Abstract: Aspects of the subject technology relate to a circuit for reducing random-telegraph noise in bandgap circuits. The circuit includes a number of diodes coupled in parallel at their respective first nodes to a ground potential. A number of switches are coupled to respective second nodes of the diodes. The circuit further includes a first resistor and a resistor voltage divider. The first node of the first resistor is coupled to a first node of a current source, and the first node of the resistor voltage divider is coupled to the first node of the current source. The switches are used to implement cyclic switching of the diodes in response to a train of pulses. An output voltage of the circuit is derived between a mid-node of the resistor voltage divider and a second node of the first resistor.

Abstract: According to some embodiments, a bi-directional converter is configured to operate in a boost mode or a buck mode. The bi-directional converter includes a hysteresis control unit that includes a comparator that can be configured to determine whether the reference voltage has a positive slope or a negative slope in conjunction with the bi-directional converter operating in boost mode or buck mode. In addition, the comparator is configured to compare a fractional load voltage to a reference voltage so that the output load voltage corresponds to the waveform shape of the reference voltage.

Abstract: A host electronic device may be coupled to an accessory electronic device. The host device and the accessory device may be connected via power supply lines and user data lines. If the host and accessory devices are improperly connected or if the accessory device is exposed to an incorrect voltage environment, the internal circuitry on the accessory device can be damaged. The accessory device may therefore include a reverse voltage protection circuit that can help prevent a large amount of current from inadvertently flowing into the accessory device. The protection circuit may include a low-side-enabled reverse current protection switch coupled between the external and internal ground terminals and also a single low-drop switch coupled to each of the user data lines. The low-drop switch will be activated whenever the voltage at the external ground terminal exceeds the voltage at the data line to help deactivate low-side-enabled reverse current protection switch.

Abstract: According to some embodiments, a bi-directional converter is configured to operate in a boost mode or a buck mode. The bi-directional converter includes a hysteresis control unit that includes a comparator that can be configured to determine whether the reference voltage has a positive slope or a negative slope in conjunction with the bi-directional converter operating in boost mode or buck mode. In addition, the comparator is configured to compare a fractional load voltage to a reference voltage so that the output load voltage corresponds to the waveform shape of the reference voltage.

Abstract: A charger-converter circuit in an electronic device detects whether an external power supply is coupled to the electronic device. The charger-converter circuit uses an inductor in an inductor-switch circuit to economize on volume occupied by the charger-converter circuit. The charger-converter circuit includes a low drop out voltage regulator (LDO) to provide, in each of three modes, a regulated supply voltage to a circuit module in the electronic device. When an external power supply is present, the charger-converter circuit charges a battery of the electronic device and operates in a buck mode or in a boost mode. When an external power supply is not present, the charger-converter circuit operates in a second buck mode. A pulse skipping technique may be applied to the inductor-switch circuit in the buck mode.

Abstract: A host electronic device may be coupled to an accessory electronic device. The host device and the accessory device may be connected via power supply lines and user data lines. If the host and accessory devices are improperly connected or if the accessory device is exposed to an incorrect voltage environment, the internal circuitry on the accessory device can be damaged. The accessory device may therefore include a reverse voltage protection circuit that can help prevent a large amount of current from inadvertently flowing into the accessory device. The protection circuit may include a low-side-enabled reverse current protection switch coupled between the external and internal ground terminals and also a single low-drop switch coupled to each of the user data lines. The low-drop switch will be activated whenever the voltage at the external ground terminal exceeds the voltage at the data line to help deactivate low-side-enabled reverse current protection switch.

Abstract: A battery system has positive and negative pack terminals, and positive and negative sense terminals. An electrochemical cell assembly has positive and negative cell terminals. An electrically conductive power path has a positive leg that connects the positive cell terminal to the positive pack terminal, and a negative leg that connects the negative cell terminal to the negative pack terminal. A power switch circuit is connected in the power path. An electrically conductive sense path separate from the power path has a positive leg that connects the positive cell terminal to the positive sense terminal, and a negative leg that connects to the negative sense terminal. A sense switch circuit is connected in the sense path. Other embodiments are also described and claimed.