ST AN2393 Application note

AN2393

Application note

Reference design: wide range 200W L6599-based

HB LLC resonant converter for LCD TV & flat panels

Introduction

This note describes the performances of a 200 W reference board, with wide-range mains
operation and power-factor-correction (PFC). Its electrical specification is tailored to a
typical high-end application for LCD TV or monitor applications.

The main features of this design are the very low no-load input consumption (<0.5 W) and
the very high global efficiency, better than 87% at full load and nominal mains voltage (115 ­230 V

The circuit consists of three main blocks; the first is a front-end PFC pre-regulator based on
the L6563 PFC controller. The second stage is a multi-resonant half-bridge converter whose
control is implemented through the STMicroelectronics L6599 resonant controller. A further
auxiliary flyback converter based on the VIPer12A-E off-line primary switcher completes the
architecture. This third block is mainly intended for microprocessor supply and display power
management operations.

ac

).

Figure 1. L6599 and L6563 200W evaluation board (EVAL6599-200W)

October 2007 Rev 5 1/35

www.st.com

Contents AN2393

Contents

1 Main characteristics and circuit description . . . . . . . . . . . . . . . . . . . . . 4

2 Electrical test results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

2.1 Efficiency measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

2.2 Resonant stage operating waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

2.3 Stand-by and no load power consumption . . . . . . . . . . . . . . . . . . . . . . . . 14

2.4 Short-circuit protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

2.5 Overvoltage protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

3 Thermal tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

4 Conducted emission pre-compliance test . . . . . . . . . . . . . . . . . . . . . . 20

5 Bill of materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

6 PFC coil specification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

6.1 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

6.2 Mechanical aspect and pin numbering . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

7 Resonant power transformer specification . . . . . . . . . . . . . . . . . . . . . 27

7.1 Electrical characteristics and mechanical aspect . . . . . . . . . . . . . . . . . . . 28

8 Auxiliary flyback power transformer . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

8.1 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

9 Reference design board layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

10 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

2/35

AN2393 List of figures

List of figures

Figure 1. L6599 and L6563 200W evaluation board (EVAL6599-200W). . . . . . . . . . . . . . . . . . . . . . . 1

Figure 2. PFC pre-regulator electrical diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Figure 3. Resonant converter electrical diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Figure 4. Auxiliary converter electrical diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Figure 5. Overall efficiency versus output power at nominal mains voltages. . . . . . . . . . . . . . . . . . . 10

Figure 6. Overall efficiency versus output power at several input voltage values . . . . . . . . . . . . . . . 11

Figure 7. Resonant circuit primary side waveforms at full load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Figure 8. Resonant circuit primary side waveforms at no-load condition. . . . . . . . . . . . . . . . . . . . . . 12

Figure 9. Resonant circuit secondary side waveforms: +24 V output . . . . . . . . . . . . . . . . . . . . . . . . 13

Figure 10. Resonant circuit secondary side waveforms: +12 V output . . . . . . . . . . . . . . . . . . . . . . . . 13

Figure 11. Low frequency (100 Hz) ripple voltage on the output voltages . . . . . . . . . . . . . . . . . . . . . . 13

Figure 12. Load transition (0 - 100%) on +24 V output voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Figure 13. Load transition (0 - 100%) on +12 V output voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Figure 14. +24 V output short-circuit waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Figure 15. +12 V output short-circuit waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Figure 16. Thermal map @115 V
Figure 17. Thermal map at 230 V
Figure 18. CE quasi peak measurement at 115 V
Figure 19. CE quasi peak measurement at 230 V

Figure 20. PFC coil electrical diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Figure 21. PFC coil pin side view. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Figure 22. Mechanical aspect and pin numbering of resonant transformer . . . . . . . . . . . . . . . . . . . . . 28

Figure 23. Resonant transformer electrical diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Figure 24. Resonant transformer winding position on coil former . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Figure 25. Auxiliary transformer electrical diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Figure 26. Auxiliary transformer winding position on coil former . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Figure 27. Copper tracks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Figure 28. Thru-hole component placing and top silk screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Figure 29. SMT component placing and bottom silk screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

- full load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

ac

- full load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

ac

and full load . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

ac

and full load . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

ac

3/35

Main characteristics and circuit description AN2393

1 Main characteristics and circuit description

The main characteristics of the SMPS are listed below:

● Universal input mains range: 90 to 264 V

● Output voltages:

– 24 V@6 A continuous operation

– 12 V@ 5 A continuous operation

– 3.3 V@ 0.7 A continuous operation

– 5 V@ 1 A continuous operation

● Mains harmonics: Compliance with EN61000-3-2 specifications

● St-by mains consumption: Typical 0.5 W @230 V

●

Overall efficiency: better than 88% at full load

● EMI: Compliance with EN55022-class B specifications

● Safety: Compliance with EN60950 specifications

● PCB single layer: 132x265 mm, mixed PTH/SMT technologies

The circuit consists of three stages. A front-end PFC pre-regulator implemented by the
controller L6563 (Figure 2), a half-bridge resonant DC/DC converter based on the resonant
controller L6599 (Figure 3) and a 7 W flyback converter intended for stand-by management
(Figure 4) utilizing the VIPer12A-E off-line primary switcher.

and frequencies between 45 and 65 Hz

ac

ac

The PFC stage delivers a stable 400 V

supply and provides for the reduction of the mains

DC

harmonics, in order to meet the requirements of the European norm EN61000-3-2 and the
JEIDA-MITI norm for Japan.

The PFC controller is the L6563 (U1), working in FOT (fixed off-time) mode and integrating
all functions needed to operate the PFC and interface the downstream resonant converter.

Note: The FOT control is implemented through components C15, C17, D5, Q3, R14, R17 and R29

(see AN1792 for a complete description of a FOT PFC pre-regulator).

The power stage of the PFC is a conventional boost converter, connected to the output of
the rectifier bridge through a differential mode filtering cell (C5, C6 and L3) for EMI
reduction. It includes a coil (L4), diode (D3) and two capacitors (C7 and C8).

The boost switch is represented by the Power MOSFET (Q2) which is directly driven by the
L6563 output drive thanks to the high current capability of the IC.

The divider (R30, R31 and R32) provides the L6563 (MULT Pin 3) with the information of the
instantaneous voltage that is used to modulate the boost current and to derive some further
information like the average value of the AC line used by the V

(voltage feed-forward)

FF

function. This function is used to keep the output voltage almost independent of the mains
one.

The first divider (R3, R6, R8, R10 and R11) is dedicated to detecting the output voltage
while the second divider (R5, R7, R9, R16 and R25) is used to protect the circuit in case of
voltage loop fail.

The second stage is an LLC resonant converter, with half bridge topology, working in ZVS
(zero voltage switching) mode.

The controller is the L6599 integrated circuit that incorporates the necessary functions to
drive properly the two half-bridge MOSFETs by a 50 percent fixed duty cycle with dead-time,

4/35

AN2393 Main characteristics and circuit description

changing the frequency according to the feedback signal in order to regulate the output
voltages against load and input voltage variations.

