A system includes: 1) a buffer circuit; 2) circuitry coupled to an input of the buffer circuit; 3) a load coupled to an output of the buffer circuit; and 4) a clamp circuit coupled between an input of the buffer circuit and the output of the buffer circuit. The clamp circuit includes: 1) a bipolar junction transistor (BJT); 2) a first resistor with a first end coupled to a base terminal of the BJT and with a second end coupled to a collector terminal of the BJT; and 3) a second resistor with a first end coupled to the collector terminal of the BJT and with a second end coupled to the input of the buffer circuit. The second resistor is between an output of the circuitry and the input of the buffer circuit.

A bandgap voltage reference circuit includes an amplifier, a voltage buffer, a first transistor, a first resistor, a second transistor, a second resistor, and a leakage current. The input terminals of the amplifier are coupled to a first reference node and a second reference node respectively. The voltage buffer is coupled to the output terminal of the amplifier for outputting a bandgap reference voltage. The first transistor is coupled to the first reference node, the second first resistor, and can receive the bandgap reference voltage. The second resistor is coupled to the first resistor and a system voltage terminal. The second transistor is coupled to the second reference node, the first resistor, and can receive the bandgap reference voltage. The leakage current compensation element is coupled to the second transistor and the system voltage terminal. A size of the first transistor is greater than the second transistor.

A power amplifier circuit includes a first transistor, a capacitor, and a second transistor. The first transistor has an emitter electrically connected to a reference potential, a base, and a collector electrically connected to a first power supply potential. A first end of the capacitor is electrically connected to the collector of the first transistor. The second transistor has an emitter electrically connected to a second end of the capacitor and electrically connected to the reference potential, a base, and a collector electrically connected to the first power supply potential. An RF output signal obtained by amplifying the RF input signal is output from the collector of the second transistor. A second bias circuit includes a third transistor having a collector electrically connected to a second power supply potential, a base, and an emitter from which the second bias current or voltage is output.

A high-speed low-noise trans-impedance amplifier (TIA) with fast overdrive recovery is suitable for use in light detection and ranging (LIDAR) receivers.

A bias circuit for a bipolar RF amplifier is described. The bias circuit includes a current source coupled to a bias network. The bias network supplies a base current to the transistors in the amplifier circuit of the bipolar RF amplifier. The bias circuit includes a buffer coupled to the bias network and to the bipolar RF amplifier. The buffer provides additional base current to the amplifier circuit of bipolar RF amplifier and sinks avalanche current generated by the amplifier circuit of the bipolar RF amplifier.

A bandgap voltage reference circuit includes an amplifier, a voltage buffer, a first transistor, a first resistor, a second transistor, a second resistor, and a leakage current. The input terminals of the amplifier are coupled to a first reference node and a second reference node respectively. The voltage buffer is coupled to the output terminal of the amplifier for outputting a bandgap reference voltage. The first transistor is coupled to the first reference node, the second first resistor, and can receive the bandgap reference voltage. The second resistor is coupled to the first resistor and a system voltage terminal. The second transistor is coupled to the second reference node, the first resistor, and can receive the bandgap reference voltage. The leakage current compensation element is coupled to the second transistor and the system voltage terminal. A size of the first transistor is greater than the second transistor.

Described herein are systems and methods that can adjust the performance of a transimpedance amplifier (TIA) in order to compensate for changing environmental and/or manufacturing conditions. In some embodiments, the changing environmental and/or manufacturing conditions may cause a reduction in beta of a bipolar junction transistor (BJT) in the TIA. A low beta may result in a high base current for the BJT causing the output voltage of the TIA to be formatted as an unusable signal output. To compensate for the low beta, the TIA generates an intermediate signal voltage, based on the base current and beta that is compared with the PN junction bias voltage on another BJT. Based on the comparison, the state of a digital state machine may be incremented, and a threshold base current is determined. This threshold base current may decide whether to compensate the operation of the TIA, or discard the chip.

A constant current generation circuit for optocoupler isolation amplifier and a current precision adjustment method are provided. The constant current generation circuit includes a start circuit, a current generation circuit and a precision adjustment and output circuit integrated into a same substrate. The start circuit can generate and output a first start current and a second start current. The current generation circuit includes a negative temperature change rate current generation circuit connected to a first start current output and a positive temperature change rate current generation circuit connected to a second start current output. The precision adjustment and output circuit outputs constant current meeting application requirements of optocoupler isolation amplifier by adjusting proportional precision of two currents output from a current generation circuit.

Disclosed is a circuit (100) for a medical device, comprising: a voltage converter (110, 300) which is configured to provide at least one supply potential (HV) depending on a control signal (302, PWM) provided to the voltage converter (110, 300), a control unit (P) which is configured to provide the control signal (302, PWM) for the voltage converter (110, 300), a signal source (TCA, 400) which is powered by the at least one supply potential (+HV) and which is configured to provide an output signal at an output of the signal source (TCA, 400), wherein the signal source (TCA, 400) is configured to provide the output signal dependent on an input signal (120) at an input of the signal source (TCA, 400), wherein the control unit (P) comprises: a prediction unit (160) which is configured to predict a change in the characteristic of the output signal based on at least one of a) at least one value of the input signal and b) at least one detected value of the output signal, and an adjusting unit (160) which is configured to adjust the control signal (302, PWM) based on the predicted change in the characteristic of the output signal.

An amplifier circuit includes an input amplifier; an output unity gain buffer; and a second unity gain buffer. The output unity gain buffer and the second unity gain buffer are each configured to receive a signal from an input amplifier. The output unity gain buffer is configured to provide an output voltage to an amplifier output, and the second unity gain buffer is configured to provide a bootstrap signal to the input amplifier. A unity gain amplifier includes an input unity gain amplifier; and an output unity gain buffer and a second unity gain buffer. The buffers are configured to receive a signal from an input amplifier. The output unity gain buffer is configured to provide an output voltage to an amplifier output, and the second unity gain buffer is configured to provide a bootstrap signal to the input unity gain amplifier.