am336-2 AME, Inc., am336-2 Datasheet - Page 6

• Manufacturer Part Number: am336-2
• Description: Ic For Opto Detector - Analog Microelectronics
• Manufacturer: AME, Inc.

IC FOR OPTO DETECTOR
frequency it to high the signal detection is not triggered. In case of a too low frequency a pulsed
signal could occur at the output stages.
Connection pins: FO, IRD, P/B
AMPLIFIER:
The input stage for the photo current is a transimpedance–amplifier. His impedance depends on the
input frequency to reject ambient light.
The input current, coming from pin INA, appears multiplied by the impedance between INA and
OUTA at pin OUTA. For low frequencies this impedance is approximately R
and for high frequencies R
Connection pins: INA, OUTA, ALR.
SIGNAL DETECTION STAGE:
The signal of the input stage is connected via a high–pass filter (C
internal) to the inputs of comparator A and B (window comparator). The threshold voltages VT
and VT
resistors R
flip–flops. Threshold and hysteresis levels are determined by external resistors (R
temperature compensated by an internal voltage reference (VR). The resistors have to be located as
analog microelectronics
Figure 2: Functional diagram
V T A + V H A
V T B - V H A
B
Q O
V T A
L E D
I N D
I R D
V T B
and the hysteresis voltages VH
TA
and R
TB
(R
TA
A
(external resistor).
= 2 u R
TB
). The hysteresis is switched by the output signals of the D–
A
and VH
B
are generated by a constant current across the
V T B = 1.5 * V T A
V H B = 1.5 * V H A
IN
between OUTA and IND, R
t
B
(internal resistor)
AM 336
February 2005
D
R
H
) and
6/12
IN
A