The main features of the L6599 are a non-linear soft-start, a current protection mode used
to program the hiccup mode timing, a dedicated pin for sequencing or brown-out (LINE) and
a stand-by pin (STBY) for burst mode operation at light loads (not used in this design).

The transformer uses the magnetic integration approach, incorporating the resonant series
and shunt inductances. Thus, no additional external coils are needed for the resonance. The
transformer configuration chosen for the secondary winding is center-tap, and the output
rectifiers are Schottky type diodes, in order to limit the power dissipation. The feedback loop
is implemented by means of a classical configuration using a TL431 (U4) to adjust the
current in the optocoupler diode (U3). A weighted resistive divider (R53, R57, R58, R60 and
R61) is used to detect both output voltages in order to get a better overall voltage regulation.
The optocoupler transistor modulates the current from Pin 4, so the frequency will change
accordingly, thus achieving the output voltage regulation. Resistors R46 and R54 set the
maximum operating frequency.

In case of a short circuit, the current entering the primary winding is detected by the lossless
circuit (C34, C39, D11, D12, R43, and R45) and the resulting signal is fed into Pin 6.

In case of overload, the voltage on Pin 6 will overpass an internal threshold that triggers a
protection sequence via Pin 2, keeping the current flowing in the circuit at a safe level.

The third stage is a small flyback converter based on the VIPer12A-E, a current mode
controller with integrated Power MOSFET, capable of delivering (approximately) 7 W output
power on the output voltages (5 V and 3.3 V). The regulated output voltage is the 3.3 V
output and, also in this case, the feedback loop bases on the TL431 (U7) and optocoupler
(U6) to control the output voltage.

This converter is able to operate in the whole mains voltage range, even when the PFC
stage is not working. From the auxiliary winding on the primary side of the flyback
transformer (T2), a voltage Vs is available, intended to supply the other controllers (L6563
and L6599) in addition to the VIPer12A-E itself.

The PFC stage and the resonant converter can be switched on and off through the circuit
based mainly on components Q7, Q8, D22 and U8, which, depending on the level of the
signal ST-BY, supplies or removes the auxiliary voltage (V

) necessary to start-up the

AUX

controllers of the PFC and resonant stages. In this way, when the AC input voltage is applied
to the power supply, the small flyback converter switches on first; then, when the ST-BY
signal is low, the PFC pre-regulator becomes operative, and last the resonant converter can
deliver the output power to the load.

Note that if Pin 9 of Connector J3 is left floating (no signal ST-BY present), the PFC and
resonant converter will be not operating, and only +5V and +3.3V supplies are available on
the output. In order to enable the +24 V and +12 V outputs, Pin 9 of Connector J3 must be
pulled down to ground.

5/35

Main characteristics and circuit description AN2393

Figure 2. PFC pre-regulator electrical diagram

Vdc

+400V

C9

2nF2-Y1

220uF/450V

C8

R2

NTC 2R5-S237

C7

470nF/630V

D3

STTH8R06

1-2

D1

1N5406

L4

PQ35-900uH

4-5

Q2

STP12NM50FP

D6

LL4148

R18

6R8

R24

0R68

R23

0R68

R22

0R68

R21

2R2

R19

1k

C18

330pF

Vrect

C6

680nF/630V

L3

DM-LSR-72uH-3A

C5

330nF/630V

Vaux

+

-

D2

D15XB60

~

~

C11

C4

Jumper

C3

L1

CM-TF2628V-5mH-3A

C2

R1

F1

6.3A/250V

1

J1

2nF2-Y2

680nF-X2

C10

2nF2-Y2

Jumper

330nF-X2

100nF-X2

1M5

2

CON2-IN

R4

47

C13

10uF/50V

C12

100nF

R6

680kR8680k

R3

680k

R5

Vdc

2M2

R11

R10

R7

2M2

R9

D5

C15

100pF

R14

1k5

R17

C17

15k

U1

L6563

100k

R13

56k

C14

100nF

C16

1uF

2M2

LL4148

15k

220pF

CSCS

PWM-Latch

R29

1k5

Q3

BC857C

R20

1k0

C21

2nF2

R28

GD

ZCD

VCC

RUN

GND

PWM-STOP

INV

COMP

MULTCSVFF

TBO

PFC-OK PWM-LATCH

R16

5k1

LINE

240k

R26

150k

C20

470nF

C19

10nF

R25

30k

C22

10nF

R32

10k

R31

620k

R30

620k

Vrect

6/35

AN2393 Main characteristics and circuit description

Figure 3. Resonant converter electrical diagram

1234567

J2

+24V

8

CON8

C25

470uF/35V

C30

+12V

R61

R53

33k

R58

0R

R51

2k2

R57

C38

C35

2200uF/35V

470uF/25V

2200uF/25V

15k

3k9

R60

3k9

L5

2uH2

D8A

Vdc

Q5

R33

D7

D8B

STPS20H100CF

0R

R35

LL4148

STPS20H100CF

13

14

15

16

T1

T-RE S-ER4 9

4

2

C28

22nF/630V

Q6

STP14NK50Z

47

STP14NK50Z

R39

0R

R40

47

D9

LL4148

L6

C29

2200uF/35V

2uH2

D10A

STPS20L40CF

12

Vaux

R38

47

C37

2200uF/25V

D10B

STPS20L40CF

91011

R43

150

C34

220pF/630V

C32

100nF

C31

10uF/50V

D11

LL4148

D12

LL4148

R45

75R

C39

220nF

C41

10uF/50V

D13

C-12V

R59

R56

1k0

R52

5k6

U3A

SFH617A-2

27k

C44

47nF

U4

TL431

C27 100nF

NC

LVG

OUT

VCC

HVG

VBOOT

U2

L6599

CSS

DELAYCFRFMIN

STBY

ISEN

LINE GND

CC by rework

16k

DIS PFC-STOP

C33

4nF7

R42

10

LINE

R36

0R

R34

2k7

C23

2uF2

C24

470nF

C26

270pF

R37

1M0

R41

C40

10nF

R47

10k

R46

5k6

PWM-Latch

U3B

SFH617A-2

R54

5k6

7/35

Main characteristics and circuit description AN2393

Q10

BC847C

C54

100nF

U7

TL431

C53

2nF2

U6A

SFH617A-2

U6B

SFH617A-2

Vs

+24V

R67

1k0

SSFB

Vdd D

D

D

D

U5

VIPER-12A

R82

1k5

R79

1k0

D15

1N5822

D16

1N5821

D20

BAV103

C56

100nF

C45

1000uF/10V

C47

1000uF/10V

C50

10uF/50V

C46

100uF/10V

C49

100uF/10V

Q9

BC857C

C48

10uF/50V

R76

1k5

U8A

SFH617A-2

R75

0R

U8B

SFH617A-2

Vdc

R74

10k

R77

4k7

D19

C-30V

St-By

D18

B-10V

+400V

C57

1nF0

R69

0R

Vdc

C52

47nF

R68

22k

C51

100nF

R71

10k

1

2

4

5

9 - 10

8

7

6

R83

1M0

Q8

BC847C

R84

150k

R72

10k

C55

10uF/50V

R66

1k0

C58

10nF

T2

T-FLY-AUX-E20

+400V

Q11

BC557C

R70

22R

+5Vst-by

+3V3

+5Vst-by

Q7

BC547C

D22

C-15V

L7

33uH

L8

33uH

D17

LL4148

123456789

10

J3

CON10

+12V

D21

B-27V

D23

B-15V

R62

47

R64

1k6

Vs

Vaux

+5Vst-by

D14

PKC-136

St-By

R73

8k2

Figure 4. Auxiliary converter electrical diagram

8/35

AN2393 Electrical test results

2 Electrical test results

2.1 Efficiency measurements

Ta bl e 1 and Tabl e 2 show the output voltage measurements at the nominal mains voltages

of 115 V
and at light load operation, the input power is measured using a Yokogawa WT-210 digital
power meter.

