LTC3388-1_15 Datasheet, PDF (1/20 Pages) Linear Technology – 20V High Efficiency Nanopower Step-Down Regulator

FEATURES
n _{720nA Input IQ in Regulation (No Load), VIN = 4V}
n _{820nA Input IQ in Regulation (No Load), VIN = 20V}
n _{400nA Input IQ in UVLO}
n _{2.7V to 20V Input Operating Range}
n _{Up to 50mA of Output Current}
n _{Pin Selectable Output Voltages:}
1.2V, 1.5V, 1.8V, 2.5V (LTC3388-1)
2.8V, 3.0V, 3.3V, 5.0V (LTC3388-3)
n _{High Efficiency Hysteretic Synchronous}
DC/DC Conversion
n _{Standby Mode Disables Buck Switching}
n _{Available in 10-Lead MSE and 3mm × 3mm}
DFN Packages
APPLICATIONS
n _{Keep Alive Power for Portable Products}
n _{Industrial Control Supplies}
n _{Distributed Power Systems}
n _{Battery-Operated Devices}
LTC3388-1/LTC3388-3
20V High Efficiency
Nanopower
Step-Down Regulator
DESCRIPTION
The LTC^®3388-1/LTC3388-3 are high efficiency step-down
DC/DC converters with internal high side and synchronous
power switches that draw only 720nA typical DC sup-
ply current at no load while maintaining output voltage
regulation.
Capable of supplying 50mA of load current, the LTC3388-1/
LTC3388-3 also incorporate an accurate undervoltage lock-
out (UVLO) feature to disable the converter and maintain
a low quiescent current state when the input voltage falls
below 2.3V. In regulation, the LTC3388-1/LTC3388-3 enter
a sleep state in which both input and output quiescent cur-
rents are minimal. The buck converter turns on and off as
needed to maintain regulation. An additional standby mode
disables buck switching while the output is in regulation
for short duration loads requiring low ripple.
Output voltages of 1.2V, 1.5V, 1.8V, 2.5V (LTC3388-1) and
2.8V, 3.0V, 3.3V, 5.0V (LTC3388-3) are pin selectable. The
LTC3388-1/LTC3388-3 can operate with V_IN up to 20V while
the no load quiescent current remains below 1μA.
L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks
of Linear Technology Corporation. All other trademarks are the property of their respective
owners.
TYPICAL APPLICATION
50mA Step-Down Converter
2.7V TO 20V
2.2μF
25V
1μF
6V
4.7μF
6V
V_IN
LTC3388-1/
LTC3388-3
CAP
SW
V_IN2
V_OUT
EN
PGOOD
STBY
D0, D1
GND
338813 TA01a
100μH
2 _OUTPUT
VOLTAGE
SELECT
V_OUT
47μF
6V
Efficiency vs Load Current
100
V_OUT = 1.8V, L = 100μH
90
80
70
60
50
40
30
20
10
0
1μ
V_IN = 3.0V
V_IN = 10V
V_IN = 20V
10μ 100μ 1m 10m
LOAD CURRENT (A)
338813 TA01b
338813f
1