LTM4609 Datasheet, PDF (1/24 Pages) Linear Technology – 36VIN, 34VOUT High Effi ciency Buck-Boost DC/DC μModule

LTM4609
36V_IN, 34V_OUT High Efficiency
Buck-Boost DC/DC µModule
FEATURES
n _{Single Inductor Architecture Allows VIN Above,}
Below or Equal to V_OUT
n _{Wide VIN Range: 4.5V to 36V}
n _{Wide VOUT Range: 0.8V to 34V}
n _{IOUT: 4A DC (10A DC in Buck Mode)}
n _{Up to 98% Efficiency}
n _{Current Mode Control}
n _{Power Good Output Signal}
n _{Phase-Lockable Fixed Frequency: 200kHz to 400kHz}
n _{Ultra-Fast Transient Response}
n _{Current Foldback Protection}
n _{Output Overvoltage Protection}
n _{Small, Low Profile Surface Mount LGA Package}
(15mm × 15mm × 2.8mm)
APPLICATIONS
n _{Telecom, Servers and Networking Equipment}
n _{Industrial and Automotive Equipment}
n _{High Power Battery-Operated Devices}
L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
μModule is a trademark of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
DESCRIPTION
The LTM^®4609 is a high efficiency switching mode buck-
boost power supply. Included in the package are the
switching controller, power FETs and support components.
Operating over an input voltage range of 4.5V to 36V, the
LTM4609 supports an output voltage range of 0.8V to
34V, set by a resistor. This high efficiency design delivers
up to 4A continuous current in boost mode (10A in buck
mode). Only the inductor, sense resistor, bulk input and
output capacitors are needed to finish the design.
The low profile package enables utilization of unused space
on the bottom of PC boards for high density point of load
regulation. The high switching frequency and current
mode architecture enable a very fast transient response
to line and load changes without sacrificing stability. The
LTM4609 can be frequency synchronized with an external
clock to reduce undesirable frequency harmonics.
Fault protection features include overvoltage and foldback
current protection. The DC/DC μModule™ is offered in a
small thermally enhanced 15mm × 15mm × 2.8mm LGA
package. The LTM4609 is Pb-free and RoHS compliant.
TYPICAL APPLICATION
30V/2A Buck-Boost DC/DC μModule with 5V to 36V Input
V_IN
6.5V TO 36V
10μF
50V
ON/OFF
0.1μF
CLOCK SYNC
V_IN PLLIN _VOUT
FCB
RUN LTM4609
SW1
SW2
R_SENSE
SENSE⁺
SS
SGND
SENSE^–
PGND
V_FB
5.6μH
R2
15mΩ
s2
2.74k
10μF ⁺
50V
330μF
50V
V_OUT
30V
2A
4609 TA01a
Efficiency and Power Loss
vs Input Voltage
99
6
98
5
97
4
96
95
3
94
2
93
1
92
EFFICIENCY
POWER LOSS
91
0
8 12 16 20 24 28 32 36
V_IN (V)
4609 TA01b
4609f
1