PowerInt公司的LCS700-708是集成了LLC控制器,高壓功率MOSFET和驅動器的HiperLCS" title="HiperLCS">HiperLCS 系列產品,能節省30%的外接元件,最高工作頻率達1MHz,正常穩定工作高達500kHz,大大降低了磁性元件SMD電容元件尺寸,滿負載的效率大于94%,50%負載時大于93%,主要用在高效電源,LCD TV" title="LCD TV">LCD TV電源,LED街燈和區域照明,打印機電源和音頻放大器.本文介紹了LCS700-708主要特性,方框圖, LCD TV和PC主電源應用電路, 150W激光打印機電源電路以及采用HiperLCSTM LCS700HG 的100W小型LLC DC/DC轉換器的主要特性和指標,電路圖和材料清單,PCB布局圖.
LCS700-708 :HiperLCS Family Integrated LLC Controller, High-Voltage Power MOSFETs and Drivers
The HiperLCS is an integrated LLC power stage incorporating a multi-function controller, high-side and low-side gate drivers, plus two power MOSFETs in a half-bridge configuration. Figure 1 shows a simplified schematic of a HiperLCS based power stage where the LLC resonant inductor is integrated into the transformer.
The variable frequency controller provides high efficiency by switching the power MOSFETs at zero voltage (ZVS), eliminating switching losses.
LCS700-708主要特性:
• LLC half-bridge power stage incorporating controller, high and low-side gate drives, and high-voltage power MOSFETs
• Eliminates up to 30 external components
• High maximum operating frequency of 1 MHz
• Nominal steady-state operation up to 500 kHz
• Dramatically reduces magnetics size and allows use of SMD ceramic output capacitors
• Precise duty symmetry balances output rectifier current, improving efficiency
• 50% ±0.3% typical at 300 kHz
• Comprehensive fault handling and current limiting
• Programmable brown-in/out thresholds and hysteresis
• Undervoltage (UV) and overvoltage (OV) protection
• Programmable over-current protection (OCP)
• Short-circuit protection (SCP)
• Over-temperature protection (OTP)
• Programmable dead-time for optimized design
• Programmable burst mode maintains regulation at no-load and improves light load efficiency
• Programmable soft-start time and delay before soft-start
• Accurate programmable minimum and maximum frequency limits
• Single package designed for high-power and high-frequency
• Reduces assembly cost and reduces PCB layout loop areas
• Simple single clip attachment to heat sink
• Exposed thermal pad connected to ground potential – no insulators required between package and heat sink
• Staggered pin arrangement for simple PC board routing and high-voltage creepage requirements
• Paired with HiperPFS PFC product gives complete, high efficiency, low part count PSU solutions
LCS700-708應用:
• High-efficiency power supplies (80 PLUS Silver, Gold and Platinum)
• LCD TV power supplies
• LED street and area lighting
• Printer power supplies
• Audio amplifier
圖1. LCS700-708方框圖
圖2. LCS700-708應用電路圖:LCD TV和PC主電源
圖3. LCS700-708應用電路圖:150W激光打印機電源
設計案例(DER282):采用HiperLCSTM LCS700HG 的100W小型LLC DC/DC轉換器
主要特性:
? Very low parts count
? Highly integrated solution for low parts count and small size
? Low cost SMD (D-PAK) output diodes eliminates cost of heat sink and mounting
? High operating frequency (270 kHz) reduces size and cost
? Enables use of ceramic output capacitors
? Reduces size of transformer, low profile EFD30 transformer used
? Burst Mode ensures no-load regulation
? High efficiency
? >94% at 100% load, >93% at 50% load
? Capacitive current sense for low power dissipation
For proper operation, the board must be used with a bulk capacitor of at least 10uF between the +380 V input and the input return placed directly across the terminals.
The board required an external bias supply of 12 V for operation. Do not apply a voltage greater than 15 V or IC damage will result.
This power supply has short-circuit protection, but no output overvoltage protection. Performing an overvoltage test by disabling the TL431 (U3) or optocoupler (U2) will cause the output voltage to rise sufficiently to break down the output Schottky rectifiers(D2-D3) and destroy them. Therefore this test should not be performed without adding overvoltage protection circuitry.
The burst mode feature may cause slightly higher ripple voltage at output typically under light load and high input voltage conditions. Burst mode -21 of the LCS700HG is selected for this design.Soft-start performance can be optimized by selecting appropriate value of capacitanceC3 depending on applicable specification.
This design uses surface mount Schottky diode rectifiers. Voltage de-rating requirements must be carefully evaluated for use of this design. Components with higher ratings should be substituted depending on de-rating requirements
This document is an engineering report describing a 12 V / 24 V, 100 W LLC DC-DC resonant converter utilizing a LCS700HG integrated LLC control/power stage IC. This power supply is intended for use in an LCD TV with LED back light. The board requires +12 VDC and +380 VDC inputs.
圖4.100W小型LLC DC/DC轉換器外形圖(頂視圖: L: 136.27 mm x W: 79.88 mm)
電源指標:
圖5. 100W小型LLC DC/DC轉換器電路圖
圖6.變壓器電路圖
圖7.100W小型LLC DC/DC轉換器PCB布局圖
100W小型LLC DC/DC轉換器材料清單:
詳情請見:
http://www.powerint.com/sites/default/files/product-docs/hiperlcs_family_datasheet.pdf
和
http://www.powerint.com/sites/default/files/PDFFiles/der282.pdf
