TPS54325 Datasheet, PDF (1/20 Pages) Texas Instruments – 4.5-V to 18-V, 3-A OUTPUT SYNCHRONOUS STEP DOWN SWITCHER WITH INTEGRATED FET (SWIFT™)

TPS54325
www.ti.com ................................................................................................................................................................ SLVS932A – MAY 2009 – REVISED JULY 2009
4.5-V to 18-V, 3-A OUTPUT SYNCHRONOUS STEP DOWN
SWITCHER WITH INTEGRATED FET (SWIFT™)
FEATURES
1
•23 D-CAP2™ Mode Enables Fast Transient
Response
• Low Output Ripple and Allows Ceramic Output
Capacitor
• Wide V_CC Input Voltage Range: 4.5 V to 18 V
• Wide V_IN Input Voltage Range: 2.0 V to 18 V
• Output Voltage Range: 0.76 V to 5.5 V
• Highly Efficient Integrated FET’s Optimized
for Lower Duty Cycle Applications
- 120 mΩ (High Side) and 70 mΩ (Low Side)
• High Efficiency, less than 10 µA at shutdown
• High Initial Bandgap Reference Accuracy
• Adjustable Soft Start
• Pre-Biased Soft Start
• 700-kHz Switching Frequency (f_SW)
• Cycle By Cycle Over Current Limit
• Power Good Output
APPLICATIONS
• Wide Range of Applications for Low Voltage
System
– Digital TV Power Supply
– High Definition Blue-ray Disc™ Players
– Networking Home Terminal
– Digital Set Top Box (STB)
DESCRIPTION
The TPS54325 is an adaptive on-time D-CAP2™
mode synchronous buck converter. The TPS54325
enables system designers to complete the suite of
various end equipment’s power bus regulators with a
cost effective, low component count, low standby
current solution. The main control loop for the
TPS54325 uses the D-CAP2™ mode control which
provides a very fast transient response with no
external components. The TPS54325 also has a
proprietary circuit that enables the device to adapt to
both low equivalent series resistance (ESR) output
capacitors, such as POSCAP or SP-CAP, and
ultra-low ESR ceramic capacitors. The device
operates from 4.5-V to 18-V VCC input , and from
2.0-V to 18-V VIN input power supply voltage. The
output voltage can be programmed between 0.76 V
and 5.5 V. The device also features an adjustable
slow start time and a power good function. The
TPS54325 is available in the 14 pin HTSSOP
package, and designed to operate from –40 °C to 85
°C.
VIN
C4
SGND
PGND
V_OUT (50 mV / div)
R1
8.42 kΩ
R2
22 kΩ
SGND
PGND
1 VO
VCC 14
2 VFB
VIN ¹³
C5
1 µF
3
VREG5
4 SS
C6
5 GND
POWERPAD VBST 12
TPS54325
PWP
SW2 11
HTSSOP14
SW1 10
SGND
Output
Signal
6 PG
PGND2 9
Input
Signal
7 EN
PGND1 8
C2
0.1 µF
L1
1.5 µH
C3
10 µF
VO1
1.05 V / 3 A
C1
PGND
100 µs / div
I_OUT (2 A / div)
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.
SWIFT, D-CAP2, PowerPAD are trademarks of Texas Instruments.
2
Blue-ray Disc is a trademark of Blu-ray Disc.
3
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 © 2009, Texas Instruments Incorporated