Abstract:
In one aspect, a circuit includes a gate driver having a first input connected to a first node and a second input connected to a second node; an epi diode connected to the first node; a switch connected to the first node; a capacitor having a top plate connected to the switch and a bottom plate connected to the second node; and a first clamp connected the first node and to the second node. The switch being open isolates the first node from negative transient effects from the top plate of the capacitor.
Abstract:
A charge pump includes a first power source having a voltage VREG generated from a regulated and circuit-limiter supply, a second power source having a voltage VBRG and a top-off capacitor adapted to be charged to a voltage of the high of VREG or VBRG to a limit of a voltage clamp across the top-off capacitor.
Abstract:
An isolation circuit is coupled between motor driver half bridge circuits and an electric motor. A motor controller circuit supplies motor drive signals to the motor driver half bridge circuits. The isolation circuit includes transistors coupled in series with the motor windings. Low to medium power diodes are coupled between a reference voltage source and control terminals of the transistors.
Abstract:
A transistor drive circuit uses multi-stage slew rate control to drive one or more switching transistors. After a decision is made to change transistor state, a first drive current may be applied to an input terminal of the transistor for a predetermined time duration. After the predetermined time duration, a second drive current may be applied to the input terminal. When the transition between states is substantially complete, the current drive to the input terminal may be changed to a voltage drive. In some embodiments, the predetermined time duration may be based on the start time of a Miller plateau during the transition period.
Abstract:
A CAN transmitter includes an output branch, a replica branch including a replica of the output branch, and a feedback network. The output branch includes a first resistive element controlled by a first bias voltage and a second resistive element controlled by a second bias voltage. The replica branch has a feedback node that is replicated at a midpoint between the CANH bus terminal and the CANL bus terminal. The feedback network has a first input coupled to the feedback node, a second input configured to receive a midpoint reference voltage indicative of a desired midpoint voltage between the CANH and CANL terminals, and an output at which the first bias voltage is provided. A resistance controller is coupled to a control terminal of the second resistive element and configured to generate the second bias voltage based on a predetermined reference voltage and a bias current.
Abstract:
In one aspect, an integrated circuit (IC) includes a level shifter configured to generate a first output signal and a second output signal, and to receive an input voltage, a first supply voltage and a second supply voltage; and a state reinforcement circuit configured to maintain a logical state of the second output signal in response to the first supply voltage having a voltage below ground and the input voltage is logical high. If the input voltage is logical high, then the first output signal is logical low and the second output signal is logical high; and, if the input voltage is logical low, the first output signal is logical high and the second output signal is logical low.
Abstract:
Methods and apparatus for a voltage regulator having a boost module and a charge pump module. In embodiments, the charge pump module is configured to operate in multiple modes. In embodiments, an IC package includes the boost module and the charge pump with a shared component, such as a capacitor.
Abstract:
A multi-mode charge pump generates a regulated voltage at an output node from a battery input voltage. The multi-mode charge pump has a plurality of flying capacitors and a plurality of switches coupled to the flying capacitors in order to selectively couple the flying capacitors to the battery, the output node or a reference potential. The regulated voltage is provided across a storage capacitor coupled to the flying capacitors, and the regulated voltage is input to a comparator. The comparator also receives a reference voltage and compares the regulated voltage to the reference voltage to generates an asynchronous regulation signal. A controller in the multi-mode charge pump can automatically transition between operation modes such as a buck mode, a doubler mode and a tripler mode by controlling actuation of the switches in response to the asynchronous regulation signal and clock signals.
Abstract:
An isolation switch driver includes a control circuit to control conduction of an isolation switch and a voltage monitor circuit to monitor a control voltage coupled to the isolation switch and to generate a fault indication if the control voltage is less than a predetermined threshold. The isolator driver can drive an isolation switch coupled between a bridge network and a motor in a motor control system. The monitor circuit can monitor a voltage between a gate terminal and a source terminal of the isolation switch and include a resistive element coupled between the gate terminal and the source terminal to generate a current proportional to the VGS voltage, a current mirror to shift a level of the current to a reference potential, and a comparator to compare the level-shifted current to a threshold current.
Abstract:
Systems and techniques detecting a reverse current are disclosed. An apparatus comprises a switching circuit coupled to a load and a reference node. The switching circuit may be capable of conducting a reverse current from the reference node to the load when a voltage at the load is lower than a voltage at the reference node. A voltage source has a first terminal coupled to the load, a second terminal configured to follow a voltage at the load, and produces a voltage proportional to a voltage drop across the switching circuit. A comparator circuit is coupled to compare a voltage at the second terminal of the voltage source to the voltage at the reference node and configured to indicate when the reverse current has a magnitude greater than a predetermined threshold.