ZHCSCO8E June 2014 – May 2019 TPS65283 , TPS65283-1
PRODUCTION DATA.
- 1 特性
- 2 應用
- 3 說明
- 4 典型電路原理圖
- 5 修訂歷史記錄
- 6 說明 （續）
- 7 Pin Configuration and Functions
- 8 Specifications
-
9 Detailed Description
- 9.1 Overview
- 9.2 Functional Block Diagram
- 9.3
Feature Description
- 9.3.1 Power Switch Detailed Description
- 9.3.2
Buck DC-DC Converter Detailed Description
- 9.3.2.1 Output Voltage
- 9.3.2.2 Adjustable Switching Frequency
- 9.3.2.3 Synchronization
- 9.3.2.4 Error Amplifier
- 9.3.2.5 Slope Compensation
- 9.3.2.6 Enable and Adjusting UVLO
- 9.3.2.7 Internal V7V Regulator
- 9.3.2.8 Short Circuit Protection
- 9.3.2.9 Bootstrap Voltage (BST) and Low Dropout Operation
- 9.3.2.10 Output Overvoltage Protection (OVP)
- 9.3.2.11 Power Good
- 9.3.2.12 Power-Up Sequencing
- 9.3.2.13 Thermal Performance
- 9.4 Device Functional Modes
- 10Application and Implementation
- 11Power Supply Recommendations
- 12Layout
- 13器件和文檔支持
- 14機械、封裝和可訂購信息
封裝選項
機械數據 (封裝 | 引腳)
- RGE|24
散熱焊盤機械數據 (封裝 | 引腳)
- RGE|24
訂購信息
9.3.2.6 Enable and Adjusting UVLO
The ENx pin provides electrical on and off control of the device. When the ENx pin voltage exceeds the threshold voltage, the device starts operation. If the ENx pin voltage is pulled below the threshold voltage, the regulator stops switching and enters low Iq state. The ENx pin has an internal pullup current source, allowing the user to float the ENx pin for enabling the device. If an application requires controlling the ENx pin, use open-drain or open-collector output logic to interface with the pin. The device implements internal UVLO circuitry on the VIN pin. The device is disabled when the VIN pin voltage falls below the internal VIN UVLO threshold. The internal VIN UVLO threshold has a hysteresis of 500 mV. If an application requires either a higher UVLO threshold on the VIN pin, or a secondary UVLO on the PVIN, in split rail applications, then the user can configure the ENx pin as shown in Figure 27. When using the external UVLO function, TI recommends to set the hysteresis to be greater than 500 mV.
The ENx pin has a small pullup current Ip which sets the default state of the pin to enable when no external components are connected. The pullup current is also used to control the voltage hysteresis for the UVLO function since it increases by Ih once the ENx pin crosses the enable threshold. The UVLO thresholds can be calculated using Equation 4 and Equation 5.
Figure 27. Adjustable VIN Undervoltage Lockout 
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where
- Ih = 3 µA
- Ip = 3.6 µA
- VENRISING = 1.2 V
- VENFALLING = 1.15 V