FEATURES
n Wide VIN Range: 3.1V to 20V
n Wide VOUT Range:
0.6V to 5V (LTC3636)
1.8V to 12V (LTC3636-1)
n Output Current per Channel: 6A
n High Efficiency: Up to 95%
n Die Temperature Monitor
n Adjustable Switching Frequency: 500kHz to 4MHz
n External Frequency Synchronization
n Current Mode Operation for Excellent Line and
Load Transient Response
n 0.6V Reference Allows Low Output Voltages
n User Selectable Burst Mode® Operation or Forced
Continuous Operation
n Output Voltage Tracking and Soft-Start Capability
n Short-Circuit Protected
n Overvoltage Input and Overtemperature Protection
n Power Good Status Outputs
n Low Profile 4mm × 5mm 28-Lead QFN Package
APPLICATIONS
n Distributed Power Systems
n Battery Powered Instruments
n Point of Load Power Supplies
LTC3636/LTC3636-1
Dual Channel 6A, 20V
Monolithic Synchronous
Step-Down Regulator
DESCRIPTION
The LTC®3636/LTC3636-1 is a high efficiency, dual-channel
monolithic synchronous buck regulator using a controlled
on-time current mode architecture, with phase lockable
switching frequency. The operating supply voltage range is
from 3.1V to 20V, making it suitable for lithium-ion battery
stacks as well as point of load power supply applications
from a 12V or 5V input.
The operating frequency is programmable from 500kHz to
4MHz with an external resistor and may be synchronized
to an external clock signal. The high frequency capability
allows the use of small surface mount inductors and
capacitors. The unique constant frequency/controlled
on-time architecture is ideal for high step-down ratio ap-
plications that operate at high frequency while demanding
fast transient response.
The LTC3636/LTC3636-1 can select between forced con-
tinuous mode and high efficiency Burst Mode operation.
The LTC3636 and LTC3636-1 differ in their output voltage
sense range.
L, LT, LTC, LTM, Burst Mode, Silent Switcher, Linear Technology and the Linear logo are
registered trademarks of Analog Devices, Inc. All other trademarks are the property of their
respective owners. Protected by U.S. Patents including 5481178, 5847554, 6580258, 6304066,
6476589, 6774611.
TYPICAL APPLICATION
VIN
10V TO 20V
47µF
x2
VOUT2
5V AT 6A
47µF
22pF
0.1µF
0.56µH
73.2k
10k
RUN1
RUN2
VIN2 VIN1
INTVCC
LTC3636/
LTC3636-1
ITH1
ITH2
RT
TMON
MODE/SYNC
TRACKSS2
TRACKSS1
PGOOD2
PGOOD1
BOOST2
BOOST1
SW2 SW1
VFB2
GND
VFB1
4.7µF
0.1µF
0.56µH
45.3k
10k
47µF
22pF
VOUT1
3.3V AT 6A
3636 TA01a
For more information www.linear.com/LTC3636
Efficiency vs Load Current
100
97
fSW = 2MHz
VIN = 12V
94
91
88
85
82
79
76
73
VOUT = 5V
VOUT = 3.3V
70
0 0.6 1.2 1.8 2.4 3 3.6 4.2 4.8 5.4 6.0
LOAD CURRENT (A)
3636 TA01b
3636f
1
