BIT3267 Datasheet PDF – Current Mode LED Driver

Part Number : BIT3267

Function : Current Mode LED Driver

Package : SOP-8 Type

Manufacturers : BiTEK ( http://www.bitek.com.tw )

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BIT3267 datasheet

Description

BIT3267 is a high frequency PWM controller integrating required functions for boost conversion in a small SOP-8 package. A low 0.21V feedback voltage, over voltage protection and over current protection and load short protection make BIT3267 an ideal controller for LED backlight supplies. Frequency selection is flexible in variable system design. Internal soft start function can avoid inrush current during startup period. Over temperature protection and UVLO make system reliable. CMOS  process greatly reduces the perating current compared with similar products.

 

 

Features

1. Current Mode PWM Controller
2. 8V ~ 28V operation voltage
3. Local dimming function
4. Internal minimum off time
5. Over current protection, OCP
6. Over voltage protection, OVP
7. Load short protection, LSP
8. Frequency selection
9. Internal Soft-Start
10. Over temperature protection, OTP
11. Internal Under Voltage Lock Out, UVLO
12. Totem Pole Output

Applications

1. Backlight for LED Panels
2. Portable Device Backlighting
3.  LCD Display Module

Functional description:

Under voltage locked out, UVLO:
The Under-voltage lockout turns-off BIT3267 if the input voltage drops below the under-voltage lockout threshold. It turns-on BIT3267 if the input voltage is higher than its threshold. The hysteresis voltage is about 1V.

LED current regulation :
Please refer following figure, a resistor RS is connected serial with LED string that can sense LED current. This sensed LED current signal feeds to INN pin and compares with its internal reference voltage of the error amplifier. The error amplifier outputs an error signal to control LED current.

Pinouts :
BIT3267 pinout

1 OUT Output pin
2 GND Ground pin
3 OCP Over current protection and frequency selection
4 OVP Over voltage protection
5 INN The inverting input of the error amplifier
6 CMP Output of the error amplifier
7 EA Enable pin
8 VDD Power supply

 

BIT3267 Datasheet PDF Download