Datasheet
Table Of Contents
- FEATURES
- APPLICATIONS
- DESCRIPTION
- ABSOLUTE MAXIMUM RATINGS
- THERMAL INFORMATION
- ELECTRICAL CHARACTERISTICS
- DEVICE INFORMATION
- TYPICAL CHARACTERISTICS
- OVERVIEW
- DETAILED DESCRIPTION
- Fixed Frequency PWM Control
- Slope Compensation Output Current
- Pulse Skip Eco-Mode
- Low Dropout Operation and Bootstrap Voltage (BOOT)
- Error Amplifier
- Voltage Reference
- Adjusting the Output Voltage
- Enable and Adjusting Undervoltage Lockout
- Slow Start/Tracking Pin (SS/TR)
- Overload Recovery Circuit
- Sequencing
- Constant Switching Frequency and Timing Resistor (RT/CLK Pin)
- Overcurrent Protection and Frequency Shift
- Selecting the Switching Frequency
- How to Interface to RT/CLK Pin
- Power Good (PWRGD Pin)
- Overvoltage Transient Protection
- Thermal Shutdown
- Small Signal Model for Loop Response
- Simple Small Signal Model for Peak Current Mode Control
- Small Signal Model for Frequency Compensation
- APPLICATION INFORMATION
- Design Guide — Step-By-Step Design Procedure
- Selecting the Switching Frequency
- Output Inductor Selection (LO)
- Output Capacitor
- Catch Diode
- Input Capacitor
- Slow Start Capacitor
- Bootstrap Capacitor Selection
- Under Voltage Lock Out Set Point
- Output Voltage and Feedback Resistors Selection
- Compensation
- Discontinuous Mode and Eco Mode Boundary
- APPLICATION CURVES
- Power Dissipation Estimate
- Layout
- Revision History
2 f
gmps gmea
p
æ ö
æ ö
´ ´ ´
= ´
ç ÷
ç ÷
´
è ø
è ø
co out out
ref
C V
R4
V
1
2 fp
=
´ ´ ´
p
C7
R4 mod
Re´
=
o
C sr
C8
R4
1
sw
f p
=
´ ´
C8
R4
TPS54060
www.ti.com
SLVS919A –JANUARY 2009–REVISED JULY 2010
(45)
(46)
Use the larger value of Equation 47 and Equation 48 to calculate the C8, to set the compensation pole.
Equation 48 yields 8.7pF so the nearest standard of 10pF is used.
(47)
(48)
Discontinuous Mode and Eco Mode Boundary
With an input voltage of 34V, the power supply enters discontinuous mode when the output current is less than
60mA. The power supply enters EcoMode when the output current is lower than 38mA.
The input current draw at no load is 228mA.
APPLICATION CURVES
Figure 51. Load Transient Figure 52. Startup With VIN
Figure 53. Output Ripple CCM Figure 54. Output Ripple, DCM
Copyright © 2009–2010, Texas Instruments Incorporated Submit Documentation Feedback 35
Product Folder Link(s): TPS54060