AS1503

Digital Potentiometers Overview

The AS1503 is an 8-bit digital potentiometer manufactured by ams-OSRAM USA INC., featuring a nominal resistance of 100kΩ between terminals A and B. It provides 256 programmable wiper taps controlled via a 3-wire serial interface (SDI, CK, CSN) with data loading rates up to 10MHz. The device operates on a single supply voltage ranging from 2.7V to 5.5V and functions within an extended industrial temperature range of –40°C to +125°C. Packaged in an 8-pin SOIC, it offers glitch-free switching and low standby current.

Digital Potentiometers Feature Summary

• Nominal Resistance: 100kΩ fixed resistor with 256 linear wiper steps
• Interface: 3-wire serial control supporting update rates up to 10MHz
• Supply Voltage: Single supply operation from 2.7V to 5.5V
• Temperature Range: Extended industrial rating from –40°C to +125°C

Digital Potentiometers Applications

• Volume controls in TV sets and audio systems
• Line impedance matching applications
• Programmable filter circuits
• Power supply adjustment mechanisms

Digital Potentiometers Procurement Notes

Verify the specific ordering suffix for packaging requirements. Standard versions are supplied in tubes, while the -T suffix indicates tape and reel delivery. Confirm package availability and lead times directly with the manufacturer or authorized distributors prior to procurement planning.

Digital Potentiometers Selection Notes

Select the AS1503 when a 100kΩ digital potentiometer is required. Ensure the application voltage remains within the 2.7V to 5.5V range. Verify that the 3-wire serial interface timing constraints meet the system clock requirements. Consider the 8-pin SOIC footprint for PCB layout compatibility.

Digital Potentiometers Part Context

The AS1503 belongs to the AS150x family of digital potentiometers, which also includes the AS1500 (10kΩ), AS1501 (20kΩ), and AS1502 (50kΩ). All variants share identical pinouts, serial interface protocols, and electrical characteristics, differing only in their nominal resistance values.

Digital Potentiometers Replacement Considerations

Direct functional replacements include other models from the AS150x series if different resistance values are acceptable. Verify pin compatibility and serial protocol support before substituting with components from other manufacturers.

Digital Potentiometers FAQ

What is the maximum current allowed through the wiper?

The maximum current through the wiper and terminal B is limited to 5mA. Exceeding this limit may degrade or damage the internal switches.

How is the resistance value determined digitally?

The resistance is set by an 8-bit code word shifted into the internal register via the SDI and CK pins. The CSN pin loads the data into the DAC register to update the resistance.

Does the device exhibit glitches during switching?

No, the switching action is designed to be glitch-free, ensuring stable operation during resistance updates.