參數(shù)資料
型號: TB62732FU
廠商: Toshiba Corporation
元件分類: LED驅(qū)動器
英文描述: The step up type DC-DC converter only for white LED driver lighting
中文描述: 唯一的白光LED驅(qū)動器照明加強(qiáng)型DC - DC轉(zhuǎn)換
文件頁數(shù): 9/15頁
文件大?。?/td> 177K
代理商: TB62732FU
TOSHIBA
T B 6 2 7 3 2 F U
27, Feb 2002 (Ver.04)
9
ABOUT THE CURRENT DERATING FUNCTION
As for the LED current, generally the current derating recommended against the rise in the ambient temperature.
The TB62732FU aims at turning on white LED of the back light illuminant of the color LCD safely and efficiently,
and builds in the current derating function which set temperature was presumed.
This IC has the character which makes the current 100(%) in the case of Tjs=45 (degree) and which makes
the current 0(%) again in the case of Tjs=100 (degree) corresponding to internal detection temperature Tjs.
When it is seen from set temperature Ta (degree), the temperature that self-fever temperature Tup (degree)
in the operation was reduced from Tjs = 45 (degree) becomes a starting temperature Ts (degree).
Starting temperature Ts (degree) = 45 (degree) - self-fever temperature Tup (degree) --- Form 4
Therefore, the derating character functions as the figure 6, and shows internal detection temperature Tjs and
the rate of change of the outout current.
Self-fever temperature Tup (degree) in the operation is calculated with the Form 5.
Self-fever temperature Tup (degree) ---- ceremony 5
= (P loss (W) - P parts(W))*Rth(j-a) (degree/W)
It is described in the following about each clause.
DC resistance of the inductance : RDC(ohm), Forward current of LED : IF LED(A),
Total forward voltage of LED : VF LED(V), Forward voltage : VF schottky(V),
Setup resistance : R_sens(ohm), Power loss of lighting circuit : P loss(W)=(Po/efficiency)-Po(W),
Power loss of parts : P parts(W)=RDC*Iin+VF schottky*IF LED+R_sens*IF LED*IF LED,
Saturation thermal resistance of package :
Rth(j-a) (degree/W) =< 260 - - - when on board, muximum
Output power :
Po(W) = VF LED*Io(A)
Input power :
Pi(W) = Vin (V)*Iin(A)
Efficiency :
Efficiency(%)=100*(Po/Pi)
Example : When the measurement of the lighting circuit tightened each following value.
RDC=0.5(ohm), Po=320(mW), Iin=0.1(A), Io=20(mA), R_sens=1.8(ohm), VF schottky=0.3(V),
Efficiency=70(%)
In this case, self-fever temperature Tup
Tup (degree)= ((0.32-(0.32*0.7))-(0.5*0.1+0.3*0.0196+2.7*0.0196*0.0196))*260 =10.16 (degree)
Start temperatue Ts(degree)=45(degree)-10.16(degree)=33.4(degree)
Io is controlled as the Fig 6 as a result within the recommendation current area of LED.
The saturation thermal resistance Rth(j-a) = 260 (degree /W) is maximum value. They sometimes become
the Rth(j-a) = 210 - 260 (degree /W) by mounting.
And, the individual difference is formed in the starting temperature with the character of the IC and the influence
of the difference in the environment of the use.
Fig 6 : the derating function of the setup current
0
25
50
75
100
Ts/Tjs (degree)
0
20
40
60
80
100
120
R
The change of
Ts=34.4(degree)
(20mA=100%)
The
recommendation
current area of LED
(25mA conversion)
The change by Tjs
相關(guān)PDF資料
PDF描述
TB6500AH 2 PHASE BIPOLAR STEPPER + FULL BRIDGE DRIVER
TB6500 2 PHASE BIPOLAR STEPPER + FULL BRIDGE DRIVER
TB6551FG 3-Phase Full-Wave Sine-Wave PWM Brushless Motor Controller
TB6556FG 3-Phase Full-Wave Sine-Wave PWM Brushless Motor Controller
TB6556F 3-Phase Full-Wave Sine-Wave PWM Brushless Motor Controller
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
TB62732FUG 制造商:TOSHIBA 制造商全稱:Toshiba Semiconductor 功能描述:Step-up DC/DC Converter for White LED Driver
TB62733FTG 制造商:TOSHIBA 制造商全稱:Toshiba Semiconductor 功能描述:Charge Pump type DC/DC Converter for White LED Driver
TB62734FMG 制造商:MARKTECH 制造商全稱:Marktech Corporate 功能描述:Step Up Type DC-DC Converter for White LED
TB62736FUG 制造商:MARKTECH 制造商全稱:Marktech Corporate 功能描述:Step-up Type DC-DC Converter for White LEDs
TB62736FUG(O,EL) 功能描述:LED照明驅(qū)動器 White LED Driver RoHS:否 制造商:STMicroelectronics 輸入電壓:11.5 V to 23 V 工作頻率: 最大電源電流:1.7 mA 輸出電流: 最大工作溫度: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:SO-16N