ISL6840IU Application Field and Working Principle

Introduction

ISL6840IU is an advanced step-down dc-dc switching controller featuring high accuracy and adjustable switching frequency and output voltage. An integrated synchronous rectifier provides improved efficiency and reduces the system cost. The controller family is available in 4A, 6A and 8A current variations enabling an optimization of price, size and efficiency for end applications. The controllers are designed for high accuracy and use a peak current mode control architecture to ensure fast and stable transient response. This enables an optimized efficiency and quick output voltage response. The ISL6840IU controller is designed for compact size and light weight applications.

Features

• Up to 250KHz adjustable frequency
• Up to 8A output current
• Low start-up, and quiescent current
• Very low profile of 0.75mm
• Output voltage adjustable from 2.5V to 4.7V
• Independent power on reset function
• Integrated synchronous rectifier control

Application Fields

The ISL6840IU is ideal for a variety of applications such as computing, consumer electronics, automotive, medical, process control, off-line power supplies, embedded systems and industrial control. It is well suited for DC - DC conversion with high input voltage and high output voltage applications such as 12V - 12V, 15V - 15V, 48V - 24V etc.

Working Principle

The ISL6840IU synchronous buck controller is a pulse width modulation (PWM) controller with a synchronous rectifier control. It is designed for use in high efficiency, high current, low cost and low components count DC - DC power systems. The controller integrates a fixed frequency current mode logic (CML) PWM control and an internal RS latch to keep output voltage regulation small. It employs a programmable peak current mode control to ensure fast and stable transient response.

The ISL6840IU Buck converter has an integrated power switch and synchronous rectifier , allowing low Rds(on) and low switching losses. The internal synchronous rectifier control programming and the gate pulse generator simplify the application circuit design. The converter control is based on peak current mode control which provides fast line and load transient response. The internal compensation circuitry minimizes the external components required for loop compensation.

In summary , the ISL6840IU is an advanced dc-dc switching controller featuring high accuracy, adjustable switching frequency and output voltage capability. It is designed for applications needing up to 8A current variations with very low quiescent current and output voltage adjustment. The controller also provides integrated synchronous rectifier control for improved efficiency and reduced system cost.