LTC3899_15 Datasheet, PDF (35/38 Pages) Linear Technology – 60V Low IQ, Triple Output, Buck/Buck/Boost Synchronous Controller

LTC3899
Typical Applications
V_OUT1
R_A1
68.1k
R_B1
357k
C_ITH1A 100pF
C_ITH1 1500pF
R_ITH1
15k
C_SS1 0.1µF
V_OUT2
R_A2
68.1k
C_ITH2 2200pF
R_ITH2
15k
C_ITH2A 68pF
R_B2
649k
C_SS2 0.1µF
LTC3899
V_FB1
TG1
C_B1 0.1µF
BOOST1
SW1
ITH1
BG1
MTOP1
L1
4.9µH
MBOT1
TRACK/SS1 SENSE1⁺
SENSE1^–
RUN1
RUN2
V_FB2
RUN3
V_BIAS
ITH2
GND
TRACK/SS2
DRV_CC
EXTV_CC
C1
1nF
C_BIAS
0.1µF
C_DRVCC
4.7µF
C_ITH3
10nF
V_OUT3
R_ITH3
3.6k
C_ITH3A 820pF
V_FB3
ITH3
TG2
C_B2 0.1µF
BOOST2
SW2
BG2
MTOP2
L2
6.5µH
MBOT2
C_SS3 0.1µF
SENSE2⁺
C2
SS3
SENSE2^–
1nF
C_INTVCC
0.1µF
FREQ
PLLIN/MODE
TG3
C_B3 0.1µF
DRVSET
VPRG3
BOOST3
SW3
BG3
MTOP3
L3
1.2µH
MBOT3
INTV_CC
SENSE3^–
C3
SENSE3⁺
1nF
R_SNS1
9mΩ
R_SNS2
15mΩ
R_SNS3
3mΩ
C_OUT1A
220µF
C_OUT2A
68µF
C_OUT3A
33µF
C_IN1
33µF
×2
3899 TA02
C_OUT1B
22µF
V_OUT1
5V
5A
C_OUT2B
4.7µF
V_OUT2
8.5V
3A
C_OUT3B
2.2µF
×6
V_OUT3
10V*
C_IN2
2.2µF
×3
V_IN
2.2V TO 60V
(START-UP ABOVE 5V)
*V_OUT3 IS 10V WHEN V_IN < 10V,
FOLLOWS V_IN WHEN V_IN > 10V
Figure 12. High Efficiency Wide Input Range Dual 5V/8.5V Converter
MTOP1, MBOT1: BSZ123N08NS3
MTOP2, MBOT2: BSZ123N08NS3
MTOP3, MBOT3: BSC042NE7NS3
L1: WÜRTH 744314490
L2: WÜRTH 744314650
L3: WÜRTH 744325120
C_OUT1A: SANYO 6TPB220ML
C_OUT2A: SANYO 10TPC68M
C_IN1, C_OUT3A: SUNCON 63HVP33M
Efficiency and Power Loss
EfficivesncLyoaadndCuProrewnetr Loss vs Load Current
100
10k
V_IN = 12V
90 _{VOUT = 5V}
EFFICIENCY
80
1k
70
60
100
50
40
POWER LOSS
10
30
20
1
10
0
0.0001
0.001 0.01 0.1
LOAD CURRENT (A)
0.1
1
10
3899 TA02b
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3899f
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