FEATURES
nn 720nA Input IQ in Regulation (No Load), VIN = 4V
nn 820nA Input IQ in Regulation (No Load), VIN = 20V
nn 400nA Input IQ in UVLO
nn 2.7V to 20V Input Operating Range
nn Up to 50mA of Output Current
nn Pin Selectable Output Voltages:
nn 1.2V, 1.5V, 1.8V, 2.5V (LTC3388-1)
nn 2.8V, 3.0V, 3.3V, 5.0V (LTC3388-3)
nn High Efficiency Hysteretic Synchronous
DC/DC Conversion
nn Standby Mode Disables Buck Switching
nn Available in 10-Lead MSE and 3mm × 3mm
DFN Packages
APPLICATIONS
nn Keep Alive Power for Portable Products
nn Industrial Control Supplies
nn Distributed Power Systems
nn 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 supply cur-
rent 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
lockout (UVLO) feature to disable the converter and main-
tain 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 quies-
cent currents 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 VIN 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
VIN
LTC3388-1/
LTC3388-3
CAP
SW
VIN2
VOUT
EN
PGOOD
STBY
D0, D1
GND
338813 TA01a
100µH
2 OUTPUT
VOLTAGE
SELECT
VOUT
47µF
6V
Efficiency vs Load Current
100
VOUT = 1.8V, L = 100µH
90
80
70
60
50
40
30
20
10
0
1µ
VIN = 3.0V
VIN = 10V
VIN = 20V
10µ 100µ 1m
LOAD CURRENT (A)
10m
338813 TA01b
For more information www.linear.com/LTC3388
338813fa
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