DS3502 Digital Potentiometer Module 10kΩ (I2C) | ATMOSFÆR ENGINEERING

Non-volatile I2C-controlled digital potentiometer with 128 positions and 10kΩ resistance. Features EEPROM memory to retain wiper position through power cycles. High-voltage capable (up to ±10V) with low wiper resistance. Ideal for digital volume control, programmable gain adjustment, sensor calibration, and replacing mechanical potentiometers in embedded systems.

Technical Specifications:

• IC: Maxim DS3502 Digital Potentiometer
• Interface: I2C (TWI)
• Resistance: 10kΩ (end-to-end)
• Resolution: 7-bit (128 positions/steps)
• Step Size: ~78Ω per step (10kΩ ÷ 128)
• Wiper Resistance: <300Ω (typical)
• Operating Voltage: 2.7V - 5.5V (logic)
• Potentiometer Voltage Range: -10V to +10V (high-voltage capability)
• Memory: Non-volatile EEPROM (retains position after power loss)
• EEPROM Endurance: 50,000 write cycles minimum
• I2C Address: Configurable (depends on address pins)
• Operating Temperature: -40°C to +85°C

Pin Configuration:

• VCC: Power supply (2.7V - 5.5V)
• GND: Ground
• SDA: I2C data line
• SCL: I2C clock line
• RH: High-side resistor terminal
• RL: Low-side resistor terminal
• RW: Wiper terminal (variable output)

Features:

• Non-volatile memory (EEPROM) - remembers position after power off
• 128-step resolution for precise adjustment
• High-voltage capability (±10V on potentiometer pins)
• I2C control for software-based adjustment
• Low wiper resistance (<300Ω)
• No mechanical wear (solid-state)
• Programmable via microcontroller
• Replace mechanical pots in digital designs

Applications:

• Digital volume controls
• Programmable gain amplifiers
• Sensor calibration and trimming
• LCD contrast adjustment
• Power supply voltage adjustment
• Audio tone controls
• Signal conditioning circuits
• Automated testing equipment
• Replacing mechanical potentiometers in harsh environments
• Variable threshold adjustments

Typical Use Cases:

• Volume Control: Replace analog volume pot with digital control
• Calibration: Programmatically adjust sensor offsets
• Power Supply: Set output voltage digitally
• Audio: Bass/treble tone control

Wiper Position Control:

• 0 = Wiper at RL (0Ω from RL)
• 127 = Wiper at RH (10kΩ from RL)
• Linear steps between positions

Advantages over Mechanical Potentiometers:

• No mechanical wear or failure
• Precise, repeatable settings
• Remote/software control
• Non-volatile memory (saves settings)
• Immune to vibration and dust
• Can be controlled digitally via microcontroller

Important Notes:

• Wiper position stored in EEPROM survives power loss
• EEPROM has limited write cycles (50,000+) - don't write continuously
• Read current position from EEPROM on startup
• High-voltage rating applies to RH/RL/RW pins, not logic pins
• Not suitable for very high-frequency AC signals

Programming:

• Write wiper position (0-127) via I2C
• Position automatically saved to EEPROM
• Read current position from EEPROM

Compatible with Arduino, ESP32, Raspberry Pi, STM32, and any microcontroller with I2C support. Simple I2C write commands to set resistance value.