Test Procedure for the NCP1566 12-V/6-A Dc-Dc Converter

Test Procedure for the

NCP1566 12-V/6-A Dc-Dc Converter

Christophe Basso April 17

^th

2019

Rev. 1

6 1

2 6 1

Q3 BSC123N08NS3

2 7 R23a 2.2

1 4

6 6

Q4 BSC123N08NS3

R24a 10k

4 9

Q6 BSC123N08NS3

5 7 5

R29a 2.2

C17

T491X227M016AT C18

T491X227M016AT C19

T491X227M016AT L2

8.2uH

12 V/6 A

0 V

6 R2 10

ac sw eep connections

B

A

7 R30 20k 1 2

1 8 D7 MMSD914

D2 MMSD914 L3

660uH

C22 22uF C31

1uF

2 1

1 3 2 2

L1 1.5uH 37-57 V P C B B anana plug - red Multi-C ontact S LB 4-I/90 23.3200-22

+

+

-

C1 C2 C3 C4

-

2 3 R10 470 CS P C B B anana plug - black

Multi-C ontact S LB 4-I/90 23.3200-21

2 8 Q1A FDMS2572

R16 10k

2 9 C26 3 1

5 8 Q2 IRF6217

SO-8L

S O-8L S O-8L

SO-8L

Power 56 SO-8

R17 10k

. . .

D4 MMSD914 3 0

C13 0.1uF V in

Fault^{3 2} P drive

N drive

C7 22uF

3 4 R6x 33k

C8 0.1uF

R11 499

C11 100p CS

3 7

C28 10nF 5 3

C32 1.5nF 3 9

R35 open

C33 open

4 0 R1 51k

R4 2k

C16 10nF

4 1 R34 499 Vref Vref

3 6 R31 24k 4 2

R8 150k 4 3

R5 51.1k 3 5

C14 4.7u R9 43k

C30 220p Vref

CS Ramp

4 5 R3 100k

C24 820p

D O1606C T-684

MSS1038-152NL

QFN24

C oilcraft

4 6 R100 2.2

C100 1nF

4 7 R101 2.2

C101 1nF 0.1uF / 200 V

Kemet

close to Q3/Q4

close to Q5/Q6

37-57 V 12 V/6 A dc-dc conv erter NCP1566 - OVP and sy nc f unction Current-Mode Control

ON Semiconductor Ver f .

