UC3907DWTR

Product Summary

The UC3907DWTR is a load share controller which provides all the necessary features to allow multiple-independent-power modules to be paralleled such that each module supplies only its proportionate share to total-load current. This sharing is accomplished by controlling each module’s power stage with a command generated from a voltage-feedback amplifier whose reference can be independently adjusted in response to a common-share-bus voltage. By monitoring the current from each module, the current share bus circuitry determines which paralleled module would normally have the highest output current and, with the designation of this unit as the master, adjusts all the other modules to increase their output current to within 2.5% of that of the master. The current share bus signal interconnecting all the paralleled modules is a low-impedance, noise-insensitive line which will not interfere with allowing each module to act independently should the bus become open or shorted to ground. The UC3907DWTR will reside on the output side of each power module and its overall function is to supply a voltage feedback loop. The specific architecture of the power stage is unimportant. Either switching or linear designs may be utilized and the control signal may be either directly coupled or isolated though the use of an optocoupler or other isolated medium. Other features of the UC3907DWTR include 1.25% accurate reference: a low-loss, fixed-gain current-sense amplifier, a fully differential, high-impedance voltage sensing capability, and a status indicator to designate which module is performing as master.

Parametrics

UC3907DWTR absolute maximum ratings: (1)Supply voltage： 35 V; (2)Opto out voltage： 35 V; (3)Opto out current： 20 mA; (4)Status indicate sink current： 20 mA; (5)C/S input voltage： 35 V; (6)Share bus voltage： –0.3 V to 35 V; (7)Other analog inputs and outputs (zener clamped) maximum forced voltage： –0.3 V to10 V; (8)Other analog inputs and outputs (zener clamped) maximum forced current： ±10 mA; (9)Ground amp sink current： 50 mA; (10)Pins 1, 9, 12, 15 sink current： 20 mA; (11)Storage temperature range, Tstg： –65℃ to 150℃; (12)Junction temperature, TJ： –55℃ to 150℃; (13)Lead temperature (solder 10 seconds)： 300℃.

Features

UC3907DWTR features: (1)Fully Differential High Impedance Voltage Sensing; (2)Accurate Current Amplifier for Precise Current Sharing; (3)Opto Coupler Driving Capability; (4)1.25% Trimmed Reference; (5)Master Status Indication; (6)4.5-V to 35-V Operation.

Diagrams