Trainning Material of PW PE371C4

Tr ai n n i n g Mat er i al o f PW PE371C4

 AOE  A OE Pro Pr o d u c t s Suppo up port rt Team 14 A pr 2013 2013

catalogue • • • • • • • • • •

1.Ta .Tactic ct ic i ntrod nt roduce uce of PSU 2.Ge 2.General neral Frame Diagram Diagr am 3.Product Specification 4.Li 4.List st of TV Set Set Matc Match h 5.Intr 5.Introd oduc uce e of PSU Board Bo ard 6. Int Introd roduc uce e of Diagram 7. List Li st of PSU Part Part 8. SERVISING FLOW 9. SERVISING GUIDE&TYPE CASES 10.Diagram

catalogue • • • • • • • • • •

1.Ta .Tactic ct ic i ntrod nt roduce uce of PSU 2.Ge 2.General neral Frame Diagram Diagr am 3.Product Specification 4.Li 4.List st of TV Set Set Matc Match h 5.Intr 5.Introd oduc uce e of PSU Board Bo ard 6. Int Introd roduc uce e of Diagram 7. List Li st of PSU Part Part 8. SERVISING FLOW 9. SERVISING GUIDE&TYPE CASES 10.Diagram

1 Tactic introduce of PSU

PE371C4 belongs to the ultrathin PSU of 11mm. It has the same characteristic characteristi c of common PSU that supplies Direct Current 24V, Direct Current 54V and STB Direct Current 3.3V. Electric circuit module contains Input module, PFC module ,STB module, PWM module, OCP/OVP module .

2 General Frame Diagram 54V/1.0A 310V 100~240 Vac

E M I

390V

PFC PFC FAN7930

Main PWM PWM FSFR1

24V/1.25A

commute filtrate out

700XS L

VCC

Commutated and Sampling then Out feedback signal

OCP OVP

PE371C4

VCC Isolated parts

Power ON/OFF

P_on

Commut ated and Sampling then Out feedback signal

PWM VIPER17L PW ST M

Isolated Switch transistor 

Commute Filtrate out

3.3V/0.2A

2.General Frame Diagram (Input module) • Input module consists of self-protected parts, EMI circuit, bridge rectifier, filter circuit and so on .

Thermistor and fuse are the main self-protected parts which is aimed to protect key components as MOSFET and transistor costly.

2.General Frame Diagram (Input module)

X capacitor

2.General Frame Diagram (Input module)

EMI Circuit mainly contains X capacitor, Y capacitor and filter which can filter noise and ripple from AC input line and highfrequency noise from PSU. Rectifier diodes of bridge structure are used to transform AC power to DC power. X-capacitor filters differential-mode noise from AC input line and high-frequency noise from PSU. Y-capacitor filters common-mode noise from AC input line and high-frequency noise from PSU.

2.General Frame Diagram ( STB module) STB means standby module which can supply DC 3.3V to main board. It uses IC VIPER17L to control operation of this part. Power supply topology of this part is FLYBACK. If DC 3.3V is abnormal, VIPER17L will start its protection function.

POINT： FEED_BACK &VDD

2.General Frame Diagram ( PFC module) The PFC circuit can be considered as the circuit that makes the phase of input voltage and input current synchronous, and it’s aimed to improve power factor, decrease aberrance of voltage and current and increase efficiency. PFC IC of PE371C4 is FAN7930, and it supplies over-voltage protection, over-current protection and input voltage monitor function. In operating FAN7930 will change it’s working frequency to regulate the feedback signals that can keep the PFC output voltage stable. It works at the critical mode.

2.General Frame Diagram ( PFC module)

PFC inductor

PFC IC

PFC diode

PFC MOSFET

2.General Frame Diagram ( PFC module)  At different AC input the PFC inductance has the following charged and discharged waves (critical mode)

~90V input, frequency=80.7kHz

~220v input, frequency=152.9kHz

~270v input, frequency=161.6kHz

2.General Frame Diagram PWM module ( LLC module) LLC is brief name of LLC resonance converter. Its principle can be considered that PFC output voltage will be modulated by pulse signal with MOSFET and be transformed to lower DC voltage by Transformer. The main IC of LLC module of PE371C4 is FSFR1700XLS, and it works in half-bridge resonant topology. In all condition it keeps the duty of driving signal be stable 50%. It’s operating frequency is 93KHz when full load and keeps during 90khz to 116KHz when load changes from empty load to full load, especially it will appears maximum frequency when low input voltage or empty load.

