Renesas ISL23415TFUZ-T7A

Overview

ISL23415TFUZ-T7A from Renesas Electronics is a volatile, low-voltage, SPI-compatible digitally controlled potentiometer (XDCP™) with 256 taps, 100kΩ end-to-end resistance, and operation from 1.7V to 5.5V VCC and 1.2V to 5.5V VLOGIC. It features mid-scale power-on default (128), shutdown mode with open-circuit RH–RL and internal RW–RL short, and is packaged in a RoHS-compliant 10-lead MSOP for battery-powered instrumentation and bias compensation.

For engineers reviewing the ISL23415TFUZ-T7A datasheet, ISL23415TFUZ-T7A pinout, ISL23415TFUZ-T7A application, or ISL23415TFUZ-T7A equivalent, key selection criteria include its dual-supply SPI interface (VLOGIC independent of VCC), 70Ω typical wiper resistance at 3.3V, ±3mA max wiper current, -40°C to +125°C extended temperature range, and compatibility with daisy-chained DCP configurations.

Technical Context

The ISL23415TFUZ-T7A implements a monolithic CMOS resistor ladder with CMOS wiper switches, supporting both voltage divider and rheostat modes. Its 8-bit volatile Wiper Register (WR) directly controls tap position, with "make-before-break" switching to minimize transient glitches during wiper transitions.

It operates in SPI Mode 0 (CPOL = 0, CPHA = 0), with SCK up to 5MHz at VLOGIC ≥ 1.7V and 1MHz at 1.2V–1.6V. The VLOGIC pin enables direct interfacing with 1.2V logic without level shifters, while shutdown mode reduces total supply current to <2.8µA and forces RH–RL open and RW–RL shorted via a 2kΩ path.

Key Specifications

Pinout & Package

ISL23415TFUZ-T7A is supplied in a 10-lead MSOP package (M10.118), 3.0mm × 3.0mm × 1.0mm body, exposed pad not connected. Pinout matches standard ISL23415 10 Ld MSOP configuration.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD5175BRMZ-100 and MCP41HV51-104E/SN, the ISL23415TFUZ-T7A uniquely supports dual-rail operation down to 1.2V logic and 1.7V analog supply, enabling integration into ultra-low-power wearable and IoT endpoints where nonvolatility is secondary to supply flexibility and minimal active current.

Availability

ISL23415TFUZ-T7A is available at Aetrix Electronics and suitable for power supply margining, RF amplifier bias compensation, LCD bias adjustment, and portable medical calibration requiring stable component supply across extended temperature and low-voltage operating conditions.

Supply support for ISL23415TFUZ-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 is a global semiconductor leader delivering high-performance, low-power analog and mixed-signal solutions for automotive, industrial, and IoT applications.

The ISL23415 belongs to Renesas' XDCP™ (eXternally Digitally Controlled Potentiometer) family, designed specifically for replacing mechanical trimmers in battery-powered, space-constrained, and thermally demanding systems requiring digital programmability and robust SPI control.

FAQ

What is the default wiper position of the ISL23415TFUZ-T7A at power-up?

The ISL23415TFUZ-T7A powers up with its volatile Wiper Register (WR) preset to 128 (0x80), placing the wiper at mid-scale-i.e., approximately 50kΩ between RL and RW, and 50kΩ between RW and RH for the 100kΩ version. This behavior is guaranteed across the full -40°C to +125°C temperature range and requires no external initialization sequence. The ISL23415TFUZ-T7A maintains this deterministic startup state regardless of prior shutdown or power-cycle history.

Does the ISL23415TFUZ-T7A support daisy-chaining, and how many devices can be cascaded?

Yes, the ISL23415TFUZ-T7A supports daisy-chaining via its SDO-to-SDI connection topology, allowing multiple devices to share one SPI bus without additional chip-select lines. The number of cascaded units is limited only by the driving strength of the host's SCK and CS outputs and bus capacitance-Renesas confirms reliable operation with ≥4 devices in typical layouts. Each device in the chain receives its instruction byte in reverse order (last device first), and the ISL23415TFUZ-T7A executes writes on the rising edge of CS simultaneously across the chain.

What is the maximum allowable wiper current for the ISL23415TFUZ-T7A, and what happens if exceeded?

The absolute maximum wiper current for the ISL23415TFUZ-T7A is ±6mA for 10 seconds (per Absolute Maximum Ratings), but the Recommended Operating Conditions specify ±3mA continuous. Exceeding ±3mA risks increased wiper resistance drift, accelerated wear of CMOS switches, and potential long-term nonlinearity degradation. Operation above ±6mA may cause irreversible damage. For safe rheostat use, ensure the RW–RL or RW–RH current remains within ±3mA under all VCC, temperature, and tap-position conditions.

Can the ISL23415TFUZ-T7A operate with VLOGIC = 1.2V while VCC = 5.5V, and is level translation required?

Yes-the ISL23415TFUZ-T7A is explicitly designed for independent VLOGIC and VCC operation, and supports VLOGIC = 1.2V with VCC = 5.5V simultaneously. Its integrated level shifter eliminates external translation circuitry: digital pins (SCK, SDI, CS, SDO) are fully compatible with 1.2V logic thresholds (VIH = 0.7×VLOGIC, VIL = 0.3×VLOGIC), and the device guarantees correct SPI timing (tSU/tH ≥50ns) at 1MHz SCK. No level translator is needed or recommended for this configuration.

How does shutdown mode affect the wiper position and terminal connectivity in the ISL23415TFUZ-T7A?

In shutdown mode (SHDN bit = 0 in ACR), the ISL23415TFUZ-T7A forces an open circuit between RH and RL while internally shorting RW to RL through a 2kΩ resistor. Crucially, the volatile Wiper Register contents-including the current tap position-are preserved. Upon exit from shutdown, the wiper returns to its pre-shutdown position within 1.5µs (tShdnRec), restoring full analog functionality without reprogramming. This behavior makes the ISL23415TFUZ-T7A ideal for power-gated subsystems requiring fast, repeatable analog state recovery.