==
!"#$%&'()*+,-./
! 318
Keith Szolusha
12V=
!"#$%&'()*+,-.,/012
=±5V= !"#$%&'()*+, ! 3mm !"#!$%&'()*+
= ( =5V= !"#) !"#$%&'
!"#$%&'()*+,-./0123
!"#$%&'(")*+,-./012
!"#$%&'()*+,-./0#1
!"#$%&'()*+,-,./01
!"#$%&'"()*+,-./01
( 5 m m ) !"#$%&'()* +
!"#$%&'()*)+,-./012
!"#$%&'()*+=PCB= !"
!"#$%&'(
! " # $ % & ' ( ) * + , - + % =( LT ® 1956==LT3431 ) !"#$%=5 00kHz
1.5A/3A= !"#$% !"&'(=1= !
=LT1956EFE==12V= !=(=36V=
9V==16V=) ==±5V OUT = !"#$%&'=2
!=LT3431EFE= !"#$%&'(
!
!"#$%&'&()*+,-.#/01
!"#$%&'()*+,-./01&2
!"#$%&'()$%*+,-.
!"#$%&'()"*+,-./-01
!"#$%&'()*+,-.&'/ 0
!"#$%&'()*
±5V= !"#=3mm
!"#$%&'()*+*,
!"#$%&'()*+*,-./012
!"#$%&'( #)%*+,(-.&
!"# $%&'()*+,-./0
!"#$%=VIN= =VOUT= !"#"$%
!"=5V= !"#$%$&'()*+
!"#$%&'()*+,-./01
!"#$%&'()*+ !"#$,"
!"#$=( 5V ) = !"#$%&'()
!"#$% &#'()*%"+,-)*
!"#$%&L1 !"#$=5 V= L2 !"#$%%&"#'
=====LTC ==LT= !"#$%&'(
VIN
9V TO 16V
36V TRANSIENT
CIN
2.2µF
50V
CER
2.2k
3300pF
BOOST
VIN
VSW
SYNC VBIAS
LT1956
SHDN
VC
FB
GND
L1
0.1µF 1N4148W
CDRH4D28-150
V
SW
15.4k
4.99k
220pF
*SEE FIGURE 3 FOR MAXIMUM LOAD CURRENT
CCOUP
10µF
6.3V
0805
CER
X5R
B0540W
VOUT
5V*
COUT
10µF 6.3V
0805 X5R
CER
COUT2
10µF 6.3V
0805 X5R
CER
VOUT2
DN318 F01 –5V*
B0540W
=1= LT1956 9V==16V==(=36V=)±5V
3mm= !"#$%&'(=(
=∆I/∆t= !"#$%&)
10/03/318
CIN
2.2µF
50V
CER
1.5k
10nF
L2
CDRH4D28-150
VSWN
VIN
9V TO 16V
36V TRANSIENT
BOOST
VIN
VSW
SYNC VBIAS
LT3431
SHDN
VC
FB
GND
0.22µF 1N4148W L1
CDRH6D28-100
VSW
15.4k
4.99k
220pF
*SEE FIGURE 6 FOR MAXIMUM LOAD CURRENT
CCOUP
10µF
6.3V
0805
CER
X5R
VOUT
5V*
B140
COUT
22µF 6.3V
X5R
CER
L2
CDRH6D28-100
COUT2
22µF 6.3V
X5R
CER
VOUT2
DN318 F02 –5V*
VSWN
B140
=2= LT3431 9V 16V =(=36V=)±5V
3mm= !"#$%&'(=(
=∆I/∆t= !"#$%&)
!"#!$%&'()#*+, -.!
=(LT1956==1.5ALT3431==3A) !"#$
=3==6 !"#$%&'()*$+,-.
