onsemi ILC6383CIRADJX

Overview

ILC6383CIRADJX from Fairchild Semiconductor is an adjustable-output synchronous step-up DC-DC converter optimized for single- to triple-cell battery input (0.9V–3.0V), delivering up to 375mA at 3.3V or 300mA at 5V, with peak efficiency >90% and true load disconnect in shutdown. It supports user-selectable PFM/PWM operation via the SEL pin and integrates power-good (POK) and low-battery detection (LBO) functions for portable wireless systems.

For engineers reviewing the ILC6383CIRADJX datasheet, pinout, applications, or equivalent options, key selection criteria include its 1.25V feedback reference (±2.4% tolerance), 255–345kHz oscillator frequency, MSOP-8 package compatibility, and ability to regulate output from 2.5V to 6.0V using external resistors - critical for compact, battery-sensitive designs requiring dynamic voltage scaling.

Technical Context

The ILC6383CIRADJX implements a dual-mode PWM/PFM control architecture: PWM mode (SEL open or high) delivers stable 300kHz switching for noise-sensitive applications like RF front-ends, while PFM mode (SEL grounded) enables pulse-skipping operation to maximize light-load efficiency in standby states. Its internal N- and P-channel MOSFETs enable synchronous rectification, eliminating the need for an external Schottky diode and reducing conduction losses.

Operation begins at 0.9V input in PWM mode, with true load disconnect achieved by turning off both internal switches during shutdown (LBI/SD < 0.4V), limiting battery drain to ≤10µA. The LBO output provides open-drain low-battery indication with 120ms hold time to reject transients, and the POK flag asserts when VOUT reaches 92–98% of regulation - both referenced to the same 1.25V internal bandgap.

Key Specifications

Pinout & Package

ILC6383CIRADJX is housed in an 8-lead MSOP package (3.0mm × 3.0mm × 0.85mm body, 0.65mm pitch), optimized for high-density portable PCB layouts. Pin 1 is marked with a dot; exposed pad is not present.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar adjustable-output boost converter applications.

Compared with ILC6383CIRADJX, the TPS61040DRVR offers higher frequency and output voltage flexibility but adds design complexity for battery monitoring, while the MAX1703EUT+T saves space and quiescent current but forfeits critical safety features like true load disconnect and transient-resistant LBO - making ILC6383CIRADJX optimal for cost-sensitive, battery-critical portable systems.

Availability

ILC6383CIRADJX is available at Aetrix Electronics and suitable for cellular handsets, portable medical sensors, wearable displays, and industrial handheld terminals requiring stable component supply with long-term lifecycle support.

Supply support for ILC6383CIRADJX 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

Fairchild Semiconductor (now part of ON Semiconductor) specialized in high-performance analog and power management ICs for consumer, computing, and communications markets before its 2016 acquisition.

The ILC6383 series was designed specifically for wireless handhelds requiring efficient, low-noise, battery-aware DC-DC conversion with integrated system monitoring - targeting GSM, CDMA, and early 3G platforms where size, efficiency, and reliability were paramount.

FAQ

What is the minimum input voltage required for ILC6383CIRADJX to start regulating in PWM mode?

The ILC6383CIRADJX guarantees startup in PWM mode at 0.9V input with 10mA load, enabling operation from deeply discharged single-cell batteries. This specification is verified across temperature and process corners, and applies only when SEL is open or pulled high. Below 0.9V, startup is not guaranteed, and PFM mode may be required for marginal conditions.

How do I configure ILC6383CIRADJX for a 4.2V output voltage?

To set ILC6383CIRADJX to 4.2V, use the formula VOUT = 1.25 × (1 + R1/R2). Select R2 = 100kΩ (typical), then calculate R1 = 100kΩ × ((4.2 / 1.25) − 1) ≈ 236kΩ. Use standard 1% resistors: R1 = 237kΩ, R2 = 100kΩ. Ensure R1 + R2 ≤ 100kΩ is not violated - this constraint applies only to total resistance, so choose lower values (e.g., R1 = 23.7kΩ, R2 = 10kΩ) if needed.

Does ILC6383CIRADJX support true load disconnect, and how is it activated?

Yes, ILC6383CIRADJX provides true load disconnect: pulling the LBI/SD pin below 0.4V places the device in shutdown, turning off both internal MOSFETs and isolating VOUT from VIN. Battery input current drops to ≤10µA with VOUT shorted, preventing parasitic drain. This feature is intrinsic to the IC's architecture and requires no external circuitry beyond the shutdown control signal.

What is the purpose of the 120ms hold time on the LBO output of ILC6383CIRADJX?

ILC6383CIRADJX incorporates a 120ms internal delay on its LBO output to reject short-duration input voltage transients - such as those caused by GSM transmit bursts or motor startup spikes - that could otherwise trigger false low-battery warnings. The LBO pin only asserts low after VIN remains below the programmed threshold for ≥120ms, ensuring reliable battery state reporting in noisy portable environments.

Can ILC6383CIRADJX be used to generate a negative output voltage?

Yes, ILC6383CIRADJX can generate a negative output voltage using an inverting configuration, as documented in Figure 10 of its datasheet. By connecting the LX pin to ground and routing the inductor to VOUT, the device operates as a flyback-derived inverter. Output current is limited to ~10mA due to internal switch ratings, making it suitable for low-current bias rails (e.g., op-amp dual supplies) but not for power-intensive loads.