LTC3565_15 Datasheet, PDF (18/22 Pages) Linear Technology – 1.25A, 4MHz, Synchronous Step-Down DC/DC Converter

LTC3565
TYPICAL APPLICATION
General Purpose Buck Regulator Using Ceramic Capacitors
V_IN
2.5V TO
5.5V
C1
22µF
RS1
BM
1M
FC
PS _RS2
1M
R3
12.1k
SV_IN
PV_{IN PGOOD}
LTC3565 SW
SYNC/MODE
V_FB
ITH
SHDN/RT
GND
C3
680pF
R5
100k
PGOOD
L1
2.2µH
R2 294k
1.8V
1.5V 1.2V
C4 22pF
R4
R1A R1B R1C
191k 147k 196k 294k
NOTE: IN DROPOUT, THE OUTPUT TRACKS THE INPUT VOLTAGE
C1, C2: TAIYO YUDEN JMK325BJ226MM
L1: TOKO A914BYW-2R2M (D52LC SERIES)
V_OUT
1.8V/1.5V/1.2V
AT 1.25A
C2
22µF
3565 TA02a
Efficiency vs Output Current
100
Burst Mode
90 OPERATION
80
70
PULSE SKIP
60
50
40
FORCED CONTINUOUS
30
20
10
0
0.1
V_IN = 3.6V
V_OUT = 1.2V
f_O = 1MHz
1
10 100 1000 10000
OUTPUT CURRENT (mA)
3565 TA02b
V_OUT
100mV/DIV
AC COUPLED
I_L
1A/DIV
I_LOAD
1A/DIV
40µs/DIV
V_IN = 3.6V
V_OUT = 1.2V
I_LOAD = 100mA TO 1.25A
Burst Mode OPERATION
3565 TA02c
18
V_OUT
100mV/DIV
AC COUPLED
I_L
1A/DIV
I_LOAD
1A/DIV
40µs/DIV
V_IN = 3.6V
V_OUT = 1.8V
I_LOAD = 100mA TO 1.25A
PULSE SKIPPING MODE
3565 TA02d
For more information www.linear.com/LTC3565
3565fc