Part # AN1231 datasheet

Part Manufacturer: ST Microelectronics

ST Microelectronics


Part Details:

AN1231 - APPLICATION NOTE ® VIPower: VIPer50 FOR USB SELF-POWERED HUB A. Bailly - F. Grilli 1 SCOPE The working frequency has been set to about This document presents the results obtained from 50KHz (47.6KHz) using R1=5.1K and a USB off-line power supply designed with C5=8.2nF. VIPer50. The potentiometer P1 could be removed, if output This design is a complete solution for powering adjustment is not necessary to compensate Self-powered 4-ports hubs. voltage drops on the following stages (mainly onPower Distributors). It supplies the USB HUB-controller by deliveringup to 15W (this is more than enough to meet the By removing P1 the value of R8 becomes the USB requirements), 500mA each port. In the case same of R7 (4K7) and a short-circuit must be that a 3.3V is needed, a voltage regulator can be placed between the ends of P1. added. 3.0 MEASUREMENTS 2 SCHEMATIC Unless otherwise noted, all measurements have The USB power supply is based on the standard been made with a high voltage DC source, schematic RCD-snubber-TL431 suggested in the ranging from 100V to 400V. This corresponds to VIPer software. an AC input voltage from 85Vac (considering the The complete schematic is shown in figure 1. voltage ripple of the bulk capacitor) to 280Vac. This circuit operates from 85Vac to 275Vac, withan output current, on 5V, varying from 20mA to3A. Figure 1: Schematic diagram D2 2362.5003A R4 5 ELDOR 7 6.8 2 1N4148 D1 4 DF06720M 6 3 1 2 R3

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AN1231.pdf Datasheet