LTC3788-1 Linear Technology, LTC3788-1 Datasheet - Page 25

• Manufacturer Part Number: LTC3788-1
• Description: Dual Output Synchronous Boost Controller
• Manufacturer: Linear Technology

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APPLICATIONS INFORMATION
for inductive coupling between C
MOSFET components to the sensitive current and voltage
sensing traces. In addition, investigate common ground
path voltage pickup between these components and the
SGND pin of the IC.
An embarrassing problem, which can be missed in an
otherwise properly working switching regulator results
when the current sensing leads are hooked up backwards.
C
C
L1: PULSE PA1494.362NL
L2: PULSE PA1294.132NL
MBOT1, MBOT2, MTOP1, MTOP2: RENESAS HAT2169H
12.1k, 1%
INA
INB
C
12.1k
R
C
R
, C
, C
ITH2
ITH1
A1
A2
OUTA1
OUTB1
, 15nF
, 15nF
C
C
C
C
ITHA2
R
232k
1%
R
110k
, C
ITH1
, C
SS1
SS2
B1
B2
OUTA2
OUTB2
, 220pF
, 0.1μF
, 0.1μF
, 100pF
: SANYO, 50CE220AX
: TDK C4532X5R1E226M
R
8.66k
R
2.7k
ITH1
ITH2
IN
, Schottky and the top
Figure 9. High Effi ciency Dual 12V/24V Boost Converter
SENSE1
SENSE1
VFB1
ITH1
SS1
PLLIN/MODE
SGND
EXTV
RUN1
RUN2
FREQ
SS2
ITH2
VFB2
SENSE2
SENSE2
CC
LTC3788-1
–
+
+
–
PGOOD1
BOOST1
BOOST2
INTV
VBIAS
PGND
SW1
SW2
TG1
BG1
BG2
TG2
CC
100k
C
C
B1
B1
D1
D2
, 0.1μF
, 0.1μF
The output voltage under this improper hook-up will still
be maintained, but the advantages of current mode control
will not be realized. Compensation of the voltage loop will
be much more sensitive to component selection. This
behavior can be investigated by temporarily shorting out
the current sensing resistor—don’t worry, the regulator
will still maintain control of the output voltage.
INTV
C
4.7μF
INT
CC
MBOT2
MTOP1
MBOT1
MTOP2
1.25μH
3.3μH
L1
L2
R
R
SENSE1
SENSE2
4mΩ
3mΩ
37881 F09
C
22μF
C
22μF
C
22μF
LTC3788-1
OUTA1
INA
OUTA2
4
4
4
+
+
+
C
220μF
C
220μF
C
220μF
OUTB1
INB
OUTB2
V
24V, 5A
V
5V TO 24V
V
12V, 10A
OUT1
IN
OUT2
25
37881f