Renesas ISL23315UFUZ

Overview

ISL23315UFUZ from Renesas (formerly Intersil) is a volatile, low-voltage, I²C-controlled digital potentiometer with 256 taps, 50 kΩ end-to-end resistance, ±0.15 LSB typical INL in voltage divider mode, and operation from 1.7V VCC / 1.2V VLOGIC - used for precision bias compensation in RF power amplifiers and laser diodes.

For engineers reviewing the ISL23315UFUZ datasheet, ISL23315UFUZ pinout, ISL23315UFUZ application, or ISL23315UFUZ equivalent, this page delivers verified specifications, MSOP-10 package mapping, real-world use cases in analog signal conditioning, and two validated alternative parts with documented functional differences.

Technical Context

The ISL23315UFUZ implements a monolithic CMOS resistor ladder with CMOS wiper switches operating in "make-before-break" mode, controlled via an 8-bit volatile Wiper Register (WR) accessible over I²C. Its dual-supply architecture isolates VLOGIC (1.2V–5.5V) from VCC (1.7V–5.5V), enabling direct interface with low-voltage microcontrollers without level shifters.

It supports up to four devices on one I²C bus using hardwired A0/A1 address pins, enters shutdown mode (SHDN bit in ACR) to open-circuit RH–RL while shorting RW to RL via ~2 kΩ, and powers up at mid-scale (WR = 128). Wiper settling time is 1.5 µs for the 50 kΩ variant, with ratiometric temperature coefficient of 4 ppm/°C at tap 0x80.

Key Specifications

Pinout & Package

ISL23315UFUZ is packaged in a 10-lead MSOP (M10.118), 3.0 mm × 3.0 mm × 1.0 mm body, RoHS-compliant, with exposed pad not connected internally.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ISL23315UFUZ, ISL23315TFUZ offers higher resistance for lower bias current but identical timing and interface behavior, while MCP45HV51-502E/P trades I²C/VLOGIC flexibility for nonvolatility and SPI compatibility - making each suitable for distinct system-level trade-offs in power, persistence, and bus architecture.

Availability

ISL23315UFUZ is available at Aetrix Electronics and suitable for RF power amplifier bias compensation, laser diode current control, LCD VCOM tuning, and power supply margining requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for ISL23315UFUZ 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, including digitally controlled potentiometers, for industrial, automotive, and communications markets.

The ISL23315UFUZ belongs to Renesas' XDCP™ (eXternally Digital Controlled Potentiometer) family, designed specifically for replacing mechanical trimmers in high-reliability analog tuning applications where programmability, temperature stability, and low-voltage operation are essential.

FAQ

What is the end-to-end resistance value of the ISL23315UFUZ?

The ISL23315UFUZ has a nominal end-to-end resistance of 50 kΩ between RH and RL terminals, as specified in the Ordering Information table of FN7778 Rev 2.00. This value is fixed per device variant and confirmed for ISL23315UFUZ (part marking "3315U"). Tolerance is ±20%, with typical end-to-end temperature coefficient of 85 ppm/°C.

Does the ISL23315UFUZ retain wiper position after power cycling?

No, the ISL23315UFUZ is a volatile digital potentiometer: its Wiper Register (WR) resets to 128 (mid-scale) on every power-up. It does not include EEPROM or nonvolatile memory. To maintain position across cycles, the host controller must reprogram the WR after initialization - a behavior explicitly defined in the "Power-on preset" feature and Table 1 (default WR = 40h).

Can the ISL23315UFUZ operate with different VCC and VLOGIC voltages simultaneously?

Yes, the ISL23315UFUZ supports independent supplies: VCC (1.7V–5.5V) powers the resistor ladder and analog circuitry, while VLOGIC (1.2V–5.5V) powers the I²C interface. This allows direct connection to a 1.2V I²C master and a 3.3V analog rail - a key design feature confirmed in the "Features" section and Absolute Maximum Ratings table of FN7778.

What is the maximum recommended I²C clock frequency for the ISL23315UFUZ?

The ISL23315UFUZ supports standard and fast-mode I²C operation up to 400 kHz, as specified in the Serial Interface Specification table (fSCL = 400 kHz). Timing parameters including tLOW (1300 ns), tHIGH (600 ns), and tSU:STA (600 ns) are guaranteed for reliable communication at this rate across the full −40°C to +125°C range.

How does shutdown mode affect the RW, RH, and RL terminals of the ISL23315UFUZ?

In shutdown mode (SHDN bit = 0 in ACR), the ISL23315UFUZ opens the RH–RL path and internally shorts RW to RL through a ~2 kΩ resistor, as shown in Figure 25. RH becomes floating, RL remains grounded or biased, and RW assumes RL potential - providing a defined, low-leakage fail-safe state while preserving the last WR value for rapid recovery.