LT1316_15 Datasheet, PDF (1/16 Pages) Linear Technology – Micropower DC/DC Converter with Programmable Peak Current Limit

LT1316
Micropower
DC/DC Converter
with Programmable
Peak Current Limit
FEATURES
s _{Precise Control of Peak Switch Current}
s _{Quiescent Current:}
33µA in Active Mode
3µA in Shutdown Mode
s _{Low-Battery Detector Active in Shutdown}
s _{Low Switch VCESAT: 300mV at 500mA}
s _{8-Lead MSOP and SO Packages}
s _{Operates with VIN as Low as 1.5V}
s _{Logic Level Shutdown Pin}
U
APPLICATIONS
s _{Battery Backup}
s _{LCD Bias}
s _{Low Power – 48V to 5V/3.3V Converters}
DESCRIPTION
The LT^®1316 is a micropower step-up DC/DC converter
that operates from an input voltage as low as 1.5V. A
programmable input current limiting function allows pre-
cise control of peak switch current. Peak switch current
can be set to any value between 30mA and 500mA by
adjusting one resistor. This is particularly useful for
DC/DC converters operating from high source impedance
inputs such as lithium coin cells or telephone lines.
The fixed off-time, variable on-time regulation scheme
results in quiescent current of only 33µA in active mode.
Quiescent current decreases to 3µA in shutdown with the
low-battery detector still active.
The LT1316 is available in 8-lead MSOP and SO packages.
, LTC and LT are registered trademarks of Linear Technology Corporation.
TYPICAL APPLICATION
2-Cell to 5V Step-Up Converter
+
2 CELLS
L1
47µH
D1
6
V_IN
7 _SHDN
5
SW
8
FB
C1
47µF
2
NC LBI
LT1316
1
LBO NC
R_SET
GND
3
4
R5
10k
1%
R1
1M
1%
+
R2
324k
1%
5V
50mA
C2
47µF
D1: MOTOROLA MBR0520L
L1: SUMIDA CD43-470
1316 TA01
Efficiency vs Load Current
90
3.3V_IN
2.5V_IN
80
1.8V_IN
70
60
0.1
1
10
LOAD CURRENT (mA)
100
1316 TA02
1