原标题：ST L6599A 180W LED TV电源解决方案

　　ST公司的L6599A是双端控制器,提供50%占空比,谐振半桥可变频率控制和高精度振荡器,工作频率高达500kHz,轻负载时工作在突发模式,能和PFC控制器接口,600V兼容的高边栅极驱动器,非线性软起动,主要用在LCD和PDP TV,台式PC,入门级服务器,通信开关电源(SMPS),高效率工业SMPS,AC/DC适配器和开架SMPS.本文介绍了L6599A主要特性,框图和系统框图,90W AC/DC适配器应用电路图以及采用L6564,L6599A和Viper27L的185W LED TV电源主要特性,电路图和材料清单.

　　The L6599A is an improved revision of the previous L6599. It is a double-ended controller specific to series-resonant half bridge topology. It provides 50% complementary duty cycle: the high-side switch and the low-side switch are driven ON/OFF 180° out-of-phase for exactly the same time. Output voltage regulation is obtained by modulating the operating frequency. A fixed deadtime inserted between the turn-off of one switch and the turn-on of the other guarantees soft-switching and enables high-frequency operation.

　　To drive the high-side switch with the bootstrap approach, the IC incorporates a high-voltage floating structure able to withstand more than 600 V with a synchronous-driven high-voltage DMOS that replaces the external fast-recovery bootstrap diode.

　　The IC enables the designer to set the operating frequency range of the converter by means of an externally programmable oscillator.

　　At startup, to prevent uncontrolled inrush current, the switching frequency starts from a programmable maximum value and progressively decays until it reaches the steady-state value determined by the control loop. This frequency shift is non-linear to minimize output voltage overshoots; its duration is programmable as well.

　　At light load the IC may enter a controlled burst mode operation that keeps the converter input consumption to a minimum.

　　IC functions include a not-latched active-low disable input with current hysteresis useful for power sequencing or for brownout protection, a current sense input for OCP with frequency shift and delayed shutdown with automatic restart. A higher level OCP latches off the IC if the first-level protection is not sufficient to control the primary current. Their combination offers complete protection against overload and short-circuits. An additional latched disable input (DIS) allows easy implementation of OTP and/or OVP.

　　An interface with the PFC controller is provided that enables the pre-regulator to be switched off during fault conditions, such as OCP shutdown and DIS high, or during burst mode operation.

　　L6599A主要特性:

　　■ 50% duty cycle, variable frequency control of resonant half bridge

　　■ High-accuracy oscillator

　　■ Up to 500 kHz operating frequency

　　■ Two-level OCP: frequency-shift and latched shutdown

　　■ Interface with PFC controller

　　■ Latched disable input

　　■ Burst mode operation at light load

　　■ Input for power-ON/OFF sequencing or brownout protection

　　■ Non-linear soft-start for monotonic output voltage rise

　　■ 600 V-rail compatible high-side gate driver with integrated bootstrap diode and high dv/dt immunity

　　■ -300/800 mA high-side and low-side gate drivers with UVLO pull-down

　　■ DIP16, SO16N package

　　L6599A应用:

　　■ LCD and PDP TV

　　■ Desktop PC, entry-level server

　　■ Telecom SMPS

　　■ High efficiency industrial SMPS

　　■ AC-DC adapter, open frame SMPS

　　图1. L6599A框图

　　图2. L6599A系统框图

　　图3. 采用L6599A,L6563H和SRK2000 90W AC/DC适配器电路图

　　采用L6564, L6599A和Viper27L的185W LED TV电源

　　The EVL185W-LEDTV is a high-end demonstration board tailored to the specifications of a typical LED TV application. The peculiarities of this design are the very high average efficiency of about 90%, without synchronous rectification, and very low no load consumption of 100 mW at 230 Vac. The result is that this converter is compliant to the most demanding ENERGY STAR?eligibility criteria. The architecture is made

　　up of two sections, based on a three-stage approach: a 10 W standby supply using the new VIPer27L,which delivers the 5 V standby dedicated to supplying the microprocessor and the logic circuitry, and a bigger section composed of a front-end PFC, using the new TM L6564 and an LLC resonant converter, using the L6599A, delivering three output voltages: 12 V dedicated to supplying the TV panel, 24 V to supplying the audio power amplifiers, and 130 V dedicated to the backlight.

　　The PFC stage delivers 400 V constant voltage and acts as the pre-regulator for both the LLC stage and the standby supply.An external signal, referred to secondary ground, turns the PFC and the LLC stage on and off.

　　185W LED TV电源主要特性:

　　■ Universal input mains range: 90÷264 Vac -frequency 45÷65 Hz

　　■ Output voltage 1: 130 V ±8 % at 620 mA for backlight

　　■ Output voltage 2: 24 V ±8 % at 2 A for audio supply

　　■ Output voltage 3: 12 V ±1 % at 4 A for panel supply

　　■ Output voltage 4: 5 V ±2 % at 2 A for microprocessor supply

　　■ Mains harmonics: acc. to EN61000-3-2 Class-D or JEITA-MITI Class-D

　　■ Standby mains consumption: <170 mW at 230 Vac with 50 mW load

　　■ Overall efficiency at full load: >90%

　　■ EMI: according to EN55022-Class-B

　　■ Safety: according to EN60065

　　■ Dimensions: 115x204 mm, 25 mm maximum component height from PCB

　　■ PCB: single side, 70 μm, CEM-1, mixed PTH/SMT introduction

　　■ RoHS compliant

　　图4. 185W LED TV电源外形图

　　230Vac主电压输入效率表:

　　185W LED TV电源材料清单: