Renesas ISL23315TFUZ-T7A

Overview

ISL23315TFUZ-T7A from Renesas Electronics (formerly Intersil) is a volatile, low-voltage, I²C-compatible digitally controlled potentiometer (DCP) with 256 taps, 100 kΩ end-to-end resistance, and operation down to 1.2 V logic supply (VLOGIC). It features wiper register volatility, mid-scale power-on default (128), shutdown mode with internal RW–RL short, and operates across –40°C to +125°C for industrial biasing applications.

For engineers reviewing the ISL23315TFUZ-T7A datasheet, ISL23315TFUZ-T7A pinout, ISL23315TFUZ-T7A application, or ISL23315TFUZ-T7A equivalent, key selection criteria include its dual-supply architecture (VCC = 1.7–5.5 V / VLOGIC = 1.2–5.5 V), 70 Ω typical wiper resistance at 3.3 V, ±0.15 LSB differential nonlinearity (U/T options), and µTQFN-10 package compatibility with high-density PCB layouts.

Technical Context

The ISL23315TFUZ-T7A implements a resistor ladder with CMOS "make-before-break" wiper switching, controlled via an 8-bit volatile Wiper Register (WR) accessible over I²C. Its dual-supply design isolates logic-level signaling (VLOGIC) from analog rail (VCC), enabling direct interface with 1.2 V microcontrollers without level shifters.

It supports up to four devices per I²C bus using A0/A1 address pins, enters shutdown mode via Access Control Register (ACR[6]) to force open-circuit RH–RL and short RW to RL (~2 kΩ), and recalls prior wiper position upon exit - with 1.5 µs recall time and 300 ns large-signal wiper settling.

Key Specifications

Pinout & Package

ISL23315TFUZ-T7A uses a 10-lead 2.1 mm × 1.6 mm µTQFN package with wettable flanks, RoHS-compliant NiPdAu (e4) termination, and MSL3 rating per J-STD-020.

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, the ISL23315TFUZ-T7A uniquely balances ultra-low-voltage I²C operation, volatile high-resolution tuning, and compact µTQFN packaging - making it optimal for battery-powered, thermally demanding, or space-constrained analog trimming where settings are dynamically managed by firmware.

Availability

ISL23315TFUZ-T7A is available at Aetrix Electronics and suitable for power supply margining, RF amplifier bias compensation, LCD panel bias compensation, and laser diode bias control requiring stable component supply across extended temperature and low-voltage operating conditions.

Supply support for ISL23315TFUZ-T7A 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, industrial-grade interface and signal-conditioning ICs.

The ISL23315TFUZ-T7A belongs to Renesas' XDCP™ (eXternally Controlled Digital Potentiometer) family, designed specifically for replacing mechanical trimpots in automated calibration, bias control, and closed-loop analog adjustment systems.

FAQ

What is the default wiper position of the ISL23315TFUZ-T7A at power-on?

The ISL23315TFUZ-T7A powers up with its volatile Wiper Register (WR) preset to 128 (0x80), placing the wiper at mid-scale - i.e., approximately 50 kΩ between RL and RW, and 50 kΩ between RW and RH for the 100 kΩ variant. This deterministic startup behavior eliminates undefined output states and simplifies system initialization in safety-critical bias applications.

Does the ISL23315TFUZ-T7A support true 1.2 V I²C operation?

Yes - the ISL23315TFUZ-T7A accepts VLOGIC down to 1.2 V while maintaining full I²C timing compliance (400 kHz), valid input thresholds (VIH = 0.7×VLOGIC), and open-drain SDA/SCL functionality. This allows direct connection to 1.2 V microcontrollers without level shifters, unlike many competing DCPs that require ≥1.8 V logic supplies.

How does shutdown mode affect the ISL23315TFUZ-T7A's terminals?

In shutdown mode (activated via ACR[6]), the ISL23315TFUZ-T7A forces RH–RL into an open circuit and internally shorts RW to RL through a ~2 kΩ resistor. The wiper register retains its last value, and wiper position is restored within 1.5 µs after exiting shutdown - ensuring fast, repeatable re-engagement in dynamic bias control loops.

What is the maximum allowable voltage on the DCP terminals of the ISL23315TFUZ-T7A?

The absolute maximum voltage on any DCP terminal (RH, RL, RW) is –0.3 V to 6.0 V, but operational specification restricts DCP terminal voltage to 0 V to VCC. Exceeding VCC risks latch-up or parametric shift; therefore, RH must not exceed VCC, and RL must remain ≥0 V - a critical constraint in floating-ground or AC-coupled bias networks.

Is the ISL23315TFUZ-T7A pin-compatible with other ISL23315 variants?

Yes - the ISL23315TFUZ-T7A shares identical pinout and electrical behavior with all ISL23315 µTQFN variants (e.g., ISL23315TFRUZ-TK), differing only in reel packaging suffix (-T7A vs -TK) and moisture sensitivity level documentation. Functionally, it is interchangeable with same-resistance, same-package variants without PCB changes.