Intersil Americas Inc.

Tyco Electronics Corporation

Oki Electric Industry Co., Ltd.

Chuck Wong

Paul W Latham, Ii

Shawn Laliberte

Paul W Latham Ii

A universal serial bus charger comprises a universal serial bus connector for providing a connection to a voltage source. An output voltage connector provides a charging voltage to a connected battery. A switching voltage regulator generates the charging voltage responsive to the voltage source. Control circuitry monitors an actual charging current applied to the connected battery and provides a programmed current signal enabling the actual charging current to operate at a programmed level if the actual charging current does not exceed a programmed charging current level. The control circuitry provides a charging current limit signal enabling the actual charging current to operate at a predetermined charge current limit if the actual charging current exceeds the programmed charging current level. PWM control circuitry generates switching control signals to control operation of the switching voltage regulator responsive to the control circuitry.

USB charger using sensor-less current limit

USB charger using current limit

A cradle charging system comprises a charging cradle defining a space for a battery of an electronic device. Transformer charging circuitry for charging the battery in the electronic device includes a primary side circuitry for receiving a charging voltage. Secondary side circuitry inductively couples the charging voltage to the battery. The secondary side circuitry provides a controlled output signal based on either constant voltage control or constant current control responsive to a charge level of the battery.

Cradle charger controller with below ground level biasing

A three-terminal low-voltage PWM controller chip includes a first terminal for receiving operating bias current supply and a feedback control signal related to an output parameter of an electrical circuit to be controlled; a second terminal connected to an output switch providing digital width-modulated control pulses to control duty cycle of the electrical circuit; a third terminal ground connection; a clocked pulse width modulation circuit responsive to current flow between the second terminal and the third terminal and the feedback control value for controlling the digital output switch; and, feedback signal separation circuitry for separating the feedback control signal from the operating bias current supply. A start-up circuit is also provided.

Three-terminal, low voltage pulse width modulation controller IC

An output isolated, switching power supply has a transformer with a primary and two secondaries, an electronic switch in series with the primary, a first rectifier and filter on the first secondary to provide bias power during both startup and operating modes, and a second rectifier and filter on the second secondary to provide regulated output power. A resistor-capacitor network on the primary side provide an initial operating condition, such as a single control pulse, to the electronic switch which causes sufficient energy to be transferred through the first secondary to supply sufficient startup energy to operate a current control integrated circuit on the secondary side in a staged fashion. After the initial operating condition, the current control integrated circuit generates and applies a control signal to the electronic switch through an isolation circuit to cause the electronic switch to turn on and off in controlled fashion in order to deliver regulated power to the output of the supply. The low voltage, secondary side, current control integrated circuit provides a further aspect of the present invention.

Growing community of inventors

Union City, CA, United States of America

Chuck Wong