ZHCSOW9C october 2022 – july 2023 TPSM82912 , TPSM82913 , TPSM82913E
PRODUCTION DATA
- 1
- 1 特性
- 2 应用
- 3 说明
- 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 Smart Config (S-CONF)
- 7.3.2 Device Enable (EN/SYNC)
- 7.3.3 Device Synchronization (EN/SYNC)
- 7.3.4 Spread Spectrum Modulation
- 7.3.5 Output Discharge
- 7.3.6 Undervoltage Lockout (UVLO)
- 7.3.7 Power-Good Output
- 7.3.8 Noise Reduction and Soft-Start Capacitor (NR/SS)
- 7.3.9 Current Limit and Short-Circuit Protection
- 7.3.10 Thermal Shutdown
- 7.4 Device Functional Modes
- 8 Application and Implementation
- 9 Device and Documentation Support
- 10Mechanical, Packaging, and Orderable Information
7.4.3 High Duty Cycle Operation (100% Duty Cycle)
The device offers a low input-to-output voltage differential by entering 100% duty cycle mode. In this mode, the high-side MOSFET switch is constantly turned on. The minimum input voltage to maintain output voltage regulation, depending on the load current and the output voltage level, is calculated as:
Equation 2. 
where
- VOUT(min) is the minimum output voltage the load can accept
- IOUT is the output current
- RDS(ON) is the RDS(ON) of the high-side MOSFET
- RL is the DC resistance of the inductor used,
76 mΩ for the TPSM8291x
To maintain fixed frequency switching, the device requires a minimum off-time of 50 ns (typical), 60 ns (maximum). If this limit is reached during a switching pulse, the device skips switching pulses to maintain output voltage regulation. If the input voltage decreases further, the device enters 100% mode.