Newport New Focus 8703, Руководство пользователя

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Model 8703 System 21
Schematic of Model 8703 System Board
4.1.7 LIDLE
Pin 6, LIDLE, is connected to the positive logic voltage to enable 8712
operation and left floating or grounded to disable the 8712. The 8703 will not
operate if Pin 6 is grounded or floating. Opto-isolator U100, Q100, R107-9
light diode D109 to indicate when Pin 6 is grounded or floating while
preserving the isolation barrier. R102 serves the same purpose as R100 and
R101. The same calculations apply for determining the value of R102. You
can just connect an 820
Ω
resistor between the 12V supply and Pin 6 to
disable LIDLE.
4.1.8 LFAULT
Pin 7 is the open collector opto-isolated LFAULT output. It goes low when
the case temperature limit is exceeded. LFAULT pulses when power is first
applied to indicate the firmware revision number. The data sheet gives an
example of the pulsed startup waveform. The customer must provide a pull-
up resistor on the LFAULT output. The pull-up resistor is connected to the
logic power supply near the destination of the LFAULT signal.
An example calculation of the pull-up resistor value is given below:
Opto-isolator diode current = 7 mA
Vce saturated = 0.3 V with Ic = 4 mA when the diode current = 7 mA
With 5V logic,