UCC24610EVM-563 - Texas Instruments

Using the UCC24610EVM-563

User's Guide

Literature Number: SLUU434

August 2010

User's Guide

SLUU434–August 2010

5-V, 25-W Flyback Converter With Secondary-Side

Synchronous Rectification

1 Introduction

The UCC24610EVM-563 evaluation module is a 25-W off-line Discontinuous Mode (DCM) flyback

converter providing an output voltage of 5 V at 5-A maximum load current, operating from a universal AC

input. The module is controlled by the UCC28610 Green-Mode Flyback Controller on the primary side

which uses a cascoded architecture that allows fully integrated current control without an external sense

resistor. Secondary-side synchronous rectification is controlled by the UCC24610 GREEN Rectifier™

Controller. The UCC24610 senses the drain-to-source voltage of the synchronous rectifier MOSFET in

order to drive the GATE signal. The GATE output duty cycle is dependent upon the system line and load

conditions, as well as the programmed minimum on-time and off-time. The converter maintains

discontinuous mode operation over the entire operating range. This innovative approach results in

efficiency, reliability, and system cost improvements over a conventional flyback.

2 Description

This evaluation module uses the UCC24610 GREEN Rectifier™ Controller (TI Literature Number

SLUSA87) in a 25-W DCM flyback converter that exceeds Energy Star™ EPS version 2.0 for efficiency

during active load and no-load power consumption for low voltage AC-to-DC external power supplies. The

input accepts a voltage range of 85 VAC to 265 VAC. The output provides a regulated output voltage of 5

VDC at a load current of up to 5 A. The converter will transition through three operating modes: Green

Mode (GM), Amplitude Modulation (AM), and Frequency Modulation (FM), depending upon the power

level and FB current of the primary-side controller. In FM Mode, which occurs between approximately 25%

and 100% rated load, the on time is fixed, resulting in a fixed peak primary current at each cycle, and the

switching frequency is increased with increasing load. In AM Mode, which occurs from approximately 2%

rated load up to 25% rated load, the switching frequency is fixed at 30 kHz and the peak primary current is

modulated with the on time as with any typical PWM controller. Green Mode operation, at loads less than

2%, consist of burst packets of 30-kHz pulses with a fixed on time and peak primary currents of 33% the

maximum programmed level.

The conduction time of the synchronous rectifier MOSFET (SR-MOSFET) is determined by comparing the

SR-MOSFET’s drain-to-source voltage against internal turn-on and turn-off thresholds. Secondary-side

control features automatic light-load management based upon internal timing conditions and the RDS(on) of

the SR-MOSFET. The UCC24610 requires a minimal amount of simple, low-power external components

to provide a cost effective, efficient solution for low-voltage power supplies.

This user’s guide provides the schematic, component list, assembly drawing, art work, and test set up

necessary to evaluate the UCC24610 in a typical off-line DCM Flyback converter application.

25-V, 25-W Flyback Converter With Secondary-Side Synchronous Rectification SLUU434–August 2010

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Description

2.1 Applications

The UCC24610 is suited for use in isolated off-line systems requiring high efficiency and advanced fault

protection features including:

• 5-V AC-to-DC Adaptors

• Housekeeping and Auxiliary 5-V Bias Supplies

• Low-Voltage Rectification Circuits

2.2 Features

The UCC24610EVM-563 features include:

• Isolated 5-V, 25-W Output

• Universal Off-Line Input Voltage Range

• Exceeds Energy Star™ EPS Version 2.0 Requirements (for active load efficiency and no-load power

consumption for low voltage external power supplies)

• Cascoded Configuration on Primary Side (allows fully integrated current control without an external

sense resistor)

• Multiple Operating Modes (for optimum efficiency over entire operating range)

• Automatic Light-Load Management

• Output Short-Circuit Protection

• Improved Efficiency Over Traditional Output Diode Applications

CAUTION

High voltage levels are present on the evaluation module whenever it is

energized. Proper precautions must be taken when working with the EVM. The

large bulk capacitor, C5, must be completely discharged before the EVM can

be handled. Serious injury can occur if proper safety precautions are not

followed.

