LM3502 Datasheet | National Semiconductor

Description The LM3502 is a white LED driver for lighting applications. For dual display or large single white LED string backlighting applications, the LM3502 provides a plete solution. The LM3502 contains two internal white LED current bypass FET(Field Effect Transitor) switches that are ideal for controlling dual display applications. The white LED current can be adjusted with a PWM signal directly from a microcontroller without the need of an RC filter network. With no external pensation, cycle-by-cycle current limit, over-voltage protection, and under-voltage protection, the LM3502 offers superior performance over other application specific standard product step-up white LED drivers. Features n Drive up to 4, 6, 8 or 10 white LEDs for Dual Display Backlighting n >80% efficiency n Output Voltage Options: 16V , 25V , 35V, and 44V n Input Under-Voltage Protection n Internal Soft Start Eliminating Inrush Current n 1 MHz Constant Switching Frequency n Wide Input Voltage: 2.5V to 5.5V n Small External ponents n Low Profile Packages: <1 mm Height -10 Bump Micro SMD -16 Pin LLP Applications n Dual Display Backlighting in Portable Devices n Cellular Phones and PDAs Typical Application FIGURE 1. Blacklight Configuration with 10 White LEDs © 2006 National Semiconductor Corporation DS201317 .national. Connection Diagrams 10-Bump Thin Micro SMD Package (TLP10) 16-Lead Thin Leadless Leadframe Package (SQA16A) TOP VIEW TOP VIEW Pin Descriptions/Functions Bump # A1 B1 C1 Pin # 9 7 6 D1 D2 2 and 3 D3 15 and 16 C3 B3 A3 A2 Name Cntrl Fb VOUT2 VOUT1 Sw PGND AGND VIN En2 En1 NC NC NC NC DAP Description...