描述 Description

The CAT4026 is a high performance, large panel LED controller designed to control six constant current high voltage LED strings. Added control circuitry monitors the lowest cathode voltage and generates a feedback control signal to an external Switch Mode Power Supply (SMPS) to provide a low cost and efficient solution for large panel high voltage LED backlighting.Each LED channel current is accurately matched and controlled by sensing an external resistor in series with a low cost bipolar power transistor. This allows current and heat dissipation concerns to be mitigated from the CAT4026 device package.For added system reliability, both Open-Cathode-Anode (OCA) and Shorted-Cathode-Anode (SCA) fault detection circuitry has been included along with independent Fault flag logic outputs for diagnostic purposes.LED current dimming in all six channels can be precisely controlled by either a Pulse Width Modulation signal via the PWM input pin or by an analog dimming voltage applied at the ANLG pin. In addition the ANLG pin provides a convenient method for limiting the overall maximum power dissipation in the event of excessive LED shorting within any LED string.The device will automatically enter low current shutdown mode by taking the PWM pin low for an extended length of time.

特性 Features

? Adaptive Feedback Control to External SMPS for Better Efficiency
? Enhanced power efficiency of the external SMPS
? PWM and Analog Mode Dimming
? Extended range of dimming control
? Open Cathode-Anode (OCA) Fault Protection
? Robustness in case of LED disconnect or large LED string voltage mismatch
? 6 Channel LED Controller
? Short Cathode-Anode (SCA) Fault Protection
? Over-Voltage Protection
? Thermal Shutdown Protection
? Automatic Inactivity Power Down Mode

應用 Application

? LED Backlighting
? LCD TVs

簡介

CAT4026屬于集成電路（IC）的LED驅動器。由制造生產的CAT4026LED 驅動器器件屬于 LED 驅動器電源管理集成電路 (PMIC) 系列，可通過標稱固定電壓的電源為負載（通常為發(fā)光二極管）提供電流，并且電流可控。它與用于電壓調節(jié)的類似產品的主要區(qū)別在于，這類器件提供較低的反饋電壓（以提高系統(tǒng)能效），而且通?？蓪ζ骷ぷ鼽c進行外部控制，可在照明應用中用于實現(xiàn)調光功能。