Particular attention has to be paid when measuring input power at full load in order to avoid
measurement errors due to the voltage drop on cables and connections. Therefore please
connect the WT210 voltmeter termination to the board input connector. For the same reason
please measure the output voltage at the output connector or use the remote sense option
of your active load for a correct output voltage measurement.

Table 1. Efficiency measurements @

+24 V(V) @load(A) +12 V(V) @load(A) +5 V(V) @load(A) +3.3 V(V) @load(A) P

23.81 - 6.00 11.86 - 4.94 4.93 - 0.98 3.35 - 0.71 208.66 235.00 88.79%

24.04 - 3.04 11.80 - 4.91 4.93 - 0.98 3.35 - 0.71 138.23 155.50 88.89%

23.84 - 3.02 11.91 - 1.98 4.93 - 0.98 3.35 - 0.71 102.79 115.47 89.02%

and 230 Vac, with different load conditions. For all measurements, both at full load

ac

VIN = 115 V

ac

(W) PIN (W) Efficiency

OUT

23.79 - 2.01 11.96 - 0.49 4.96 - 0.31 3.35 - 0.31 56.25 63.55 88.52%

23.94 - 0.53 11.92 - 0.49 4.97 - 0.31 3.35 - 0.31 21.11 25.56 82.58%

Table 2. Efficiency measurements @V

+24 V(V) @load(A) +12 V(V) @load(A) +5 V(V) @load(A) +3.3 V(V) @load(A) P

23.82 - 6.00 11.86 - 4.94 4.94 - 0.98 3.35 - 0.71 208.73 229.96 90.77%

24.05 - 3.04 11.80 - 4.91 4.94 - 0.98 3.35 - 0.71 138.27 152.85 90.46%

23.85 - 3.02 11.91 - 1.98 4.94 - 0.98 3.35 - 0.71 102.83 114.05 90.16%

23.80 - 2.01 11.96 - 0.49 4.96 - 0.31 3.35 - 0.31 56.27 63.47 88.66%

23.94 - 0.53 11.92 - 0.49 4.96 - 0.31 3.35 - 0.31 21.11 26.47 79.73%

= 230 V

IN

ac

(W) PIN (W) Efficiency

OUT

In Ta bl e 1 , Table 2 and Figure 5 the overall circuit efficiency is measured at each load
condition, at both nominal input mains voltages of 115 V

and 230 Vac. The values were

ac

measured after 30 minutes of warm-up at maximum load. The high efficiency of the PFC
pre-regulator working in FOT mode and the very high efficiency of the resonant stage
working in ZVS (i.e. with negligible switching losses), provides for an overall efficiency better
than 88%. This is a significant high value for a two-stage converter with two output voltages
delivering an output current in excess of 5 amps, especially at low input mains voltage
where the PFC conduction losses increase. Even at lower loads, the efficiency still remains
high.

The global efficiency at full load has been measured even at the limits of the input voltage
range, with good results:

● At V

● At V

= 90 Vac - full load, the efficiency is 86.88% (P

IN

= 264 Vac - full load, the efficiency is 90.90% (P

IN

= 208.8 W and PIN = 240.3 W)

OUT

= 208.7 W and PIN =

OUT

229.6 W)

9/35

Electrical test results AN2393

%

Also at light load, at an output power of about 10% of the maximum level, the overall
efficiency is very good, reaching a value better than 79% over the entire input mains voltage
range.

Figure 6 shows the efficiency measured at various input voltages versus output power.

Figure 5. Overall efficiency versus output power at nominal mains voltages

95.00%

94.00%

93.00%

92.00%

91.00%

90.00%

89.00%

88.00%

87.00%

86.00%

85.00%

84.00%

efficiency (

83.00%

82.00%

81.00%

80.00%

79.00%

78.00%

77.00%

76.00%

75.00%
0 102030405060708090100110120130140150160170180190200210

Output power (W)

eff% @ 115 V a c
eff% @ 230 V a c

10/35

AN2393 Electrical test results

%

%

Figure 6. Overall efficiency versus output power at several input voltage values

95.00%

94.00%

93.00%

92.00%

91.00%

90.00%

89.00%

88.00%

87.00%

86.00%

85.00%

84.00%

efficiency (

83.00%

82.00%

81.00%

80.00%

79.00%

78.00%

77.00%

76.00%

75.00%

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210

95.00%

94.00%

93.00%

92.00%

91.00%

90.00%

89.00%

88.00%

87.00%

86.00%

85.00%

84.00%

efficiency (

83.00%

82.00%

81.00%

80.00%

79.00%

78.00%

77.00%

76.00%

75.00%
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210

Outp u t po w e r (W)

Output power (W)

eff% @ 90 Vac
eff% @ 100 Vac
eff% @ 115 Vac
eff% @ 135 Vac

eff% @ 170 Vac
eff% @ 200 Vac
eff% @ 230 Vac
eff% @ 264 Vac

2.2 Resonant stage operating waveforms

Figure 7 shows some waveforms during steady state operation of the resonant circuit at full

load. The Ch3 waveform is the half-bridge square voltage on Pin 14 of L6599, driving the
resonant circuit. In the picture it is not evident, but the switching frequency is normally
slightly modulated following the PFC pre-regulator 100-Hz ripple that is rejected by the
resonant control circuitry. The switching frequency has been selected approximately at
95-kHz in order to have a good trade off between transformer losses and dimensions.

The Ch4 waveform represents the transformer primary current flowing into the resonant
tank. As shown, it is almost sinusoidal because the operating frequency is close to the
resonance of the leakage inductance of the transformer and the resonant capacitor (C28).
In this condition, the circuit has a good margin for ZVS operation, providing good efficiency,

11/35

Electrical test results AN2393

while the almost sinusoidal current waveform just allows for an extremely low EMI
generation.

Figure 8 shows the same waveforms of previous figure, when both the outputs are not

loaded. This picture demonstrates the ability of the converter to operate down to zero load,
with the output voltages still within regulation. The resonant tank current has obviously a
triangular shape and represents the magnetizing current flowing into the transformer
primary side.

