LM3432SQE

• Dynamic headroom control (DHC) to maximize efficiency when used with National Semiconductor's LM3430 boost controller when output LED backlighting
• Each string can be adjusted to sink current to 40mA
• Fast current switching slew rate, T_R= 60ns typical
• Wide dimming ratio up to 4000:1 F_DIM= 500Hz
• High-power LEDs are driven at voltages up to 80V
• ± 2.0% current matching between strings
• Receive digital and analog dimming controls
• LED open/short fault indication (no open fault indication for LM3432B)
• Overtemperature indication
• Internal thermal shutdown with hysteresis
• Low profile, heat-resistant enhanced LLP-24 (5x4x0.8mm) and eTSSOP-28 (9.7x6.4x1.1mm) packages (LM3432B is in LLP-24pcs)

illustrate

The LM3432/LM3432B 6-channel high voltage current regulator provides a simple solution for LED backlight applications. These devices include six independent current regulator channels that give each LED string accurate drive current. String-to-string tolerance is kept within ± 2.0%. In addition, the headroom control output can be combined with an LM3430 boost regulator to adjust the LED supply voltage to maintain the minimum level required for string current regulation, resulting in optimal overall system efficiency.

The 6-channel sink current is adjustable from 15 mA to 40mA with an external resistor. Their output drivers can withstand up to 80V. Digital PWM or analog voltage signals can be used to control the duty cycle of all channels. With fast current switching slew rate, T_R= 60ns typical, accurate current control and wide dimming ratio during PWM dimming are guaranteed.

The LM3432/LM3432B contain LED open/short and overtemperature fault signal system microcontrollers (excluding the LM3432B for open fault signals). These devices are available in a low-profile, thermally enhanced 24-pin LLP package. The LM3432 is also available on 28-pin eTSSOP.

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• LCD backlight applications
• General lighting solutions