SLUU434–August 2010 5-V, 25-W Flyback Converter With Secondary-Side Synchronous Rectification

Electrical Performance Specifications

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3 Electrical Performance Specifications

Table 1. UCC24610EVM-563 Electrical Performance Specifications

PARAMETER NOTES AND CONDITIONS MIN NOM MAX UNITS

Input Characteristics

VIN Input voltage 85 265 VRMS

VIN = 115 VRMS, IOUT = 5 A 0.6

IIN Input current A

VIN = 115 VRMS, IOUT = 0 A 0.03

VUVLO Brown out IOUT = 5 A 69 V

Output Characteristics

VOUT Output voltage VIN = 85 VRMS to 265 VRMS, IOUT = 0 A to 5 A 4.5 5 5.6 V

VRIPPLE Output voltage ripple VIN = 115 VRMS, IOUT = 5 A 200 mVpp

IOUT Output current VIN = 85 VRMS to 265 VRMS 0 5 A

Output over current

IOCP VIN = 115 VRMS 7

inception point

VOVP Output OVP IOUT = 0 A to 5 A 6.5 V

Transient response voltage VIN = 115 VRMS, IOUT = 0 A to 5 A 600 mV

over shoot

System Characteristics

fSW Switching frequency 26.3 140.4 kHz

hPEAK Peak efficiency VIN = 115 VRMS, IOUT = 1.75 A 82.7%

VIN = 115 VRMS, IOUT = 25%, 50%, 75%, 100% 82.3%

rated load

hAVG Average efficiency VIN = 230 VRMS, IOUT = 25%, 50%, 75%, 100% 82.3%

rated load

VIN = 115 VRMS 181

No-load power consumption mW

VIN = 230 VRMS 368

Operating temperature VIN = 85 VRMS to 265 VRMS, IOUT = 0 A to 5 A 25 °C

range

Mechanical Characteristics

Width 2.3

Length Dimensions 3.5 inches

Height Component height 1

45-V, 25-W Flyback Converter With Secondary-Side Synchronous Rectification SLUU434–August 2010

+ ++

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Schematic

4 Schematic

Figure 1. UCC24610EVM-563 Schematic

SLUU434–August 2010 5-V, 25-W Flyback Converter With Secondary-Side Synchronous Rectification

Schematic

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4.1 Circuit Description

Diode bridge D1, input capacitor C5, transformer (a.k.a. flyback inductor) T1, HV MOSFET Q2, UCC28610

controller U3, synchronous rectification MOSFET Q1, output capacitors C8, C9, and C10 form the power

stage of the converter. Note that the UCC28610 U3 is part of the power stage. This is because the DRV

and GND pins carry the full-peak primary-side current of the converter.

UCC24610 controller U1 drives the synchronous rectification MOSFET Q1, R11 sets the minimum time

that Q1 will remain off, ignoring any resonant ringing that may inadvertently trigger the turn-on detection

circuit. Resistor R12 performs a similar function in regards to the on-time of Q1 by programming the

minimum time that Q1 will remain on despite any ringing due to noise that may inadvertently trigger a

turn-off response. Resistor R9 dampens any resonant tank ringing on the gate of Q1. To reduce the

current drawn out of VD, resistor R5 is added between VD and the drain of Q1. Because VD and VS are

inputs to a differential comparator, a resistor, R8, is also needed between VS and the source of Q1.

Bench testing concluded that using a slightly larger value for R8 on VS extended the on-time of Q1, and

reduced the body diode conduction time.

Capacitors C6, C7, and C12 filter the high-frequency noise directly across the electrolytic input and output

capacitors.

The input EMI filter is made up of X2 capacitors, C3 and C4, and common mode inductor L1. Excessive

surge current protection is provided by a slow blow fuse, F1.

Resistor R1, capacitor C1, and diode D2 make up the primary side voltage clamp for the HV MOSFET.

The clamp prevents the drain voltage on Q2 from exceeding its maximum rating. The integrated snubber,

composed of R2 and C1, reduces the ringing on the primary-side windings that might inadvertently trigger

the light-load shutdown point of the UCC24610 gate drive.

Resistors R4, R6, and R7 supply start-up bias current to the VGG shunt regulator of U3. Schottky diode

D5 is required to provide initial start up to VDD from VGG at start up.