Christophe Basso - February 4th 2019

C1210C225M1RACTU C1210C225M1RACTU

C1210C225M1RACTU C1210C225M1RACTU

C2220X104K2RACTU

Q1B FDMS2572 Power 56

C27 2.2nF T1

R23b 2.2

R24b 10k

R25b 10k

1 0 R15 0 R39

4.7 R40 4.7

7-8-9

10-11-12 2

5 1

6

close to Q5/Q6 gates

C4532X7R3D222K 2000 V - TDK

220 uF Kemet x 3

Power GND

1 9

V ref

V aux

C104 0.1uF

Vcc 5 5

Q8 2N2222

R41 open

D10 1N963

R42 open 470 Vcc

J1a

J1b

J2a

J2b C39

0.1uF

close to U1 close to U1

5 4

4 8 U2 PS2801 R19

1Meg 5 1

R45 10

C40 0.1uF

200 V 100 V

DT limit 55%

240 kHz

R47 1k

100 V

ra m p S S DL M T DT RT A Gn d

RE F A FLT/ SD O UTA

P Gn d O UTM

V c c

Vs c lam pNC Vin NCSy ncUVLO

c om pr es ov pCS RefO TP

NCP1566

1 2 3 4 5 6

7 8 9 1 01 11 2

1 3 1 4 1 5 1 6 1 7 1 8 2 01 9 2 1 2 2 2 3 2 4

6 0 2 5 U1

NCP1566

R102 10k

OV P Gnd

6 3 6 2

U6 PS2801 R36

499 Vref

out

6 4

6 5 U9 NCP431

R37 1k out

R38 4.2k

R43 1k C10 100p R44 1k

OVP s et to 13 V R T

R D T R D L MT

4 U8 NCP431

Quiet GND

R7 56m

C12 100pF Adjust max V-s based

on transformer selection

1 7 R60 2.2k Hi-freq

pole

5 6 R12 0

C5 0.1u C6 0.1uF 2

D1 MMSD914 D3 MMSD914

5 0 R13 10k

D5 MMSZ4691

V cc 12 V

Q7 MMBTA06LT1G

C9 0.1uF

D6 1N751 open C15

10nF

50 V R14

18k C23 1uF

3 8 R18 10k

R20 0 9

R21 5.6k

C25 22nF

Open

Open 1 W

1 W

2 W

R26 open R27

0 5%

1%

1 1 R103

C29 E P C 3786G-LF

P C A E lectronics

X A L1010-822ME 5 9

Q10 FMMT624

Q5 BSC123N08NS3

R25a 10k

R29b 2.2

D8 MMSZ4699T1G

12 V D9 1N4148

R104

C20 100p 2k

D11 1N4148 close to

Q3/Q4

S O-8L

* only 1 MOS FE T is w ired

* only 1 MOS FE T is w ired

6 7 Q9

FMMT624 D12 1N4148 R22

2k

C21

100p D13

MMSZ4699T1G

* only 1 MOS FE T is w ired 12 V

E R JB 1C FR 056U 8

4

3

C34 470pF

11.5-V auxiliary voltage

DA 1N4148 soldered in replacement of R26

RA 5.6k soldered in replacement of D6

Board Electrical Schematic

Dc input voltage 36 – 57 V

Max is 72 V

12 V/6 A

Output voltage +

-

+

V_in -

V_out

Board Picture

Output voltage is 12 V nominal.

Output current is 6 A 36 to 57 V

+

-

12 V 6 A

NCP1566POEGEVB Input voltage is 48 V nominal.

Range is from 36 to 57 V.

Needed Equipment

The needed equipments are the following:

 a dc voltage source, delivering up to 60 V dc and up to 2 A

 a dc load absorbing up to 100 W, V

_in,max

< 20 V, I

_out,max

< 10 A

 either the above load can display dc V and dc A or separated V and A-meters are necessary

 An oscilloscope with single shot capability

 Kelvin sensing is necessary to connect the load to the board. If

no precautions are taken, it is likely that the voltage drop at the

load cables ends induces a reading error

Basic Test Setup

+ -

source load

Kelvin sense

Test n°1

• Start the power supply V_in = 48 V while the load current is 6 A

• Monitor the output voltage on a scope

• Verify the voltage is monotonically rising

+ -

Kelvin sense

source load

Test n°1

out

 

v t

• It is important to verify the absence of negative slope

• Repeat the test for V_in = 36 V and 57 V

• Change load to 0 A, repeat tests. Wait 10 s between re-starts

• A small glitch at the begining of the rising edge is acceptable V_in = 0 to 48 V – I_out = 6 A

out

 

v t

V_in = 0 to 48 V – I_out = 0 A

Test n°2

Press short

• Press short circuit at V_in = 36 V, I_out = 6 A. Board enters hiccup and ticks.

• Repeat test for V_in = 57 V

• Release short and make sure output resumes at 12 V

+ -

Kelvin sense

source load

Test n°3

• Program load to dynamic current mode

• I_out from 4 A to 6 A, slope 1 A/µs

• 1 ms interval, observe V_out on scope in ac, 50 mV/div No pigtail!

+ -

Kelvin sense

source load

Test n°3

out

 

v t

• Run the test from V_in = 36 V (worst case) to V_in = 57 V.

• Spec is to have an under/over shoot less than 150 mV

V_in = 36 V – 2 to 6 A – 1 A/µs V_in = 48 V – 2 to 6 A – 1 A/µs

50 mV/div 50 mV/div

out

 

v t

Test n°4

• Leave the board for 5 mn at V_in = 36 V/6 A and room temperature.

• Check no thermal triping occurs.

• Board is declared sound.

+ -

Kelvin sense

source load