Renesas ISL23315UFRUZ-TK

Overview

ISL23315UFRUZ-TK from Renesas (formerly Intersil) is a volatile, low-voltage, I²C-controlled digital potentiometer with 256 taps, 50kΩ total resistance, and 10-lead µTQFN package. It operates from 1.7V to 5.5V analog supply (VCC) and 1.2V to 5.5V logic supply (VLOGIC), features 70Ω typical wiper resistance at 3.3V, and supports shutdown mode with <2.8µA max current - used for precision bias compensation in RF power amplifiers and laser diodes.

For engineers reviewing the ISL23315UFRUZ-TK datasheet, ISL23315UFRUZ-TK pinout, ISL23315UFRUZ-TK application, or ISL23315UFRUZ-TK equivalent, key selection criteria include its dual-supply I²C interface (VLOGIC independent of VCC), mid-scale power-on default (128), monotonic ±0.15 LSB DNL in voltage divider mode, and -40°C to +125°C extended industrial temperature range.

Technical Context

The ISL23315UFRUZ-TK implements a resistor ladder with CMOS switches in "make-before-break" switching mode, controlled by an 8-bit volatile Wiper Register (WR) accessible via I²C. Its architecture supports both three-terminal potentiometer and two-terminal rheostat configurations, with RH/RL/RW terminals referenced to relative wiper position-not absolute voltage levels.

It integrates a dedicated VLOGIC pin enabling direct connection to low-voltage microcontrollers (down to 1.2V) without level shifters, and includes an Access Control Register (ACR) with SHDN bit to force end-to-end open circuit and short RW to RL internally during shutdown - preserving WR state across mode transitions.

Key Specifications

Pinout & Package

ISL23315UFRUZ-TK uses a 10-lead 2.1mm × 1.6mm µTQFN package (Pb-free, RoHS compliant), with exposed thermal pad for enhanced thermal performance in high-density layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD5175BCPZ-10-R7 and MCP45HV51-503E/MS, the ISL23315UFRUZ-TK uniquely balances ultra-low logic voltage support (1.2V), mid-scale power-on default, and industry-leading 0.15 LSB DNL - making it optimal for thermally demanding, I²C-constrained, and calibration-critical analog biasing tasks.

Availability

ISL23315UFRUZ-TK is available at Aetrix Electronics and suitable for RF power amplifier bias compensation, laser diode bias compensation, and LCD VCOM adjustment requiring stable component supply across extended temperature and long product lifecycles.

Supply support for ISL23315UFRUZ-TK 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 high-performance analog portfolio, focusing on power management, precision analog, and interface solutions for industrial, automotive, and communications markets.

The ISL23315UFRUZ-TK belongs to Renesas' XDCP™ (eXternally Digital Controlled Potentiometer) family, designed specifically for replacing mechanical trimmers in thermally harsh, space-constrained, and digitally calibrated analog subsystems.

FAQ

What is the total resistance value of the ISL23315UFRUZ-TK?

The ISL23315UFRUZ-TK has a nominal total resistance (RH to RL) of 50kΩ, as indicated by the "U" in its part number per the ordering information table. This value is guaranteed within ±20% tolerance over temperature and process variation, and exhibits an end-to-end temperature coefficient of 85 ppm/°C - optimized for stable biasing in RF and optical applications.

Does the ISL23315UFRUZ-TK retain its wiper setting after power cycling?

No, the ISL23315UFRUZ-TK is a volatile digital potentiometer: its 8-bit Wiper Register (WR) resets to 128 (mid-scale) on every power-up. It does not include nonvolatile memory. For persistent settings, consider alternatives like the AD5175BCPZ-10-R7, but note that ISL23315UFRUZ-TK's deterministic mid-scale start simplifies system initialization and avoids undefined output states.

Can the ISL23315UFRUZ-TK operate with a 1.2V I²C bus while VCC is at 5V?

Yes - the ISL23315UFRUZ-TK features a dedicated VLOGIC pin that accepts 1.2V to 5.5V, fully decoupled from VCC (1.7V–5.5V). This allows direct connection to 1.2V microcontrollers without level shifters, while powering the analog DCP core from a separate 5V rail - a key differentiator for mixed-voltage system designs.

What happens to the RW pin during shutdown mode of the ISL23315UFRUZ-TK?

In shutdown mode (SHDN bit = 0 in Access Control Register), the ISL23315UFRUZ-TK forces an end-to-end open circuit between RH and RL, and internally shorts the RW pin to the RL pin through a ~2kΩ resistor. This provides a defined, low-impedance path for bias networks during standby - preventing floating nodes and ensuring safe power-down behavior in laser diode or amplifier bias circuits.

Is the ISL23315UFRUZ-TK pin-compatible with other variants in the ISL23315 family?

Yes - all ISL23315 variants, including ISL23315UFRUZ-TK (50kΩ, µTQFN) and ISL23315TFUZ-TK (100kΩ, MSOP), share identical 10-pin functional mapping and I²C command structure. However, package dimensions differ (µTQFN vs. MSOP), and resistance value, tempco, and noise performance vary by option - requiring layout verification for footprint interchangeability.