This post explains for the PWM Controller.
The Part Number is BIT3260.
The function of this semiconductor is Low Cost LED Driver.
The package is SOP-8 Pin Ttpe
Manufacturer: BiTEK ( Beyond Innovation Technology )
Preview images :
Description
BIT3260 is a high frequency PWM controller integrating required functions for boost conversion in a small SOP-8 package. A low 0.2V feedback voltage and over voltage protection make BIT3260 an ideal controller for LED backlight supplies. CMOS process greatly reduces the operating current compared with similar products.
Features
1. Voltage Mode PWM Controller
2. 10V ~ 18V operation voltage
3. Current limit
4. Frequency adjustable
5. Internal Soft-Start
6. Maximum duty cycle output
7. Over temperature protection, OTP
8. Internal Under Voltage Lock Out, UVLO
9. Totem Pole Output
The PWM generator:
The pulse width modulation control circuit includes a reference voltage, an error amplifier, a ramp wave generator, and a comparator. A signal input to the INN pin is compared with reference voltage in the error amplifier, there will be an error signal output in the error amplifier. This error signal can be modulated into PWM signal in the comparator output when it compares to ramp wave signal in the comparator.