TPS40190 Datasheet, PDF (1/22 Pages) Texas Instruments – LOW PIN COUNT SYNCHRONOUS BUCK CONTROLLER

TPS40190
www.ti.com
SLUS658A – JULY 2005 – REVISED AUGUST 2005
LOW PIN COUNT SYNCHRONOUS BUCK CONTROLLER
FEATURES
• Input Operating Voltage Range: 4.5 V to 15 V
• Reference 0.591 V ±1%
• Voltage Mode Control
• Internal 5-V Regulator For Internal
Housekeeping, Driver Power and Light
External Loads
• Selectable Short-Circuit Protection
Thresholds
• Pre-Bias Ouput Safe
• Fixed Switching Frequency of 300 kHz
• Internal Soft-Start
• Small 3 mm × 3 mm, 10-Pin SON Package
• Bootstrapped Drivers for N-Channel MOSFET
• Adaptive Anti-Cross Conduction
• Internal Bootstrap Diode
• 1.2-A Drivers for Decreased Switching Loss
APPLICATIONS
• Cable modem CPE
• Digital Set Top Box
• Graphics/Audio Cards
• Entry-level and Mid-Range Servers
DESCRIPTION
The TPS40190 is a cost-optimized synchronous buck
controller that operates from 4.5 V to 15 V nominally,
and implements a fixed frequency voltage mode
power supply. The controller uses an adaptive
anti-cross conduction scheme to prevent both the
high-side and the rectifier MOSFET to be turned on at
the same time, preventing shoot through current in
the two MOSFETs.
The controller also provides a short circuit protection
threshold that is user selectable between one of three
values. The protection level is set with a single
external resistor connected from COMP to GND.
During start-up, the impedance connected to COMP
is sensed, and the information is decoded to select
one of the three thresholds. When the controller
senses an output short circuit, both MOSFETs are
turned off and a timeout period is observed before
attempting to restart. This provides limited power
dissipation in the event of a sustained fault.
The TPS40190 provides strong drivers to minimize
switching losses in the power stage, reducing heat
build up in the MOSFETs and allowing larger
MOSFETs to be used without undue switching time
penalty.
SIMPLIFIED APPLICATION DIAGRAM
VDD
TPS40190
1 ENABLE HDRV 10
SHUTDOWN
2 FB
3 COMP
SW ⁹
BOOT 8
V_OUT
4 VDD
LDRV 7
5 GND
BP5 ⁶
UDG−05059
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 © 2005, Texas Instruments Incorporated