LT3693_15 Datasheet, PDF (1/24 Pages) Linear Technology – 36V, 3.5A, 2.4MHz Step-Down Switching Regulator

LT3693
36V, 3.5A, 2.4MHz
Step-Down Switching Regulator
FEATURES
■ _{Wide Input Range: 3.6V to 36V}
■ _{3.5A Maximum Output Current}
■ _{Adjustable Switching Frequency: 200kHz to 2.4MHz}
■ _{Low Shutdown Current: IQ < 1μA}
■ _{Integrated Boost Diode}
■ _{Synchronizable Between 250kHz to 2MHz}
■ _{Power Good Flag}
■ _{Saturating Switch Design: 95m On-Resistance}
■ _{0.790V Feedback Reference Voltage}
■ _{Output Voltage: 0.79V to 30V}
■ _{Thermal Protection}
■ _{Soft-Start Capability}
■ _{Small 10-Pin Thermally Enhanced MSOP and}
(3mm × 3mm) DFN Packages
U
APPLICATIO S
■ _{Automotive Battery Regulation}
■ _{Power for Portable Products}
■ _{Distributed Supply Regulation}
■ _{Industrial Supplies}
■ _{Wall Transformer Regulation}
DESCRIPTIO
The LT^®3693 is an adjustable frequency (200kHz to
2.4MHz) monolithic buck switching regulator that accepts
input voltages up to 36V. A high efficiency 95m switch
is included on the die along with a boost Schottky diode
and the necessary oscillator, control, and logic circuitry.
Current mode topology is used for fast transient response
and good loop stability. Shutdown reduces input supply
current to less than 1μA while a resistor and capacitor on
the RUN/SS pin provide a controlled output voltage ramp
(soft-start). A power good flag signals when V_OUT reaches
91% of the programmed output voltage. The LT3693 is
available in 10-Pin MSOP and 3mm × 3mm DFN packages
with exposed pads for low thermal resistance.
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
TYPICAL APPLICATIO
5V Step-Down Converter
V_IN
6.3V TO 36V
OFF ON
V_IN
RUN/SS
BD
BOOST
15k
10mF
680pF
63.4k
V_C
LT3693
SW
RT
PG
SYNC
GND
FB
V_OUT
5V
3.5A
0.47mF _4.7mH
536k
100k
47mF
3693 TA01a
Efficiency
100
V_IN = 12V
90
V_IN = 34V
80
V_IN = 24V
70
60 _{VOUT = 5V}
L = 4.7μH
f = 600kHz
50
0 0.5 1 1.5 2 2.5
OUTPUT CURRENT (A)
3 3.5
3693 G01
3693f
1