Abstract: A voltage reference circuit provides a reference voltage in response to a programmed threshold voltage of a first non-volatile memory (NVM) transistor. The threshold voltage of the first NVM transistor is programmed by applying a programming voltage to commonly connected source/drain regions of a tunneling capacitor, which shares a floating gate with the first NVM transistor. During normal operation of the voltage reference circuit, the source/drain regions of the tunneling capacitor are connected to a second NVM transistor that has the same electrical and thermal characteristics as the floating gate of the first NVM transistor. As a result, charge loss from the floating gate of the first NVM transistor is advantageously minimized.

Abstract: A non-volatile memory cell fabricated with a conventional CMOS process, including a flip-flop circuit having an NMOS transistor that shares a floating gate with a write PMOS capacitor and an erase PMOS capacitor. An erase function is implemented by inducing Fowler-Nordheim tunneling through the erase PMOS capacitor, thereby providing a positive charge on the floating gate. A write function is implemented by inducing Fowler-Nordheim tunneling through the NMOS transistor, thereby providing a negative charge on the floating gate. The write PMOS capacitor provides bias voltages during the erase and write operations. Prior to a read operation, the flip-flop circuit is reset. If the floating gate stores a positive charge, the NMOS transistor turns on, thereby switching the state of the flip-flop circuit. If the floating gate stores a negative charge, the NMOS transistor turns off, thereby leaving the flip-flop circuit in the reset state.

Abstract: A hysteresis circuit including a comparator and capacitive voltage divider circuit. The capacitive voltage divider circuit includes a first capacitor coupled between an input terminal and a positive comparator input, a second capacitor coupled between ground and the positive comparator input, and a third capacitor coupled between the comparator output and positive comparator input. A reference voltage is applied to the negative comparator input. The comparator is powered by the input signal provided on the input terminal. When the voltage on the positive comparator input is less than the reference voltage, the third capacitor is effectively coupled in parallel with the first capacitor. When the voltage on the positive comparator input is greater than the reference voltage, the third capacitor is effectively coupled in parallel with the second capacitor.

Abstract: A voltage reference circuit provides a reference voltage in response to a programmed threshold voltage of a first non-volatile memory (NVM) transistor. The threshold voltage of the first NVM transistor is programmed by applying a programming voltage to commonly connected source/drain regions of a tunneling capacitor, which shares a floating gate with the first NVM transistor. During normal operation of the voltage reference circuit, the source/drain regions of the tunneling capacitor are connected to a second NVM transistor that has the same electrical and thermal characteristics as the floating gate of the first NVM transistor. As a result, charge loss from the floating gate of the first NVM transistor is advantageously minimized.

Abstract: A non-volatile memory cell fabricated with a conventional CMOS process, including a flip-flop circuit having an NMOS transistor that shares a floating gate with a write PMOS capacitor and an erase PMOS capacitor. An erase function is implemented by inducing Fowler-Nordheim tunneling through the erase PMOS capacitor, thereby providing a positive charge on the floating gate. A write function is implemented by inducing Fowler-Nordheim tunneling through the NMOS transistor, thereby providing a negative charge on the floating gate. The write PMOS capacitor provides bias voltages during the erase and write operations. Prior to a read operation, the flip-flop circuit is reset. If the floating gate stores a positive charge, the NMOS transistor turns on, thereby switching the state of the flip-flop circuit. If the floating gate stores a negative charge, the NMOS transistor turns off, thereby leaving the flip-flop circuit in the reset state.

Abstract: A voltage reference circuit provides a reference voltage that can be precisely programmed. The threshold voltage of a first non-volatile memory (NVM) transistor is programmed while coupled in parallel with a reference NVM transistor. During programming, the reference NVM transistor has a floating gate coupled to ground through a first set of capacitors, and coupled to a reference voltage through a second set of capacitors. The program threshold voltage of the first NVM transistor is dependent on the first and second sets of capacitors. The first and reference NVM transistors are then coupled in parallel, and a differential amplifier is used to generate a single-ended reference voltage in response to the programmed threshold voltage of the first NVM transistor. Capacitors can be transferred between the first set and the second set, thereby providing precise adjustment of the single ended reference voltage.

Abstract: A voltage reference circuit provides a reference voltage that can be precisely programmed. The threshold voltage of a first non-volatile memory (NVM) transistor is programmed while coupled in parallel with a reference NVM transistor, wherein a first voltage is applied to the control gate of the first NVM transistor, and a reference voltage is applied to the control gate of the reference NVM transistor. The threshold voltage of a second NVM transistor is programmed while coupled in parallel with the reference NVM transistor, wherein a second voltage is applied to the control gate of the second NVM transistor, and the reference voltage is applied to the control gate of the reference NVM transistor. The first and second NVM transistors are then coupled in parallel, and a differential amplifier is used to generate a single-ended reference voltage in response to the programmed threshold voltages of the first and second NVM transistors.