Test Procedure for the NCP1565 3.3-V/20-A Dc-dc Converter 1 Christophe Basso – March 2014 Board Electrical Schematic D2a BAV23CL L3 660uH Vcc 18 D O1606C T-684 D2b BAV23CL 12 T1 Payton 1. + Vin - R6 10 J1a 36-75 V + R23a 2.2 8 V in R23b 2.2 C1 C2 C3 C4 R1 51k 40 EN Mill-Max 3104-2-00-80-00-00-08-0 J3a J3b J1c on/off jumper R45 10 100 V R3 75k - Group of components close to the IC R4 2k CS R32 7.5 51 24 ra m p 1 42 36 SS Vin NC NC 23 22 21 20 2 DT 4 RT 5 1 5 P Gn d NCP1565 C14 22nF R5 13k R8 66k 7 R31 19.8k c om p 53 DT limit 63% 8 9 10 11 1 3 Vc c 12 r es NC CS Ref O TP 37 U4 LM8261 C104 0.1uF close to U1 Vout Mill-Max 3104-2-00-80-00-00-08-0 6 C25 0.33uF R30 1.5k R33 10k R20 82 48 R28 910 7 C15 10nF 8 - R15 0 R22 1k 13 50 R14 22k sec. SS C6 0.1uF V cc 55 17 Quiet GND SOT-23 Q7 2N2222 Mill-Max 3231-2-00-01-00-00-08-0 C29 47nF VEE C37 0.1uF 16V 7 to 12 V 0V RTN J2e 60 close to U 4 Q1 FDMS2572 Power 56 - R12 13 R21 162 Vcc 4 N drive C7 1uF close to U1 Trim Mill-Max 3104-2-00-80-00-00-08-0 R2 10 J2d close to op amp 11 C103 10nF Vref R46 33k J2c 52 S- Sense - R16 10k 34 + Mill-Max 3104-2-00-80-00-00-08-0 T520V227M004ATE007 T520V227M004ATE007 T520V227M004ATE007 V CC D4 MMSD914 S+ Sense + C100 1nF A Power GND Vcc 39 R13 12k R47 130 C20 C41 12nF 28 CS C19 ac sw eep connections V ref 500 kHz R35 open Vref 1 4O UTM C18 B R19 1Meg 200 V Fault + 3.3 V/30 A J2b 10 Power GND 32 30 46 close to Q5/Q6 Q6 NTMFS4982NF SO-8L C2220X224K2RACTU 0.22uF / 200 V Kemet 29 R17 10k 19 1 6 O UTA A Gn d6 C24 390pF 19 1 8REF A C26 Q2 IRF6217 SO-8 R25b 10k Q4 NTMFS4982NF SO-8L P drive UVLO 1 7 FLT/ SD DL M T3 2 27 J2a T520V227M004ATE007 C101 1nF .1 T2 CT02 31 C13 0.1uF 22 NC . 3 58 Vs c la m p 4 R18 10k R39 2.2 R9 1k 14 23 R40 2.2 C40 0.1uF 100 V U1 NCP1565 QFN24 43 R25a 10k R101 2.2 close to Q3/Q4 47 S O-8L 25 26 C16 10nF Q3 NTMFS4982NF R100 2.2 49 C17 R24b 10k 21 . 7 D8 MMSD914 R10 100 Mill-Max 3104-2-00-80-00-00-08-0 35 5 1 9 4 220 uF Kemet x 4 P ayton Q5 NTMFS4982NF S O-8L R24a 10k 38 20 MSS1038-152NL L1 1.5uH J1b 0V . 2 C1210C225M1RACTU C1210C225M1RACTU C1210C225M1RACTU C1210C225M1RACTU Mill-Max 3231-2-00-01-00-00-08-0 L2 0.5uH R29a 2.2 2 Mill-Max 3104-2-00-80-00-00-08-0 close to Q5/Q6 gates R29b 2.2 DUAL SOT23 C31 1uF D9 MMSD914 Vcc 4.3 V 59 D3 MBR130TG R26 270 R11 499 D6 MBR130TG 9 R7 10k R36 270 57 C10 0.1uF C38 0.1uF C33 open C9 0.1uF 2.45 V D1 1N751 C99 1nF 1 2 U5 LM4041DIM3-1.2 SOT-23 R27 10 C5 NC Quiet GND D11 Red LED U3 TL431QDBVR SOT-23 C32 C28 C11 C8 1.5nF 10nF 330pF 0.1uF Lit when fault 45 Fault Vref 41 54 R34 499 U2 PS2801 C27 2.2nF C4532X7R3D222K 2000 V - TDK Dc input voltage 36 – 72 V 2 Christophe Basso – March 2014 36-75 V 3.3 V/20 A dc-dc conv erter f or telecom applications. 1/4th brick NC - non connected ON Semiconductor Christophe Basso - February 17th 2014. Rev 1c. PCB rev 1 3.3 V/20 A Output voltage Board Picture Sense + 36 to 72 V Trim Sense - Jumper must be removed Lit when fault Input voltage from 36 V to 72 V dc. Nominal input is 48 V 3 Christophe Basso – March 2014 Output voltage is 3.3 V nominal current is 20 A Needed Equipment The needed equipments are the following: a dc voltage source, delivering up to 80 V dc and up to 3 A a dc load absorbing up to 100 W, Vin,max < 20 V, Iout,max < 40 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 4 Christophe Basso – March 2014 Basic Test Setup source load Jumper is removed + - Socket in which the dc-dc is firmly plugged 5 Christophe Basso – March 2014 Kelvin sense Test n°1 Source = 36 V Load = 20 A + - • Start the power supply while the load current is 20 A • Monitor the output voltage on a scope • Verify the voltage is monotonically rising 6 Christophe Basso – March 2014 Test n°1 vout t vout t Ok Bad • It is important to verify the absence of double slope • Repeat the test for Vin = 48 V and 72 V • Change load to 0 A, repeat tests. Wait 10 s between re-starts. 7 Christophe Basso – March 2014 Test n°2 source load Press short Jumper is removed + - • Press short circuit at Vin = 36 V. Led blinks, board ticks. • Repeat test for Vin = 48 V and 72 V • Release short and make sure output resumes at 3.3 V. 8 Christophe Basso – March 2014 Test n°3 source load + Probe here • Program load to dynamic current mode • Iout from 20 A to 15 A, slope 1 A/µs No pigtail! • 1 ms interval, observe Vout on scope in ac, 20 mV/div 9 Christophe Basso – March 2014 Test n°3 vout t vout t 40 mV Vin = 36 V Iout = 15 to 20 A, 1 A/µs 20 mV Vin = 48 V Iout = 15 to 20 A, 1 A/µs • Run the test from Vin = 36 V (worst case) to Vin = 72 V. • Spec is to have an under/over shoot less than 60 mV 10 Christophe Basso – March 2014 Test n°4 source load + - • Leave the board for 5 mn at Vin = 36 V/20 A. • Check no thermal disjonction occurs. • Board is declared sound. 11 Christophe Basso – March 2014