36VIN, 34VOUT High Efﬁciency
Buck-Boost DC/DC µModule
n Single Inductor Architecture Allows VIN Above,
Below or Equal to VOUT
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)
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.
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.
30V/2A Buck-Boost DC/DC μModule with 5V to 36V Input
6.5V TO 36V
VIN PLLIN VOUT
Efﬁciency and Power Loss
vs Input Voltage
8 12 16 20 24 28 32 36