ZHCSQ77B February 2023 – June 2024 TPS25948
PRODUCTION DATA
- 1
- 1 特性
- 2 應用
- 3 說明
- 4 Device Comparison Table
- 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 Undervoltage Lockout (UVLO and UVP)
- 7.3.2 Overvoltage Lockout (OVLO)
- 7.3.3 Inrush Current, Overcurrent, and Short Circuit Protection
- 7.3.4 Analog Load Current Monitor
- 7.3.5 Reverse Current Protection
- 7.3.6 Overtemperature Protection (OTP)
- 7.3.7 Fault Response and Indication (FLT)
- 7.3.8 Supply Good Indication (SPLYGD/SPLYGD)
- 7.4 Device Functional Modes
- 8 Application and Implementation
- 9 Device and Documentation Support
- 10Revision History
- 11Mechanical, Packaging, and Orderable Information
8.4 Active ORing
A typical redundant power supply configuration is shown in Figure 8-11 below. Schottky ORing diodes have been popular for connecting parallel power supplies, such as parallel operation of wall adapter with a battery or a hold-up storage capacitor. The disadvantage of using ORing diodes is high voltage drop and associated power loss. The TPS25948xx with integrated, low-ohmic, back-to-back FETs provide a simple and efficient solution. Figure 8-11 below shows the Active ORing implementation using TPS259480x devices.
Figure 8-11 Two Devices, Active ORing ConfigurationThe linear ORing mechanism in TPS25948xx ensures that there's no reverse current flowing from one power source to the other during fast or slow ramp of either supply.
The following waveform illustrates the active ORing behavior when the supply rails are being ramped up sequentially.
Figure 8-12 Active ORing Response
Figure 8-13 Active ORing ResponseWhen the bus voltages (IN1 and IN2) are matched, device in each path sees a forward voltage drop and is ON delivering the load current. During this period, current is shared between the rails in the ratio of differential voltage drop across each device.
In addition to supply ORing, the devices protect the system from overvoltage, excessive inrush current, overload and short-circuit faults at all times.