Operating bias to the UCC28610 controller is provided by the auxiliary winding on T1, diode D3, and bulk

capacitor C16. The zener diode, D7, maintains the bias voltage on U3 VDD below the absolute maximum

rating at full load.

Primary switch gate drive circuitry is composed of gate drive resistor R13, used for damping oscillations

during turn on. Resistor R14 and diode D4 are required to provide a current path at turn off because the

gate is shorted to the source of the HV MOSFET during each switching cycle. Ferrite bead FB1 reduces

the high ringing on VGG at turn off.

Capacitors C17, C18, and C13 are decoupling capacitors which should always be good quality low

ESR/ESL type capacitors placed as close to the controller device pins as possible and returned directly to

the device ground reference.

C2 filters the common mode noise between the primary and secondary sides.

Inductor L2, with capacitor C11, reduces the output voltage ripple.

Resistors R19 and R21 program the over voltage threshold. Capacitor C15 can be used to add a small

delay to U3 ZCD, to align the turn-on time of the primary switch with the resonant valley of the primary

winding.

Resistor R23 programs the maximum on time of the primary side HV MOSFET.

Resistor R22 sets the maximum value for the peak-primary current.

Resistor R18 and capacitor C14 provide a filter for the U3 FB signal while resistor R20 ensures that the

optocoupler emitter current can go to 0 A. Output voltage regulation is provided by diode D6, resistors R15

and R17, and the optocoupler U2. Using an opto with a low current transfer ratio provides better noise

immunity. Resistor R10 is used as an injection point for small signal frequency response testing.

65-V, 25-W Flyback Converter With Secondary-Side Synchronous Rectification SLUU434–August 2010

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EVM Test Set Up

5 EVM Test Set Up

Figure 2 shows the equipment set up when measuring the input power consumption during no load.

Notice the addition of the 10-Ωshunt resistor in Figure 2.

During the no-load test, the power analyzer should be set for long averaging in order to include several

cycles of operation and an appropriate current scale factor for using the external shunt must be used.

Figure 3 shows the basic test set up recommended to evaluate the UCC24610EVM-563 with a load.

WARNING

High voltages that may cause injury exist on this evaluation

module (EVM). Please ensure all safety procedures are followed

when working on this EVM. Never leave a powered EVM

unattended.

5.1 Test Equipment

See Figure 2 and Figure 3 for recommended test set ups.

•AC Input Source: The input source shall be an isolated variable AC source capable of supplying

between 85 VRMS and 265 VRMS at no less than 30 W and connected as shown in Figure 2 and

Figure 3. For accurate efficiency calculations, a power meter should be inserted between the neutral

line of the AC source and the Neutral terminal of the EVM. For highest accuracy, connect the voltage

terminals of the power meter directly across the Line and Neutral terminals of the EVM.

•Load: For the output load, a programmable electronic load set to constant current mode and capable

of sinking 0 to 5 ADC at 5 VDC shall be used. For highest accuracy, VOUT can be monitored by

connecting a DC voltmeter, DMM V1, directly across the VOUT+ and VOUT– terminals as shown in

Figure 3. A DC current meter, DMM A1, should be placed in series with the electronic load for accurate

output current measurements.

•Power Meter: The power analyzer shall be capable of measuring low input current, typically less than

50 mA, and a long averaging mode if low power standby mode input power measurements are to be

taken. An example of such an analyzer is the Voltech PM100 Single Phase Power Analyzer. To

measure the intermittent bursts of current and power drawn from the line during no-load operation, an

external 10-Ωshunt, with a current scale factor of 10A/V, was used at a high sample rate over an

extended period of time in order to display the averaged results (refer to Figure 2).

•Multimeters: Two digital multimeters are used to measure the regulated output voltage (DMM V1) and

load current (DMM A1).

•Oscilloscope: A digital or analog oscilloscope with a 500-MHz scope probe is recommended.

•Fan: Forced air cooling is not required.

•Recommended Wire Gauge: a minimum of AWG18 wire is recommended. The wire connections

between the AC source and the EVM, and the wire connections between the EVM and the load should

be less than two feet long.

SLUU434–August 2010 5-V, 25-W Flyback Converter With Secondary-Side Synchronous Rectification

AC SOURCE

LINE NEUTRAL

POWER METER

VHI VLO AHI

ALO AEXT

+ + -

EXAST

NSTRUMENTS

EVM Test Set Up

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5.2 Recommended Test Set Up for Operation Without a Load

Figure 2. Recommended Test Set Up Without a Load.

