參數(shù)資料
型號: Nl27wz08
廠商: ON SEMICONDUCTOR
英文描述: Dual 2-Input AND Gate(雙端兩輸入與門)
中文描述: 雙2輸入與門(雙端兩輸入與門)
文件頁數(shù): 1/8頁
文件大小: 62K
代理商: NL27WZ08
Semiconductor Components Industries, LLC, 2001
October, 2001 – Rev. 0
1
Publication Order Number:
AND8067/D
AND8067/D
NL27WZ04 Dual Gate
Inverter Oscillator
Increases the Brightness
of LEDs While Reducing
Power Consumption
Prepared by: Jim Lepkowski
Senior Applications Engineer
Mike Hoogstra
JTL Design
Christopher Young
Arizona State University
INTRODUCTION
ON Semiconductor’s new family of two–gate logic
devices offer space saving solutions to the logic designer.
The LV–CMOS two gate logic family consists of inverters,
buffers and logic gates in both the SC–88 and TSOP–6
package. These versatile devices have several features
including a wide 2.3 V to 5.5 V operating voltage range, low
quiescent power supply current and an output capable of
sinking or sourcing 24 mA.
Figure 1. LED Oscillator Circuit
NL27WZ04
NL27WZ04
V
4
R
1
12 k
V
1
V
2
V
3
U
1A
U
1B
R
4
1 M
R
3
39
R
2
12 k
C
2
0.01
μ
F
C
1
0.1
μ
F
LED
D
1
The versatile features of the two gate devices will be
demonstrated by using the NL27WZ04 dual inverter IC to
create the Light Emitting Diode (LED) oscillator circuit
shown in Figure 1. An oscillator can be used to increase the
brightness of an LED without increasing the system’s power
requirements. The brightness of an LED is directly
proportional to the current through the LED, which creates
a challenge for low voltage and battery powered
applications. Thus, a high peak current is required to obtain
a bright LED, while a low average current is needed to
minimize the power consumption. The LED oscillator
circuit achieves these requirements by providing a low duty
cycle waveform with a short duration “ON” time and a long
“OFF” time.
Light Emitting Diodes
LEDs are manufactured out of a variety of semiconductor
materials and are comprised of a “P” and “N” type junction,
which establishes a voltage potential across the junction.
The LED provides a light output when the diode is forward
biased, causing current to flow through the device. The
forward voltage (V
f
) of the diode will be different for the
various materials and colors and ranges from approximately
1.5 V for red to 3.3 V for blue LEDs.
A pulsating LED drive circuit can enhance the light output
of an LED by using a peak current of a much higher level
than sustainable under direct drive conditions [1][2]. A high
peak current pulse of short duration with a “OFF” period
between pulses allows time for the LED’s junction to cool
down. High drive currents can result in a degradation of the
light output and the life expectancy (time to half light output)
of an LED. However, the reduction in the life of a pulsed
LED is minimal if the peak current is below the maximum
current limit specified for the device.
Why Are Pulsed LEDs Brighter Than DC LEDs
There are two main reasons why LEDs are brighter when
pulsed. First, the human eye functions as both a peak
detector and an integrator; therefore, the eye perceives a
pulsed LED’s brightness somewhere between the peak and
the average brightness [4]. Thus, an LED driven by a high
intensity low duty cycle light looks brighter in a pulsed
circuit compared to a DC drive circuit that is equal to the
average of the pulsed signal.
The second factor controlling the improved brightness is
shown in the relative efficiency versus peak current curves
of an LED. Figure 2 shows the efficiency curves for the
http://onsemi.com
APPLICATION NOTE
相關(guān)PDF資料
PDF描述
NLSV4T3234 4−Bit Dual−Supply Bus Buffer Level Translator with 26 ohm Output Series Resistor
NLSV4T3234FCT1G 4−Bit Dual−Supply Bus Buffer Level Translator with 26 ohm Output Series Resistor
NLV17SZU04 Single Unbuffered Inverter(單路無緩沖反向器)
NLVAS4599 Low Voltage Single Supply SPDT Analog Switch(低壓單電源SPDT模擬開關(guān))
NM-BM-10 50OHM, 3,6,10 dB, DC to 2000 MHz Adaptenuators
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
NL27WZ08/D 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Dual 2-Input AND Gate
NL27WZ08_06 制造商:ONSEMI 制造商全稱:ON Semiconductor 功能描述:Dual 2−Input AND Gate
NL27WZ08US 功能描述:邏輯門 1.65-5.5V Dual RoHS:否 制造商:Texas Instruments 產(chǎn)品:OR 邏輯系列:LVC 柵極數(shù)量:2 線路數(shù)量(輸入/輸出):2 / 1 高電平輸出電流:- 16 mA 低電平輸出電流:16 mA 傳播延遲時間:3.8 ns 電源電壓-最大:5.5 V 電源電壓-最小:1.65 V 最大工作溫度:+ 125 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:DCU-8 封裝:Reel
NL27WZ08USG 功能描述:邏輯門 1.65-5.5V Dual 2-Input AND RoHS:否 制造商:Texas Instruments 產(chǎn)品:OR 邏輯系列:LVC 柵極數(shù)量:2 線路數(shù)量(輸入/輸出):2 / 1 高電平輸出電流:- 16 mA 低電平輸出電流:16 mA 傳播延遲時間:3.8 ns 電源電壓-最大:5.5 V 電源電壓-最小:1.65 V 最大工作溫度:+ 125 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:DCU-8 封裝:Reel
NL27WZ08USG 制造商:ON Semiconductor 功能描述:Logic IC