LTC3603_15 Datasheet, PDF (1/22 Pages) Linear Technology – 2.5A, 15V Monolithic Synchronous Step-Down Regulator

Features
n _{Wide Input Voltage Range: 4.5V to 15V}
n _{2.5A Output Current}
n _{Low RDS(ON) Internal Switches: 45mΩ and 85mΩ}
n _{Programmable Frequency: 300kHz to 3MHz}
n _{Low Quiescent Current: 75µA}
n _{0.6V ±1% Reference Allows Precise,}
Low Output Voltage
n _{99% Maximum Duty Cycle}
n _{Adjustable Burst Mode}^® _Clamp
n _{Synchronizable to External Clock}
n _{Power Good Output Voltage Monitor}
n _{Overtemperature Protection}
n _{Overvoltage Protection}
n _{Available in 16-Lead Thermally Enhanced eMSOP}
and 4mm × 4mm QFN Packages
Applications
n _{Point-of-Load Supplies}
n _{Portable Instruments}
n _{Communications Infrastructure}
LTC3603
2.5A, 15V Monolithic
Synchronous Step-Down
Regulator
Description
The LTC^®3603 is a high efficiency, monolithic synchronous
step-down DC/DC converter utilizing a constant-frequency,
current mode architecture. It operates from an input voltage
range of 4.5V to 15V and provides an adjustable regulated
output voltage from 0.6V to 14.5V while delivering up to
2.5A of output current. The internal synchronous power
switch with 45mΩ on-resistance increases efficiency
and eliminates the need for an external Schottky diode.
The switching frequency can either be set by an external
resistor or synchronized to an external clock. OPTI-LOOP^®
compensation allows the transient response to be optimized
over a wide range of loads and output capacitors.
The LTC3603 can be configured for either Burst Mode op-
eration or forced continuous operation. Forced continuous
operation reduces noise and RF interference, while Burst
Mode operation provides the highest efficiency at light
loads. In Burst Mode operation, external control of the burst
clamp level allows the output voltage ripple to be adjusted
according to the requirements of the application.
L, LT, LTC, LTM, Burst Mode, OPTI-LOOP, Linear Technology and the Linear logo are registered
trademarks and ThinSOT is a trademark of Linear Technology Corporation. All other trademarks
are the property of their respective owners. Protected by U.S. Patents including 5481178,
6580258, 6498466, 6611131, 6177787, 5705919, 5847554.
Typical Application
3.3V, 2.5A, 1MHz Step-Down Regulator
V_IN
4.5V TO 15V
22µF
105k
4.32k
1nF
PV_IN INTV_CC
RUN
BOOST
RT LTC3603
PGOOD
SW
TRACK/SS
ITH
PGND
SYNC/MODE V_FB
105k
1µF
0.22µF
2.2µH
V_OUT
3.3V
100µF ^2.5A
475k
10pF
3603 TA01
Efficiency and Power Loss vs Load Current
100
V_IN = 12V
95 ^VOUT ^{= 3.3V}
90
EFFICIENCY
10000
1000
85
80
100
75
POWER LOSS
70
10
65
60
0.001
0.01
0.1
1
LOAD CURRENT (A)
1
10
3603 TA01b
For more information www.linear.com/LTC3603
3603fc
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