Datasheet

LT3462/LT3462A
3462af
1
APPLICATIO S
U
DESCRIPTIO
U
FEATURES
TYPICAL APPLICATIO
U
Integrated Schottky Rectifier
Fixed Frequency 1.2MHz/2.7MHz Operation
Very Low Noise: 1mV
P-P
Output Ripple
Low V
CESAT
Switch: 270mV at 250mA
–5V at 100mA from 5V Input
–12V at 30mA from 3.3V Input
Low Input Bias Current GND Based FB Input
Low Impedance (40) 1.265V Reference Output
High Output Voltage: Up to –38V
Wide Input Range: 2.5V to 16V
Uses Tiny Surface Mount Components
Low Shutdown Current: <10µA
Low Profile (1mm) SOT-23 (ThinSOT
TM
) Package
CCD Bias
LCD Bias
GaAs FET Bias
General Purpose Negative Voltage Supply
Inverting 1.2MHz/2.7MHz
DC/DC Converters with
Integrated Schottky in ThinSOT
The LT
®
3462/LT3462A are general purpose fixed fre-
quency current mode inverting DC/DC converters. Both
devices feature an integrated Schottky and a low V
CESAT
switch allowing a small converter footprint and lower parts
cost. The LT3462 switches at 1.2MHz while the LT3462A
switches at 2.7MHz. These high speeds enable the use of
tiny, low cost and low height capacitors and inductors.
The LT3462/LT3462A operate in a dual inductor inverting
topology that filters both the input and output currents.
Very low output voltage ripple approaching 1mV
P-P
can be
achieved when ceramic capacitors are used. Fixed fre-
quency switching ensures a clean output free from low
frequency noise typically present with charge pump solu-
tions. The 40V switch allows a V
IN
to V
OUT
differential of
up to 38V for dual inductor topologies.
Both devices provide a low impedance 1.265V reference
output to supply the feedback resistor network. A ground
referenced, high impedance FB input allows high feedback
resistor values without compromising output accuracy.
The LT3462/LT3462A are available in a 6-lead SOT-23
package.
, LTC and LT are registered trademarks of Linear Technology Corporation.
5V to –5V, 100mA Inverting DC/DC Converter
Efficiency
ThinSOT is a trademark of Linear Technology Corporation
LOAD CURRENT (mA)
0
EFFICIENCY (%)
75
70
65
60
55
3462 TA01b
20
40
8060
100
V
IN
= 3.3V
V
IN
= 5V
T
A
= 25°C
V
IN
5V
22µH
22µH
267k
68.1k
10µF
22pF
1µF
1µF
V
OUT
–5V
100mA
V
IN
SW
FB
SDREF
GND
LT3462A
3462 TA01
D

Summary of content (8 pages)