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QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 1317A-B 

ACTIVE RESET ISOLATED 18-72V INPUT  TO 5V @25A DC/DC POWER CONVERTER 

 

 

1

 

LT1952 

DESCRIPTION

DESCRIPTION

DESCRIPTION

DESCRIPTION

Demonstration  circuit  1317A-B  is  isolated  input  to 
high  current  output  1/8th  Brick  footprint

1/8th  Brick  footprint

1/8th  Brick  footprint

1/8th  Brick  footprint  converter 

featuring  the  LT

®

1952  switching  controller  with  Ac-

tive  Reset  circuit.  The  Active  Reset  circuit  can  im-
prove  the  efficiency  in  wide  input  voltage  applica-
tions.  Also,  the  Active  Reset  allows  the  implementa-
tion  of  self-driven  synchronous  secondary  rectifiers 
in some applications.  

The  DC1317A-B  converts  isolated  wide  18V  to  72V 
input  to  5V  output  and  provides  over  30A  of  output 
current depending on cooling. When determining the 
cooling  requirements  the  actual  input  voltage  range 
and  continuous  maximum  output  current  must  be 
taken into account. The converter operates at 200kHz 
with  the  peak  efficiency  greater  than  94%.  The 
DC1317  can  be  easily  modified  to  generate  output 
voltages  in  the  range  from  0.6V  to  48V.  The  output 
currents  are  limited  by  total  output  power  of  up  to 
150W.  

The available versions of DC1317A are: 

DC1317A-A, 34-75Vin to 3.3V, 35A 

DC1317A-B, 18-72Vin to 5V, 25A 

DC1317A-C, 18-72Vin to 12V, 10A 

DC1317A-D, 18-72Vin to 24V, 5A 

DC1317A-E, 36-72Vin to 5V, 12A  

DC1317A-F, 9-36Vin to 3.3V, 20A 

DC1317A-G, 9-36Vin to 12V, 5A 

DC1317A-H, 9-36Vin to 48V, 1.5A 

 

The DC1317 circuit features soft-start which prevents 
output voltage overshoot on startup or when recover-
ing from overload condition.  

The  DC1317  has  precise  over-current  protection  cir-
cuit that allows for continuous operation under short 
circuit  conditions.  The  low  power  dissipation  under 
short  circuit  conditions  insures  high  reliability  even 
during short circuits. 

The LT1952 can be synchronized to an external clock 
of up to 400kHz. Please refer to LT1952 data sheet for 
design details and applications information. 

Design  files  for  this  circuit  board  are  ava

Design  files  for  this  circuit  board  are  ava

Design  files  for  this  circuit  board  are  ava

Design  files  for  this  circuit  board  are  avaiiiillllable. 

able. 

able. 

able. 

Call the LTC factory.

Call the LTC factory.

Call the LTC factory.

Call the LTC factory.    

LT is a trademark of Linear Technology Corporation 

    

    

Table 1.

Table 1.

Table 1.

Table 1.

 

Performance Summary

Performance Summary

Performance Summary

Performance Summary    

PARAMETER

PARAMETER

PARAMETER

PARAMETER    

CONDITION

CONDITION

CONDITION

CONDITION    

VALUE

VALUE

VALUE

VALUE    

Minimum Input Voltage 

IOUT = 0A to 25A 

18V 

Maximum Input Voltage 

IOUT = 0A to 25A 

72V 

VOUT 

VIN = 18V to 72V, IOUT = 0A to 25A 

(30Amax) 

5V ±3% 

Typical Output Ripple VOUT 

VIN = 18V to 72V, IOUT = 0A to 25A 

50mVP–P 

Nominal Switching Frequency 

 

200kHz 

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Содержание DC1317A-B

Страница 1: ...72Vin to 24V 5A DC1317A E 36 72Vin to 5V 12A DC1317A F 9 36Vin to 3 3V 20A DC1317A G 9 36Vin to 12V 5A DC1317A H 9 36Vin to 48V 1 5A The DC1317 circuit features soft start which prevents output voltage overshoot on startup or when recover ing from overload condition The DC1317 has precise over current protection cir cuit that allows for continuous operation under short circuit conditions The low p...

Страница 2: ...irectly across the Vin or Vout and GND terminals See Figure 2 for proper scope probe technique 1 1 1 1 With power off connect the input power supply to Vin and GND Make sure that the input power sup ply has sufficient current rating at minimum input voltage for the required output load 2 2 2 2 Turn on the power at the input NOTE NOTE NOTE NOTE Make sure that the input voltage does not exceed 72V 3...

Страница 3: ...P Channel MOSFET Q13 and reset capacitor C25 The MOSFET Q13 is used to connect the reset capacitor across the transformer T1 primary winding during the reset period when Q1 MOSFET is off The voltage across capacitor C25 automatically adjusts with the duty cycle to provide complete transformer reset under all oper ating conditions Also the active reset circuit shapes the reset voltage into a square...

Страница 4: ...nsient response of DC1317 is Figure 4 Fast transient response of DC1317 is Figure 4 Fast transient response of DC1317 is s s s su u u uperior to many competing power modules perior to many competing power modules perior to many competing power modules perior to many competing power modules without the additional output capac without the additional output capac without the additional output capac w...

Страница 5: ...es The PCB layout schematic does not show the compo nent values In some cases a different component like a diode is used in a place holder for a capacitor such as in the case of C6 Please modify the reference designators in your schematic to reflect the actual component used The following simple PCB layout rules should be help ful If possible use solid ground planes on layers 2 and n 1 The ground ...

Страница 6: ...X55 R10 1k D9 PDZ7 5B R8 1uF FG FG CG CG C3 1u R5 10R Q12 BC856T D3 Q10 PBSS8110 Vb Vb L2 1 5mH U6 PS2801 1 T1 Inp 3 Vcc 1 TS 4 Boost 6 GND 2 TG 5 U2 LTC4440 5 C21 470p D1 BAS516 Vu1 D11 BAS516 GND Vout C7 220p Out C8 100p C6 BAS516 D7 B0540W C4 BAS516 Csys 470uF 6 3V C24 22p C9 100p C25 33n Q13 Si2325 D14 BAS516 R45 10k Vr2 Vr2 Co3 D17 BAS516 R53 200 2 5 7 8 10 11 C33 0 1u R29 PMEG3002 R2 560k C3...

Страница 7: ...B ACTIVE RESET ISOLATED 18 72V INPUT TO 5V 25A DC DC POWER CONVERTER 7 Downloaded from Arrow com Downloaded from Arrow com Downloaded from Arrow com Downloaded from Arrow com Downloaded from Arrow com Downloaded from Arrow com Downloaded from Arrow com ...

Страница 8: ...T ISOLATED 18 72V INPUT TO 5V 25A DC DC POWER CONVERTER 8 Downloaded from Arrow com Downloaded from Arrow com Downloaded from Arrow com Downloaded from Arrow com Downloaded from Arrow com Downloaded from Arrow com Downloaded from Arrow com Downloaded from Arrow com ...

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