Renesas ISL23315TFRUZ-TK

Overview

ISL23315TFRUZ-TK from Renesas Electronics is a volatile, low-voltage, I²C-compatible digitally controlled potentiometer (DCP) with 256 taps, 100 kΩ end-to-end resistance, and operation across -40°C to +125°C. It features independent VLOGIC (1.2V–5.5V) and VCC (1.7V–5.5V) supplies, 70 Ω typical wiper resistance at 3.3V, and shutdown mode forcing RW–RL short with 2 kΩ series resistance - used for precision bias compensation in RF power amplifiers and laser diode drivers.

For engineers reviewing the ISL23315TFRUZ-TK datasheet, ISL23315TFRUZ-TK pinout, ISL23315TFRUZ-TK application, or ISL23315TFRUZ-TK equivalent, key selection criteria include its µTQFN-10 package, I²C address configurability via A0/A1 pins, mid-scale power-on default (128), and guaranteed monotonicity in both voltage divider and rheostat modes.

Technical Context

The ISL23315TFRUZ-TK implements a resistor ladder with CMOS "make-before-break" switches controlled by an 8-bit volatile Wiper Register (WR), enabling precise digital adjustment of analog signal paths. Its dual-supply architecture isolates I²C logic level (VLOGIC) from analog rail (VCC), eliminating need for external level shifters when interfacing with 1.2V microcontrollers.

Shutdown mode disables DCP conduction while preserving WR state; exit recovery includes 1.5 µs wiper recall time and automatic mid-scale reset if VCC drops below 1.3V for >0.2 µs. All DCP terminal voltages are restricted to 0 V to VCC, enforcing safe operation during power sequencing.

Key Specifications

Pinout & Package

ISL23315TFRUZ-TK is housed in a 10-lead 2.1 mm × 1.6 mm µTQFN package (Pb-free, RoHS compliant, MSL 3). Pinout matches the ISL23315 µTQFN variant per FN7778 Rev 2.00.

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 ISL23315TFRUZ-TK uniquely supports true 1.2 V I²C operation without level shifters and delivers lower temperature coefficient (70 ppm/°C) for 100 kΩ resistance, making it optimal for thermally demanding bias networks where analog stability outweighs nonvolatile memory needs.

Availability

ISL23315TFRUZ-TK is available at Aetrix Electronics and suitable for RF power amplifier bias compensation, laser diode driver calibration, and LCD VCOM adjustment requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for ISL23315TFRUZ-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 is a global semiconductor leader delivering microcontrollers, analog power, and connectivity solutions for automotive, industrial, and IoT markets.

The ISL23315 belongs to Renesas' XDCP™ (eXternally Digitally Controlled Potentiometer) family, designed specifically for replacing mechanical potentiometers in precision analog tuning applications where digital control, small footprint, and extended temperature reliability are essential.

FAQ

What is the default wiper position of the ISL23315TFRUZ-TK at power-on?

The ISL23315TFRUZ-TK powers up with its volatile Wiper Register (WR) preset to 128 (0x80 hex), placing the wiper at mid-scale between RH and RL terminals. This behavior is guaranteed across all operating conditions and ensures predictable startup in voltage divider or rheostat configurations without requiring host initialization.

Does the ISL23315TFRUZ-TK support I²C bus voltages below 1.8 V?

Yes, the ISL23315TFRUZ-TK supports I²C logic levels down to 1.2 V via its dedicated VLOGIC pin, allowing direct interface with ultra-low-voltage microcontrollers such as ARM Cortex-M0+ derivatives. The device's input thresholds scale with VLOGIC, and VOL remains ≤0.2×VLOGIC at 1.5 mA sink current - eliminating need for external level translators.

How does shutdown mode affect the RW, RH, and RL terminals of the ISL23315TFRUZ-TK?

In shutdown mode (SHDN bit = 0 in ACR), the ISL23315TFRUZ-TK forces an open circuit between RH and RL while internally connecting RW to RL through a ~2 kΩ resistor. This configuration removes active DCP conduction paths, reducing total current draw to <2.8 µA, and preserves the last-written WR value for immediate restoration upon exit.

What is the maximum allowable voltage on the RH, RL, or RW pins of the ISL23315TFRUZ-TK?

The absolute maximum voltage on any DCP terminal (RH, RL, RW) of the ISL23315TFRUZ-TK is limited to the VCC supply voltage - i.e., 0 V to VCC. Exceeding VCC risks latch-up or permanent damage. This constraint applies during power-up sequencing, transient events, and normal operation, and is enforced by internal ESD protection structures rated to 6.5 kV HBM.

Can multiple ISL23315TFRUZ-TK devices share the same I²C bus?

Yes, up to four ISL23315TFRUZ-TK devices can operate on a single I²C bus using hardwired A0 and A1 pins to configure unique 7-bit slave addresses. Each device responds only to commands matching its A0/A1 combination, enabling compact multi-channel bias control in space-constrained designs like optical modules or multi-output power supplies.