SLUSDW9A June 2020 – June 2020 TPS51215A
PRODUCTION DATA.
- 1 Features
- 2 Applications
- 3 Description
- 4 Revision History
- 5 Pin Configuration and Functions
- 6 Specifications
-
7 Detailed Description
- 7.1 Overview
- 7.2 Functional Block Diagram
- 7.3
Feature Description
- 7.3.1 Switch Mode Power Supply Control
- 7.3.2 VREF, V0, V1, V2, V3 and Output Voltage
- 7.3.3 Soft-Start and Power Good
- 7.3.4 SLEW and VID Function
- 7.3.5 MODE Pin Configuration
- 7.3.6 Light-Load Operation
- 7.3.7 Out-of-Bound Operation
- 7.3.8 Current Sensing and Overcurrent Protection
- 7.3.9 Overvoltage and Undervoltage Protection
- 7.3.10 V5IN Undervoltage Lockout Protection
- 7.3.11 Thermal Shutdown
- 7.4 D-CAP2 Control Mode
- 8 Application and Implementation
-
9 Typical Applications
- 9.1 Design Requirements
- 9.2
Detailed Design Procedure
- 9.2.1 Step One: Determine the Specifications
- 9.2.2 Step Two: Determine System Parameters
- 9.2.3 Step Three: Determine Inductor Value and Choose Inductor
- 9.2.4 Step Four: Set the Output Voltages
- 9.2.5 Step Five: Calculate SLEW Capacitance
- 9.2.6 Step Six
- 9.2.7 Step Seven: Determine the Output Capacitance
- 9.2.8 Step Eight: Select Decoupling and Peripheral Components
- 9.3 Application Examples
- 9.4 Application Curves of Design 1
- 10Power Supply Recommendations
- 11Layout
- 12Device and Documentation Support
- 13Mechanical, Packaging, and Orderable Information
封裝選項
機械數(shù)據(jù) (封裝 | 引腳)
- RUK|20
散熱焊盤機械數(shù)據(jù) (封裝 | 引腳)
- RUK|20
訂購信息
7.3.3 Soft-Start and Power Good
Prior to asserting EN high, the power stage conversion voltage and V5IN voltage should be ready. When EN is asserted high, TPS51215A provides soft start to suppress in-rush current during start-up. The soft start action is achieved by an internal SLEW current of 4.5 µA (typ) sourcing into a external MLCC capacitor connected from SLEW pin to GND.
Use Equation 1 to determine the soft-start timing.
where
- CSLEW is the soft start capacitance
- VOUT is the output voltage
- ISLEW is the internal 4.5-µA current source
The TPS51215A has a open-drain PowerGood output pin that indicates the Vout voltage is within the target range. The target voltage window and transition delay times of the PGOOD comparator are ±8% (typ) and 1-ms delay for assertion from low to high, and ±16% (typ) and 0.2-µs delay for de-assertion from high to low during operation.