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부품번호 | KA7540 기능 |
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기능 | Simple Dimming Ballast Control IC | ||
제조업체 | Samsung | ||
로고 | |||
전체 14 페이지수
KA7540
Simple Dimming Ballast Control IC
www.fairchildsemi.com
Features
• Internal soft start
• No lamp protection
• Voltage controlled dimming
• Trimmed 1.5% internal bandgap reference
• Under voltage lock out with 1.8V of hysteresis
• Totem pole output with high state clamp
• Low start-up and operating current
• 8-pin DIP & 8-pin SOP
Applications
• Electronic Ballast
• Lighting Control System
• Half-bridge Drive Control System
Descriptions
The KA7540 provides simple and high performance
electronic ballast control functions. KA7540 is optimized for
electronic ballast requiring a minimum board area, reduced
component count and low power dissipation. Internal soft
start circuitry eliminates the need for an external soft start
PTC resistor. Voltage controlled dimming circuit is built into
the IC to control the lighting output in a wide range.
Protection circuitry has also been added to prevent switches
from burning out in no lamp condition. Output gate drive
circuit clamps power MOSFET gate voltage irrespective of
supply voltage.
8-DIP
1
8-SOP
1
©2001 Fairchild Semiconductor Corporation
Rev. 1.0.1
KA7540
Absolute Maximum Ratings
Parameter
Supply voltage
Peak drive output current
Drive output clamping diodes
VO>VCC, or VO<−0.3
Dimming, soft start, and no lamp detection input voltage
Operating temperature range
Storage temperature range
Power dissipation
8-DIP
8-SOP
Thermal resistance (Junction-to-air)
8-DIP
8-SOP
Symbol
VCC
IOH, IOL
Iclamp
VIN
Topr
Tstg
Pd
θja
Absolute Maximum Ratings (-25°C≤Ta≤125°C)
Parameter
Temperature stability for reference voltage (Vref)
Temperature stability for operating frequency (fos)
Symbol
∆Vref (Typ)
∆fos (Typ)
Value
30
±300
±10
−0.3 to 6
-25 to 125
−65 to 150
0.8
0.5
100
165
Value
15
5
Unit
V
mA
mA
V
°C
°C
W
°C/W
Unit
mV
kHz
4
4페이지 KA7540
Vct
(Pin #2)
Voutput
(Pin #6, 7)
Vhigh
Vlow
14V
0V
Charging
Period(∆Tch)
Discharging
Period(∆Tdis)
Figure 2. Oscillator sawtooth & Output gate drive waveform
As a result, the switching frequency is as following
Ts = 2 × (∆Tch + ∆Tdis) = 40µs
fsw = 1 / TS = 25kHz
The explicit equation calculating the value of the timing capacitor for a certain switching frequency is written below.
Ct = 1----1---.--7---6-----×-----1---0----–--6-
fsw
Soft Start
The switching frequency is decreasing linearly from the pre-heating frequency to the normal switching frequency. In KA7540,
the normal timing capacitor charging current is increased by 25µA during the pre-heating mode. This addition of the charging
current sets the pre-heating frequency to be 1.33 times the switching frequency at the normal mode.
fsw, VCS
fsw (pre)
fsw (dim)
fsw (nor)
3.5V
2.7V
2V
0.95
ts/s td1 td2
Figure 3. Frequency & Soft start capacitor voltage variation during soft start and dimming mode
7
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구매 문의 | 일반 IC 문의 : 샘플 및 소량 구매 ----------------------------------------------------------------------- IGBT, TR 모듈, SCR 및 다이오드 모듈을 포함한 광범위한 전력 반도체를 판매합니다. 전력 반도체 전문업체 상호 : 아이지 인터내셔날 사이트 방문 : [ 홈페이지 ] [ 블로그 1 ] [ 블로그 2 ] |
부품번호 | 상세설명 및 기능 | 제조사 |
KA7540 | Simple Dimming Ballast Control IC | Samsung |
KA7540D | Simple Dimming Ballast Control IC | Samsung |
DataSheet.kr | 2020 | 연락처 | 링크모음 | 검색 | 사이트맵 |