TPS40304A_1 Datasheet, PDF (1/20 Pages) Texas Instruments – 3-V TO 20-V INPUT SYNCHRONOUS BUCK CONTROLLER

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TPS40304A
SLUSA30 – FEBRUARY 2010
3-V TO 20-V INPUT SYNCHRONOUS BUCK CONTROLLER
Check for Samples: TPS40304A
FEATURES
1
CONTENTS
• Input Voltage Range from 3 V to 20 V
Device Ratings
2
• Fixed 600-kHz Switching Frequency
Electrical Characteristics
3
• High- and Low-Side FET R_DS(on) Current
Device Information
8
Sensing
Application Information
10
• Programmable Thermally Compensated OCP
Additional References
13
Levels
• Programmable Soft-Start
X
• 591-mV, 1% Reference Voltage
• Voltage Feed-Forward Compensation
• Supports Pre-Biased Output
• Frequency Spread Spectrum
• Thermal Shutdown Protection at 145°C
• 10-Pin 3 mm × 3 mm SON Package with
Ground Connection to Thermal Pad
APPLICATIONS
• POL Modules
• Printer
• Digital TV
• Telecom
DESCRIPTION
The TPS40304A is a cost-optimized synchronous buck controller that operates from 3-V to 20-V input. The
controller implements a voltage-mode control architecture with input-voltage feed-forward compensation that
responds instantly to input voltage change. The switching frequency is fixed at 600 kHz.
Frequency Spread Spectrum feature adds dither to the switching frequency, significantly reducing the peak EMI
noise and making it much easier to comply with EMI standards.
The TPS40304A offers design with a variety of user programmable functions, including soft-start, overcurrent
protection (OCP) levels, and loop compensation.
The OCP level is programmed by a single external resistor connected from LDRV pin to circuit ground. During
initial power on, the TPS40304A enters a calibration cycle, measures the voltage at the LDRV pin, and sets an
internal OCP voltage level. During operation, the programmed OCP voltage level is compared to the voltage drop
across the low-side FET when it is on to determine whether there is an overcurrent condition. The TPS40304A
then enters a shutdown and restart cycle until the fault is removed.
SIMPLIFIED APPLICATION DIAGRAM
V_OUT
SD
V
IN
TPS40304A
5 FB
BOOT 6
4 COMP HDRV 7
3 PGOOD
SW 8
2 EN/SS LDRV/OC 9
1 VDD
GND
PAD
BP 10
V
IN
V_OUT
UDG-10008
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.
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 © 2010, Texas Instruments Incorporated