LTC3414IFE Datasheet, PDF (1/16 Pages) Linear Technology – 4A, 4MHz, Monolithic Synchronous Step-Down Regulator

LTC3414
4A, 4MHz, Monolithic
Synchronous Step-Down Regulator
FEATURES
DESCRIPTIO
■ _{High Efficiency: Up to 95%}
■ _{4A Output Current}
■ _{Low Quiescent Current: 64μA}
■ _{Low RDS(ON) Internal Switch: 67mΩ}
■ _{Programmable Frequency: 300KHz to 4MHz}
■ _{2.25V to 5.5V Input Voltage Range}
■ _{±2% Output Voltage Accuracy}
■ _{0.8V Reference Allows Low Output Voltage}
■ _{Selectable Forced Continuous/Burst Mode}^® _Operation
with Adjustable Burst Clamp
■ _{Synchronizable Switching Frequency}
■ _{Low Dropout Operation: 100% Duty Cycle}
■ _{Power Good Output Voltage Monitor}
■ _{Overtemperature Protected}
■ _{Available in 20-Lead Exposed TSSOP Package}
U
APPLICATIO S
■ _{Point-of-Load Regulation}
■ _{Notebook Computers}
■ _{Portable Instruments}
■ _{Distributed Power Systems}
, LTC and LT are registered trademarks of Linear Technology Corporation.
Burst Mode and OPTI-LOOP are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
Protected by U.S. Patents, Including 5481178, 6580258, 6304066, 6127815, 6498466,
6611131, 6724174
The LTC^®3414 is a high efficiency monolithic synchro-
nous, step-down DC/DC converter utilizing a constant
frequency, current mode architecture. It operates from an
input voltage range of 2.25V to 5.5V and provides a
regulated output voltage from 0.8V to 5V while delivering
up to 4A of output current. The internal synchronous
power switch with 67mΩ on-resistance increases effi-
ciency and eliminates the need for an external Schottky
diode. Switching frequency is set by an external resistor or
can be synchronized to an external clock. 100% duty cycle
provides low dropout operation extending battery life in
portable systems. OPTI-LOOP^® compensation allows the
transient response to be optimized over a wide range of
loads and output capacitors.
The LTC3414 can be configured for either Burst Mode
operation or forced continuous operation. Forced continu-
ous operation reduces noise and RF interference while
Burst Mode operation provides high efficiency by reduc-
ing gate charge losses 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.
TYPICAL APPLICATIO
V_IN
2.7V TO 5.5V
22μF
2.2M
294k
PV_IN SV_IN
RT
PGOOD
LTC3414
SW
1000pF
470pF
R_ITH*
RUN/SS PGND
I_TH
SGND
SYNC/MODE V_FB
75k
110k
0.47μH
V_OUT
2.5V AT 4A
C_OUT*
392k
3414 F01a
*Burst Mode OPERATION: C_OUT = 470μF SANYO POSCAP 4TPB470M, R_ITH = 20k
FORCED CONTINUOUS: C_OUT = (2) 100μF TDKC4532X5ROJ107M, R_ITH = 12.1k
Figure 1. 2.5V/4A Step-Down Regulator
LTC3414 Efficiency Curve
100
95 ^{Burst Mode OPERATION}
90
85
80
FORCED
CONTINUOUS
75
70
65
60
55
50
0.001
0.01
0.1
1.0
LOAD CURRENT (A)
10
3414 F01b
3414fb
1