ZHCSBT5C October 2013 – January 2017 TPS54541
PRODUCTION DATA.
- 1 特性
- 2 應用
- 3 說明
- 4 修訂歷史記錄
- 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 Fixed-Frequency PWM Control
- 7.3.2 Slope Compensation Output Current
- 7.3.3 Pulse Skip Eco-mode
- 7.3.4 Low Dropout Operation and Bootstrap Voltage (BOOT)
- 7.3.5 Error Amplifier
- 7.3.6 Adjusting the Output Voltage
- 7.3.7 Enable and Adjusting Undervoltage Lockout
- 7.3.8 Soft-Start/Tracking Pin (SS/TR)
- 7.3.9 Sequencing
- 7.3.10 Constant Switching Frequency and Timing Resistor (RT/CLK) Pin)
- 7.3.11 Synchronization to RT/CLK Pin
- 7.3.12 Maximum Switching Frequency
- 7.3.13 Accurate Current Limit Operation
- 7.3.14 Power Good (PWRGD Pin)
- 7.3.15 Overvoltage Protection
- 7.3.16 Thermal Shutdown
- 7.3.17 Small-Signal Model for Loop Response
- 7.3.18 Simple Small-Signal Model for Peak-Current-Mode Control
- 7.3.19 Small Signal Model for Frequency Compensation
- 7.4 Device Functional Modes
-
8 Application and Implementation
- 8.1 Application Information
- 8.2
Typical Applications
- 8.2.1
Buck Converter for 6-V to 42-V Input and 3.3-V at 5-A Output
- 8.2.1.1 Design Requirements
- 8.2.1.2
Detailed Design Procedure
- 8.2.1.2.1 Custom Design with WEBENCH® Tools
- 8.2.1.2.2 Selecting the Switching Frequency
- 8.2.1.2.3 Output Inductor Selection (LO)
- 8.2.1.2.4 Output Capacitor
- 8.2.1.2.5 Catch Diode
- 8.2.1.2.6 Input Capacitor
- 8.2.1.2.7 Slow-Start Capacitor
- 8.2.1.2.8 Bootstrap Capacitor Selection
- 8.2.1.2.9 Undervoltage Lockout Set Point
- 8.2.1.2.10 Output Voltage and Feedback Resistors Selection
- 8.2.1.2.11 Compensation
- 8.2.1.2.12 Power Dissipation Estimate
- 8.2.1.2.13 Safe Operating Area
- 8.2.1.2.14 Discontinuous Conduction Mode and Eco-mode Boundary
- 8.2.1.3 Application Curves
- 8.2.2 Inverting Buck-Boost Topology for Positive Input to Negative Output
- 8.2.3 Split-Rail Topology for Positive Input to Negative and Positive Output
- 8.2.1
Buck Converter for 6-V to 42-V Input and 3.3-V at 5-A Output
- 9 Power Supply Recommendations
- 10Layout
- 11器件和文檔支持
- 12機械、封裝和可訂購信息
5 Pin Configuration and Functions
DPR Package
10-Pin WSON With Exposed Thermal Pad
Top View
Pin Functions
| PIN | I/O | DESCRIPTION | ||
|---|---|---|---|---|
| NAME | NO. | |||
| BOOT | 1 | O | A bootstrap capacitor is required between BOOT and SW. If the voltage on this capacitor is below the minimum required to operate the high-side MOSFET, the gate drive is switched off until the capacitor is refreshed. | |
| COMP | 7 | O | Error amplifier output and input to the output switch current (PWM) comparator. Connect frequency compensation components to this pin. | |
| EN | 3 | I | Enable pin, with an internal pullup current source. Pull below 1.2 V to disable. Float to enable. Adjust the input undervoltage lockout with two resistors. See the Enable and Adjusting Undervoltage Lockout section. | |
| FB | 6 | I | Inverting input of the transconductance (gm) error amplifier. | |
| GND | 8 | – | Ground | |
| PWRGD | 10 | O | Power Good is an open drain output that asserts low if the output voltage is out of regulation due to thermal shutdown, dropout, over-voltage or EN shut down. | |
| RT/CLK | 5 | I | Resistor Timing and External Clock. An internal amplifier holds this pin at a fixed voltage when using an external resistor to ground to set the switching frequency. If the pin is pulled above the PLL upper threshold, a mode change occurs and the pin becomes a synchronization input. The internal amplifier is disabled and the pin is a high impedance clock input to the internal PLL. If clocking edges stop, the internal amplifier is re-enabled and the operating mode returns to resistor frequency programming. | |
| SS/TR | 4 | I | Soft-start and Tracking. An external capacitor connected to this pin sets the output rise time. Because the voltage on this pin overrides the internal reference, SS/TR can be used for tracking and sequencing. | |
| SW | 9 | O | The source of the internal high-side power MOSFET and switching node of the converter. | |
| VIN | 2 | I | Input supply voltage with 4.5-V to 42-V operating range. | |
| Thermal Pad | 11 | – | The GND pin must be electrically connected to the exposed pad on the printed circuit board for proper operation. | |