1993_Motorola_Linear_Interface_ICs_Vol_2.pdf

Optional Waveform Disable
Pin 2 on the MC44615A is provided for blanking the output
waveforms. When the voltage applied at this pin is less than
about 2.5 V, all outputs are blanked and within 50 mV of
ground. The impedance presented at this pin is> 500 kQ. The
outputs can be permanently enabled by a pull-up resistor from
Symbol
VCC
Waveform
Blank
fH
Pin
2
3
4
(See Note)
Internal Equivalent Circuit
Nole: All pins (except Vee and VEE) have ESD diodes between Vee and VEE.
lk
MC44615A
PIN DESCRIPTION TABLE
25k
25k
MOTOROLA LINEAR/INTERFACE ICs DEVICE DATA
9-266
Pin 2 to the positive supply, VCC. An external RC is
anotheroption. A resistor (1 a kQ to 1 00 kQ) coupled from Pin 2
to VCC and a capacitor coupled from Pin 2 to ground will delay
the appearance of the waveforms by an amount,
tdelay = RC (0.69)
Description
Positive rail voltage. Requires 33 mA at 4.5 < Vdc < 5.5.
Output waveform blanking pin. An external RC may be used
to delay the appearance of the output waveforms.
Waveforms are present when Pin 2 voltage exceeds 2.5 V.
Input impedance is nominally 500 kQ.
Positive horizontal flyback input. Input impedance is
nominally 10 kQ. (See Figure 2)
Horizontal oscillator capacitor (CH). The charge and
discharge rate of this capacitor's voltage determines the
horizontal frequency. Charging current set predominantly
by RHset. (See Figure 3)