Figure 7. Resonant circuit primary side waveforms at full load

Ch3: half-bridge square voltage
Ch4: resonant tank current

Figure 8. Resonant circuit primary side waveforms at no-load condition

Ch1: +12V output voltage
Ch2: +24V output voltage
Ch3: half-bridge square voltage
Ch4: resonant tank current

In Figure 9 and Figure 10, waveforms relevant to the secondary side are represented: the
rectifiers reverse voltage is measured by CH1 (for both +24 V and +12 V outputs) and the
peak to peak value is indicated on the right side of the figure. It is a bit higher than the
theoretical value that would be 2(V

OUT+VF

): it is possible to observe a small ringing on the

bottom side of the waveform, responsible for this difference.

12/35

AN2393 Electrical test results

Waveform CH3 shows the current flowing into one of the two output diodes for each output
voltage (respectively D8A and D10A). Also this current shape is almost a sine wave, whose
average value is one half the output current.

The ripple and noise on the output voltage is shown on CH2. Thanks to the advantages of
the resonant converter, the high frequency noise of the output voltages is less than 50 mV,
while the residual ripple at twice the mains frequency is lower than 75 mV at maximum load
and any line condition, as shown in Figure 11.

Figure 9. Resonant circuit secondary side

+24 V output waveforms:
Ch1: +24 V diode reverse voltage
Ch2: high freq. ripple on +24 V output voltage
Ch3: diode D8A current

waveforms: +24 V output

Figure 11. Low frequency (100 Hz) ripple voltage on the output voltages

Figure 10. Resonant circuit secondary side

waveforms: +12 V output

+12 V output waveforms:
Ch1: +12V diode reverse voltage
Ch2: high freq. ripple on +12 V output voltage
Ch3: diode D10A current

Ch1: 100 Hz ripple voltage on +12 V
Ch2: 100 Hz ripple voltage on +24 V

Figure 12 shows the dynamic behavior of the converter during a load variation from 0 to

100% on one output, with the other output at maximum load. This figure also highlights the
induced effect of this load change on the PFC pre-regulator output voltage (+400 V on Ch3
track). Both the transitions (from 0 to 100% and from 100% to 0) are clean and do not show
any problem for the output voltage regulation.

13/35

Electrical test results AN2393

Thus, it is clear that the proposed architecture is really suitable for power supplies operating
with strong load variation without any problem related to the load regulation.

Figure 12. Load transition (0 - 100%) on +24 V

output voltage

Figure 13. Load transition (0 - 100%) on +12 V

output voltage

Dynamic load +24 V @0-6 A - 12 V @ max load (5 A)

Ch1: +24 V output voltage
Ch2: +12 V output current
Ch3: PFC output voltage (400 V)
Ch4: + 24 V output current

Dynamic load +12 V @0-5 A - 24 V @ max load (6 A)

Ch1: +24 V output voltage
Ch2: +12 V output current
Ch3: PFC output voltage (400 V)
Ch4: + 12 V output current

2.3 Stand-by and no load power consumption

The board is specifically designed for light load and zero load operation, as during Stand-by
or Power-off operation, when no power is requested from the +24 V and +12 V outputs.

Though the resonant converter can operate down to zero load, some tricks are required to
keep very low the input power drawn from the mains when the system is in this load
condition. Thus, when entering this power management mode, the ST-BY signal needs to be
set high (by the microcontroller of the system). This forces the PFC pre-regulator and the
resonant stage to switch off (because the supply voltage of the two control ICs is no longer
present (Figure 4) and only the auxiliary flyback converter continues working just to supply
the microprocessor circuitry.

Ta bl e 3 and Tabl e 4 show the measurements of the input power in several light load

conditions at 115 and 230 V

These tables show that at no load the input power is lower than 0.5 W.

ac

.

14/35

AN2393 Electrical test results

Table 3. Stand-by consumption at V

+5 V(V) @load(A) +3.3 V(V) @load(A) P

5.08 - 0.018 3.35 - 0.102 0.43 0.863

5.04 - 0.018 3.35 - 0.079 0.36 0.751

4.98 - 0.018 3.35 - 0.046 0.24 0.582

4.92 - 0.018 3.35 - 0.023 0.17 0.445

4.47 - 0.000 3.35 - 0.000 0.00 0.221

Table 4. Stand-by consumption at VIN = 230 V

+5 V(V) @load(A) +3.3 V(V) @load(A) P

5.08 - 0.018 3.35 - 0.102 0.43 1.138

5.04 - 0.018 3.35 - 0.079 0.36 1.022

4.98 - 0.018 3.35 - 0.046 0.24 0.857

4.92 - 0.018 3.35 - 0.023 0.17 0.740

4.47 - 0.000 3.35 - 0.000 0.00 0.470

= 115 V

IN

ac

ac

(W) PIN (W)

OUT

(W) PIN (W)

OUT

2.4 Short-circuit protection

The L6599 is equipped with a current sensing input (pin #6, ISEN) and a dedicated over­current management system. The current flowing in the circuit is detected (through the not
dissipative sensing circuit already mentioned in Section 1 and the signal is fed into the ISEN
pin. It is internally connected to the input of a first comparator, referenced to 0.8 V, and to
that of a second comparator referenced to 1.5 V. If the voltage externally applied to the pin
exceeds 0.8 V, the first comparator is tripped causing an internal switch to be turned on
discharging the soft-start capacitor CSS.

For output short-circuits, this operation results in a nearly constant peak primary current.
Using the L6599, the designer can externally program the maximum time (t
converter is allowed to run overloaded or under short-circuit conditions. Overloads or short­circuits lasting less than t
immunity to short duration phenomena. If, instead, t
(OLP) procedure is activated that shuts down the L6599 and, in case of continuous
overload/short circuit, results in continuous intermittent operation with a user-defined duty
cycle. This function is realized with the pin DELAY (#2), by means of a capacitor C24 and
the parallel resistor R37 connected to ground. As the voltage on the ISEN pin exceeds 0.8 V,
the first OCP comparator, in addition to discharging CSS, turns on an internal current
generator that via the DELAY pin charges C24. As the voltage on C24 reaches 3.5 V, the
L6599 stops switching and the PFC_STOP pin is pulled low. Also the internal generator is
turned off, so that C24 will now be slowly discharged by R37. The IC will restart when the
voltage on C24 becomes less than 0.3 V. Additionally, if the voltage on the ISEN pin reaches

1.5 V for any reason (e.g. transformer saturation), the second comparator will be triggered,
the L6599 will shutdown and the operation will be resumed after an on-off cycle.

will not cause any other action, hence providing the system with

SH

) that the

SH

is exceeded, an overload protection

SH

Figure 14 and Figure 15 illustrate the L6599 short-circuit protection sequence described

above. The on-off operation is controlled by the voltage on pin #2 (DELAY), providing for the
hiccup mode of the circuit. Thanks to this control pin, the designer can select the hiccup
mode timing and thus keep the average output current at a safe level. Please note on the left

15/35

Electrical test results AN2393

side of the figure the very low mean current flowing in the shorted output which is less than

0.3 A.

Figure 14. +24 V output short-circuit

waveforms

Figure 15. +12 V output short-circuit

waveforms

Short circuit on +24 V output voltage

Ch1: +24 V output voltage
Ch2: L6599 pin 6 (ISEN)
Ch3: L6599 pin 2 (DELAY)
Ch4: +24 V output current

2.5 Overvoltage protection

Both the PFC pre-regulator and the resonant converter are equipped with their own over­voltage protection circuit. The PFC controller L6563 is internally equipped with a dynamic
and a static overvoltage protection circuit sensing the error amplifier via the voltage divider
dedicated to the feedback loop to sense the PFC output voltage. If an internal threshold is
exceeded, the IC limits the PFC output voltage to a programmable, safe value.

