- 您現(xiàn)在的位置：買(mǎi)賣IC網(wǎng) > PDF目錄362652 > EL7630ICZ-T7 (INTERSIL CORP) White LED Boost Regulator PDF資料下載
參數(shù)資料
| 型號(hào)： | EL7630ICZ-T7 |
| 廠商： | INTERSIL CORP |
| 元件分類： | 穩(wěn)壓器 |
| 英文描述： | White LED Boost Regulator |
| 中文描述： | 0.35 A SWITCHING REGULATOR, 1900 kHz SWITCHING FREQ-MAX, PDSO6 |
| 封裝： | ROHS COMPLIANT, SC-70, 6 PIN |
| 文件頁(yè)數(shù)： | 5/7頁(yè) |
| 文件大小： | 223K |
| 代理商： | EL7630ICZ-T7 |
5
FN7371.0
June 28, 2005
can drive up to 6 LEDs in series or 15 LEDs in
parallel/series configuration, with efficiencies of up 86%.
EL7630 operates from an input voltage of 2.7V to 5.5V and
can boost up to 27V.
Steady-State Operation
EL7630 operates with constant frequency PWM. The
switching frequency is around 1.2MHz. Depending on the
input voltage, inductance, number of LEDs and the LED
current, the converter operates in either continuous
conduction mode or discontinuous conduction mode. Both
are normal. The forward current of the LED is set using the
R
SET
resistor. In steady state mode, this current is given by
the equation:
V
SET
Shut-Down
The ENAB pin, when taken low places EL7630 into power
down mode. When in power down, the supply current
reduced to less than 1μA.
Dimming Control
The ENAB pin also doubles as a brightness control. There
are two different types of dimming control methods. The first
dimming control is controlled through the duty-cycle of the
ENAB input PWM waveform, which can operate at
frequencies of 400Hz to 1kHz. The LEDs operate at either
zero or full current. This is called PWM dimming control
method. The relationship between the average LED current
and the duty-cycle (D) of the ENAB pin’s waveform is as
follows:
V
SET
The magnitude of the PWM signal should be higher than the
minimum ENAB voltage high. The bench PWM dimming test
results are shown in Figure 9. In the test, two PWM
frequencies 400Hz and 1kHz are chosen to compare the
linear dimming range. It is clear that for lower PWM
frequency, the linear dimming range is wider than one for
higher PWM frequency. In the PWM dimming test, the output
capacitor is 0.22μF.
The second dimming control is to apply a variable DC
voltage to adjust the LED current. This is called analog
dimming control. The dimming control using a DC voltage is
shown in Figure 10. As the DC dimming signal voltage
increases, the voltages drop on R
1
and R
2
increases and
the voltage drop on R
SET
decreases. Thus, the LED current
decreases. The DC dimming signal voltage can be a variable
DC voltage or a DC voltage generated from a PWM control
signal. For some application areas, the PWM control signal
is a high frequency signal. To make dimming controllable
with these high frequency PWM signals, the high frequency
components of the PWM control signal should be filtered to
get the equivalent DC voltage. The equivalent DC voltage is
then used as the variable DC voltage for dimming LED
current.
where F is the brightness with respect to the undimmed
value.
I
LED
--------------
=
(EQ. 1)
average I
LED
--------------
D
=
(EQ. 2)
0
5
10
15
20
25
0 10 20 30 40 50 60 70 80 90 10
DUTY-CYCLE (%)
I
O
FIGURE 9. PWM DIMMING LINEAR RANGE (FOR 400Hz AND
1kHz PWM FREQUENCIES CONDITION,
C
OUT
= 0.22μF)
1kHz
400Hz
I
LED
V
R
SET
--------------
R
--------------------
R
2
+
R
2
V
R
1
R
SET
R
2
--------------------------
–
=
(EQ. 3)
V
Dim
R
2
R
1
------
V
FB
1
R
1
R
2
------
F
–
+
=
(EQ. 4)
EL7630
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| EL7630ICZ-T7A | White LED Boost Regulator |
| EL7630 | White LED Boost Regulator |
| EL7630ICZ | White LED Boost Regulator |
| EL7630IWTZ-T7 | White LED Boost Regulator |
| EL7630IWTZ-T7A | White LED Boost Regulator |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| EL7630ICZ-T7A | 功能描述:LED顯示驅(qū)動(dòng)器 EL7630ICZ WHT LED BOOSTG RoHS:否 制造商:Micrel 數(shù)位數(shù)量:5 片段數(shù)量: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:PLCC-44 工作電源電壓:4.75 V to 11 V 最大電源電流:10 mA 最大工作溫度:+ 85 C 最小工作溫度:- 40 C 封裝:Tube |
| EL7630IWTZ | 制造商:Intersil Corporation 功能描述:LED DRVR 6SEGMENT 2.7V TO 5.5V 5PIN TSOT - Bulk |
| EL7630IWTZ-EVAL | 功能描述:LED 照明開(kāi)發(fā)工具 EL7630IWTZ-EVAL DEMO BRD RoHS:否 制造商:Fairchild Semiconductor 產(chǎn)品:Evaluation Kits 用于:FL7732 核心: 電源電壓:120V 系列: 封裝: |
| EL7630IWTZ-T7 | 功能描述:LED顯示驅(qū)動(dòng)器 EL7630IWTZ WHT LED BOOSTG RoHS:否 制造商:Micrel 數(shù)位數(shù)量:5 片段數(shù)量: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:PLCC-44 工作電源電壓:4.75 V to 11 V 最大電源電流:10 mA 最大工作溫度:+ 85 C 最小工作溫度:- 40 C 封裝:Tube |
| EL7630IWTZ-T7A | 功能描述:LED顯示驅(qū)動(dòng)器 EL7630IWTZ WHT LED BOOSTG RoHS:否 制造商:Micrel 數(shù)位數(shù)量:5 片段數(shù)量: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:PLCC-44 工作電源電壓:4.75 V to 11 V 最大電源電流:10 mA 最大工作溫度:+ 85 C 最小工作溫度:- 40 C 封裝:Tube |
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。