Datasheet TPS62902 (Texas Instruments) - 10

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TPS62902
SLVSFM1 – MARCH 2021
www.ti.com Table 7-1. SmartConfig Setting Table LEVEL OR RESISTOR FB/VSET- OUTPUT MODE (AUTO OR DYNAMIC MODE # F VALUE [Ω] (1) PIN SW (MHz) DISCHARGE FORCED PWM) CHANGE Setting Options by Level
Auto PFM/PWM with 1 GND external FB 2.5 yes AEE active 2 HIGH (>VIH_MODE) external FB 2.5 yes Forced PWM
Setting Options by Resistor
Auto PFM/PWM with 3 7.15 k external FB 2.5 no AEE 4 8.87 k external FB 2.5 no Forced PWM 5 11.0 k external FB 1 yes Auto PFM/PWM 6 13.7 k external FB 1 yes Forced PWM 7 16.9 k external FB 1 no Auto PFM/PWM 8 21.0 k external FB 1 no Forced PWM Auto PFM/PWM with 9 26.1 k VSET 2.5 yes AEE not active 10 32.4 k VSET 2.5 yes Forced PWM Auto PFM/PWM with 11 40.2 k VSET 2.5 no AEE 12 49.9 k VSET 2.5 no Forced PWM 13 61.9 k VSET 1 yes Auto PFM/PWM 14 76.8 k VSET 1 yes Forced PWM 15 95.3 k VSET 1 no Auto PFM/PWM 16 118 k VSET 1 no Forced PWM (1) E96 Resistor Series, 1% Accuracy, Temperature Coefficient better or equal than ±200 ppm/°C
7.3.2 Adjustable VO Operation (External Voltage Divider)
The TPS62902 can be programmed by the MODE/S-CONF pin to either classical configuration where the FB/ VSET pin is used as the feedback pin, sensing VO through an external resistive divider. The TPS62902 can also be programmed to 16 different fixed output voltages. These are set through an external resistor between the FB/VSET pin and GND. In this configuration, VO is directly sensed at the VOS terminal of the device. If the device is configured to operate in classical adjustable VO operation, the FB/VSET pin is used as the feedback pin and needs to sense VO through an external divider network. Figure 7-2 shows the typical schematic for this configuration. VIN VOUT TPS6290x L1 3V t 17V 0.6V t 5.5V VIN SW EN VOS C1 C2 R1 10…F 22…F FB/ SS/TR VSET MODE/ R2 PG S-CONF C3 R3 GND
Figure 7-2. Adjustable VO Operation Schematic
10 Submit Document Feedback Copyright © 2021 Texas Instruments Incorporated 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