85-V, 25-W Flyback Converter With Secondary-Side Synchronous Rectification SLUU434–August 2010

AC SOURCE

LINE NEUTRAL

POWER METER

VHI VLO AHI

ALO AEXT

+ + --

DMM A 1

+ -

DMM V 1

+ -

ELECTRONIC

LOAD

+ -

EXAS

NSTRUMENTS

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EVM Test Set Up

5.3 Recommended Test Set Up for Operation With a Load

Figure 3. Recommended Test Set Up With a Load.

SLUU434–August 2010 5-V, 25-W Flyback Converter With Secondary-Side Synchronous Rectification

EVM Test Set Up

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5.4 List of Test Points

Table 2. Test Point and Connector Functional Descriptions

TEST POINT NAME DESCRIPTION

Output voltage of EVM; this designator is not populated with a pin in order to facilitate tip and

TP1 Vout+ barrel output ripple voltage measurements in conjunction with TP3, Vout-.

TP2 PGND Primary side power ground. Use this pin as a reference for TP15, VGG.

Output return of EVM; use this pin to facilitate tip and barrel output ripple voltage

TP3 Vout- measurements in conjunction with TP1, Vout+.

TP4 SW Secondary side switch node, reference the probe to U1_GND, TP11 or TP12.

TP5 VD VD pin, U1. Reference the probe to U1_GND, TP11 or TP12.

Located on the drain trace of the primary side HV MOSFET, the user can cut the trace

TP6 - between this test point and TP8 to insert their own current loop to monitor primary side drain

current.

EN/TOFF pin, U1, shorting this pin to U1_GND (TP11 or TP12) will disable the GATE of U1

TP7 EN resulting in body diode conduction.

Located on the drain trace of the primary side HV MOSFET, the user can cut the trace

TP8 - between this test point and TP6 to insert their own current loop to monitor primary side drain

current.

TP9 GATE Gate pin, U1. Reference the probe to U1_GND, TP11 or TP12.

TP10 +LOOP Loop injection point, EVM output.

TP11 U1_GND GND pin of U1, use as a return for TP4, TP5, TP7, and TP9.

TP12 U1_GND GND pin of U1, use as a return for TP4, TP5, TP7, and TP9.

TP13 -LOOP Loop injection point

TP14 AUX Auxiliary winding of T1. Reference the probe to TP17, PGND.

TP15 VGG VGG pin, U3. Reference the probe to TP2, PGND.

TP16 ZCD ZCD pin, U3. Reference the probe to TP17, PGND.

TP17 PGND Primary side power ground. Use this pin as a reference for TP14, AUX, and TP16, ZCD.

TP18 - PGND, can be used as a reference when probing the drain pin of Q2

J1 Line Line input from AC source

J2 Vout+ Positive output terminal of the EVM to the load

J3 Neutral Neutral input from the AC Source

J4 Vout- Return connection of the EVM output to the load

10 5-V, 25-W Flyback Converter With Secondary-Side Synchronous Rectification SLUU434–August 2010

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Test Procedure

6 Test Procedure

All tests should use the set up as described in Section 5 of this user’s guide. The following test procedure

is recommended primarily for power up and shutting down the evaluation module. Never leave a powered

EVM unattended for any length of time.

6.1 Applying Power to the EVM

1. Set up the EVM as shown in Section 5 of this user’s guide.

(a) If no-load input power measurements are to be made, set the power analyzer to long averaging and

external shunt mode. Insert a shunt, such as a 10-Ωresistor as shown in Figure 2, in series with

the Neutral terminal of the EVM. Set the appropriate current scale on the power analyzer.

(b) For operation with a load, as shown in Figure 3, set the electronic load to constant current mode to

sink 0 A.

2. Prior to turning on the AC source, set the voltage to between 85 VAC and 265 VAC.

3. Turn on the AC source.

4. Monitor the output voltage on DMM V1.

5. Monitor the output current on DMM A1.

6. The EVM is now ready for testing.

6.2 No-Load Power Consumption

1. Use the test set up shown in Section 5

(a) Set the power analyzer to external shunt mode.