Moreover, in the L6563 there is an additional protection against loop failures using an
additional divider (R5, R7, R9, R16 and R25) connected to a dedicated pin (PFC_OK, Pin 7)
protecting the circuit in case of loop failures or disconnection or deviation from the nominal
value of the feedback loop divider. Hence the PFC output voltage is always under control
and in case a fault condition is detected the PFC_OK circuitry will latch the L6563
operations and, by means of the PWM_LATCH pin (Pin 8) it will latch the L6599 as well via
the DIS pin (Pin 8).

The OVP circuit (see Figure 4) for the output voltages of the resonant converter uses two
zener diodes (D21 and D23) to sense the +24 V and+12 V. If one of the output voltages
exceeds the threshold imposed by these zener diodes plus the V
Q9 starts conducting and the optocoupler U8 opens Q7, so that the V
the controller ICs L6563 and L6599 is no longer available. This state is latched until a mains
voltage recycle occurs.

Short circuit on +12 V output voltage

Ch1: +12 V output voltage
Ch2: L6599 pin 6 (ISEN)
Ch3: L6599 pin 2 (DELAY)
Ch4: +12 V output current

of Q10, the transistor

BE

supply voltage of

AUX

16/35

AN2393 Thermal tests

3 Thermal tests

In order to check the design reliability, a thermal mapping by means of an IR Camera was
performed. Figure 16 and Figure 17 show the thermal measurements of the board,
component side, at nominal input voltage. The correlation between measurement points and
components is indicated for both diagrams.

Figure 16. Thermal map @115 V

Figure 17. Thermal map at 230 V

- full load

ac

- full load

ac

17/35

Thermal tests AN2393

Table 5. Key components temperature at 115 Vac - full load

Ambient temperature: 25° C

Item Temp (°C)

D2 44.9

Q2 53.7

D3 50.3

L1 47.0

L3 46.0

L4 (Fe) 45.8

L4 (Cu) 49.2

C8 37.3

R2 78.0

Q5 40.2

Q6 46.7

D8A 56.2

D8B 56.7

D10A 42.1

D10B 42.7

C29 45.1

C30 46.1

C37 42.0

C38 41.6

L5 71.2

L6 56.0

T1 51.7

T1 56.8

U5 81.4

D14 74.2

D15 57.6

D16 55.3

T2 56.4

18/35

AN2393 Thermal tests

Table 6. Key components temperature at 230 V

Ambient temperature: 25° C

Item Temp (°C)

D2 37.1

Q2 46.6

D3 44.0

L1 33.6

L3 34.9

L4 (Fe) 39.1

L4 (Cu) 41.2

C8 37.1

R2 65.8

Q5 38.3

Q6 43.7

D8A 56.4

D8B 55.6

D10A 42.1

- full load

AC

D10B 43.8

C29 48.2

C30 47.4

C37 44.3

C38 44.5

L5 73.6

L6 57.3

T1 (Fe) 51.3

T1 (Cu) 58.8

U5 81.8

D14 74.4

D15 59.4

D16 56.3

T2 56.8

All other board components work within the temperature limits, assuring a reliable long term
operation of the power supply.

Note that the temperatures of L4 and T1 have been measured both on the ferrite core (Fe)
and on the copper (Cu).

19/35

Conducted emission pre-compliance test AN2393

4 Conducted emission pre-compliance test

The limits indicated on both diagrams at 115 Vac and 230 Vac comply with EN55022 Class-B
specifications. The measurements have been taken in Quasi Peak detection mode.

Figure 18. CE quasi peak measurement at 115 V

Figure 19. CE quasi peak measurement at 230 V

and full load

ac

and full load

ac

20/35

AN2393 Bill of materials

5 Bill of materials

Table 7. Bill of materials

Item Part type/value Description Supplier

C2 100 nF-X2 275 V

C3 330 nF-X2 275 V

C4 680 nF-X2 275 V

X2 Safety Capacitor MKP R46 Arcotronics

ac

X2 Safety Capacitor MKP R46 Arcotronics

ac

X2 Safety Capacitor MKP R46 Arcotronics

ac

C5 330 nF/630 V Polypropylene Capacitor High Ripple MKP R71 Arcotronics - Epcos

C6 680 nF/630 V Polypropylene Capacitor High Ripple MKP R71 Arcotronics - Epcos

C7 470 nF/630 V Polypropylene Capacitor High Ripple MKP R71 Arcotronics - Epcos

C8 220 µF/450 V Aluminium ELCAP USC Series 85 DEG SNAP-IN Rubycon

C9 2nF2-Y1 400 V

C10 2nF2-Y1 250 V

C11 2nF2-Y1 250 V

Y1 Safety Ceramic Disk Capacitor Murata

ac

Y1 Safety Ceramic Disk Capacitor Murata

ac

Y1 Safety Ceramic Disk Capacitor Murata

ac

C12 100 nF 50 V 1206 SMD Cercap General Purpose BC Components

C13 10 µF/50 V Aluminium ELCAP General Purpose 85 DEG Rubycon

C14 100 nF 50 V 1206 SMD Cercap General Purpose BC Components

C15 100 pF 100 V 0805 SMD Cercap General Purpose BC Components

C16 1 µF 25 V 1206 SMD Cercap General Purpose BC Components

C17 220 pF 100 V 0805 SMD Cercap General Purpose BC Components

C18 330 pF 100 V 0805 SMD Cercap General Purpose BC Components

C19 10 nF 100 V 0805 SMD Cercap General Purpose BC Components

C20 470 nF 50 V 1206 SMD Cercap General Purpose BC Components

C21 2nF2 100 V 1206 SMD Cercap General Purpose BC Components

C22 10 nF 100 V 0805 SMD Cercap General Purpose BC Components

C23 2 µF2 25 V 1206 SMD Cercap General Purpose BC Components

C24 470 nF 25 V 1206 SMD Cercap General Purpose BC Components

C25 470 µF/35 V Aluminium ELCAP YXF Series 105 DEG Rubycon

C26 270 pF 100 V 0805 SMD Cercap General Purpose BC Components

C27 100 nF 50 V 1206 SMD Cercap General Purpose BC Components

C28 22 nF/630 V/400 V

Polypropylene Capacitor High Ripple PHE450 RIFA-EVOX

ac

C29 2200 µF/35 V Aluminium ELCAP YXF Series 105 DEG Rubycon

C30 2200 µF/35 V Aluminium ELCAP YXF Series 105 DEG Rubycon

C31 10 µF/50 V Aluminium ELCAP General Purpose 85 DEG Rubycon

C32 100 nF 50 V 1206 SMD Cercap General Purpose BC Components

C33 4 nF7 100 V 1206 SMD Cercap General Purpose BC Components

21/35

Bill of materials AN2393

Table 7. Bill of materials (continued)

