Sanyo EP92H manual Amorphous Optical Sensors, Amorphous Optical Sensor Structure, AM-30-26

: 10 to 10k Lx

Achieving Low Power and Superb Viewability

Amorphous Optical Sensors

Amorphous Silicon Solar Cells

Amorphous Optical Sensors

These devices are a type of photodiode that can detect light with about the same sensitivity as the human eye. Since these devices flexibly support a wide range of end product designs and sizes, they can be used to control the LCD backlight and button lamps in cell phones to implement power saving automatic brightness adjustment

Amorphous Optical Sensor Structure

These devices are a type of photodiode that can detect the presence/absence of ambient light, or the intensity of ambient light.

Like amorphous silicon solar cells, amorphous optical sensor use the photovoltaic effect in semiconductors.

Light

Amorphous optical sensor spectral sensitivity

Visible wavelength amorphous optical sensor

Human visual sensitivity

Single-crystal silicon optical sensors

Illumination-dependent characteristics of ISC Amorphous optical sensor pattern examples

Measured at FL (for color illuminator): 1 to 10 kLx at SS (Solar Simulator)

When light hits a semiconductor, electrons and holes are created, the electrons diffuse in the n-type semiconductor, and the holes diffuse in the p-type semiconductor. As a result, a current will flow when the

(+) Anode

Transparent electrode

+

sensitivity	1
Relative	0.5

400 500 600 700 800 900 1000

Isc(A)

1.E-03

1.E-04

1.E-05

1.E-06

1.E-07

1.E-08

1.E-09

1.E-10

1

[AM-30-26]

10 100 1,000 10,000 100,000

2.1 1.2

2.0

0.88

0.84

[AM-30-26]

two semiconductor types are connected externally.

p	+	+ +	+	+	+			+
			+	+		+		+
					+		+
i	+		+					+
							+
			+		+			+		(-) Cathode
n
Metallic electrode									Electron

Wavelength [nm]

High sensitivity in the visible region

The human eye is sensitive to light with wavelengths from about 400 nm to about 700 nm. Since these amorphous optical sensors have sensitivity to essentially the same wavelengths, they provide sensing that is close to that of the

Illumination [Lux]

The output current is proportional

to the illumination

Since the output current changes proportionally to the light striking the sensor, these devices provide precise detection.

Flexible pattern geometries and sizes

These devices support designs with sizes and shapes that correspond to the target application.

+ Electron hole

Amorphous Optical Sensor Circuit Examples

human eye.

With an operational amplifier

Without an operational amplifier

Amorphous Optical Sensor Application Examples

Automatic adjustment of LCD backlight and operating panel buttons

A/D

A/D converter

These sensors can be used to sense the ambient illumination level and automatically turn off these lamps in bright operating environments. This reduces unnecessary power consumption and creates LCD screen display that is easy to see whatever the ambient lighting.

Cell phone with built-in optical sensor

Bright environments		Dark environments
LCD backlight OFF	LCD backlight ON	LCD backlight ON

Amorphous Optical Sensor (AM-30-26)

converter

C

Amorphous

Optical Sensor

(AM-30-26)

R

●Increased operating time for portable electronic equipment due to reduced power consumption!

●LCD backlight level automatically adjusted to just the right level for viewing according to the ambient illumination level

Bright environments	Dark environments
	LCD backlight
OFF	Automatic brightness adjustment ON
	Button lamps

	About 300Lx	About 3Lx
Button lamps OFF		Button lamps OFF	Button lamps ON
	5 to 20mA	55 to 70mA	95 to 110mA
	Cell phone without built-in optical sensor
	Bright environments	Dark environments
LCD backlight ON		LCD backlight ON	LCD backlight ON
	Unnecessary power	Unnecessary power
	consumption occurs	consumption occurs
Button lamps ON		Button lamps ON	Button lamps ON
	95 to 110mA	95 to 110mA	95 to 110mA

The current output from the amorphous optical sensor is	The amorphous optical sensor is connected to a resistor and the
converted to a voltage, and signal processing is applied to that	voltage is input directly to an A/D converter for discrimination.
voltage.
Normally, an operational amplifier is used for linear amplification.

Amorphous Optical Sensor Product Lineup

Type No.	External dimensions (mm)	Short-circuit current (ISC, typical)	Dark current (VR = 50 mV) MAX.
AM-30-26	2.1 ⋅ 2.0 mm2	1.2 A *1	10 pA
	(glass thickness: 0.4 mm)
		*1 : at 1000Lux, Fluorescent Light for color illuminator
Contact your SANYO sales representative for details on these products

32 33