Datasheet.kr   

BD9478F PDF 데이터시트 : 부품 기능 및 핀배열

부품번호 BD9478F
기능 PWM pulse Generator
제조업체 ROHM
로고 ROHM 로고 



전체 15 페이지

		

No Preview Available !

BD9478F 데이터시트, 핀배열, 회로
BD9478F
Datasheet
LED Drivers series for LCD Backlights
PWM pulse Generator for
LCD Panels
BD9478F
General Description
BD9478F is PWM pulse generator for LCD panel. This
IC compares triangle waveform which is generated
inside IC and external DC signal, and generates a
PWM pulse. This PWM pulse is provided to LED driver
and controls LED grayscale. PWM pulse frequency
can be synchronized to external signal frequency
inputted to SYNC terminal. Even if this frequency gets
out of range, it works in the setting frequency, is
protected and it always provides stable PWM pulse to
LED driver.
Key Specification
Operating power supply voltage range: 4.5V to 5.5V
Free Run frequency:
150Hz (CT=0.01µF)
Operating Current:
Operating temperature range:
℃ ℃2mA (typ.)
-40 to +85
Applications
LED backlight of monitor, TV, NOTE PC, etc.
Features
The signal that the frequency synchronizes with the
VSYNC signal is output to PWMOUT.
The PWM pulse is generated with the DC signal of a
triangular wave and PDIM generated with the LCT
capacitor.
When the VSYNC frequency exceeds the stipulated
range, it fixes by a set frequency.
(fSYNC<fPLLtyp*0.35 -> fPLL=0.36*fPLLtyp , fSYNC>
fPLLtyp*2.75 -> fPLL=2.75*fPLLtyp)
When VSYNC is a no signal input, the self-oscillation is
operated by set frequency decided on the CT capacitance.
When the pulse signal is input to the terminal EXTPWM,
it shifts automatically to external PWM mode.
Package
SOP-8:
Pin Pitch:
W(Typ.) D(Typ.) H(Max.)
5.00mm x 6.20mm x 1.71mm
1.27mm
Typical Application Circuit
CVCC
VIN
PDIM
fVSYNC
1 VCC
CEXTPWM
Connector CPDIM
CVSYNC
2 EXTPWM
3 PDIM
4 VSYNC
PWMOUT 8
PWM signal out
(to LED driver)
GND 7
CLPF1 CLPF2
LPF 6
RLPF2
CT 5
CCT
Figure 1. SOP-8
Figure 2. Typical Application Circuit
○ :Product structure Silicon monolithic integrated circuit
.www.rohm.com
・ ・© 2012 ROHM Co., Ltd. All rights reserved.
TSZ22111 14 001
This product is not designed protection against radioactive rays
1/12
TSZ02201-0F1F0C100010-1-2
24. Jul.2012 Rev.002




BD9478F pdf, 반도체, 판매, 대치품
BD9478F
Pin Descriptions
Pin No
Pin Name
1 VCC
2 EXTPWM
3 PDIM
4 VSYNC
5 CT
6 LPF
7 GND
8 PWMOUT
In/Out
-
In
In
In
Out
In/Out
-
Out
Function
Power supply
External PWM signal input
DC signal input for Internal PWM
Synchronous signal input
Capacitance pin for VCO
LPF output for PLL
Ground
PWM dimming signal output
Datasheet
Rating [V]
-0.3~7
-0.3~20
-0.3~20
-0.3~20
-0.3~7
-0.3~7
-
-0.3~7
Pin ESD Type
VCC
LPF
EXTPWM / VSYNC /PDIM
GND
CT
VCC
CT
7V
PWMOUT
Figure 5. Pin ESD Type
www.rohm.com
・ ・© 2012 ROHM Co., Ltd. All rights reserved.
TSZ22111 15 001
4/12
TSZ02201-0F1F0C100010-1-2
24. Jul.2012 Rev.002

4페이지










BD9478F 전자부품, 판매, 대치품
BD9478F
Pin Function
Pin 1: VCC
Power supply pin of the IC. Input range is from 4.5V to 5.5V
Operation starts at VCC=3.8VTYP.or higher and shuts down at VCC=3.5V(TYP.) or lower.
Pin 2: EXTPWM
External PWM signal input terminal.
In case of the following equation, the signal input to EXTPWM is output directly to PWMOUT.
The equation ; f(PLL) < 2 * f(EXTPWM)
f(EXTPWM) ; frequency of signal input to EXTPWM
f(PLL) ; frequency of signal that synchronizes with VSYNC signal
Pin 3: PDIM
DC signal input terminal to generate internal PWM signal.
The PWM signal is generated with compare it with a triangular waveform in IC.
If PDIM input DC level is changed, PWM Duty can be changed.
PDIM input DC voltage range is from 0.5V to 3.0V. (PWM Duty is changed from 0% to 100%)
Pin 4: VSYNC
Synchronous signal input terminal.
The signal that synchronizes with the frequency of the signal input to VSYNC is generated with PLL.
A triangular wave is generated based on the frequency of this synchronized signal, and the PWM
pulse is generated with compare it with the PDIM signal
Pin 5: CT
Capacitor connection terminal that decides the oscillation frequency of VCO..
Please adjust the capacity of CT by the following equation so that the voltage of the terminal LPF
may become 0.9V when the frequency of the signal that synchronizes is input.
CT = 1.5
 [uF ] 
f PLLtyp [ Hz]
Pin 6: LPF
Low pass filter connection pin.
The pulse signal output from Phase Comparator is smoothed by Low path filter, and it inputs to Voltage.
Controlled Oscillator (VCO).
Pin 7: GND
Ground pin of this IC.
Pin 8: PWMOUT
PWM signal output pin.
The PWM signal generated in IC is output.
Datasheet
www.rohm.com
・ ・© 2012 ROHM Co., Ltd. All rights reserved.
TSZ22111 15 001
7/12
TSZ02201-0F1F0C100010-1-2
24. Jul.2012 Rev.002

7페이지



구       성총 15 페이지
다운로드[ BD9478F.PDF 데이터시트 ]
구매 문의
일반 IC 문의 : 샘플 및 소량 구매
-----------------------------------------------------------------------

전력 반도체 판매 ( IGBT, TR 모듈, SCR, 다이오드 모듈 )

휴대전화 : 010-3582-2743


상호 : 아이지 인터내셔날

전화번호 : 051-319-2877, [ 홈페이지 ]



링크공유

링크 :

관련 데이터시트

부품번호상세설명 및 기능제조사
BD9478F

PWM pulse Generator

ROHM
ROHM

DataSheet.kr    |   2019   |  연락처   |  링크모음   |   검색  |   사이트맵