Item Part type/value Description Supplier

C34 220 pF/630 V Polypropylene Capacitor High Ripple PFR RIFA-EVOX

C35 470 µF/25 V Aluminium ELCAP YXF Series 105 DEG Rubycon

C37 2200 µF/25 V Aluminium ELCAP YXF Series 105 DEG Rubycon

C38 2200 µF/25 V Aluminium ELCAP YXF Series 105 DEG Rubycon

C39 220 nF 50 V 1206 SMD Cercap General Purpose BC Components

C40 10 nF 100 V 1206 SMD Cercap General Purpose BC Components

C41 10 µF/50 V Aluminium ELCAP General Purpose 85 DEG Rubycon

C44 47 nF 100 V 1206 SMD Cercap General Purpose BC Components

C45 1000 µF/10 V Aluminium ELCAP YXF Series 105 DEG Rubycon

C46 100 µF/10 V Aluminium ELCAP YXF Series 105 DEG Rubycon

C47 1000 µF/10 V Aluminium ELCAP YXF Series 105 DEG Rubycon

C48 10 µF/50 V Aluminium ELCAP General Purpose 85 DEG Rubycon

C49 100 µF/10 V Aluminium ELCAP YXF Series 105 DEG Rubycon

C50 10 µF/50 V Aluminium ELCAP General Purpose 85 DEG Rubycon

C51 100 nF 100 V 0805 SMD Cercap General Purpose BC Components

C52 47 nF 100 V 0805 SMD Cercap General Purpose BC Components

C53 2 nF2 100 V 0805 SMD Cercap General Purpose BC Components

C54 100 nF 50 V 1206 SMD Cercap General Purpose BC Components

C55 10 µF/50 V Aluminium ELCAP General Purpose 85 DEG Rubycon

C56 100 nF 50 V 1206 SMD Cercap General Purpose BC Components

C57 1nF0 100 V 0805 SMD Cercap General Purpose BC Components

C58 10 nF 50 V X7R Standard Ceramic Capacitor BC Components

D1 1N5406 General Purpose Rectifier Vishay

D2 D15XB60 Single Phase Bridge Rectifier Shindengen

D3 STTH8R06 TO220FP Ultrafast High Voltage Rectifier STMicroelectronics

D5 LL4148 MINIMELF Fast Switching Diode Vishay

D6 LL4148 MINIMELF Fast Switching Diode Vishay

D7 LL4148 MINIMELF Fast Switching Diode Vishay

D8A-B STPS20H100CF TO220FP Power Schottky Rectifier STMicroelectronics

D9 LL4148 MINIMELF Fast Switching Diode Vishay

D10A-B STPS20L40CF TO220FP Power Schottky Rectifier STMicroelectronics

D11 LL4148 MINIMELF Fast Switching Diode Vishay

D12 LL4148 MINIMELF Fast Switching Diode Vishay

D13 C-12 V BZV55-C Series Zener Diode Vishay

D14 PKC-136 Peak Clamp Transil STMicroelectronics

22/35

AN2393 Bill of materials

Table 7. Bill of materials (continued)

Item Part type/value Description Supplier

D15 1N5822 Power Schottky Rectifier STMicroelectronics

D16 1N5821 Power Schottky Rectifier STMicroelectronics

D17 LL4148 MINIMELF Fast Switching Diode Vishay

D18 B-10 V BZV55-B Series Zener Diode Vishay

D19 C-30 V BZV55-C Series Zener Diode Vishay

D20 BAV103 General Purpose Diode Vishay

D21 B-27 V BZV55-B Series Zener Diode Vishay

D22 C-15 V BZV55-C Series Zener Diode Vishay

D23 B-15 V BZV55-B Series ZENER DIODE Vishay

F1 6.3A/250 V T Type Fuse 5 X 20 High Capability & Fuseholder Wickmann

J1 CON2-IN 3-Pin Connector (Central Removed) P 3.96 KK Series Molex

J2 CON8 8-Pin Connector P 3.96 KK Series Molex

J3 CON10 10-Pin Connector P 2.54 MTA Series AMP

L1 CM-TF2628V-5 mH-3 A TF2628 Series Common Mode Toroidal Inductor TDK

L3 DM-LSR-72 µH-3 A LSR1803-2 Differential Mode Toroidal Inductor Delta

L4 PQ35-900 µH 86H-5409 Boost Inductor Delta

L5 2 µH2 RFB0807 Drum Core Inductor Coilcraft

L6 2 µH2 RFB0807 Drum Core Inductor Coilcraft

L7 33 µH RFB0807 Drum Core Inductor Coilcraft

L8 33 µH RFB0807 Drum Core Inductor Coilcraft

Q2 STP12NM50FP TO220FP N-Channel Power MOSFET STMicroelectronics

Q3 BC857C SOT23 Small Signal PNP Transistor STMicroelectronics

Q5 STP14NK50Z TO220FP N-Channel Power MOSFET STMicroelectronics

Q6 STP14NK50Z TO220FP N-Channel Power MOSFET STMicroelectronics

Q7 BC547C TO92 Small Signal PNP Transistor STMicroelectronics

Q8 BC847C SOT23 Small Signal PNP Transistor STMicroelectronics

Q9 BC857C SOT23 Small Signal PNP Transistor STMicroelectronics

Q10 BC847C SOT23 Small Signal NPN Transistor STMicroelectronics

Q11 BC547C TO92 Small Signal PNP Transistor STMicroelectronics

R1 1M5 VR25 Type High Voltage Resistor BC Components

R2 NTC 2R5-S237 NTC RESISTOR 2R5 S237 Series Epcos

R3 680 kΩ 1206 SMD Standard Film RES 1/4 W 5% 200 ppm/°C BC Components

R4 47 0805 SMD Standard Film RES 1/8 W 5% 200 ppm/°C BC Components

R5 2M2 1206 SMD Standard Film RES 1/4 W 1% 100 ppm/°C BC Components

R6 680 kΩ 1206 SMD Standard Film RES 1/4 W 5% 20 0ppm/°C BC Components

23/35

Bill of materials AN2393

Table 7. Bill of materials (continued)

