PD5053-B

GENERAL DESCRIPTION

The PD5036 is a unique pul se w idth m odulator c ontroller, des igned pri marily f or a vari ety of hi gh voltage s inusoidal t elephone ring generat or applications. The PD5036 is suitable for applications requiring up to 6 Watt and provides all necessary controls for implementing advanced overload protection, zero crossing relay switching synchronization, Off-Hook detection, multiple ringing frequency selection and output amplitude adjustment. The power train, designed to be used with the PD5036, is an i solated, open l oop flyback topology. The P D5036 generates a P WM signal, which drives a FE T transistor that switches the primary of a f lyback transformer. This produces a rec tified half sine wave on the secondary side of the transformer. An additional control signal synchronizes a 4-out put transistor bridge, which converts the rectified half sine wave to full sine wave. In order to maintain the ring generator’s input to output isolation, the synchronization signals control the bridge via an opto coupler pair. The controller also includes overload protection, A/D function for measuring the input voltage, and a report signal for indicating over current

FEATURES

♦ Integrated Overload and Short Circuit Protection
♦ Programmable Large Swing Output Amplitude
♦ Digitally Selectable Ringing Frequencies; 16.7/20/25 or 50Hz
♦ Line Regulated Output Amplitude, 45-93Vrms
♦ Overload Protection with Adaptive Output Amplitude
♦ Off-Hook / Overload Detection
♦ Zero Crossing Synchronization Output
♦ Operates from a Single 5V Supply
♦ Open Loop Flyback Topology Reduces Component Count
♦ Total Bill of Material Cost as Low as $5 Including the PD5036
for 2W Ring Generator Applications

APPLICATIONS

♦ 1 to 3 Watt Low Cost Sine Wave Ring Generators
♦ 3 to 6 Watt advanced Sine Wave Ring Generators
♦ Large Variety of Customized Sine Wave Ring Generators
♦ Ring Generator for PBX, PABX, DCL, CTI and Key Systems
♦ Ring Generator for Rural Telephony and Wireless Local Loop Systems
♦ Ring Generator for Short/Long Loop Applications
♦ Ring Generator for Telecom Test Equipment