Simplified schematic diagram of the structure of the three-terminal digital potentiometer. The resistor network switch is usually a CMOS switch.
Components 12-Digital potentiometer principle and application circuit, the following uses X9511W digital potentiometer as an example to introduce the working principle of digital potentiometer. The typical resistance limit of X9511W is 10K ohm, and its characteristics are as follows
32 sliding contacts, button control, terminal voltage -5V ~ + 5V; sliding terminal position data can be saved for 10 years after power down; low power CMOS, maximum operating current 3 mA; small size, 8-pin SOIC or DIp package.
The principle and application circuit of component 12-digital potentiometer is the pin layout of X9511W. Component 12-Digital potentiometer principle and Application Circuit
The x9511W digital potentiometer contains 5-bit up-down counter, 5-bit EEpROM memory and storage and recall control circuit.
/ pU is the input terminal of the counter, which is pulled up to a high level. When a low level of 40 milliseconds is added, the counter performs up counting, and the sliding output terminal moves upward, the resistance between Vl and Vw increases, and between Vh and Vw The resistance becomes smaller, / pD is the input terminal of the down counter, which is pulled up to a high level. When a low level of 40 milliseconds is added, the counter performs down counting, and the slide output moves down, the resistance between Vl and Vw Decrease, the resistance between Vh and Vw increases, VH and VL are the high voltage end and the low voltage end respectively, equivalent to the two fixed ends of the mechanical potentiometer, VCC and VSS are the power supply and ground respectively, the typical value of VCC is + 5V, / ASE is the automatic storage mode or manual storage through the button grounding, VW is the sliding end, which is equivalent to the movable end of the mechanical potentiometer.
After the low-voltage pulse is added to / pU or / pD, it is equivalent to the up / down operation of the counter. The output of the counter is decoded to turn on a single-node electronic switch, so that a point of the resistor array is connected to the sliding output terminal. The purpose of the digital adjustment potentiometer is that the sliding end will not exceed the terminal position when moving, that is, it will not cycle back when the counter reaches the terminal.
Looking for deals? digital potentiometer programmable from Heisener is the right answer. Request a real-time quote on our web and choose from different manifacturers.

related articles：
Principles of digital potentiometers for components
principle of current controller
Variation characteristics of potentiometer resistance
potentiometer structure and type
DYNAMIC NOISE OF POTENTIOMETER