Panasonic Semiconductor Asia Pte. Ltd.

Matsushita Electric Industrial Co., Ltd.

Panasonic Corporation

Panasonic Intellectual Property Management Co., Ltd.

Panasonic Asia Pacific Pte. Ltd.

Tien Yew Kang

Kian Teck Teo

Shiah Siew Wong

Wee Sien Hong

Yubin Liu

Gorou Mori

Jing Sun

Narciso Repollo Semira

Muhammad S/o Abuturab

Chew Yuan Woong

Hong Meng Tang

Chung Kiong Leslie Khoo

A plurality of batteries connected in series are monitored by a plurality of monitor devices, respectively. The monitor devices are connected in series to communicate under the daisy chain communication system. The daisy chain communication system includes a micro-control unit for producing a binary signal, a communication device for converting the binary signal to a pulsating signal. The communication device produces a special code based on an instructions from the micro-control unit. Each monitor device changes between a communication OFF state and a communication ON state. Each monitor device has a signal detector which operates during the communication OFF state and detects the special code, whereby upon detection of the special code, the signal detector generates a wakeup signal so that the monitor device is changed from the communication OFF state to communication ON state.

Wakeup sequence for two-wire daisy chain communication system

A slew rate control circuit in output driver of switching circuit to prevent power ground undershoot is introduced. The gate capacitance of lower power transistor is first fast discharged to ensure the operation of the output signal. The gate capacitance of lower power transistor is then slowly discharged to limit OUT SLEW RATE. The gate capacitance of lower power transistor is further slowly discharged when the power ground level is below common ground. With above controlling, the gate voltage slew rate of lower power transistor is reduced when the lower power transistor is almost fully turned OFF. Therefore, undershoot at the power ground is avoided. Similar slew rate control circuit can also be derived in output driver of switching circuit to prevent PVCC overshoot.

Slew rate control in output driver

An analog voltage latch for use in a controller for controlling a motor equipped electric bicycle, includes a window comparator for comparing an analog voltage latch output and an analog input voltage to produce a comparison result, an S-R latch for producing HIGH or LOW according to the comparison result, a selector for selecting an operation, an up/down counter for counting up or down according to the HIGH or LOW from the S-R latch, and holding the counted result according to the selector result, and a DA converter for converting the counted result to analog signal.

Analog voltage latch

A differential input Class D audio power amplifier incorporating a differential error amplifier is introduced. In response of differential input signal, this differential error amplifier generates two error signals, which subsequently generates final output signal. This architecture makes it the effect of feedback signal error correction doubled, which helps in achieving good THD. In addition, input port of this architecture is also compatible with single-ended signal. A pop noise suppression technique for this differential input Class D audio power amplifier is also introduced.

Differential input Class D amplifier

An electric motor speed controller for use in a bicycle includes a motor to provide a propulsion force to move the bicycle. The actual motor speed and a target motor speed are compared, and if the actual motor speed is lower, more current is supplied to the motor, and if the actual motor speed is higher, less current is supplied to the motor.

Electric motor speed controller for vehicle

An electric power-assist system for a manually operated vehicle, such as a bicycle, has a pedal with Hall sensors for producing a signal representing a rotational speed of the pedal, and an electric motor for power assisting the driving force of the bicycle. A speed counter, speed decision block, up/down counter, and comparator are provided so that the power assist by the electric motor increases or degreases, as the speed of the manual controlling device increases or decreases, respectively.

Growing community of inventors

Singapore, Singapore

Tien Yew Kang