Analog Devices Inc./Maxim Integrated DS3503U+

Overview

DS3503U+ from Maxim Integrated is a nonvolatile, I²C-compatible dual stepping digital potentiometer with two synchronized 7-bit resistive networks - one delivering RW output and the other fixed at code 40h (64 decimal) on Y pin - both referenced to RH/RL terminals, supporting analog voltage range up to +15.5V and digital supply from +2.7V to +3.6V, used for precision VCOM calibration in TFT-LCD panels.

For engineers reviewing the DS3503U+ datasheet, DS3503U+ pinout, DS3503U+ application, or DS3503U+ equivalent, key selection considerations include its 128 wiper positions, programmable stepping range (±2 to ±31 steps), 10-pin µSOP package, EEPROM-backed initial value register, and SYNC-controlled stepping timing - all critical for closed-loop analog tuning without microcontroller intervention.

Technical Context

The DS3503U+ integrates two independent but synchronized potentiometric paths: RW is fully programmable via I²C and supports stepping under SYNC control, while Y is centered at 40h and tracks RW's step count offset. Its internal architecture includes volatile Wiper Register (WR), nonvolatile Initial Value Register (IVR), Step Control Register (SCR), and Control Register (CR), enabling power-on recall and selective EEPROM write behavior.

Stepping logic uses a bidirectional counter (COUNT) that increments/decrements every PERIOD SYNC pulses (32/64/128/256), clamping RW between STEPCOUNT and 127−STEPCOUNT and Y between 64−STEPCOUNT and 64+STEPCOUNT. The device operates I²C at up to 400kHz and tolerates analog voltages up to +15.5V on V+, RH, RL, RW, and Y pins.

Key Specifications

Pinout & Package

DS3503U+ is housed in a 10-pin µSOP (micro Small Outline Package) with 0.5 mm pitch, exposed pad optional, RoHS-compliant and lead-free.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar digital potentiometer applications.

Compared with AD5170BRMZ-5 and MCP41HV51-502E/MS, the DS3503U+ uniquely integrates dual synchronized stepping outputs, EEPROM-backed power-on defaults, and 15.5V analog capability in a single 10-pin µSOP - eliminating external logic and simplifying VCOM calibration architectures.

Availability

DS3503U+ is available at Aetrix Electronics and suitable for TFT-LCD VCOM calibration, instrumentation offset trimming, mechanical potentiometer replacement, and automated test equipment requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for DS3503U+ includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Maxim Integrated (now part of Analog Devices) designs precision analog, mixed-signal, and power management ICs for industrial, communications, and consumer applications.

The DS3503U+ belongs to Maxim's nonvolatile digital potentiometer product line, engineered specifically for high-reliability analog tuning tasks where EEPROM retention, stepping autonomy, and wide analog voltage range are essential - such as display biasing and sensor calibration.

FAQ

What is the maximum analog voltage the DS3503U+ can handle on its RH, RL, RW, and Y pins?

The DS3503U+ supports an analog voltage range of +4.5V to +15.5V on RH, RL, RW, and Y pins relative to GND. Absolute maximum rating is +17V on V+, but operational specification limits V+ and all resistor-terminal voltages to +15.5V. Exceeding this may cause permanent damage or parametric shift. This makes DS3503U+ suitable for high-voltage display bias applications like TFT-LCD VCOM generation without external level-shifting circuitry.

How does the DS3503U+ implement stepping without a microcontroller?

The DS3503U+ implements autonomous stepping using its dedicated SYNC input pin and internal STEP CONTROL REGISTER (SCR). When a nonzero STEPCOUNT is programmed and SYNC pulses are applied, the device internally increments or decrements a bidirectional counter on each falling edge of SYNC, updating both RW and Y outputs simultaneously. No host processor is required - the stepping sequence (range, period, direction) is fully defined by SCR bits 4:0 and 6:5, making DS3503U+ ideal for open-loop calibration systems.

Does the DS3503U+ retain its wiper setting after power cycling?

Yes, the DS3503U+ retains its initial wiper setting after power cycling via its nonvolatile Initial Value Register (IVR), which is factory-programmed to 40h and reloads into the volatile Wiper Register (WR) at power-on. The IVR value persists across >30,000 write cycles and operates over −40°C to +100°C. However, WR updates made with Control Register (CR) bit 7 = 1 do not alter IVR, preserving EEPROM endurance for infrequent calibration updates.

What is the function of the Y pin on the DS3503U+?

The Y pin on the DS3503U+ delivers a second analog output fixed at code 40h (64 decimal) and synchronized to RW's stepping behavior. Its voltage equals (V_RH − V_RL) × (64 ± COUNT)/127, where COUNT is the same step counter driving RW. This enables ratiometric or differential applications - for example, generating matched positive/negative VCOM offsets or tracking references in instrumentation - without requiring two separate digital potentiometers or additional control logic.

Can the DS3503U+ be used with a 5V digital supply?

No, the DS3503U+ requires a digital supply (V_CC) between +2.7V and +3.6V only. Applying 5V to V_CC exceeds the absolute maximum rating of +6.0V relative to GND but violates the recommended operating condition and risks latch-up or accelerated degradation. For 5V logic systems, level translation on SDA/SCL lines is mandatory, and V_CC must be supplied from a regulated 3.3V source. The analog supply V+ may be up to +15.5V independently.