SLVSDP3
December 2016
TPS54262-EP
PRODUCTION DATA.
1
Features
2
Applications
3
Description
4
Revision History
5
Pin Configuration and Functions
6
Specifications
6.1
Absolute Maximum Ratings
6.2
ESD Ratings
6.3
Recommended Operating Conditions
6.4
Thermal Information
6.5
DC Electrical Characteristics
6.6
Typical Characteristics
7
Detailed Description
7.1
Overview
7.2
Functional Block Diagram
7.3
Feature Description
7.3.1
Unregulated Input Voltage
7.3.2
Regulated Output Voltage
7.3.3
Regulation and Feedback Voltage
7.3.4
Enable and Shutdown
7.3.5
Soft Start
7.3.6
Oscillator Frequency
7.3.6.1
Selecting the Switching Frequency
7.3.6.2
Synchronization With External Clock
7.3.7
Slew Rate Control
7.3.8
Reset
7.3.9
Reset Delay
7.3.10
Reset Threshold and Undervoltage Threshold
7.3.11
Overvoltage Supervisor
7.3.12
Noise Filter on RST_TH and OV_TH Terminals
7.3.13
Boot Capacitor
7.3.14
Short Circuit Protection
7.3.15
Overcurrent Protection
7.3.16
Internal Undervoltage Lockout (UVLO)
7.3.17
Thermal Shutdown (TSD)
7.3.18
Loop Control Frequency Compensation - Type 3
7.3.18.1
Bode Plot of Converter Gain
7.4
Device Functional Modes
7.4.1
Active Mode Continuous Conduction Mode (CCM)
7.4.2
Active Mode Discontinuous Conduction Mode (DCM)
7.4.3
Pulse Skip Mode (PSM)
7.4.4
Low-Power Mode (LPM)
7.4.5
Hysteretic Mode
7.4.6
Output Tolerances in Different Modes of Operation
8
Application and Implementation
8.1
Application Information
8.2
Typical Application
8.2.1
Design Requirements
8.2.2
Detailed Design Procedure
8.2.2.1
Component Selection
8.2.2.1.1
Input Capacitors (C1, C11)
8.2.2.1.2
Output Capacitor (C4, C12)
8.2.2.1.3
Soft-Start Capacitor (C6)
8.2.2.1.4
Bootstrap Capacitor (C3)
8.2.2.1.5
Power-On Reset Delay (PORdly) Capacitor (C2)
8.2.2.1.6
Output Inductor (L1)
8.2.2.1.7
Flyback Schottky Diode (D2)
8.2.2.1.8
Resistor to Set Slew Rate (R7)
8.2.2.1.9
Resistor to Select Switching Frequency (R8)
8.2.2.1.10
Resistors to Select Output Voltage (R4, R5)
8.2.2.1.11
Resistors to Set Undervoltage, Overvoltage, and Reset Thresholds (R1, R2, R3)
8.2.2.1.11.1
Overvoltage Resistor Selection
8.2.2.1.11.2
Reset Threshold Resistor Selection
8.2.2.1.11.3
Undervoltage Threshold for Low-Power Mode and Load Transient Operation
8.2.2.1.12
Low-Power Mode (LPM) Threshold
8.2.2.1.13
Enable Pin Pull-Up Resistor (R11) and Voltage Divider Resistor (R10)
8.2.2.1.14
Pull-Up Resistor (R12) at RST Pin
8.2.2.1.15
Type 3 Compensation Components (R5, R6, R9, C5, C7, C8)
8.2.2.1.15.1
Resistors
8.2.2.1.15.2
Capacitors
8.2.2.1.16
Noise Filter on RST_TH and OV_TH Terminals (C9, C10)
8.2.2.2
Design Example 1
8.2.2.2.1
Calculate the Switching Frequency (fsw)
8.2.2.2.2
Calculate the Ripple Current (IRipple)
8.2.2.2.3
Calculate the Inductor Value (L1)
8.2.2.2.4
Calculate the Output Capacitor and ESR (C4)
8.2.2.2.4.1
Calculate Capacitance
8.2.2.2.4.2
Calculate ESR
8.2.2.2.5
Calculate the Feedback Resistors (R4, R5)
8.2.2.2.6
Calculate Type 3 Compensation Components
8.2.2.2.6.1
Resistances (R6, R9)
8.2.2.2.6.2
Capacitors (C5, C8, C7)
8.2.2.2.7
Calculate Soft-Start Capacitor (C6)
8.2.2.2.8
Calculate Bootstrap Capacitor (C3)
8.2.2.2.9
Calculate Power-On Reset Delay Capacitor (C2)
8.2.2.2.10
Calculate Input Capacitor (C1, C11)
8.2.2.2.11
Calculate Resistors to Control Slew Rate (R7)
8.2.2.2.12
Resistors to Select Undervoltage, Overvoltage and Reset Threshold Values (R1, R2, R3)
8.2.2.2.13
Diode D1 and D2 Selection
8.2.2.2.14
Noise Filter on RST_TH and OV_TH Terminals (C9 and C10)
8.2.2.2.15
Power Budget and Temperature Estimation
8.2.2.3
Design Example 2
8.2.2.3.1
Calculate the Switching Frequency (fsw)
8.2.2.3.2
Calculate the Ripple Current (IRipple)
8.2.2.3.3
Calculate the Inductor Value (L1)
8.2.2.3.4
Calculate the Output Capacitor and ESR (C4, C12)
8.2.2.3.4.1
Calculate Capacitance
8.2.2.3.4.2
Calculate ESR
8.2.2.3.5
Calculate the Feedback Resistors (R4, R5)
8.2.2.3.6
Calculate Type 3 Compensation Components
8.2.2.3.6.1
Resistances (R6, R9)
8.2.2.3.6.2
Capacitors (C5, C8, C7)
8.2.2.3.7
Calculate Soft-Start Capacitor (C6)
8.2.2.3.8
Calculate Bootstrap Capacitor (C3)
8.2.2.3.9
Calculate Power-On Reset Delay Capacitor (C2)
8.2.2.3.10
Calculate Input Capacitor (C1, C11)
8.2.2.3.11
Calculate Resistors to Control Slew Rate (R7)
8.2.2.3.12
Resistors to Select Undervoltage, Overvoltage and Reset Threshold Values (R1, R2, R3)
8.2.2.3.13
Diode D1 and D2 Selection
8.2.2.3.14
Noise Filter on RST_TH and OV_TH Terminals (C9 and C10)
8.2.2.3.15
Power Budget and Temperature Estimation
8.2.3
Application Curves
9
Power Supply Recommendations
10
Layout
10.1
Layout Guidelines
10.2
Layout Example
10.3
Power Dissipation and Temperature Considerations
11
Device and Documentation Support
11.1
Receiving Notification of Documentation Updates
11.2
Community Resources
11.3
Trademarks
11.4
Electrostatic Discharge Caution
11.5
Glossary
12
Mechanical, Packaging, and Orderable Information
Package Options
Mechanical Data (Package|Pins)
PWP|20
MHTS001G
Thermal pad, mechanical data (Package|Pins)
PWP|20
PPTD122P
Orderable Information
slvsdp3_oa
4
Revision History
DATE
REVISION
NOTES
December 2016
*
Initial release.