Renesas ISL23315TFUZ

Overview

ISL23315TFUZ from Renesas (formerly Intersil) is a volatile, low-voltage, I²C-controlled digital potentiometer with 256 taps, 100kΩ end-to-end resistance, ±0.5 LSB integral nonlinearity, and operation from 1.7V VCC / 1.2V VLOGIC - used for precision bias compensation in RF power amplifiers and laser diode drivers.

For engineers reviewing the ISL23315TFUZ datasheet, ISL23315TFUZ pinout, ISL23315TFUZ application, or ISL23315TFUZ equivalent, key selection criteria include its 10 Ld MSOP package, shutdown mode with RW–RL shorting, mid-scale power-on default, and independent logic/analog supply rails enabling direct interface with sub-1.8V microcontrollers.

Technical Context

The ISL23315TFUZ implements a monolithic CMOS resistor ladder with "make-before-break" CMOS wiper switches, controlled via an 8-bit volatile Wiper Register (WR) accessible over I²C. Its dual-supply architecture separates VLOGIC (1.2V–5.5V) from VCC (1.7V–5.5V), eliminating level shifters in mixed-voltage systems.

It supports four device addresses via A0/A1 pins, enters shutdown mode via the Access Control Register (ACR[6]), and maintains wiper position during shutdown while forcing RW to RL through ~2kΩ - critical for fail-safe bias control in power-sensitive analog signal paths.

Key Specifications

Pinout & Package

ISL23315TFUZ is packaged in a 10-lead MSOP (M10.118) with exposed pad, RoHS-compliant matte tin (e3) termination, and MSL3 moisture sensitivity rating.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD5175BRMZ-100 and MCP45HV51-103E/MS, ISL23315TFUZ uniquely combines 1.2V logic compatibility, mid-scale power-on default, and RW–RL shorting in shutdown - making it optimal for safety-critical, low-power, mixed-voltage analog control loops.

Availability

ISL23315TFUZ is available at Aetrix Electronics and suitable for RF power amplifier bias compensation, laser diode driver setpoint control, and power supply margining requiring stable component supply across extended temperature and long product lifecycles.

Supply support for ISL23315TFUZ 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 full technical and supply chain continuity for legacy Intersil precision analog products.

The ISL23315TFUZ belongs to Renesas' XDCP™ (eXternally Controlled Digital Potentiometer) family, designed specifically for replacing mechanical potentiometers in high-reliability, programmable analog signal conditioning and bias control applications.

FAQ

What is the total resistance value of the ISL23315TFUZ?

The ISL23315TFUZ has a nominal end-to-end resistance of 100kΩ, as confirmed by the Ordering Information table (Note 5) and Analog Specifications section. This value is fixed for this specific part number and is not user-configurable. The 100kΩ option provides higher impedance for low-current bias networks while maintaining acceptable wiper resistance (70Ω typical at 3.3V) and thermal coefficient (70ppm/°C).

Does the ISL23315TFUZ retain wiper position during shutdown mode?

Yes, the ISL23315TFUZ retains its wiper register (WR) value during shutdown mode. As described in the Shutdown Function section, the SHDN bit (ACR[6]) forces the DCP into an end-to-end open circuit while shorting RW to RL internally via ~2kΩ - but the WR contents remain unchanged. Upon exit from shutdown, the wiper returns to the pre-shutdown position after a 1.5µs recall time (tShdnRec).

Can the ISL23315TFUZ operate with a 1.2V I²C bus while VCC is at 3.3V?

Yes, the ISL23315TFUZ explicitly supports independent supply rails: VLOGIC can be as low as 1.2V (for I²C logic levels) while VCC operates from 1.7V to 5.5V (for analog functionality). This is verified in the Recommended Operating Conditions table and enables direct interface with 1.2V FPGA I/O banks or ultra-low-power MCUs without external level shifters - a key differentiator versus most competing DCPs.

What is the power-on behavior of the ISL23315TFUZ wiper position?

At power-on, the ISL23315TFUZ wiper always initializes to mid-scale (128 decimal, or 0x80 hex), as stated in the first paragraph of the datasheet and confirmed in the Memory Description section. This deterministic start-up condition ensures predictable analog output voltage (e.g., VCC/2 in voltage divider mode), preventing transient overdrive in sensitive downstream circuits like RF amplifiers or laser drivers.

Is the ISL23315TFUZ pin-compatible with other variants in the ISL23315 family?

Yes, all ISL23315 variants - including ISL23315TFUZ (100kΩ, MSOP), ISL23315UFUZ (50kΩ), and ISL23315WFUZ (10kΩ) - share identical 10-lead MSOP pinouts and register maps. The only differences are total resistance value and corresponding analog performance parameters (e.g., INL, TCR, cutoff frequency). This allows drop-in replacement during design iteration or cost optimization without PCB changes.