Self biased differential amplifier with hysteresis

An integrated circuit having a differential amplifier circuit integrated thereon for receiving a logic input signal, said differential amplifier circuit having a predetermined switching point, said differential amplifier circuit providing hysteresis about said predetermined switching point, said differential amplifier circuit comprising:

• a reference circuit having a reference voltage applied thereto;
• an input circuit for receiving the logic input signal, said input circuit having a beta ratio associated therewith;
• a current supplying device coupled to said reference circuit and to said input circuit for providing a reference current thereto;
• and
• a hysteresis circuit having an input coupled to an output of said differential amplifier circuit, and having an output coupled to bias said current supplying device, said hysteresis circuit modifying the beta ratio of said input circuit in a first direction when the output of said differential amplifier circuit is in a first state and modifying the beta ratio in a second direction when the output of said differential amplifier circuit is in a second state.

An integrated circuit having a differential amplifier circuit integrated thereon for receiving a logic input signal, said differential amplifier circuit having a predetermined switching point with output controlled hysteresis about said predetermined switching point, said differential amplifier circuit comprising:

• a reference inverter having a reference voltage applied to an input thereof;
• an input inverter for receiving the logic input signal, said input inverter having a beta ratio associated therewith;
• a current supplying device coupled for providing a reference current to said reference inverter and to said input inverter, said current supplying device further having an input coupled to an output of said input inverter;
• and
• a hysteresis circuit having an input coupled to an output of said reference inverter, and having an output coupled to the input of said current supplying device, said hysteresis circuit modifying the beta ratio of said input inverter in a first direction when said output of said reference inverter is in a first state and modifying the beta ratio in a second direction when said output of said reference inverter is in a second state.

An integrated circuit having a self biased differential amplifier with hysteresis integrated thereon, said self biased differential amplifier comprising:

• a first inverter having first and second series connected transistors coupled for receiving a first signal;
• a second inverter having series connected third and fourth transistors coupled for receiving a reference voltage;
• a bias circuit having a fifth transistor coupled between a supply voltage and the first and third transistors, and having a sixth transistor coupled between a ground supply voltage and said second and fourth transistors, a gate of said fifth transistor and a gate of said sixth transistor coupled to an output of said first inverter;
• and
• a hysteresis inverter comprising seventh and eighth series connected transistors having an input connected to an output of said second inverter, and having an output connected to the output of said first inverter.