DESCRIPTION
The TK75002 monitors the output voltage of a power supply, generates an error signal, and transmits the error signal across an isolation barrier using a small pulse transformer. In conjunction with the pulse transformer, it replaces the TL431/opto-coupler combination and eliminates the undesirable zero created in the feedback loop by that combination. The transformer is driven with pulse amplitude modulation in a free-running oscillator configuration. The period of oscillation is proportional to the inductance of the pulse transformer. The magnitude of the voltage pulse is internally limited so that the pulse transformer design need not be changed for various output voltages.
The TK75002 is available in an 8-pin DIP package.

FEATURES
■ Eliminates Opto-coupler from Feedback Loop
■ Replaces TL431 and Eliminates Parasitic Zero
■ Pulse Transformer Driver
■ Same Transformer for Any Output Voltage
■ Peak Current Controlled
■ Automatic Volt-Second Balancing
■ Self-running Oscillator
■ Hi-performance Op-amp & Bandgap Reference
■ Functionally Integrated & Simplified 5-pin Design

APPLICATIONS
■ Power Supplies with Primary-Side Controller
■ Low Isolation-Barrier Capacitance Equipment
■ Instrumentation
■ Industrial Process Control
■ Test Equipment
■ Data Acquisition