPI Bus: Connect the CLK, DIN, and DOUT pins directly to the corresponding SPI pins on the MCU (e.g., SCK, MOSI, MISO).

5. Chip Select: Connect the CS/SHDN pin to a digital I/O pin on the MCU for device selection.

6. Analog Inputs: Connect sensors to the CH0-CH3 pins. For most applications, a simple low-pass RC filter on each input is recommended to suppress high-frequency noise.

ICGOODFIND Summary:

The Microchip MCP3004-I/ST is a highly practical and easy-to-use ADC, ideal for hobbyists and engineers needing to digitize multiple analog signals without complexity. Its SPI interface ensures broad compatibility, its 4-channel input offers flexibility, and its wide operating voltage range allows for use in diverse projects. While it lacks the high speed or resolution of more advanced ADCs, its simplicity and reliability make it a perennial favorite for data acquisition tasks in consumer, industrial, and IoT applications.

Keywords:

MCP3004

Analog-to-Digital Converter

SPI Interface

10-bit Resolution

Sensor Interfacing