AL3353 HIGH PERFORMANCE BOOST LED CONTROLLER Description Pin Assignments The AL3353 is a highly-integrated and cost-effective Light Emitting Diode (LED) controller optimized for LCD monitor and LCD TV (Top View) backlighting application. It provides a high-performance LED backlight solution with low-BOM cost. VIN 1 8 PWM The AL3353 contains a PWM boost driver, which uses current mode control and fixed frequency operation to regulate the LED current. GATE 2 7 OVP The LED current is sensed through an external current sense resistor. The voltage across the sensing resistor is compared with reference GND 3 COMP 6 level of 400mV the error is amplified to control the pulse width of the power switch thus to regulate the current flowing the LED. CS 4 5 FB The AL3353 offers PWM-to-analog dimming mode for a wide range of SO-8 (Type TH2) dimming control. The AL3353 has comprehensive protection features such as power MOSFET overcurrent protection (OCP), output overvoltage protection (OVP), diode and inductor short protection, LED cathode short-to- GND protection, IC power supply undervoltage lockout (UVLO), LED open protection, V short protection, and overtemperature OUT protection (OTP). The AL3353 is available in the SO-8 (Type TH2) package. Features Applications Wide Input Voltage Range: 9V to 40V LCD TV High Precision Feedback Reference Voltage: 400mV/1.5% LCD Monitor Current Mode PWM Controller with Good Dynamic Response Flat Panel Display PWM to Analog Dimming Mode Built-In Comprehensive Protections Undervoltage Lockout (UVLO) Output Overvoltage Protection (OVP) Power MOSFET Overcurrent Protection (OCP) Diode and Inductor Short Protection LED Cathode Short to GND Protection LED Open Protection V Short Protection OUT Overtemperature Protection (OTP) Available in Pb-Free SO-8 (Type TH2) Package Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2) Halogen and Antimony Free. Green Device (Note 3) Notes: 1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS), 2011/65/EU (RoHS 2) & 2015/863/EU (RoHS 3) compliant. 2. See AL3353 Typical Applications Circuit L1 F1 VIN D2 D1 EN R4 C3 PWM VIN PWM R1 C1 GATE OVP GND GND CMP Q1 C2 R5 CS FB R2 R3 R6 Figure 1. Typical Application Schematic Pin Descriptions Pin Number Pin Name Function 1 VIN Power Supply Input 2 GATE Gate Drive Output 3 GND Ground 4 CS Current Sense Input 5 FB LED Current Feedback 6 COMP Boost Converter Loop Compensation 7 OVP Overvoltage Protection Sense 8 PWM PWM Signal Input for Analog Dimming Control 2 of 15 August 2019 AL3353 Diodes Incorporated www.diodes.com Document number: DS41487 Rev. 3 - 2 NEW PRODUCT AL3353