UCD74120
www.ti.com
SLUSAV8 –OCTOBER 2012
High-Current, Synchronous Buck Power Stage
Check for Samples: UCD74120
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FEATURES
DESCRIPTION
UCD74120 is a multi-chip module integrating a driver
device and two NexFET power MOSFETs into a
thermally enhanced compact, 5 mm × 7 mm, QFN
package. A 25-A output current capability makes the
device suitable for powering DSP and ASIC. The
device is designed to complement digital or analog
PWM controllers. The PWM input of the driver device
is 3-state compatible. Two driver circuits provide high
charge and discharge current for the high-side N-
channel FET switch and the low-side N-channel FET
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Integrates Synchronous Buck Driver and
NexFET™ Power MOSFETS for High Power
Density and High Efficiency
•
25-A Output Current Capability for DSP and
ASIC
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4.7-V to 14-V Input Voltage Range
Operational up to 2 MHz Switching Frequency
Built-In High-Side Current Protection
synchronous rectifier in
converter.
a
synchronous buck
DCR Current Sensing for Overcurrent
Protection and Output Current Monitoring
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Voltage Proportional to Load Current Monitor
Output
Output current is measured and monitored by a
precision current sensing amplifier that processes the
voltage present across an external current sense
element. The amplified signal is available for use by
the PWM controller on the IMON pin. On-board
comparators monitor the voltage across the high-side
switch and the voltage across the external current
sense element to safeguard the power stage from
sudden high-current loads. Blanking delay is set for
the high-side comparator by a single resistor in order
to avoid false reports coincident with switching edge
noise. In the even of a high-side fault or an
overcurrent fault, the high-side FET is turned off and
the fault flag (FLT) is asserted to alert the PWM
controller.
Tri-state PWM Input for Power Stage
Shutdown
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UVLO Housekeeping Circuit
Integrated Thermal Shutdown
40-Pin, 5 mm x 7 mm, PQFN PowerStack™
Package
APPLICATIONS
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Digital or Analog POL Power Modules
High Power Density DC-DC Converters for
Telecom and Networking Applications
APPLICATION DIAGRAM
From
Controller
SRE
FLT
PWM
VDD
To
Controller
HS_SNS
IMON
VIN
VIN
SRE_MD
BOOT
VOUT
BP3 UCD74120
SW
CSP
CSN
ILIM
RDLY
AVGG
VGG
VGG_DIS AGND
PGND
UDG-11281
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Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
NexFET, PowerStack are trademarks of Texas Instruments.
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PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2012, Texas Instruments Incorporated