Abstract: A low power consumption LED constant current drive circuit includes a power source input circuit, a constant current source circuit, an output voltage detection circuit, and a reference current control circuit, having the advantage of lower power consumption.

Abstract: A PWM signal generation and error calibration circuit includes an amplifier OP1, an amplifier OP2, a comparator CMP1, a comparator CMP2, PMOS field-effect transistors M1-M16, a resistor R14, a resistor R_FRE, variable resistors R15-R16, a resistor R17, a capacitor C1, a matched resistance module circuit, a current drain IDC, and a 14-bit counter. The PWM signal generation and error calibration circuit saves chip costs and supports a wide PWM signal frequency range, while being able to calibrate all duty cycle errors of PWM signals in the range between 0% and 100% with improved accuracy.

Abstract: A PWM signal generation and error calibration circuit includes an amplifier OP1, an amplifier OP2, a comparator CMP1, a comparator CMP2, PMOS field-effect transistors M1-M16, a resistor R14, a resistor R_FRE, variable resistors R15-R16, a resistor R17, a capacitor C1, a matched resistance module circuit, a current drain IDC, and a 14-bit counter. The PWM signal generation and error calibration circuit saves chip costs and supports a wide PWM signal frequency range, while being able to calibrate all duty cycle errors of PWM signals in the range between 0% and 100% with improved accuracy.

Abstract: A PWM control circuit for a driving chip and an LED driving chip for an automotive reading lamp are compatible to existing car interior lighting solutions, that is, PWM signals output by MCUs are used to turn on and off LEDs. Also provided is a PWM signal automatically generated within a driving chip and used to control the lighting status of an LED. By using PWM signals generated internally in chips to control LEDs, MCUs can be unburdened from complicated operation, and thereby can operate with improved efficiency.

Abstract: An LED driver chip for a car reading light and a state control method thereof are provided. The LED driver chip includes a state machine control circuit module, a state machine output logic module, a current on/off control logic circuit module, and a current source module. An OUT pin of the LED driver chip is connected with an LED. The LED driver chip determines the next state of LED current according to a driver chip PWM input signal, an EN pin low lever pulse input signal, and a present LED state, enabling the LED to switch among nine different states.

Abstract: An LED scanning array driver chip and a regulation method capable of self-regulating brightness linear change are provided. The LED scanning array driver chip is provided with LED current non-linear automatic control circuits to automatically regulate the average current of LEDs for the brightness of the LEDs to become bright or dark linearly, enabling each LED of the LED array to control the current non-linear change individually. This greatly reduces the time resource for a MCU to write registers inside the driver chip.

Abstract: An LED driver chip for a car reading light and a state control method thereof are provided. The LED driver chip includes a state machine control circuit module, a state machine output logic module, a current on/off control logic circuit module, and a current source module. An OUT pin of the LED driver chip is connected with an LED. The LED driver chip determines the next state of LED current according to a driver chip PWM input signal, an EN pin low lever pulse input signal, and a present LED state, enabling the LED to switch among nine different states.

Abstract: An LED scanning array driver chip and a regulation method capable of self-regulating brightness linear change are provided. The LED scanning array driver chip is provided with LED current non-linear automatic control circuits to automatically regulate the average current of LEDs for the brightness of the LEDs to become bright or dark linearly, enabling each LED of the LED array to control the current non-linear change individually. This greatly reduces the time resource for a MCU to write registers inside the driver chip.

Abstract: The present invention relates to a method for compensating timing errors of real-time clocks, which comprises a compensating step, wherein in step 1, assign CNT to be 0 and execute step two; in step 2, assign FLAG to be 1 when a rising edge of 1 Hz clock is arrived and execute step 3; in step 3, judge FLAG and M3, if FLAG=1 and M3<0, execute step 4 while waiting until CNT=S4; if FLAG=1, CNT=0 and M3>0, execute step 5; otherwise execute step 2; in step 4, execute an assignment operation, CNT=0, M3=M3+S4, FLAG=0 and restart step 2; in step 5, execute an assignment operation, CNT=S4, M3=M3?S4, FLAG=0, and restart step 2. A sampling frequency of relative errors ERR of the present invention is adjustable, and a compensatory accuracy is much higher.