Renesas ISL23318TFUZ-T7A

Overview

ISL23318TFUZ-T7A from Renesas Electronics is a volatile, low-voltage, 128-tap digitally controlled potentiometer (XDCP™) with I²C interface, 10kΩ total resistance, 70Ω typical wiper resistance at 3.3V, and operation from 1.7V to 5.5V VCC and 1.2V to 5.5V VLOGIC. It serves as a precision programmable voltage divider or rheostat in battery-powered sensor trimming and power supply margining circuits.

For engineers reviewing the ISL23318TFUZ-T7A datasheet, ISL23318TFUZ-T7A pinout, ISL23318TFUZ-T7A application, or ISL23318TFUZ-T7A equivalent, key selection considerations include its dual-supply I²C compatibility (VLOGIC independent of VCC), mid-scale power-on default (64 tap), shutdown mode with RW–RL short, and guaranteed monotonicity in both voltage divider and rheostat modes across –40°C to +125°C.

Technical Context

The ISL23318TFUZ-T7A implements a resistor ladder with CMOS make-before-break wiper switches controlled by a volatile 7-bit Wiper Register (WR), directly accessible via I²C. Its architecture supports two operating modes: three-terminal voltage divider (RH–RW–RL) and two-terminal rheostat (RW–RL or RW–RH), with full-scale error ≤ –0.7 LSB and integral non-linearity ±0.15 LSB over temperature.

It features dedicated VLOGIC pin enabling direct connection to 1.2V–5.5V logic buses without level shifting, two address pins (A0/A1) supporting up to four devices per I²C bus, and shutdown mode that forces RH–RL open while internally connecting RW to RL through ~2kΩ. Power-on reset initializes WR to 0x40 (64 decimal), ensuring repeatable mid-scale startup behavior.

Key Specifications

Pinout & Package

ISL23318TFUZ-T7A is packaged in a 10-lead UTQFN (2.1mm × 1.6mm, 0.5mm pitch), RoHS-compliant, with wettable flanks. Pinout matches the 10 Ld UTQFN configuration shown in Figure 1 (Page 2 of FN7887 Rev 1.00).

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD5170BRMZ-10 and MCP4017T-103E/MS, the ISL23318TFUZ-T7A uniquely balances I²C flexibility with 1.2V logic compatibility, 128-tap resolution, and sub-3µA shutdown current-making it optimal for battery-constrained, multi-voltage embedded systems requiring repeatable mid-scale startup and monotonic analog tuning.

Availability

ISL23318TFUZ-T7A is available at Aetrix Electronics and suitable for battery-powered instrumentation, industrial sensor conditioning, and RF power management requiring stable component supply, extended temperature operation, and low-power I²C configurability.

Supply support for ISL23318TFUZ-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 trusted embedded solutions for automotive, industrial, infrastructure, and IoT applications.

The ISL23318 series belongs to Renesas' precision analog XDCP™ portfolio, designed specifically for replacing mechanical potentiometers in digitally calibrated systems demanding low noise, wide supply flexibility, and guaranteed monotonicity across harsh environments.

FAQ

What is the default wiper position of the ISL23318TFUZ-T7A at power-on?

The ISL23318TFUZ-T7A powers up with its volatile Wiper Register (WR) preset to 0x40 (64 decimal), placing the wiper at mid-scale - exactly halfway between RL and RH terminals. This ensures a known, repeatable output voltage (VCC/2 in standard voltage divider configuration) at system startup, critical for safe initialization of analog signal chains and feedback loops.

Does the ISL23318TFUZ-T7A support true 1.2V I²C bus operation?

Yes, the ISL23318TFUZ-T7A supports true 1.2V I²C bus operation via its dedicated VLOGIC pin, which accepts 1.2V to 5.5V. This allows direct connection to 1.2V microcontrollers or FPGAs without external level shifters. The device meets I²C timing specifications (tLOW, tHIGH, etc.) down to VLOGIC = 1.2V, as verified in the FN7887 datasheet Table "Serial Interface Specification".

Can the ISL23318TFUZ-T7A be used in rheostat mode, and what are the key specs in that configuration?

Yes, the ISL23318TFUZ-T7A supports rheostat mode (RW–RL or RW–RH). In this mode, it delivers ±0.15 LSB differential non-linearity, 0.3–1.0 MI offset error (depending on VCC), and 120 kHz –3dB bandwidth (10kΩ option). The wiper resistance remains 70Ω typical, and terminal voltage range stays 0V to VCC - enabling precise, low-distortion variable resistance for bias and current-setting applications.

What happens to the wiper position during shutdown mode of the ISL23318TFUZ-T7A?

In shutdown mode (SHDN bit = 0 in Access Control Register), the ISL23318TFUZ-T7A opens the RH–RL path and internally shorts RW to RL through a ~2kΩ resistor. Crucially, the current WR value is retained in volatile memory. Upon exit from shutdown, the wiper returns to its pre-shutdown position after ≤1.5µs settling time (tShdnRec), preserving calibration state without host intervention.

Is the ISL23318TFUZ-T7A RoHS-compliant and what package does it use?

Yes, the ISL23318TFUZ-T7A is RoHS-compliant and supplied in a 10-lead UTQFN package (2.1mm × 1.6mm, 0.5mm pitch) with NiPdAu (e4) termination. This package supports Pb-free reflow per J-STD-020, has MSL3 rating, and features wettable flanks for reliable automated optical inspection (AOI) of solder joints in high-volume manufacturing.