RT4500A数据手册Richtek中文资料规格书

描述 Description

The RT4500A is a high efficiency driver for LEDs. It is suitable for single/two cell battery input to drive LED light bars which contains six strings in parallel and up to 12 LEDs per string. The internal current sinks support a maximum of ±2% current mismatching for excellent brightness uniformity in each string of LEDs. To provide enough headroom for current sink operation, the Boost controller monitors the minimum voltage of the feedback pins and regulates an optimized output voltage for power efficiency.

The RT4500A has a wide input voltage range from 2.7V to 24V and can provide adjustable LED current from 5mA to 40mA. The internal 150mΩ, 43V power switch with current mode control provides cycle-by-cycle over-current protection. The RT4500A also integrates analog dimming function for accurate LED current control. The input PWM dimming frequency can operate from 100Hz to 15kHz without inducing any inrush in LED current or inductor current. The switching frequency of the RT4500A is also adjustable from 300kHz to 1.2MHz, which allows flexibility between efficiency and component size.

The RT4500A is available in the WQFN-20L 4x4 package.

特性 Features

· Wide Operating Input Voltage : 2.7V to 24V
· High Output Voltage : Up to 43V
· Adjustable Channel Current : 5mA to 40mA
· Channel Current Regulation with Accuracy ±3% and Matching ±2%
· Dimming Controls► PWM to Analog Dimming Up to 15kHz with 10-bit Resolution► Direct PWM Dimming Up to 15kHz
· Switching Frequency : 300kHz to 1.2MHz
· Protections► LED Strings Open Detection► SBD Short Protection► Current Limit► Programmable Over-Voltage Protection► Output Under-Voltage Protection► Over-Temperature Protection
· 20-Lead WQFN Package
· RoHS Compliant and Halogen Free

应用 Application

· Tablet and Notebook Backlight