Item Part type/value Description Supplier

R7 2M2 1206 SMD Standard Film RES 1/4 W 1% 100 ppm/°C BC Components

R8 680 kΩ 1206 SMD Standard Film RES 1/4 W 5% 200 ppm/°C BC Components

R9 2M2 1206 SMD Standard Film RES 1/4 W 1% 100 ppm/°C BC Components

R10 100 kΩ 0805 SMD Standard Film RES 1/8 W 5% 200 ppm/°C BC Components

R11 15 kΩ 0805 SMD Standard Film RES 1/8W 5% 200ppm/°C BC Components

R13 56 kΩ 1206 SMD Standard Film RES 1/8 W 5% 200 ppm/°C BC Components

R14 1k5 0805 SMD Standard Film RES 1/8 W 1% 100 ppm/°C BC Components

R16 5k1 1206 SMD Standard Film RES 1/4 W 1% 100 ppm/°C BC Components

R17 15 kΩ 0805 SMD Standard Film RES 1/8 W 1% 100 ppm/°C BC Components

R18 6R8 0805 SMD Standard Film RES 1/8 W 5% 200 ppm/°C BC Components

R19 1K0 0805 SMD Standard Film RES 1/8 W 5% 200 ppm/°C BC Components

R20 1k0 Standard Metal Film RES 1/4 W 5% 200 ppm/°C BC Components

R21 2R2 Standard Metal Film RES 1/4 W 5% 200 ppm/°C BC Components

R22 0R68 PR01 Power Resistor BC Components

R23 0R68 PR01 Power Resistor BC Components

R24 0R68 PR01 Power Resistor BC Components

R25 30 kΩ 0805 SMD Standard Film RES 1/8 W 1% 100 ppm/°C BC Components

R26 150 kΩ 1206 SMD Standard Film RES 1/8 W 5% 200 ppm/°C BC Components

R28 240 kΩ 0805 SMD Standard Film RES 1/8 W 5% 200 ppm/°C BC Components

R29 1k5 0805 SMD Standard Film RES 1/8 W 5% 200 ppm/°C BC Components

R30 620 kΩ 1206 SMD Standard Film RES 1/4 W 5% 200 ppm/°C BC Components

R31 620 kΩ 1206 SMD Standard Film RES 1/4 W 5% 200 ppm/°C BC Components

R32 10 kΩ 0805 SMD Standard Film RES 1/8 W 5% 200 ppm/°C BC Components

R33 0R 0805 SMD Standard Film RES 1/8 W BC Components

R34 2k7 0805 SMD Standard Film RES 1/8 W 5% 200 ppm/°C BC Components

R35 47 0805 SMD Standard Film RES 1/8 W 5% 200 ppm/°C BC Components

R36 0R 0805 SMD Standard Film RES 1/8 W BC Components

R37 1M0 0805 SMD Standard Film RES 1/8 W 5% 200 ppm/°C BC Components

R38 47 Standard Metal Film RES 1/4W 5% 200ppm/°C BC Components

R39 0R 0805 SMD Standard Film RES 1/8 W BC Components

R40 47 0805 SMD Standard Film RES 1/8 W 5% 200 ppm/°C BC Components

R41 16 kΩ 0805 SMD Standard Film RES 1/8 W 1% 100 ppm/°C BC Components

R42 10 1206 SMD Standard Film RES 1/8 W 5% 200 ppm/°C BC Components

R43 150 1206 SMD Standard Film RES 1/4 W 5% 200 ppm/°C BC Components

R45 75R 1206 SMD Standard Film RES 1/4 W 1% 100 ppm/°C BC Components

24/35

AN2393 Bill of materials

Table 7. Bill of materials (continued)

Item Part type/value Description Supplier

R46 5k6 0805 SMD Standard Film RES 1/8 W 5% 200 ppm/°C BC Components

R47 10 kΩ 1206 SMD Standard Film RES 1/8 W 5% 200 ppm/°C BC Components

R51 2k2 0805 SMD Standard Film RES 1/8 W 5% 200 ppm/°C BC Components

R52 5k6 0805 SMD Standard Film RES 1/8 W 5% 200 ppm/°C BC Components

R53 33 kΩ 1206 SMD Standard Film RES 1/4 W 1% 100 ppm/°C BC Components

R54 5k6 1206 SMD Standard Film RES 1/8 W 5% 200 ppm/°C BC Components

R56 1k0 0805 SMD Standard Film RES 1/8 W 5% 200 ppm/°C BC Components

R57 15 kΩ 1206 SMD Standard Film RES 1/4 W 1% 100 ppm/°C BC Components

R58 0R 1206 SMD Standard Film RES 1/4 W BC Components

R59 27 kΩ 0805 SMD Standard Film RES 1/8 W 5% 200 ppm/°C BC Components

R60 3k9 0805 SMD Standard Film RES 1/8 W 1% 100 ppm/°C BC Components

R61 3k9 0805 SMD Standard Film RES 1/8 W 1% 100 ppm/°C BC Components

R62 47 0805 SMD Standard Film RES 1/8 W 5% 200 ppm/°C BC Components

R64 1k6 0805 SMD Standard Film RES 1/8 W 1% 100 ppm/°C BC Components

R66 1k0 0805 SMD Standard Film RES 1/8 W 5% 200 ppm/°C BC Components

R67 1k0 0805 SMD Standard Film RES 1/8 W 5% 200 ppm/°C BC Components

R68 22 kΩ 0805 SMD Standard Film RES 1/8 W 5% 200 ppm/°C BC Components

R69 0R 0805 SMD Standard Film RES 1/8W 5% 200ppm/°C BC Components

R70 22R 0805 SMD Standard Film RES 1/8 W 5% 200 ppm/°C BC Components

R71 10 kΩ 0805 SMD Standard Film RES 1/8 W 5% 200 ppm/°C BC Components

R72 10 kΩ 0805 SMD Standard Film RES 1/8 W 5% 200ppm/°C BC Components

R73 8k2 0805 SMD Standard Film RES 1/8 W 5% 200 ppm/°C BC Components

R74 10 kΩ 0805 SMD Standard Film RES 1/8 W 5% 200 ppm/°C BC Components

R75 0R 1206 SMD Standard Film RES 1/4 W BC Components

R76 1k5 1206 SMD Standard Film RES 1/4 W 1% 100 ppm/°C BC Components

R77 4k7 0805 SMD Standard Film RES 1/8 W 1% 100 ppm/°C BC Components

R79 1k0 0805 SMD Standard Film RES 1/8 W 5% 200 ppm/°C BC Components

R82 1k5 1206 SMD Standard Film RES 1/4 W 1% 100 ppm/°C BC Components

R83 1M0 VR25 Type High Voltage Resistor BC Components

R84 15 0kΩ Standard Metal Film RES 1/4 W 5% 200 ppm/°C BC Components

T1 T-RES-ER49 86H-5411 Type Resonant Transformer ER49-27-17 Delta

T2 T-FLY-AUX-E20 86A-6079-R Type Flyback Transformer E20 Core Delta

U1 L6563 Advanced Transition Mode PFC Controller STMicroelectronics

U2 L6599 High Voltage Resonant Controller STMicroelectronics

U3 SFH617A-2 63-125% CTR Selection Optocoupler Infineon

25/35

PFC coil specification AN2393

Table 7. Bill of materials (continued)

