LTC3601_15 Datasheet, PDF (1/26 Pages) Linear Technology – 1.5A, 15V Monolithic Synchronous Step-Down Regulator

FEATURES
n _{4V to 15V Operating Input Voltage Range}
n _{1.5A Output Current}
n _{Up to 96% Efficiency}
n _{Very Low Duty Cycle Operation: 5% at 2.25MHz}
n _{Adjustable Switching Frequency: 800kHz to 4MHz}
n _{External Frequency Synchronization}
n _{Current Mode Operation for Excellent Line and Load}
Transient Response
n _{User Selectable Burst Mode}^® _{(No Load IQ = 300μA) or}
Forced Continuous Operation
n _{0.6V Reference Allows Low Output Voltages}
n _{Short-Circuit Protected}
n _{Output Voltage Tracking Capability}
n _{Programmable Soft-Start}
n _{Power Good Status Output}
n _{Available in Small, Thermally Enhanced 16-Pin QFN}
(3mm × 3mm) and MSOP Packages
APPLICATIONS
n _{Distributed Power Systems}
n _{Lithium-Ion Battery-Powered Instruments}
n _{Point-of-Load Power Supply}
L, LT, LTC, LTM, Burst Mode, Linear Technology and the Linear logo are registered trademarks
and Hot Swap is a trademark of Linear Technology Corporation. All other trademarks are the
property of their respective owners. Protected by U.S. Patents, including 5481178, 5847554,
6580258, 6304066, 6476589, 6774611.
LTC3601
1.5A, 15V Monolithic
Synchronous Step-Down
Regulator
DESCRIPTION
The LTC^®3601 is a high efficiency, monolithic synchronous
buck regulator using a phase-lockable controlled on-time,
current mode architecture capable of supplying up to 1.5A
of output current. The operating supply voltage range is
from 4V to 15V, making it suitable for a wide range of
power supply applications.
The operating frequency is programmable from 800kHz to
4MHz with an external resistor enabling the use of small
surface mount inductors. For switching noise sensitive
applications, the LTC3601 can be externally synchronized
over the same frequency range. An internal phase-locked
loop aligns the on-time of the top power MOSFET to the
internal or external clock. This unique constant frequency/
controlled on-time architecture is ideal for high step-down
ratio applications that demand high switching frequencies
and fast transient response.
The LTC3601 offers two operational modes: Burst Mode
operation and forced continuous mode to allow the user
to optimize output voltage ripple, noise, and light load
efficiency for a given application. Maximum light load
efficiency is achieved with the selection of Burst Mode
operation while forced continuous mode provides minimum
output ripple and constant frequency operation.
TYPICAL APPLICATION
V_IN
4V TO 15V
22μF
2.2μF
V_IN
BOOST
RUN
PGOOD
SW
TRACK
V_ON
LTC3601
INTV_CC
FB
ITH
RT
MODE/SYNC
SGND PGND
0.1μF _2.2μH
180k
10pF
V_OUT
3.3V
1.5A
22μF
40k
3601 TA01a
Efficiency and Power Loss vs Load Current
100
90
80
70
60
50
40
30
20
10
0
0.001
1000
100
10
0.01
0.1
V_IN = 5V
V_IN = 12V
1
1
10
LOAD CURRENT (A)
3601 TA01b
3601fb
1