(b) Set the appropriate current scale factor for using an external shunt on the power analyzer. A 10-Ω

shunt scales at 10,000 mV/A for the PM100 Voltech.

Voltech should be set to a long averaging time of 10 or more for accurate Burst Mode

measurements.

2. Apply power to the EVM per Section 6.1.

3. Monitor the input power on the power analyzer while varying the input voltage.

4. Make sure the input power is off and the bulk capacitor and output capacitors are completely

discharged before handling the EVM.

6.3 Output Voltage Regulation and Efficiency

1. For load regulation:

(a) Use the test set up shown in Figure 3.

(i) Be sure to remove the external shunt from the power analyzer and set the analyzer to normal

mode (not long averaging).

(b) Set the AC source to a constant voltage between 85 VAC and 265 VAC.

(d) Vary the load current from 0 A up to 5 A, as measured on DMM A1.

(e) Observe that the output voltage on DMM V1 remains within 15% of 5 VDC.

2. For line regulation:

(a) Set the load to sink 5 A.

(b) Vary the AC source from 85 VAC to 265 VAC.

3. Make sure the input power is off and the bulk capacitor and output capacitors are completely

discharged before handling the EVM.

SLUU434–August 2010 5-V, 25-W Flyback Converter With Secondary-Side Synchronous Rectification

Test Procedure

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6.4 Output Voltage Ripple

1. Expose the ground barrel of the scope probe. Insert the tip of the probe into the plated via located on

the VOUT+ pad of the EVM (TP1) and lean the probe so that the exposed ground barrel is resting on the

test point on the Vout- pad of the EVM (TP3) for a tip and barrel measurement as shown in the

example depicted in Figure 4.

2. Apply power to the EVM per Section 6.1.

3. Monitor the output voltage ripple on the oscilloscope.

Figure 4. Typical Example of Tip and Barrel Measurement Technique

NOTE: This photo was not taken on the UCC24610EVM specifically but serves as a visual aid to

perform the test measurement.

6.5 Equipment Shutdown

1. Ensure the load is at maximum of 5 A; this will quickly discharge the output capacitors.

2. Turn off the AC source.

12 5-V, 25-W Flyback Converter With Secondary-Side Synchronous Rectification SLUU434–August 2010

80 120 200 220 260

VAC - Line Voltage - V

100

250

350

500

160

150

200

300

400

Input Power - mW

NO-LOAD POWER CONSUMPTION

LINE VOLTAGE

100 140 180 240 280

85 VAC

115 VAC 230 VAC

265 VAC

450

0 1 3 4 5

Load - A

0.40

0.50

0.65

0.75

0.85

0.45

0.55

0.60

0.70

0.80

h- Efficiency - %

EFFICIENCY

LOAD

85 VAC

115 VAC

230 VAC

265 VAC

0 1.0 3.0 4.0 5.0

Load Current - A

4.0

5.5

6.0

2.0

4.5

5.0

VOUT - Output Voltage - V

OUTPUT VOLTAGE

LOAD CURRENT

0.5 1.5 2.5 3.5 4.5 5.5

85 VAC

115 VAC

230 VAC

265 VAC

0 1 3 4 5

Load Current - A

100

120

fSW - Switching Frequency - kHz

AVERAGE SWITCHING FREQUENCY

LOAD CURRENT

85 VAC

115 VAC

230 VAC

265 VAC

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Typical Characteristic Curves

7 Typical Characteristic Curves

Figure 5 through Figure 10 present typical performance curves for the UCC24610EVM-563.

Figure 5. Efficiency Figure 6. No-Load Input Power

(as a function of load current and input voltage) (as a function of input voltage)

Figure 7. Average Switching Frequency Figure 8. Output Voltage (as a function of load current

(as a function of load current) and line voltage)

SLUU434–August 2010 5-V, 25-W Flyback Converter With Secondary-Side Synchronous Rectification

100 10000

f - Frequency - Hz

-40

-20

Gain -dB

GAIN/PHASE

FREQUENCY

1000 100000

-30

-180

135

180

-90

Phase Margin - degrees

-135

-45

-10

Gain

Phase

100 10000

f - Frequency - Hz

-40

-20

Gain -dB

GAIN/PHASE

FREQUENCY

1000 100000

-30

-180

135

180

-90

Phase Margin - degrees

-135

-45

-10

Gain

Phase

80 120 220 260

VAC - Input Voltage - V

5.0

8.0

8.5

160

6.0

7.0

Load Current - A

LOAD OVER CURRENT

INPUT VOLTAGE

100 140 180 200 240 280

85 VAC

115 VAC

230 VAC

265 VAC

5.5

6.5

7.5

Typical Characteristic Curves

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Figure 9. Gain Phase Bode Plot Figure 10. Gain Phase Bode Plot

(Input voltage = 115-VAC, 5-A load.) (Input voltage = 230-VAC, 5-A load.)

