LTC3616 Datasheet, PDF (1/28 Pages) Linear Technology – 6A, 4MHz Monolithic Synchronous Step-Down DC/DC Converter

FEATURES
n _{6A Output Current}
n _{2.25V to 5.5V Input Voltage Range}
n _{Low Output Ripple Burst Mode}^® _{Operation: IQ = 75μA}
n _{±1% Output Voltage Accuracy}
n _{Output Voltage Down to 0.6V}
n _{High Efficiency: Up to 95%}
n _{Low Dropout Operation: 100% Duty Cycle}
n _{Programmable Slew Rate on SW Node Reduces}
Noise and EMI
n _{Adjustable Switching Frequency: Up to 4MHz}
n _{Optional Active Voltage Positioning (AVP) with}
Internal Compensation
n _{Selectable Pulse-Skipping/Forced Continuous/Burst}
Mode Operation with Adjustable Burst Clamp
n _{Programmable Soft-Start}
n _{Inputs for Start-Up Tracking or External Reference}
n _{DDR Memory Mode, IOUT = ±3A}
n _{Available in a 24-Pin 3mm × 5mm QFN}
Thermally Enhanced Package
APPLICATIONS
n _{Point-of-Load Supplies}
n _{Distributed Power Supplies}
n _{Portable Computer Systems}
n _{DDR Memory Termination}
n _{Handheld Devices}
LTC3616
6A, 4MHz Monolithic
Synchronous Step-Down
DC/DC Converter
DESCRIPTION
The LTC^®3616 is a low quiescent current monolithic syn-
chronous buck regulator using a current mode, constant
frequency architecture. The no-load DC supply current
in sleep mode is only 70μA while maintaining the output
voltage (Burst Mode operation) at no load, dropping to zero
current in shutdown. The 2.25V to 5.5V input supply voltage
range makes the LTC3616 ideally suited for single Li-Ion
as well as fixed low voltage input applications. 100% duty
cycle capability provides low dropout operation, extending
the operating time in battery-powered systems.
The operating frequency is externally programmable up to
4MHz, allowing the use of small surface mount inductors.
For switching noise-sensitive applications, the LTC3616
can be synchronized to an external clock at up to 4MHz.
Forced continuous mode operation in the LTC3616 reduces
noise and RF interference. Adjustable compensation allows
the transient response to be optimized over a wide range
of loads and output capacitors.
The internal synchronous switch increases efficiency and
eliminates the need for an external catch diode, saving
external components and board space. The LTC3616 is
offered in a leadless 24-pin 3mm × 5mm thermally en-
hanced QFN package.
L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks of
Linear Technology Corporation. All other trademarks are the property of their respective owners.
Protected by U.S. Patents, including 6580258, 5481178, 5994885, 6304066, 6498466, 6611131.
TYPICAL APPLICATION
V_IN
2.7V TO 5.5V
SV_IN
PV_IN
RUN
SRLIM/DDR
TRACK/SS
RT/SYNC
LTC3616 SW
PGOOD
SGND
ITH
PGND
MODE
V_FB
210k
22μF
s4
220nH
665k
V_OUT
2.5V
47μF ^6A
s2
3616 TA01a
Efficiency and Power Loss
vs Load Current
100
90
80
1
70
60
0.1
50
40
0.01
30
20
10
0 ^{VOUT = 2.5V}
1
10
V_IN = 2.8V ⁰
V_IN = 3.3V
V_IN = 5V
100
1000 10000
OUTPUT CURRENT (mA)
3616 TA01b
3616f
1