2.General Frame Diagram

(OCP/OVP module) OCP at primary Transformer Winding is realized by control IC. OVP circuit senses voltage by zener diode and flows through delay circuit and self-locked circuit. If DC voltage goes high to some degree abnormally, the self-locked circuit will output a signal to pulls down P_ON signal to stop operation.

3 SPECIFICATION SPECIFICATION

POWER PE371C4

Module number

08-PE371C5-PW200AA

First used model Input voltage

120Vac — 240Vac

Rated load current

24V — 1.25A ；54V — 1 A 3.3V — 0.2A

Standby power loss

≤0.3W

Rate power

100W

Choose TV Adaptive LED panel

L42-phlips

Adaption range

Small size

notice

4 TV LIST

PE371C4 FOR TV LIST

5 Introduce of Diagram (PE371C4 POWE MODULE PICTURE) EMI, bridge rectifier, Filter

PWM module

STB module STB IC:13-VIPER1-7LP

OCP,OVPmodule

LLC IC:13-FSFR17-00S

LLC module

5 Introduce of Diagram (EMI filter& rectifier circuit)

RN1： Thermistor; it’s resistance is large when TV starts, then becomes small when it’s hot ，to avoid rush current. CX1,CX2: restrain differential mode interference, CY1,CY2: restrain common mode interference, LF1，LF2,LF3: restrain common mode interference, RD1~RD8： discharge after power been turned off  BD1~BD4: bridge rectifier diodes C301: high frequency filter 

5 Introduce of Diagram (STB module—STB assistant POWER) Output sample1.25V A OVP

Opreation at 18V Standby module uses IC VIPER17LN,flyback structure. When turning on power, IC Pin 7, 8 charge C204 at Pin 2. When voltage of C204 exceeds 14V, IC starts to work; the transformer exchange energy constantly and outputs 3.3V to main board. R219, R220 sample voltage from 3.3V, and sampling signal feeds back to IC pin FB through TL431 and PC1. It is 3.3V pulse in FB when over current .

5 Introduce of Diagram (STB module—STB assistant POWER) Function of viper17 pins

5 Introduce of Diagram Standby operation description

3.3VRate Load Pin 7 、8 wave (A point)

Zoom wave (A point)

3.3V hiccup at null load (A point)

5 Introduce of Diagram (PFC Module—Power Factor)

C B

Output sensing. You had better to check if this circuit is all right when the capacitors CE2&CE3 explode.

B The current flowing from the MOSFET will increase when the input voltage decrease. So we have to detect this current via the resistor to prevent MOSFET destroyed

B 390v

On semiconductor’s FAN7930 is used for PFC module, it operates on critical conduction mode. The frequency of the MOSFET drive signal will increase and the duty cycle of the drive signal will decrease when the input AC voltage increase or load decrease. When the input AC voltage is over 275V, the PFC module will work intermittently ,at the same time the LP1 will shout. Simply the PFC is a boost topology ,it makes the system look like a pure resistor, in other words it makes the current’s wave shape & phase be the same as voltage’s.

5 Introduce of Diagram (FAN7930 PART FUNCTION )

Normal operation MOS driving wave(point B in picture)

bridge current in normal operation

bridge current at null load （C point in picture

5 Introduce of Diagram (LLC MODULE—PULSE MODULATE)

F D

CURRENT DETECTION

OUTPUT SAMPLE (DC2.5V)

5 Introduce of Diagram (LLC MODULE—PULSE MODULATE)

The of Fairchild company is used for LLC module. It is a controller specific for half-bridge resonant topology. It provides 50% complementary duty cycle: the high-side switch and the low-side switch are driven ON/OFF 180°out-of-phase. Output voltage regulation is obtained by modulating the operating frequency. Normally the frequency of the drive signal is approximately 100KHz. A voltage about 2.5V is sampled by R429&R430 which is fed back to the U401 PIN3 via U402&PC2. At light load the IC may enter a controlled burst-mode operation that keeps the converter input consumption to minimum. The peak-peak voltage of the point FB’s waveform will increase, when the load turn heavy, we use the R401,R402,R403&R410 and C410 to detect the load current. When you face this status that the output 24V DC is ok at light load, but there is no output DC24V at normal load. You’d better to check if the current detecting circuit is ok and if the OCP circuit is triggered .

