Datasheet

LTC3812-5
5
38125fc
Short-Circuit/Foldback Operation Pulse-Skipping Mode Operation
Effi ciency vs Input Voltage
Effi ciency vs Load Current Frequency vs Input Voltage
Frequency vs Load Current
Load Transient Response
Start-Up
Short-Circuit/Fault Timeout
Operation
TYPICAL PERFORMANCE CHARACTERISTICS
V
OUT
50mV/DIV
10μs/DIV
FRONT PAGE CIRCUIT
V
IN
= 25V
0A TO 5A LOAD STEP
38125 G01
I
OUT
5A/DIV
V
IN
20V/DIV
2ms/DIV
FRONT PAGE CIRCUIT
V
IN
= 30V
I
LOAD
= 0.5A
FCB = 0V
38125 G02
INTV
CC
,
V
OUT
2V/DIV
I
L
2A/DIV
INTV
CC
V
OUT
V
OUT
5V/DIV
5ms/DIV
FRONT PAGE CIRCUIT
V
IN
= 25V
R
SHORT
= 0.1Ω
38125 G03
SS/TRACK
2V/DIV
I
L
5A/DIV
V
OUT
5V/DIV
200μs/DIV
FRONT PAGE CIRCUIT
V
IN
= 25V
38125 G04
I
L
5A/DIV
V
OUT
100mV/DIV
I
TH
0.5A/DIV
20μs/DIV
FRONT PAGE CIRCUIT
V
IN
= 25V
I
OUT
= 100mA
FCB = INTV
CC
38125 G05
I
L
2A/DIV
INPUT VOLTAGE (V)
0
80
EFFICIENCY (%)
85
90
95
100
10 20 30 40
38125 G06
50 60
I
LOAD
= 5A
FORCED
CONTINUOUS
I
LOAD
= 0.5A
FORCED
CONTINUOUS
I
LOAD
= 0.5A
PULSE-SKIPPING
FRONT PAGE CIRCUIT
f = 250kHz
LOAD CURRENT (A)
0
85
EFFICIENCY (%)
90
95
100
1
234
38125 G07
56
V
IN
= 24V
V
IN
= 42V
V
OUT
= 12V
FCB = INTV
CC
f = 250kHz
INPUT VOLTAGE (V)
0
200
FREQUENCY (kHz)
220
240
260
10
20
30 40
LT1108 • TPC12
50
280
300
210
230
250
270
290
60
LOAD = 0A
LOAD = 5A
FRONT PAGE CIRCUIT
FCB = 0V
LOAD CURRENT (A)
0
250
300
350
4
38125 G09
200
150
123 5
100
50
0
FREQUENCY (kHz)
FORCED
CONTINUOUS
PULSE SKIPPING
FRONT PAGE CIRCUIT