TPS40021-EP_15 Datasheet, PDF (1/37 Pages) Texas Instruments – ENHANCED, LOW-INPUT VOLTAGE-MODE SYNCHRONOUS BUCK CONTROLLER

TPS40021-EP
www.ti.com
SLUSB58 – SEPTEMBER 2012
ENHANCED, LOW-INPUT VOLTAGE-MODE SYNCHRONOUS BUCK CONTROLLER
Check for Samples: TPS40021-EP
FEATURES
1
•2 Operating Input Voltage 2.25 V to 5.5 V
• Output Voltage as Low as 0.7 V
• 1% Internal 0.7-V Reference
• Predictive Gate Drive™ N-Channel MOSFET
Drivers for Higher Efficiency
• Externally Adjustable Soft-Start and Short
Circuit Current Limit
• Programmable Fixed-Frequency 100-kHz to
1-MHz Voltage-Mode Control
• Source or Sink Current
• Quick Response Output Transient
Comparators With Power Good Indication
Provide Output Status
• 16-Pin PowerPAD™ Package
APPLICATIONS
• Networking Equipment
• Telecom Equipment
• Base Stations
• Servers
• DSP Power
SUPPORTS DEFENSE, AEROSPACE,
AND MEDICAL APPLICATIONS
• Controlled Baseline
• One Assembly and Test Site
• One Fabrication Site
• Available in Military (–55°C to 125°C)
Temperature Range ⁽¹⁾
• Extended Product Life Cycle
• Extended Product-Change Notification
• Product Traceability
(1) Custom temperature ranges available
DESCRIPTION
The TPS40021 is a dc-to-dc controller designed for non-isolated synchronous buck regulators, providing
enhanced operation and design flexability through user programmability.
The device utilizes a proprietary Predictive Gate Drive technology to minimize the diode conduction losses
associated with the high-side and synchronous rectifier N-channel MOSFET transistions. The integrated charge
pump with boost circuit provides a regulated 5-V gate drive for both the high side and synchronous rectifier
N-channel MOSFETs. The use of the Predictive Gate Drive technology and charge pump/boost circuits combine
to provide a highly efficient, smaller and less expensive converter.
Design flexibility is provided through user programmability of such functions as: operating frequency, short circuit
current detection thresholds, soft-start ramp time, and external synchronization frequency. The operating
frequency is programmable using a single resistor over a frequency range of 100 kHz to 1 MHz. Higher operating
frequencies yield smaller component values for a given converter power level as well as faster loop closure.
The short circuit current detection is programmable through a single resistor, allowing the short circuit current
limit detection threshold to be easily tailored to accommodate different size (R_DS(on)) MOSFETs. The short circuit
current function provides pulse-by-pulse current limiting during soft-start and short term transient conditions as
well as a fault counter to handle longer duration short circuit current conditions. If a fault is detected the controller
shuts down for a period of time determined by six consecutive soft-start cycles. The controller automatically
retries the output every seventh soft-start cycle.
In addition to determining the off time during a fault condition, the soft-start ramp provides a closed loop
controlled ramp of the converter output during startup. Programmability allows the ramp rate to be adjusted for a
wide variety of output L-C component values.
1
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.
Predictive Gate Drive, PowerPAD are trademarks of Texas Instruments.
2
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