Renesas ISL22317TFRTZ

Overview

ISL22317TFRTZ from Renesas (formerly Intersil) is a precision single digitally controlled potentiometer (XDCP™) with I²C interface, 128-tap resolution, 100 kΩ end-to-end resistance, ±10 ppm/°C ratiometric temperature coefficient matched to external reference, and non-volatile EEPROM storage. It operates from 2.7V to 5.5V and supports voltage divider or rheostat modes for high-accuracy analog tuning in calibration-critical systems.

For engineers reviewing the ISL22317TFRTZ datasheet, ISL22317TFRTZ pinout, ISL22317TFRTZ application, or ISL22317TFRTZ equivalent, this device delivers 99% typical resistance accuracy across temperature, zero-compensated wiper resistance, monotonic performance, and precise 100 kΩ total resistance-key for DC margining, backlight control, and test instrumentation where resistor drift and repeatability are design constraints.

Technical Context

The ISL22317TFRTZ implements a resistor ladder with CMOS switches and "make-before-break" wiper switching, controlled via an I²C slave interface with pin-selectable address (A1). Its volatile Wiper Register (WR) and non-volatile Initial Value Register (IVR) enable power-up recall of last-set resistance value.

It requires an external 0.5% reference resistor connected between REF_A and REF_B to achieve ±10 ppm/°C TC matching and 99% tap accuracy; without it, precision mode is disabled and resistance tolerance degrades. The device supports two operating modes-voltage divider (3-terminal) and rheostat (2-terminal)-configured via the Mode Select Register.

Key Specifications

Pinout & Package

ISL22317TFRTZ uses a 10-lead 3 mm × 3 mm Thin DFN package (0.75 mm max height, 0.65 mm pitch) with exposed thermal pad internally connected to GND.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD5171BRMZ-100 and MCP45HV51-104E/MS, ISL22317TFRTZ uniquely delivers 128-tap resolution combined with ±10 ppm/°C TC matching to an external reference-enabling system-level accuracy unattainable with monolithic DCPs-while maintaining full -40°C to +125°C operation and 1M-cycle EEPROM endurance.

Availability

ISL22317TFRTZ is available at Aetrix Electronics and suitable for DC margining, backlight control, and test instrumentation requiring stable component supply, long-term calibration retention, and extended industrial temperature operation.

Supply support for ISL22317TFRTZ 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

Renesas Electronics acquired Intersil in 2017 and maintains its precision analog portfolio, emphasizing high-reliability, extended-temperature ICs for industrial and automotive markets.

The ISL22317TFRTZ belongs to Renesas' XDCP™ (eXternally Defined Controlled Potentiometer) family, designed specifically for applications demanding resistor accuracy, temperature stability, and non-volatile programmability beyond monolithic DCP capabilities.

FAQ

What is the purpose of the REF_A and REF_B pins on the ISL22317TFRTZ?

The REF_A and REF_B pins connect an external 0.5% precision resistor that defines the ISL22317TFRTZ's total resistance and temperature coefficient. This external reference enables ±10 ppm/°C TC matching and 99% tap accuracy. REF_A must never be tied to GND-doing so risks permanent damage to the ISL22317TFRTZ. If RL is grounded, REF_B must also be grounded.

Does the ISL22317TFRTZ retain its wiper setting after power loss?

Yes-the ISL22317TFRTZ stores the wiper position in non-volatile EEPROM. At power-up, the device recalls the value from the Initial Value Register (IVR) into the volatile Wiper Register (WR), restoring the last-saved resistance. Retention is rated for 50 years at ≤+55°C and 15 years at +125°C, ensuring reliable calibration persistence in embedded systems.

Can the ISL22317TFRTZ operate in both voltage divider and rheostat modes?

Yes-the ISL22317TFRTZ supports both configurations via the Mode Select Register (MSR). In voltage divider mode (MSR<7> = 1), RH and RL form fixed terminals with RW as the adjustable tap. In rheostat mode (MSR<7> = 0), RH is left unconnected and RW–RL functions as a two-terminal variable resistor-ideal for current-setting applications like LED biasing.

What is the maximum I²C clock frequency supported by the ISL22317TFRTZ?

The ISL22317TFRTZ supports standard-mode I²C up to 400 kHz. All timing parameters-including t_LOW, t_HIGH, t_SU:STA, and t_BUF-are specified for operation at this rate. Pull-up resistors must be selected based on bus capacitance (Cb ≤ 400 pF) to meet rise/fall time limits; for 400 pF, R_PU ≈ 2–2.5 kΩ is recommended.

How does the ISL22317TFRTZ achieve 99% resistance accuracy?

The ISL22317TFRTZ achieves 99% typical tap accuracy by mirroring the value and temperature coefficient of an external 0.5% reference resistor connected between REF_A and REF_B. Its internal circuitry actively compensates for process variation and temperature drift relative to that reference-eliminating the need for factory calibration or software correction algorithms in the host system.