A reference voltage generation circuit includes a supply voltage terminal, a node, a current source, an output terminal, a common voltage terminal, a bandgap reference circuit and a feedback circuit. The supply voltage terminal is used to provide a supply voltage. The current source is coupled between the supply voltage terminal and the node, and used to receive the supply voltage and generate a current according to a feedback signal, and output the current to establish at the node a first voltage substantially insensitive to the supply voltage. The common voltage terminal is used to provide a common voltage. The bandgap reference circuit is coupled between the node and the common voltage terminal, and used to establish a temperature-invariant bandgap voltage at the output terminal. The feedback circuit is coupled to the node and the current source, and used to generate the feedback signal according to the first voltage.

A reference voltage generation circuit includes a supply voltage terminal, a node, a current source, an output terminal, a common voltage terminal, a bandgap reference circuit and a feedback circuit. The supply voltage terminal is used to provide a supply voltage. The current source is coupled between the supply voltage terminal and the node, and used to receive the supply voltage and generate a current according to a feedback signal, and output the current to establish at the node a first voltage substantially insensitive to the supply voltage. The common voltage terminal is used to provide a common voltage. The bandgap reference circuit is coupled between the node and the common voltage terminal, and used to establish a temperature-invariant bandgap voltage at the output terminal. The feedback circuit is coupled to the node and the current source, and used to generate the feedback signal according to the first voltage.

An apparatus for generating a temperature-dependent current. The apparatus includes an input current scaling circuit configured to generate a first current that varies with temperature in accordance with a first programmable slope, and a second current that varies with temperature in accordance with a second programmable slope; and a current temperature blending circuit configured to generate a third current based on the first current over a first temperature range and the second current over a second temperature range, wherein the first temperature range is different than the second temperature range.

A bandgap reference voltage generating circuit includes a first current generator generating a first complementary-to-absolute temperature (CTAT) current and a first proportional-to-absolute temperature (PTAT) current, a second current generator generating a second CTAT current and a second PTAT current, and an output circuit outputting a reference voltage based on a difference between a first voltage based on the first CTAT current and the first PTAT current and a second voltage based on the second CTAT current and the second PTAT current, wherein the first CTAT current is cancelled by the second CTAT current.

An apparatus is provided which includes: a first supply node; a second supply node; a first transistor coupled to the first supply node, the first transistor is to provide a first current which is complementary to absolute temperature (CTAT); a second transistor coupled to the first supply node, the second transistor is to provide a second current which is proportional to absolute temperature (PTAT); a resistive device coupled in series at a node with the first and second transistors, and coupled to the second supply node, wherein the node is to sum the CTAT and the PTAT currents.

A bandgap reference circuit includes a bandgap reference core circuit that includes a first bipolar transistor having a first emitter current density and a first base-emitter voltage, a second bipolar transistor having a second emitter current density that is smaller than the first emitter current density and having a second base-emitter voltage, a resistor that is connected to the emitter of the second bipolar transistor, and a differential amplifier circuit that is configured to control first and second emitter currents through the first and second bipolar transistors, respectively, such that a sum of the second base-emitter voltage and a voltage drop across the resistor approximates the first base-emitter voltage. The bandgap reference circuit further includes a first replica bipolar transistor that emulates an operating point of the first bipolar transistor and a second replica bipolar transistor that emulates an operating point of the second bipolar transistor.

A bandgap reference circuit includes a bandgap reference core circuit that includes a first bipolar transistor having a first emitter current density and a first base-emitter voltage, a second bipolar transistor having a second emitter current density that is smaller than the first emitter current density and having a second base-emitter voltage, a resistor that is connected to the emitter of the second bipolar transistor, and a differential amplifier circuit that is configured to control first and second emitter currents through the first and second bipolar transistors, respectively, such that a sum of the second base-emitter voltage and a voltage drop across the resistor approximates the first base-emitter voltage. The bandgap reference circuit further includes a first replica bipolar transistor that emulates an operating point of the first bipolar transistor and a second replica bipolar transistor that emulates an operating point of the second bipolar transistor.

Certain aspects of the present disclosure provide methods and apparatus for current-limiting protection of an amplifier, such as a power amplifier in a radio frequency (RF) front-end. One example current-limiting circuit generally includes a node coupled to a current source, a plurality of current-sinking devices coupled to the node, one or more switches coupled between the node and at least one of the plurality of current-sinking devices, and a bias circuit having an input coupled to the node and an output for coupling to an input of the amplifier.

A non-volatile memory cell includes a floating gate transistor having a floating gate. A method for operating the non-volatile memory cell includes, during a program operation, performing an initial program searching operation to identify a first initial value of a threshold voltage of the floating gate transistor, coupling the floating gate of the floating gate transistor to a first program voltage to raise the threshold voltage of the floating gate transistor, performing a program searching operation to identify a first variation of the threshold voltage, generating a second program voltage according to the first variation of the threshold voltage, and coupling the floating gate of the floating gate transistor to the second program voltage to raise the threshold voltage of the floating gate transistor.

A non-volatile memory cell includes a floating gate transistor having a floating gate. A method for operating the non-volatile memory cell includes, during a program operation, performing an initial program searching operation to identify a first initial value of a threshold voltage of the floating gate transistor, coupling the floating gate of the floating gate transistor to a first program voltage to raise the threshold voltage of the floating gate transistor, performing a program searching operation to identify a first variation of the threshold voltage, generating a second program voltage according to the first variation of the threshold voltage, and coupling the floating gate of the floating gate transistor to the second program voltage to raise the threshold voltage of the floating gate transistor.