Datasheet

LT3800
19
3800fc
APPLICATIONS INFORMATION
The LT3800 packaging has been designed to effi ciently
remove heat from the IC via the Exposed Pad on the
backside of the package. The Exposed Pad is soldered to
a copper footprint on the PCB. This footprint should be
made as large as possible to reduce the thermal resistance
of the IC case to ambient air.
Orientation of Components Isolates Power Path and PGND
Currents, Preventing Corruption of SGND Reference
BOOST
V
CC
SW
PGNDSGND
LT3800
SGND
REFERRED
COMPONENTS
+
+
BG
TG
V
OUT
3800 AI05
V
IN
I
SENSE
SW
TYPICAL APPLICATIONS
6.5V-55V to 5V 10A DC/DC Converter with Charge Pump Doubler V
CC
Refresh and Current Limit Foldback
V
IN
NC
SHDN
C
SS
BURST_EN
V
FB
V
C
SENSE
–
BOOST
TG
SW
NC
V
CC
BG
PGND
SENSE
+
LT3800
SGND
C7
1.5nF
R3
62k
R5
47k
D2
1N4148
R4 75k
C9
470pF
C10
100pF
R2
309k
1%
R1
100k
1%
R
A
1M
R
S
0.01Ω
D1
BAS19
C1 1µF
16V X7R
C3 1µF
16V X7R
C2
1µF
100V
X7R ×3
C8
56µF
63V
×2
+
C6
10µF
6.3V
X7R
C5
220µF
×2
+
M1
Si7850DP
×2
M2
Si7370DP
×2
M3
1/2 Si1555DL
M4
1/2 Si1555DL
DS3
B160
×2
DS1
MBRO520L
C4
1µF
DS2
MBRO520L
L1
5.6µH
V
IN
6.5V TO 55V
V
OUT
5V AT 10A
3800 TA02a
C5: SANYO POSCAP 6TP220M
L1: IHLP-5050FD-01
Effi ciency and Power Loss
I
OUT
(A)
0
70
EFFICIENCY (%)
POWER LOSS (W)
75
80
85
90
95
100
0
2
4
6
8
10
12
2468
3800 TA02b
10
V
IN
= 13.8V
V
IN
= 55V
V
IN
= 24V
V
IN
= 48V
POWER LOSS
V
IN
= 48V
POWER LOSS
V
IN
= 13.8V