Renesas ISL80111IRAJZ-T

Overview

ISL80111IRAJZ-T from Renesas is a 1A ultra-low-dropout NMOS LDO regulator optimized for low-voltage post-regulation in datacom, medical, and embedded systems. It operates with VIN as low as 0.7V, delivers ±1.6% output accuracy over –40°C to +125°C, achieves 27mV dropout at 1A/2.5V, and provides 70dB PSRR at 1kHz - enabling stable core power for FPGAs and low-voltage ASICs.

For engineers reviewing the ISL80111IRAJZ-T datasheet, ISL80111IRAJZ-T pinout, ISL80111IRAJZ-T application, or ISL80111IRAJZ-T equivalent, key selection criteria include its dual-supply architecture (VIN/VBIAS), adjustable 0.5V–3.3V output via external resistor divider, fast load transient response, integrated PGOOD flag, and thermal shutdown with 160°C trip point.

Technical Context

The ISL80111IRAJZ-T uses an NMOS pass device driven by a separate VBIAS rail (2.9V–5.5V), decoupling control circuitry from the low-VIN path and enabling sub-1V operation. Its internal error amplifier compares ADJ pin voltage (502mV nominal) against a precision bandgap reference to regulate VOUT.

Protection logic includes foldback current limiting (2.2A short-circuit current), thermal shutdown with 20°C hysteresis, and UVLO on VBIAS (2.3V rising threshold). The open-drain PGOOD pin asserts low when VOUT falls below 82% of nominal, supporting system-level power sequencing.

Key Specifications

Pinout & Package

ISL80111IRAJZ-T is housed in a RoHS-compliant 10-lead 3×3 mm DFN package with exposed thermal pad (EPAD) soldered to GND plane for optimal thermal performance (θJA = 48°C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar LDO regulator applications.

Compared with TPL7407LDR and MCP1826T-3302E/DB, the ISL80111IRAJZ-T uniquely combines ultra-low dropout (27mV), wide VOUT adjustability (0.5V–3.3V), and dual-supply architecture - making it suitable for noise-critical, low-voltage, and thermally constrained applications where precision and flexibility are mandatory.

Availability

ISL80111IRAJZ-T is available at Aetrix Electronics and suitable for datacom infrastructure, medical instrumentation, and industrial embedded systems requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for ISL80111IRAJZ-T 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 SoC solutions for automotive, industrial, and enterprise applications.

The ISL80111IRAJZ-T belongs to Renesas' ultra-low-dropout NMOS LDO family, designed specifically for post-regulation in size- and noise-constrained systems where input voltage may fall below 1V and output accuracy must hold across extreme temperatures.

FAQ

What is the minimum input voltage required for ISL80111IRAJZ-T to regulate properly?

The ISL80111IRAJZ-T supports a minimum VIN of 0.7V, but actual minimum depends on VOUT and load. For example, at 1A and VOUT = 2.5V, VIN must be ≥2.527V (VOUT + VDO). The datasheet specifies VIN ≥ VOUT + 0.20V under full load. Always verify margin using worst-case VDO (90mV max) and thermal conditions.

How does the VBIAS pin function in ISL80111IRAJZ-T, and what happens if it's omitted?

The VBIAS pin (2.9V–5.5V) powers ISL80111IRAJZ-T's internal reference, error amplifier, and gate driver - enabling stable regulation even when VIN is <1V. Omitting VBIAS or applying <2.3V causes UVLO activation, disabling regulation. A 1µF ceramic capacitor must be placed between VBIAS and GND within 5mm.

Can ISL80111IRAJZ-T be used without the ADJ pin connection?

No - the ADJ pin is mandatory for feedback. ISL80111IRAJZ-T is not a fixed-output LDO; it requires an external resistor divider (R3/R4) from VOUT to ADJ to GND to set VOUT between 0.5V and 3.3V. Leaving ADJ floating or shorting it to GND prevents regulation and may damage the part.

What is the purpose of the NC pin (Pin 8) on ISL80111IRAJZ-T, and how should it be handled on the PCB?

Pin 8 is a no-connect (NC) terminal - it is not bonded internally and serves no electrical function. On the PCB, it must remain unconnected and unpopulated. Do not route traces to or place solder mask openings on this pad, as unintended coupling or shorts could compromise reliability.

Does ISL80111IRAJZ-T include thermal protection, and how does it behave during overload?

Yes, ISL80111IRAJZ-T includes thermal shutdown triggered at ~160°C junction temperature, with ~20°C hysteresis. During sustained overload, it cycles on/off as die temperature crosses the trip point. Unlike current-limit-only devices, this prevents permanent damage but requires thermal design (EPAD soldering, copper area, vias) to avoid repeated cycling in normal operation.