Renesas ISL22317UFRTZ

Overview

ISL22317UFRTZ from Renesas (formerly Intersil) is a precision single digitally controlled potentiometer (XDCP™) with I²C interface, 128-tap resolution, 50kΩ end-to-end resistance, ±1% tolerance, and ±10ppm/°C ratiometric temperature coefficient matched to an external 0.5% reference resistor. It operates from 2.7V to 5.5V and supports voltage divider or rheostat mode in precision analog calibration circuits.

For engineers reviewing the ISL22317UFRTZ datasheet, ISL22317UFRTZ pinout, ISL22317UFRTZ application, or ISL22317UFRTZ equivalent, this device delivers 99% typical resistance accuracy across temperature, non-volatile wiper position storage (15-year retention at +125°C), and monotonic performance - critical for DC margining, backlight control, and test instrumentation where repeatability and long-term stability are mandatory.

Technical Context

The ISL22317UFRTZ implements a resistor ladder with CMOS switches and "make-before-break" wiper switching, enabling glitch-free tap transitions. Its wiper position is controlled via a volatile 7-bit Wiper Register (WR), initialized at power-up from a non-volatile Initial Value Register (IVR) preloaded with 0x40.

It features dual operating modes selected by the Mode Select Register: voltage divider mode (RH–RL–RW, 3-terminal) with precise ratiometric tracking of an external reference resistor, or rheostat mode (RW–RL only, RH floating) with zero-compensated wiper resistance. Precision mode is enabled by default and requires connection of a 50kΩ ±0.5% resistor between REF_A and REF_B.

Key Specifications

Pinout & Package

ISL22317UFRTZ is housed in a 10-lead 3mm × 3mm thin DFN package (0.75mm max height, 0.65mm 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 AD5175BRMZ-50 and MCP45HV51-502E/MS, the ISL22317UFRTZ uniquely delivers ±1% tolerance and ±10ppm/°C ratiometric TC via external reference matching - making it the only option among the three that guarantees system-level accuracy without software correction or hardware trimming.

Availability

ISL22317UFRTZ is available at Aetrix Electronics and suitable for precision calibration, DC margining, and backlight control applications requiring stable component supply, long-term parameter retention, and guaranteed monotonicity across extended temperature ranges.

Supply support for ISL22317UFRTZ 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 Corporation, formed from the merger of Intersil and Renesas, designs high-performance analog and mixed-signal ICs for industrial, automotive, and computing markets.

The ISL22317UFRTZ belongs to Renesas' XDCP™ (eXternally-Referenced Digitally Controlled Potentiometer) product line, engineered specifically for applications demanding metrology-grade resistance accuracy, non-volatile setting retention, and seamless integration into I²C-based calibration architectures.

FAQ

What is the total resistance and tolerance of the ISL22317UFRTZ?

The ISL22317UFRTZ has a nominal end-to-end resistance of 50kΩ with a tolerance of ±1% over temperature and supply voltage. This value is achieved only when used with a 50kΩ ±0.5% external reference resistor connected between REF_A and REF_B, and precision mode is enabled. Without the reference resistor or with precision mode disabled, resistance accuracy degrades significantly.

Does the ISL22317UFRTZ require an external reference resistor?

Yes - the ISL22317UFRTZ requires a 50kΩ ±0.5% external resistor connected between REF_A and REF_B to achieve its specified 99% resistance accuracy and ±10ppm/°C ratiometric temperature coefficient. The device mirrors both the resistance value and TC of this external component. Omitting it or using a non-matching value invalidates the precision specification.

How does the ISL22317UFRTZ retain its wiper setting after power loss?

The ISL22317UFRTZ stores the wiper position in a non-volatile Initial Value Register (IVR). At power-up, the device automatically recalls the IVR contents into the volatile Wiper Register (WR), restoring the last-saved setting. This IVR retains data for 15 years at +125°C or 50 years at ≤+55°C, ensuring long-term configuration persistence without battery backup.

Can the ISL22317UFRTZ operate in both voltage divider and rheostat modes?

Yes - the ISL22317UFRTZ supports both modes via the Mode Select Register (MSR). In voltage divider mode (MSR<7> = 1), it functions as a 3-terminal potentiometer (RH–RW–RL) with ratiometric tracking of the external reference. In rheostat mode (MSR<7> = 0), RH is left unconnected and the device operates as a 2-terminal variable resistor between RW and RL.

What is the maximum wiper current rating for the ISL22317UFRTZ?

The ISL22317UFRTZ specifies a maximum wiper current of ±3.0mA. Exceeding this limit may cause irreversible damage or parametric shift. When used in rheostat mode, the current forced through RW must satisfy V(RW) ≥ V(RL) + 0.3V to maintain accuracy; minimum/maximum valid tap codes depend on applied voltage and RTOTAL per datasheet Equation 20.