Renesas ISL95811UFRTZ-TK

Overview

ISL95811UFRTZ-TK from Renesas (formerly Intersil) is a single-channel, I²C-compatible digitally controlled potentiometer (XDCP™) with 256-tap resolution, 50kΩ end-to-end resistance, and integrated 5-byte non-volatile general-purpose memory. It operates from 2.7V to 5.5V, features 70Ω typical wiper resistance at 3.3V, and supports voltage divider or rheostat configurations in precision analog trimming applications.

For engineers reviewing the ISL95811UFRTZ-TK datasheet, ISL95811UFRTZ-TK pinout, ISL95811UFRTZ-TK application, or ISL95811UFRTZ-TK equivalent, this device serves as a programmable resistor for calibration, gain/offset adjustment, sensor biasing, and power supply feedback loop tuning-requiring confirmed I²C timing compliance, wiper position retention, and low-noise operation under extended temperature.

Technical Context

The ISL95811UFRTZ-TK implements a monolithic CMOS resistor ladder with CMOS switch matrix, enabling precise wiper positioning via an 8-bit volatile Wiper Register (WR) and non-volatile Initial Value Register (IVR). At power-up, IVR contents (default 0x80) are loaded into WR, establishing repeatable startup behavior without host intervention.

Its I²C interface complies with standard-mode (400kHz max) timing, supports write protection via hardware WP pin, and distinguishes volatile vs. non-volatile register access using the Access Control Register (ACR) VOL bit. The device delivers ±0.5 LSB DNL and ±1 LSB INL in voltage divider mode, with ratiometric temperature coefficient of ±4 ppm/°C.

Key Specifications

Pinout & Package

ISL95811UFRTZ-TK uses an 8-lead 3×3 mm TDFN package (RoHS-compliant, exposed pad internally connected to GND). Pin layout matches the 8 Ld TDFN top view shown in FN6759 Rev 1.00, Page 1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ISL95811UFRTZ-TK, ISL95810UFRTZ-TK offers identical analog performance but omits general-purpose memory, while AD5175BRMZ-50 trades I²C compatibility and ratiometric stability for SPI integration-making ISL95811UFRTZ-TK optimal for I²C-based calibration systems needing embedded non-volatile data storage.

Availability

ISL95811UFRTZ-TK is available at Aetrix Electronics and suitable for LED driver calibration, DC-DC feedback tuning, sensor biasing, and audio gain control applications requiring stable component supply across automotive, industrial, and medical product lifecycles.

Supply support for ISL95811UFRTZ-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 acquired Intersil in 2017 and continues to manufacture and support its precision analog portfolio, including digitally controlled potentiometers and power management ICs.

The ISL95811UFRTZ-TK belongs to Intersil's XDCP™ family, designed specifically for replacing mechanical potentiometers in automated calibration, closed-loop control, and programmable analog signal conditioning systems.

FAQ

What is the default wiper position after power-up for the ISL95811UFRTZ-TK?

At power-up, the ISL95811UFRTZ-TK loads the value stored in its non-volatile Initial Value Register (IVR) into the volatile Wiper Register (WR). The device ships pre-programmed with 0x80 (128 decimal) in the IVR, placing the wiper at the midpoint of the 50kΩ resistor string-ensuring predictable startup behavior without host initialization. This occurs after VCC exceeds the power-on recall voltage (1.8V–2.6V) and completes within 3ms.

Does the ISL95811UFRTZ-TK support both voltage divider and rheostat configurations?

Yes, the ISL95811UFRTZ-TK supports both configurations. In voltage divider mode, RH and RL are connected to fixed potentials (e.g., VCC and GND), and RW provides a programmable tap voltage. In rheostat mode, either RH or RL is left unconnected, and RW–RL (or RW–RH) forms a two-terminal variable resistor. Performance specs-including DNL, INL, and tempco-are separately characterized for each mode per FN6759 Rev 1.00 Pages 3–4.

How does the WP pin function on the ISL95811UFRTZ-TK?

The WP (Write Protect) pin on the ISL95811UFRTZ-TK is active-low: when held at logic LOW, it disables all write operations-including volatile and non-volatile register updates-regardless of I²C commands received. This hardware-level protection prevents accidental overwrites during power sequencing or firmware errors. WP must be HIGH to enable writes; no software register controls this function.

What is the maximum I²C clock frequency supported by the ISL95811UFRTZ-TK?

The ISL95811UFRTZ-TK supports I²C Fast Mode with a maximum SCL frequency of 400kHz, as specified in FN6759 Rev 1.00 Page 5. All timing parameters-including tLOW (1300ns), tHIGH (600ns), and tSU:STA (600ns)-are guaranteed across the full -40°C to +125°C operating range and 2.7V–5.5V supply. Exceeding 400kHz may violate setup/hold margins and cause communication failures.

Can the ISL95811UFRTZ-TK retain wiper settings after power loss?

Yes, the ISL95811UFRTZ-TK retains wiper settings across power cycles using its non-volatile Initial Value Register (IVR). When a non-volatile write is executed (e.g., writing to address 0x00 with VOL=0), the value is stored in the IVR and recalled automatically at next power-up. Data retention is rated for 50 years at ≤+55°C, and endurance is 1,000,000 write cycles-verified per JEDEC standards.