Leadtrend Technology Corporation

Yang-Sheng Lin

Chung-Wei Lin

Ching-Tsan Lee

Wen-Chung Yeh

A power supply detects a falling rate of an output voltage for fast load-transient response. The power supply with a primary side and a secondary side isolated from each other comprises a primary-side control circuit and a secondary-side control circuit. The primary-side control circuit controls a power switch to convert an input power source on the primary side into an output power source on the secondary side. The output power source has the output voltage. The secondary-side control circuit detects the falling rate and sending information to the primary-side control circuit when the falling rate exceeds a predetermined rate. In response to the information, the primary-side control circuit starts anew switching cycle of the power switch.

Switching mode power supplies with fast load-transient response

A synchronous rectifier applied to a power converter includes a gate coupling effect suppressing unit. The gate coupling effect suppressing unit is used for suppressing an induced voltage coupled to a gate of a metal-oxide-semiconductor transistor coupled to a secondary side of the power converter to ensure that the metal-oxide-semiconductor transistor is turned off when the power converter operates in a start-up condition and a power switch of the power converter is turned on. When the power converter operates in the start-up condition, a driving voltage of the secondary side of the power converter for driving the synchronous rectifier is not enough to drive the synchronous rectifier yet.

Synchronous rectifier applied to a power converter and operation method thereof

A method for controlling a dead time of a secondary side of a power converter includes giving a previous first turning-on time and a current first turning-on time corresponding to a primary side of the power converter, generating a first voltage and a second voltage according to the previous first turning-on time and the current first turning-on time, respectively, generating a current first target voltage according to the first voltage, the second voltage, and an ideal voltage corresponding to a previous ideal second turning-on time of the secondary side, and determining a current second turning-on time of the secondary side according to the current first target voltage and a first ramp voltage corresponding to a current ideal second turning-on time of the secondary side. A difference between the current second turning-on time and the current ideal second turning-on time is a current dead time.

Method for controlling a dead time of a secondary side of a power converter

A synchronous rectification control method suitable for a switching mode power supply with a synchronous rectifier is disclosed. A synchronous rectification controller with a first pin is provided. A pin voltage at the first pin is sampled to generate a sampled voltage. After the sampling, a detection current is provided and it flows out of the synchronous rectification controller from the first pin. Digital dead-time control signals are generated in response to the pin voltage and the sampled voltage. The synchronous rectifier is controlled to determine a dead time of the synchronous rectifier, based upon the digital dead-time control signals.

Synchronous rectification controller and relative dead-time control method

A timing controller provides adaptive timings to control a synchronous rectifier with a body diode. The timing controller has a ramp generator providing a ramp signal at a first capacitor. The ramp signal corresponds to a discharge time when the body diode is forward biased. A second capacitor records an estimated duration signal. An update circuit is connected between the first and second capacitors, for shorting the first and second capacitor to update the estimated duration signal by charge sharing. A comparator with two inputs coupled to the ramp signal and the estimated duration signal respectively compares the ramp signal and the estimated duration signal to control the synchronous rectifier.

Growing community of inventors

Hsinchu County, Taiwan

Yang-Sheng Lin