Receive circuit for use in a power converter

Abstract

A multi-die isolated integrated circuit controller includes a magnetically coupled communication link, a transmitter circuit coupled to the magnetically coupled communication link, and a receiver circuit coupled to the magnetically coupled communication link. The transmitter circuit is galvanically isolated from the receiver circuit. The transmitter circuit is coupled to send an input pulse to the receiver circuit by way of the magnetically coupled communication link. The receiver circuit is coupled to receive a receiver voltage by way of the magnetically coupled communication link to generate an output voltage in response to the receiver voltage and a threshold voltage.

What is claimed is: 
     
         1 . A multi-die isolated integrated circuit controller, comprising:
 a magnetically coupled communication link;   a transmitter circuit coupled to the magnetically coupled communication link; and   a receiver circuit coupled to the magnetically coupled communication link, wherein the transmitter circuit is galvanically isolated from the receiver circuit, wherein the transmitter circuit is coupled to send an input pulse to the receiver circuit by way of the magnetically coupled communication link, wherein the receiver circuit is coupled to receive a receiver voltage by way of the magnetically coupled communication link to generate an output voltage in response to the receiver voltage and a threshold voltage.   
     
     
         2 . The multi-die isolated integrated circuit controller of  claim 1 , further comprising a secondary die, wherein the transmitter circuit is included in the secondary die. 
     
     
         3 . The multi-die isolated integrated circuit controller of  claim 1 , further comprising a primary die, wherein the receiver circuit is included in the primary die. 
     
     
         4 . The multi-die isolated integrated circuit controller of  claim 1 , wherein the input pulse comprises a transmitter current that varies over time. 
     
     
         5 . The multi-die isolated integrated circuit controller of  claim 4 , wherein the magnetically coupled communication link comprises a conductive loop. 
     
     
         6 . The multi-die isolated integrated circuit controller of  claim 5 , wherein the transmitter current induces a transmitter voltage across the conductive loop. 
     
     
         7 . The multi-die isolated integrated circuit controller of  claim 1 , wherein the transmitter circuit is coupled to send consecutive pulses that are separated by a time period to the receiver circuit. 
     
     
         8 . The multi-die isolated integrated circuit controller of  claim 7 , wherein the time period has a length determined by a switching period of a switch mode power converter. 
     
     
         9 . The multi-die isolated integrated circuit controller of  claim 1 , wherein the receiver circuit is coupled to generate a logic low output voltage in response to the receiver voltage being less than the threshold voltage. 
     
     
         10 . The multi-die isolated integrated circuit controller of  claim 1 , wherein the receiver circuit is coupled to generate a logic high output voltage in response to the receiver voltage being greater than the threshold voltage. 
     
     
         11 . The multi-die isolated integrated circuit controller of  claim 1 , wherein the multi-die isolated integrated circuit controller is included in a monolithic package. 
     
     
         12 . A method of controlling a receiver circuit for a power converter controller, comprising:
 receiving an input pulse representative of a state of a power converter;   amplifying the input pulse and generating a first output;   amplifying the first output and generating a second output;   generating an output signal in response to comparing the second output to a threshold voltage; and   resetting the first output and the second output to prepare the receiver circuit to receive and amplify subsequent input pulses.   
     
     
         13 . The method of  claim 12 , further comprising receiving the output signal and generating a pre-bias control signal in response to the output signal to reset the first output and the second output. 
     
     
         14 . A receiver circuit for use in a power converter controller, comprising:
 a first amplifier comprising a differential amplifier having a first transistor and a second transistor coupled together at their bases, wherein the first transistor is coupled to receive an input pulse at an emitter of the first transistor and generate a first output;   a second amplifier coupled to receive the first output to compare a gate-source voltage of a second transistor to a threshold voltage, wherein the second transistor is coupled to be turned ON in response to the gate-source voltage and the threshold voltage; and   an output circuit coupled to the second amplifier to generate an output signal.   
     
     
         15 . The receiver circuit of  claim 14 , further comprising:
 a delay circuit coupled to receive the output signal, wherein the delay circuit is coupled to generate a pre-bias control signal responsive to the output signal;   a first pre-bias circuit coupled to an output of the first amplifier, and coupled to receive the pre-bias control signal from the delay circuit; and   a second pre-bias circuit coupled to an output of the second amplifier, and coupled to receive the pre-bias control signal from the delay circuit.   
     
     
         16 . The receiver circuit of  claim 15 , wherein the delay circuit is coupled to generate a pulse of the pre-bias control signal that is delayed from a corresponding pulse of the output signal by at least a pulse width of the input pulse.