Datasheet TPS62902 (Texas Instruments) - 9

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TPS62902 www.ti.com
SLVSFM1 – MARCH 2021
7.3 Feature Description 7.3.1 Mode Selection and Device Configuration MODE/S-CONF
With MODE/S-CONF (SmartConfig), this device features an input with two functions. It can be used to customize the device behavior in two ways: • Select the device mode (FPWM or auto PFM/PWM with AEE operation) traditionally with a HIGH- or LOW- level. • Select the device configuration (switching frequency, internal/external feedback, output discharge, and PFM/PWM mode) by connecting a single resistor to the MODE/S-CONF pin. The device interprets this pin during the start-up sequence after the internal OTP readout and before it starts switching in soft start. If the device reads a HIGH- or LOW-level, the Dynamic Mode Change is active and PFM/PWM mode can be changed during operation. If the device reads a resistor value, there is no further interpretation during operation and device mode or other configurations cannot be changed afterwards. spacing
Note
The MODE/S-CONF pin must not be left floating. Connect the pin high, low, or to a resistor to configure the device according to Table 7-1. spacing EN & UVLO Precise PG -> High OTP S-CONF VSET Enable Softstart Switching Readout Readout Readout detection Operation No interpretation of Resistor-to-Digitial MODE/S-CONF or VSET readout & MODE-Pin toggling detection interpretation VOUT
Figure 7-1. Interpretation of S-CONF and VSET Flow
Copyright © 2021 Texas Instruments Incorporated Submit Document Feedback 9 Product Folder Links: TPS62902 Document Outline 1 Features 2 Applications 3 Description Table of Contents 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 Electrical Characteristics 6.6 Typical Characteristics 7 Detailed Description 7.1 Overview 7.2 Functional Block Diagram 7.3 Feature Description 7.3.1 Mode Selection and Device Configuration MODE/S-CONF 7.3.2 Adjustable VO Operation (External Voltage Divider) 7.3.3 Setable VO Operation (VSET and Internal Voltage Divider) 7.3.4 Soft Start / Tracking (SS/TR) 7.3.5 Smart Enable with Precise Threshold 7.3.6 Power Good (PG) 7.3.7 Undervoltage Lockout (UVLO) 7.3.8 Current Limit And Short Circuit Protection 7.3.9 Thermal Shutdown 7.4 Device Functional Modes 7.4.1 Pulse Width Modulation (PWM) Operation 7.4.2 AEE (Automatic Efficiency Enhancement) 7.4.3 Power Save Mode Operation (Auto PFM/PWM) 7.4.4 100% Duty-Cycle Operation 7.4.5 Output Discharge Function 7.4.6 Starting into a Pre-Biased Load 8 Application and Implementation 8.1 Application Information 8.2 Typical Application with Adjustable Output Voltage 8.2.1 Design Requirements 8.2.2 Detailed Design Procedure 8.2.2.1 Custom Design With WEBENCH® Tools 8.2.2.2 Programming the Output Voltage 8.2.2.3 External Component Selection 8.2.2.4 Inductor Selection 8.2.2.5 Capacitor Selection 8.2.2.5.1 Output Capacitor 8.2.2.5.2 Input Capacitor 8.2.2.5.3 Soft-Start Capacitor 8.2.2.6 Tracking Function 8.2.2.7 Output Filter and Loop Stability 8.2.3 Application Curves 8.2.4 Typical Application with Setable VO using VSET 8.2.4.1 Design Requirements 8.2.4.2 Detailed Design Procedure 8.2.4.3 Application Curves 8.3 System Examples 8.3.1 LED Power Supply 8.3.2 Powering Multiple Loads 8.3.3 Voltage Tracking 8.3.4 Precise Soft-Start Timing 9 Power Supply Recommendations 10 Layout 10.1 Layout Guidelines 10.2 Layout Example 10.2.1 Thermal Considerations 11 Device and Documentation Support 11.1 Device Support 11.1.1 Development Support 11.1.1.1 Custom Design With WEBENCH® Tools 11.2 Receiving Notification of Documentation Updates 11.3 Support Resources 11.4 Trademarks 11.5 Electrostatic Discharge Caution 11.6 Glossary 12 Mechanical, Packaging, and Orderable Information