Figure 11. Overcurrent Threshold as a Function of Line Voltage

14 5-V, 25-W Flyback Converter With Secondary-Side Synchronous Rectification SLUU434–August 2010

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Performance Data

8 Performance Data

Figure 12. Primary-Side Waveforms (Input voltage = Figure 13. Primary-Side Waveforms (Input voltage =

115-VAC, no load, Green Mode operation.) 115-VAC, 1-A load, Amplitude Modulation Mode.)

Figure 14. Primary-Side Waveforms (Input voltage = Figure 15. Primary and Secondary Currents (Current

115-VAC, 5-A load, Frequency Modulation Mode.) loops were added to EVM in the HV MOSFET drain and

the trace from the transformer to the SR FET drain.

Input voltage = 115-VAC, 5-A load.)

Figure 16. Secondary-Side Current (Current loop Figure 17. Secondary-Side Waveforms (Input voltage =

added between transformer and drain of SR FET and 115-VAC, 5-A load.)

SR GATE signal, Input voltage = 115-VAC, 5-A load.)

SLUU434–August 2010 5-V, 25-W Flyback Converter With Secondary-Side Synchronous Rectification

Performance Data

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Figure 18. Close-Up View of VD and SR GATE (Input Figure 19. Secondary-Side Waveforms (Current loop

voltage = 115-VAC, 5-A load.) added from transformer to SR FET gate. Input voltage

= 115-VAC, 0-A load, Green Mode.)

Figure 20. Secondary-Side Waveforms (Current loop Figure 21. Secondary-Side Waveforms (Current loop

added between transformer and SR FET gate. Low added between transformer and SR FET gate. Normal

power mode. Input voltage = 115-VAC, 0.311-A load.) operating mode. Input voltage = 115-VAC, 5-A load.)

Figure 22. Output Voltage During Transient Load (0% Figure 23. Output Voltage Ripple (Input voltage =

to 100% load transient, input voltage = 115-VAC.) 115-VAC, 0-A load.)

16 5-V, 25-W Flyback Converter With Secondary-Side Synchronous Rectification SLUU434–August 2010

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Performance Data

Figure 24. Output Voltage Ripple (Input voltage = Figure 25. Low Frequency Output Voltage Ripple

115-VAC, 5-A load.) (Input voltage = 115-VAC, 5-A load.)

SLUU434–August 2010 5-V, 25-W Flyback Converter With Secondary-Side Synchronous Rectification

EVM Assembly Drawing and PCB Layout

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9 EVM Assembly Drawing and PCB Layout

Figure 26 through Figure 34 present EVM Assembly Drawing and PCB Layout drawings for the

UCC24610EVM-563.

Figure 26. Top Assembly

Figure 27. Bottom Assembly

18 5-V, 25-W Flyback Converter With Secondary-Side Synchronous Rectification SLUU434–August 2010

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EVM Assembly Drawing and PCB Layout

Figure 28. Top Paste

Figure 29. Bottom Silk

SLUU434–August 2010 5-V, 25-W Flyback Converter With Secondary-Side Synchronous Rectification

EXAS

NSTRUMENTS

EVM Assembly Drawing and PCB Layout

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Figure 30. Top Silk

Figure 31. Layer 3 Copper

20 5-V, 25-W Flyback Converter With Secondary-Side Synchronous Rectification SLUU434–August 2010

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EVM Assembly Drawing and PCB Layout

Figure 32. Layer 2 Copper

Figure 33. Bottom Layer Copper

SLUU434–August 2010 5-V, 25-W Flyback Converter With Secondary-Side Synchronous Rectification