Item Part type/value Description Supplier

U4 TL431 TO92 Programmable Shunt Voltage Regulator STMicroelectronics

U5 VIPer12A-E Low Power Off Line SMPS Primary Switcher STMicroelectronics

U6 SFH617A-2 63-125% CTR Selection Optocoupler Infineon

U7 TL431 TO92 Programmable Shunt Voltage Regulator STMicroelectronics

U8 SFH617A-2 63-125% CTR Selection Optocoupler Infineon

Note: Q9 and R72: Mounted by reworking on PCB

Q11, R83, R84 and C58: Added by reworking on PCB

6 PFC coil specification

● Application type: Consumer, home appliance

● Transformer type: Open

● Coil former: vertical type, 6+6 pins

● Maximum temperature rise: 45° C

● Maximum operating ambient temperature: 60° C

6.1 Electrical characteristics

● Converter topology: FOT-PFC Pre-regulator

● Core type: PQ35-35 material grade PC44 or equivalent

● Maximum operating frequency: 100 kHz

● Primary inductance: 900 µH ±10% @1 kHz - 0.25 V (see Note 1)

● Primary RMS current: 2.65 A

Note: 1 Measured between Pins 2 and 3 and Pins 10 and 11

Figure 20. PFC coil electrical diagram

4-5

1-2

Note: The auxiliary winding is not used in this design, but is foreseen for another application

12

AuxiliaryPrimary

8

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AN2393 Resonant power transformer specification

39 mm

30.5 mm

11

1

12

10

3
2

35.5 mm

4

6
5

9

7
8

Table 8. PFC coil winding characteristics

Start pins End pins Turn number Wire type Wire diameter (mm) Notes

12 8 5 (spaced) Single 0.28∅ Bottom

4 and 5 1 and 2 70 Multistrand - G2 Litz 0.2∅ x 20 Top

6.2 Mechanical aspect and pin numbering

● Maximum height from PCB: 38 mm

● Cut pins: 7, 10 and 11

● Pin distance: 5.08 mm

● Row distance: 35.5 mm

Figure 21. PFC coil pin side view

Note: External copper shield 15 x 0.05 (mm) connected to pin 12 by tinned wire

Manufacturer: DELTA ELECTRONICS - Part number: 86H-5409

7 Resonant power transformer specification

● Application type: Consumer, home appliance

● Transformer type: Open

● Coil former: Horizontal type, 7+7 pins, 2 Slots

● Maximum temperature rise: 45° C

● Maximum operating ambient temperature: 60° C

● Mains insulation: Compliance with EN60065 specifications

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Resonant power transformer specification AN2393

7.1 Electrical characteristics and mechanical aspect

● Converter topology: half-bridge, resonant

● Core type: ER49 - PC44 or equivalent

● Typical operating frequency: 100 kHz

● Primary inductance: 585 µH ±10% @1 kHz - 0.25 V (see Note 1)

● Leakage inductance: 110 µH ±10% @1 kHz - 0.25 V (see Note 1 and Note 2)

Note: 1 Measured between Pins 1 and 3

2 Measured between Pins 1 and 3 with ONLY a secondary winding shorted

Figure 22. Mechanical aspect and pin numbering of resonant transformer

Table 9. Resonant transformer dimensions

ABCDE F

Dimensions (mm) 39.0 MAX 3.5

±0.5 41.6±0.4 51 MAX 7.0±0.2 51.5 MAX

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AN2393 Resonant power transformer specification

Figure 23. Resonant transformer electrical diagram

14

SEC. A

13

SEC. B

1

PRIM.

3

Table 10. Resonant transformer winding characteristics

12

11

SEC. C

10

9

SEC. D

8

Pins Winding RMS current Turn number Wire type [mm]

1 - 3 Primary 1.5 A

14 - 13 Sec. A

13 - 12 Sec. B

11 - 10 Sec. C

9 - 8 Sec. D

1. Secondary windings A and B must be wound in parallel

2. Aux winding is wound on top of primary winding

(1)

(1)

(2)

(2)

6.7 A

6.7 A

5.6 A

5.6 A

RMS

RMS

RMS

RMS

RMS

36 LITZ - dia. 0.15x20

4 LITZ - dia. 0.20x30

4 LITZ - dia. 0.20x30

2 LITZ - dia. 0.20x30

2 LITZ - dia. 0.20x30

Figure 24. Resonant transformer winding position on coil former

Note: Manufacturer: DELTA ELECTRONICS - Part number: 86H-5411

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Auxiliary flyback power transformer AN2393

8 Auxiliary flyback power transformer

● Application type: Consumer, home appliance

● Transformer type: Open

● Winding type: Layer

● Coil former: Horizontal type, 4+5 pins

● Maximum temperature rise: 45° C

● Maximum operating ambient temperature: 60° C

● Mains insulation: Complies with EN60065 specifications

8.1 Electrical characteristics

● Converter topology: Flyback, DCM/CCM mode

● Core type: E20-N67 or equivalent

● Operating frequency: 60 kHz

● Primary inductance: 4.20 mH ±10% @1 kHz - 0.25 V (see Note 1)

● Leakage inductance: 50 µH MAX @100 kHz - 0.25 V (see Note 2)

● Maximum peak primary current: 0.38 Apk

● RMS primary current: 0.2 A

Note: 1 Measured between Pins 4 and 5

2 Measured between Pins 4 and 5 with all secondary windings shorted

RMS

Figure 25. Auxiliary transformer electrical diagram

5

4

2

1

6

+5VPrimary

7

8

+3.3VAuxliary

10

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AN2393 Auxiliary flyback power transformer

Figure 26. Auxiliary transformer winding position on coil former

Insulating

3.3 V/5 V

Coil Former

Auxiliary

Primary

Table 11. Auxiliary transformer winding characteristics

Pins

Start - End

4-5 PRIMARY 0.2 A

2-1 AUX 0.05 A

8-10 3.3 V 1.2 A

6-7 5 V 1 A

Winding RMS current Number of turns Wire type

RMS

RMS

RMS

RMS

140 G2 - φ0.25 mm

29 G2 - φ0.25 mm

7TIW - φ0.75 mm
3TIW - φ0.75 mm

Note: Manufacturer: DELTA ELECTRONICS - Part number: 86A-6079-R

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Reference design board layout AN2393

9 Reference design board layout

Figure 27. Copper tracks

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AN2393 Reference design board layout

Figure 28. Thru-hole component placing and top silk screen

Figure 29. SMT component placing and bottom silk screen

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Revision history AN2393

10 Revision history

Table 12. Document revision history

Date Revision Changes

02-Aug-2006 1 Initial release

08-Sep-2006 2 Figure 2. modified

25-Jan-2007 3 Minor text change

23-Apr-2007 4

25-Oct-2007 5

– Cross references updated
– Table 7: Bill of materials modified

– Modified: Section 8.1: Electrical characteristics
– VIPer12A replaced by VIPer12A-E

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AN2393

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