!"#$%&'()*+,-.&'/0
!"#$%&!'()*+,-./01
V OUT2 3% !"#$%&'()*+,
!"#$ 1.5A 3A
IOUT(MAX) [5V] = 1.5==3 – IOUT2 [–5V] – 2 • ILP-P/2
(
!"#$%&)
=LT1956==LT3431= !"#$%&'()
! "#$=±5V= !"#$%&'()*
= ( !"#$%&'()*+,-./0 )
ILP-P = (VIN – 5VOUT) • DC/(L • 500kHz)
!"#$%&'()*+,-./01
5.30
600
LT1956
500
90
5.20
12VIN
400
300
9VIN
200
5.10
5.05
750mA
5.00
4.95
60
50
40
20
500mA
4.80
10
0
4.75
200
400
600
800
VOUT LOAD CURRENT (mA)
0
1000
200
400
VOUT2 LOAD CURRENT (mA)
600
=3 1 !"#$%&
5.30
100
90
|VOUT2| (V)
600
9VIN
400
EFFICIENCY (%)
5.15
12VIN
5.10
5.05
1.5A
5.00
4.95
1A
4.90
200
4.85
0
4.75
1500
500
1000
VOUT LOAD CURRENT (mA)
DN318 F07
=7 =(VOUT2 )= ±5%
!"
!"#
!"
(010)6801-1080
(010)6805-4030
60
0
200
400
800
600
VOUT2 LOAD CURRENT (mA)
1000
DN318 F08
=8 2 !
!"#$% !" !"#$%
!"#$%&'()*+,-./01
www.linear.com.cn [email protected]
!"#$%
!"#
Linear Technology Corporation Ltd. Cytech Technology Ltd.
www. cytecht.com
www.linear.com.cn
!"(852)2375-8866
!"(010)8268-4280
!"(021)6440-1373
!"(0755)8386-7431
!"(025)481-0877
!"(028)8652-7116
!"(029)837-8918
!"(027)8736-0546
!"(0592)563-8488
1.5A
75
http://www.linear.com.cn/go/dnLT1956
http://www.linear.com.cn/go/dnLT3431
1000
200
400
600
800
VOUT2 LOAD CURRENT (mA)
DN318 F06
=6 2 !"#$%&
1A
80
65
0
2000
500mA
85
70
500mA
4.80
!"
(021)6375-9478
(021)6375-9479
LT3431
12VIN
95
5.20
16VIN
!"
(852)2428-0303
(852)2348-0885
500
=5 1 !"#$%
LT3431
12VIN
5.25
1000
0
100
300
400
200
VOUT2 LOAD CURRENT (mA)
DN318 F05
=4 =(VOUT2 )= ±5%
!"
LT3431
800
0
DN318 F04
DN318 F03
1200
250mA
70
250mA
4.85
1
LT1956
12VIN
750mA
30
4.90
100
500mA
80
5.15
EFFICIENCY (%)
16VIN
0
MAXIMUM VOUT2 LOAD CURRENT (mA)
100
LT1956
12VIN
5.25
|VOUT2| (V)
MAXIMUM VOUT2 LOAD CURRENT (mA)
=4 =7 !"#$$%&'()*=VOUT2
!"#$%&'()*+,-./012
! " # $ % & ' =1 2mA=( LT1956 ) =2 5mA
(LT3431)==V OUT2 !"#$%&'()*+,
!=V OUT !"#$%&'()*+,
!"#$%&
(852)2375-7700
(010)8268-4277
(021)6440-0166
(0755)8386-7954
(025)480-8023
(028)8652-7556
(029)837-8919
(027)8736-0547
(0592)563-7169
!"#$ ! !"#$%
Unique-A Division of Memec (Asia Pacific) Ltd.
www.unique-ap.com
[email protected]
!"(852)2410-2778
!"(010)8519-1866
!"(021)6317-8226
!"(0755)8366-4329
!"(028)8652-8252
!"(027)8732-2646
!"(029)822-9180
!"(0592)516-4701
!"(0532)582-1322
(852)2370-3247
(010)8519-1865
(021)6317-3446
(0755)8366-4330
(028)8652-8253
(027)8732-2729
(029)825-8595
(0592)516-4702
(0532)583-8372
dn318f 0803 39K • PRINTED IN CHINA
LINEAR TECHNOLOGY CORPORATION 2003