LTC3620 Datasheet, PDF (14/16 Pages) Linear Technology – Ultralow Power 15mA Synchronous Step-Down Switching Regulator

LTC3620
TYPICAL APPLICATIONS
High Efficiency Low Power Step-Down Converter,
Externally Programmed f_MIN
V_IN
2.9V TO 5.5V
1μF
CER
V_IN
RUN LOBATB
SW
LTC3620
LOBATB
1M
22μH
22pF
V_OUT
1.1V
FMIN/MODE
FMIN/MODE V_FB
GND
432k
523k
1μF
CER
3620 TA03a
100
90
80
70
60
50
40
30
20
10
0
0.1
Efficiency vs Load Current
T_A = 25°C
V_IN = 3.6V
V_OUT = 1.1V
f_MIN = 20kHz
f_MIN = 100kHz
f_MIN = 200kHz
1
LOAD CURRENT (mA)
10
3620 TA03b
Efficiency vs V_IN
100
90
80
70
60
50
40
30
20 _{TA = 25°C}
10 VOUT = 1.1V
0 ^{fMIN = 200kHz}
2.5
3.5
4.5
V_IN (V)
I_OUT = 500μA
I_OUT = 1mA
I_OUT = 10mA
5.5
6.5
3620 TA03c
Spectral Content,
FMIN/MODE = 20kHz Clock
–40
–60
20.0kHz
–64.9dBm
–80
–100
–120
1kHz
–140
RBW = 3Hz
V_OUT = 1.1V
V_IN = 3.6V
I_OUT = 500μA
T_A = 25°C
2.99kHz/DIV
30kHz
3620 TA03d
Spectral Content,
FMIN/MODE = 100kHz Clock
–40
–60
99.9kHz
–59.9dBm
–80
–100
–120
–140 ^1kHz
V_OUT = 1.1V
V_IN = 3.6V
I_OUT = 1mA
T_A = 25°C
14.9kHz/DIV
150kHz
3620 TA03e
Spectral Content,
FMIN/MODE = 200kHz Clock
–40
–60
199.7kHz
–80
–100
–120
–140 ^1kHz
V_OUT = 1.1V
V_IN = 3.6V
I_OUT = 1mA
T_A = 25°C
21.9kHz/DIV
220kHz
3620 TA03f
3620f
14