EVM Assembly Drawing and PCB Layout

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Figure 34. Top Layer Copper

22 5-V, 25-W Flyback Converter With Secondary-Side Synchronous Rectification SLUU434–August 2010

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List of Materials

10 List of Materials

Table 3. List of Materials for UCC24610EVM-563

COUNT REF DES DESCRIPTION PART NUMBER MFR

1 C1 Capacitor, ceramic, 330 pF, 630 V, C0G, NP0, ±5%, 1206 Std Std

C2 Capacitor, ceramic disk, 1000 pF, 250 V, X1/Y1, ±20%, ECK-ANA102MB Panasonic

10.394 inch x 0.315 inch

C3, C4 Capacitor, film, 0.33 µF, 275 VAC, X2, ±20%, 15 mm ECQ-U2A334ML Panasonic

2pitch, 0.690 inch x 0.374 inch

C5 Capacitor, aluminum electrolytic, 100 µF, 400 VDC, ±20%, EET-HC2G101BA Panasonic

1105°C, 25 mm x 20 mm

1 C6 Capacitor, ceramic, 0.1 µF, 630 V, X7R, ±10%, 1812 C4532X7R2J104K TDK Corporation

2 C7, C12 Capacitor, ceramic, 1 µF, 25 V, X5R, ±10%, 0805 Std Std

C8, C9, Capacitor, aluminum electrolytic, 1500 µF, 6.3 V, ±20%, EEU-FM0J152 Panasonic

3C10 105°C, 10 mm x 25 mm

C11 Capacitor, aluminum electrolytic, 100 µF, 6.3 V, ±20%, 5.0 UPW0J101MDD Nichicon

1mm x 11.0 mm

1 C13 Capacitor, ceramic, 0.68 µF, 25 V, X5R, ±10%, 0805 Std Std

1 C14 Capacitor, ceramic, 100 pF, 50 V, NP0, ±5%, 0603 Std Std

0 C15 Capacitor, ceramic, no pop., 50 V, NP0, ±5%, 0603 Std Std

C16 Capacitor, aluminum electrolytic, 68 µF, 35 V, ±20%, EEU-FM1V680 Panasonic

1105°C, 6.3 mm x 11.2mm

1 C17 Capacitor, ceramic, 0.1 µF, 50 V, X7R, ±10%, 0805 Std Std

1 C18 Capacitor, ceramic, 0.1 µF, 100 V, X7R, ±10%, 1206 Std Std

1 D1 Diode, bridge, 1 A, 600 V, DF-M DF06M Diodes Inc.

1 D2 Diode, fast recovery glass passivated, 1 A, 1 kV, DO-41 UF4007-TP Micro Commercial Co.

D3 Diode, super fast rectifier, 1 A, 200 V, 0.220 inch x 0.115 ES1D-13-F Diodes Inc.

1inch

1 D4 Diode, Schottky, 1 A, 30 V, SOD-323 SDM100K30L-7 Diodes Inc.

1 D5 Diode, Schottky, 100 mA, 40 V, SOD-323 RB501V-40TE-17 Rohm Semiconductor

1 D6 Diode, Zener, 3.9 V, 500 mW, SOD-123 BZT52C3V9-7-F Diodes Inc.

1 D7 Diode, Zener, 25 V, 500 mW, SOD-123 MMSZ5253BT1G On Semiconductor

1 F1 Fuse, slow blow, 1 A, 250 V, 0.335 inch diameter 38211000410 Littelfuse / Wickmann

1 FB1 Bead, SMD ferrite, 70 Ωat 100 MHz, 4 A, ±25%, 0603 BLM18SG700TN1D Murata Electronics

1 HS1 Heatsink, TO-220, vertical mount, 0.5 inch x 0.750 inch 577102B00000G Aavid

1 HS2 Heatsink, alloy 1110 copper, 0.530 inch x 1.200 inch HS001 NH Stamp

J1, J3 Connector, 4-mm safety jack, white, 1000 V, 25 A, 0.530 CT3151-9 Cal Test Electronics

2inch x 0.950 inch

J2 Connector, 4-mm safety jack, red, 1000 V, 25 A, 0.530 CT3151-2 Cal Test Electronics

1inch x 0.950 inch

J4 Connector, 4-mm safety jack, black, 1000 V, 25 A, 0.530 CT3151-0 Cal Test Electronics

1inch x 0.950 inch

1 JP1 Jumper, 0.500 inch length, PVC insulation, AWG 22 923345-05-C 3M

L1 Inductor, AC line, common choke, 27 mH, 1 A, 0.660 inch 54PR512-276 Vitec Electronics

1x 0.670 inch Corp.

