Light source driver

A light emitting diode (LED) driver, comprising:

• a light emitting diode;
• a converter connected to the light emitting diode, wherein the converter receives an input voltage and converts the input voltage to a voltage for driving the light emitting diode;
• a light emitting diode connected to the converter;
• a first current regulator connected to the light emitting diode;
• a first operational amplifier connected to the first current regulator;
• a second current regulator connected to the first current regulator and the first operational amplifier;
• an analog dimming voltage generating unit connected to the first operational amplifier, an analog dimming voltage generating unit comprising a second operational amplifier, a first resistor, and a second resistor, wherein a first terminal of the first resistor and a first terminal of the second resistor are connected to a non-inversion terminal of the second operational amplifier;
• and
• a pulse-width-modulation dimming pulse generating unit connected to the second current regulator.

A light source driver for a light source, comprising:

• a voltage converter connected to the light source;
• a current regulator connected to the light source;
• an operational amplifier connected to the current regulator;
• an analog dimming voltage generating unit including a first terminal, a second terminal, and a third terminal, wherein the first terminal is connected to a reference voltage, and the second terminal is connected to a non-inversion terminal of the operation amplifier;
• and
• a pulse-width-modulation (PWM) dimming pulse generating unit connected to the third terminal of the analog dimming voltage generating unit, wherein the analog dimming voltage generating unit adjusts an analog dimming voltage so that a micro current flows through the light source when a PWM dimming pulse is turned off by the PWM dimming pulse generating unit.