5 Introduce of Diagram (LLC MODULE—PULSE MODULATE) Function of FSFR1700XLS pins:

5 Introduce of Diagram (LLC MODULE—PULSE MODULATE)

Double MOS midpoint wave at light load D point wave

Double MOS midpo int wave at rate load D point wave

Resonant capacitance wave  At rate load F point

5 Introduce of Diagram (power on module )

PFC IC&LLC IC supply power 

PS-ON

Power on process： When P_ON signal is on logic high level, Q407 turns on, then the photo coupler turns on. The voltage of the dynatron(Q205)’B base has 18V and the Q205 turns on. The voltage VC is transmitted to the LLC IC&PFC IC respectively via R431& R305 and Q350, then PSU starts to work.

7 List of PSU Part

08-PE371C5-PW20 0AA BOM

工作表

8 SERVISING FLOW ＋3.3V OUTPUT

NO

YES

YES

NO

NO YES

Check standy module

load fail Ok?

＋24V OUTPUT

Check voltage of vcc

NO

Check VCC circuit

Check voltage of CE2 395V±5V

YES

Check PWM module

NO Check PFC module

9 SERVISING GUIDE&TYPE CASES

The first thing of servicing PSU is locating the position of problem.  According to the phenomenon of problem, we can divide the PSU(PE371C4)to 5 modules. STANDBY module . If DC3.3V disappearing and the AC input running, we can locate the failure happened in Standby module. Please check the compents of D201,DS1,U202,PC1,D203, D206, D212,D204,D207,U201,R201,R202 by Multimeter. PFC module. If voltage of CE2、CE3 is low level. That maybe have two reasons. One is VCC module failure.Another reason is PFC modulefailure.CheckR314,Q306,Q205,U301,R302,R306, QW3, D30 3,CE1-CE3,R307-R310 by Multimeter when PFC module is failure.

9 SERVISING GUIDE&TYPE CASES LLC module. It has two reason: VCC circuit failure or LLC module failure that +24V voltage has no output when +3.3V and voltage of CE2 are ok. Check U401,R401,R403,R403,D406,PC2,U402,D401,DS4,DS3,L401, PC2 by millimeter to find the bad component. VCC CIRCUIT. This part circuit is simple. It output voltage of +18V to

U301 and U401 through TS1,D204,C206 of standby module. VCC is controlled by PC3. Check voltage of C206 and D204 to find the reason of VCC circuit failure. P_ON signals can control VCC circuit.

9 SERVISING GUIDE&TYPE CASES +3.3V OUPUT FAILURE Phenomenon

no +3.3V,no +24V， voltage of CE2 near to 310V

 Analysis 1st,Check voltage of C301 near 300V to make sure source input be ok. 2 nd, Check voltage of U201.PIN2 by oscillograph. we can make sure that driver part of standby is ok when seeing that it’s waving between 4.8-26.8V (blue track) and driving track (yellow track) of U201.PIN7&PIN8. 3rd,We can make sure overload protection by checking track of U201.PIN4 over 3V(pink track). 4 th, We find DS1 opening by checking DS1 and C208.Failure disappeared by replace DS1.

Summarize OLP (overload protection) is brought by DS1 opening.

9 SERVISING GUIDE&TYPE CASES +24V OUTPUT WHEN STANDBY Phenomenon  Analysis

voltage of +24V holding when standby (voltage of PS_ON=0V)

:

1st ,Power of PWM module should turn off when standby. We find the voltage of U401.PIN12 =13V.This phenomenon indicate VCC circuit failure. 2nd,What show Q205 failure that(PC3.PIN3=18V)&(Q205.E=18V)&(Q205.C=18V)&(Q205.B=16V). 3rd,We find that Q205.C short to Q205.E.It indicate Q205 bad.

Summarize

P_ON control vcc of PFC module and PWM module.

10 Diagram

PE371C4 SCH