TSL230AR ETC1 [List of Unclassifed Manufacturers], TSL230AR Datasheet - Page 5

• Manufacturer Part Number: TSL230AR
• Description: PROGRAMMABLE LIGHTTOFREQUENCY CONVERTERS
• Manufacturer: ETC1 [List of Unclassifed Manufacturers]

Power-supply considerations
Input interface
Output interface
Sensitivity adjustment
The LUMENOLOGY r Company
Power-supply lines must be decoupled by a 0.01- F to 0.1- F capacitor with short leads placed close to the
TSL230 device package. A low-noise power supply is required to minimize jitter on output pulses.
A low-impedance electrical connection between the device OE pin and the device GND pin is required for
improved noise immunity.
The output of the device is designed to drive a standard TTL or CMOS logic input over short distances. If lines
greater than 12 inches are used on the output, a buffer or line driver is recommended.
Sensitivity is controlled by two logic inputs, S0 and S1. Sensitivity is adjusted using an electronic iris technique
— effectively an aperture control — to change the response of the device to a given amount of light. The
sensitivity can be set to one of three levels: 1 , 10 or 100 , providing two decades of adjustment. This allows
the responsivity of the device to be optimized to a given light level while preserving the full-scale
output-frequency range. Changing of sensitivity also changes the effective photodiode area by the same factor.
1.010
1.005
1.000
0.995
0.990
0.985
0.980
2.5
T
f
O
A
TYPICAL CHARACTERISTICS
= 100 kHz
APPLICATION INFORMATION
= 25 C
t
3
V
OUTPUT FREQUENCY
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SUPPLY VOLTAGE
3.5
– Supply Voltage – V
Figure 5
vs
4
4.5
5
t
5.5
Copyright E 2002, TAOS Inc.
TAOS048 – OCTOBER 2002
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