LM3432 Datasheet | National Semiconductor

Description The LM3432/LM3432B are 6-channel high voltage current regulators which provide a simple solution for LED backlight applications. These devices incorporate six individual current regulator channels to give accurate driving current for each LED string. The string-to-string tolerance is kept within ±2.0%. Additionally, the Dynamic Headroom Control output can municate with a LM3430 boost regulator to adjust the LED supply voltage to the lowest level needed to keep the string current in regulation, yielding optimal overall system efficiency. The 6-channel current sink can be adjusted from 15m A to 40m A by an external resistor. Their output drivers can withstand up to 80V. Digital PWM or analog voltage signal can be used to control the duty cycle of all the channels. With a fast current switching slew rate, tr = 60ns typical, accurate current control and wide dimming ratio during PWM dimming are ensured. The LM3432/LM3432B contain LED open/short circuit and over-temperature fault signaling to the system micro-controller (the LM3432B does not include open circuit fault signaling). These devices are available in a low profile, thermally enhanced 24 lead LLP package. The LM3432 is also available in the 28 lead e TSSOP. Features - Dynamic Headroom Control (DHC) output to maximize efficiency when used in conjunction with National Semiconductor's LM3430 Boost Controller for LED Backlighting Current sinking adjustable up to 40m A in each string Fast current switching slew rate, tr = 60ns typical Wide dimming ratio, up to 4000:1 with f DIM = 500Hz High LED driving voltage up to 80V ±2.0% current matching between strings Accepts both Digital and Analog dimming control LED open/short fault indication (For LM3432B, no open fault indication) Over-Temperature Indication Internal Thermal Shutdown with Hysteresis Low profile, thermally enhanced LLP-24 (5x4x0.8mm) and e TSSOP-28 (9.7x6.4x1.1mm) packages (The LM3432B is available in the LLP-24 only) - - - - - - - - - -...