L2 Inductor, ferrite core, 1.0 µH, 7.5 A, ±10%, 0.521 inch x 744772010 Wuerth Elektronik

10.502 inch

Q1 MOSFET, N-channel, logic level gate, 55 V, 75 A, 8 mΩ, IRL3705ZPBF International Rectifier

1TO-220AB

1 Q2 MOSFET, N-channel, 800 V, 6.5 A, 0.95 Ω, TO-220V STP7NM80 STMicroelectronics

SLUU434–August 2010 5-V, 25-W Flyback Converter With Secondary-Side Synchronous Rectification

References

www.ti.com

Table 3. List of Materials for UCC24610EVM-563 (continued)

COUNT REF DES DESCRIPTION PART NUMBER MFR

1 R1 Resistor, chip, 64.9 kΩ, 1 W, ±1%, 2512 Std Std

1 R2 Resistor, chip, 33 Ω, 1 W, ±5%, 2512 Std Std

1 R3 Resistor, chip, 20 Ω, 1/4 W, ±1%, 1206 Std Std

R4, R6, Resistor, chip, 2.05 MΩ, 1/8 W, ±1%, 0805 Std Std

3R7

1 R5 Resistor, chip, 10 Ω, 1/10 W, ±1%, 0603 Std Std

1 R8 Resistor, chip, 100 Ω, 1/10 W, ±1%, 0603 Std Std

1 R9 Resistor, chip, 6.19 Ω, 1/10 W, ±1%, 0603 Std Std

1 R10 Resistor, chip, 20.5 Ω, 1/10 W, ±1%, 0603 Std Std

1 R11 Resistor, chip, 196 kΩ, 1/10 W, ±1%, 0603 Std Std

1 R12 Resistor, chip, 133 kΩ, 1/10 W, ±1%, 0603 Std Std

1 R13 Resistor, chip, 205 Ω, 1/8 W, ±1%, 0805 Std Std

1 R14 Resistor, chip, 2.26 Ω, 1/10 W, ±1%, 0603 Std Std

1 R15 Resistor, chip, 442 Ω, 1/10 W, ±1%, 0603 Std Std

1 R16 Resistor, metal film, 1.00 kΩ, 1/4 W, ±1%, TH-400 Std Std

1 R17 Resistor, chip, 1.00 kΩ, 1/10 W, ±1%, 0603 Std Std

1 R18 Resistor, chip, 20.5 kΩ, 1/10 W, ±1%, 0603 Std Std

R19 Resistor, metal film, 130 kΩ, 1/4 W, ±1%, 0.300 inch x Std Std

10.100 inch

1 R20 Resistor, chip, 100 kΩ, 1/10 W, ±1%, 0603 Std Std

2 R21, R22 Resistor, chip, 59.0 kΩ, 1/10 W, ±1%, 0603 Std Std

1 R23 Resistor, chip, 68.1 kΩ, 1/10 W, ±1%, 0603 Std Std

1 T1 Transformer, flyback, 200 µH, ±10%, 24.5 mm x 24.5 mm G104070LF GCi

1 U1 Secondary-Side Synchronous Rectifier Controller, SO-8 UCC24610D Texas Instruments

U2 Optocoupler, CTR 40% - 80%, 70 VCEO, 5000 VRMS, DIP6 CNY17F1M Fairchild

1Optoelectronics

1 U3 Green-Mode Flyback Controller, SO-8 UCC28610D Texas Instruments

11 References

1. UCC24610 GREEN Rectifier™ Controller Device, Datasheet, SLUSA87

2. UCC28610 Green-Mode Flyback Controller, Datasheet, SLUS888

3. Standby and Low Power Measurements, VOLTECHNOTES, VPN 104-054/1,

http://www.voltech.com/Downloads/PMAppNotes/Low%20Power%20Standby.pdf

24 5-V, 25-W Flyback Converter With Secondary-Side Synchronous Rectification SLUU434–August 2010

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