Renesas ISL23328TFRUZ-T7A

Overview

ISL23328TFRUZ-T7A from Renesas (formerly Intersil) is a dual, volatile, 128-tap digitally controlled potentiometer (DCP) with I²C interface, 100kΩ total resistance, 16-pin UTQFN package, and extended industrial temperature range (–40°C to +125°C). It serves as programmable analog gain/offset adjustment in battery-powered instrumentation and power supply margining circuits.

For engineers reviewing the ISL23328TFRUZ-T7A datasheet, ISL23328TFRUZ-T7A pinout, ISL23328TFRUZ-T7A application, or ISL23328TFRUZ-T7A equivalent, key selection considerations include its dual-channel architecture, independent wiper registers, VLOGIC=1.2V–5.5V logic supply enabling direct low-voltage bus interfacing, shutdown mode with end-to-end open-circuit behavior, and guaranteed monotonicity in both voltage-divider and rheostat modes.

Technical Context

The ISL23328TFRUZ-T7A integrates two independent DCP cores on a monolithic CMOS die, each with an 8-bit volatile wiper register (WR0/WR1), make-before-break switching, and ratiometric temperature coefficient as low as 2.3 ppm/°C (T-option). Its I²C interface supports up to 400 kHz clock rate, three hardware address pins (A0–A2), and operates with VLOGIC decoupled from VCC - enabling direct connection to 1.2V microcontrollers without level shifters.

Each DCP functions as either a three-terminal potentiometer (RH–RW–RL) or two-terminal variable resistor (RW–RL or RW–RH), with wiper resistance of 70 Ω typical at VCC = 3.3 V and full-scale error ≤ –0.9 LSB for the 100kΩ variant. Power-on defaults both wipers to mid-scale (64 decimal), and shutdown mode disconnects RH while connecting RW to RL via internal 2 kΩ path.

Key Specifications

Pinout & Package

ISL23328TFRUZ-T7A is housed in a 16-lead, 2.6 mm × 1.8 mm, 0.5 mm pitch UTQFN package (Pb-free, RoHS compliant, MSL3). Pin 7 is NC (Not Connected); all other pins are electrically functional per datasheet FN7902 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-100 and MCP45HV51-103E/MS, the ISL23328TFRUZ-T7A uniquely delivers dual 100kΩ DCPs with true 1.2 V logic compatibility and sub-2 µA standby current - making it optimal for space-constrained, ultra-low-power, dual-parameter calibration systems.

Availability

ISL23328TFRUZ-T7A is available at Aetrix Electronics and suitable for power supply margining, RF amplifier bias compensation, sensor trimming, and battery-powered instrument gain calibration requiring stable component supply across extended temperature ranges.

Supply support for ISL23328TFRUZ-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 Corporation acquired Intersil in 2017 and maintains full product support, documentation, and manufacturing continuity for the ISL23328 family.

The ISL23328 product line was designed specifically for replacing mechanical potentiometers in high-reliability, low-power, and thermally demanding applications - emphasizing I²C configurability, supply flexibility, and guaranteed monotonic analog performance.

FAQ

What is the default wiper position of ISL23328TFRUZ-T7A at power-on?

At power-on, both wiper registers (WR0 and WR1) of the ISL23328TFRUZ-T7A reset to 64 decimal (0x40), positioning each wiper at mid-scale - i.e., 50 kΩ from RH and 50 kΩ from RL in a 100 kΩ DCP. This behavior is guaranteed across the full –40°C to +125°C temperature range and ensures predictable startup in calibration-critical systems.

Does ISL23328TFRUZ-T7A support true 1.2 V I²C bus operation?

Yes, ISL23328TFRUZ-T7A supports true 1.2 V I²C bus operation via its dedicated VLOGIC pin, which powers the SDA/SCL input buffers and address logic independently of VCC. The device meets I²C specification requirements down to 1.2 V VLOGIC, including VIH ≥ 0.7×VLOGIC and VOL ≤ 0.2×VLOGIC at 1.5 mA load - eliminating need for external level shifters.

Can ISL23328TFRUZ-T7A be used in rheostat mode?

Yes, ISL23328TFRUZ-T7A supports rheostat mode by connecting only RW and RL (or RW and RH) terminals while leaving the third terminal unconnected. In this configuration, it provides 128-step variable resistance from 0 Ω to 100 kΩ with guaranteed monotonicity and ±0.15 LSB differential non-linearity - validated for VCC = 1.7 V to 5.5 V.

What happens to the wiper position during ISL23328TFRUZ-T7A shutdown mode?

In shutdown mode (SHDN bit = 0 in ACR register), ISL23328TFRUZ-T7A forces RH terminals into high-impedance open-circuit while internally connecting RW to RL through a 2 kΩ resistor. The wiper register values (WR0/WR1) remain unchanged, and upon exit from shutdown, the wipers return to their pre-shutdown positions after ≤1.5 µs settling time - preserving calibration state.

Is ISL23328TFRUZ-T7A pin-compatible with other ISL23328 variants?

No - ISL23328TFRUZ-T7A uses a 16-lead UTQFN package (2.6 mm × 1.8 mm), whereas TSSOP variants (e.g., ISL23328TFVZ-T7A) use a 14-lead TSSOP package. Pin counts, layouts, thermal characteristics (θJA = 110°C/W vs. 112°C/W), and land patterns differ; PCB redesign is required when substituting between UTQFN and TSSOP versions of the ISL23328 family.