EVL185W-LEDTV STMicroelectronics, EVL185W-LEDTV Datasheet - Page 6

• Manufacturer Part Number: EVL185W-LEDTV
• Description: DEMO BOARD VIPER27L L6564 L6599A
• Manufacturer: STMicroelectronics
• Series: VIPER™r

Specifications of EVL185W-LEDTV

• Design Resources: EVL185W-LED BOM EVL185W-LED Schematic
• Main Purpose: Power Supply with PFC
• Outputs And Type: 4, Isolated
• Power - Output: 185W
• Voltage - Output: 130V, 24V, 12V, 5V
• Current - Output: 620mA,2A, 4A, 2A
• Voltage - Input: 90 ~ 264VAC
• Regulator Topology: -
• Frequency - Switching: -
• Board Type: Fully Populated
• Utilized Ic / Part: Viper27L, L6564, L6599A
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 497-11255

Main characteristics and circuit description
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Main characteristics and circuit description
The main features of the SMPS are:
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The circuit is made up of two sections: a 10 W standby supply delivering 5 V, dedicated to
supplying the microprocessor and the logic circuitry, and a bigger section made up of a
front-end PFC and an LLC resonant converter delivering three output voltages, 12 V is
dedicated to supplying the TV panel, 24 V to supplying the audio power amplifiers and 130
V is 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.
Startup
At turn-on the standby supply begins startup and delivers 5 V dedicated to the TV
microprocessor and other logic circuitry. It also generates the auxiliary voltage powering the
PFC and LLC controllers at primary side via the linear regulator Q7. Q7 is activated by the
optocoupler U5 that is driven by the logic signal on/off. At startup, the on/off signal (active
high) from the microprocessor is supposed to be low, so the PFC and the LLC do not work.
Once the on/off signal is asserted high, the regulator Q7 delivers 14 V powering the PFC
controller L6564 and the LLC controller L6599A; to always ensure proper operation of the
LLC, the circuit is designed so that the PFC starts first, then the downstream converter. The
LINE pin of L6599A allows the resonant stage to operate only if the PFC output is delivering
its rated output voltage. It prevents the resonant converter from working with too low input
voltage that can cause undesirable capacitive mode operation.
The L6599A LINE pin internal comparator has a hysteresis which allows to independently
set the turn-on and turn-off voltage. The LLC turn-on voltage (PFC output) has been set to
380 V while the turn-off threshold has been set to 300 V. This last value avoids capacitive
mode operation by the LLC stage but allows the resonant stage to operate even in the case
of mains sag and consequent lowering of PFC output voltage.
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: acc. to EN55022-Class-B
Safety: acc. to EN60065
Dimensions: 115x204 mm, 25 mm maximum component height from PCB
PCB: single side, 70 µm, CEM-1, mixed PTH/SMT
Doc ID 18449 Rev 1
AN3339