
MC44002 MC44007
24
MOTOROLA ANALOG IC DEVICE DATA
PIN FUNCTION DESCRIPTION
Pin
Equivalent Internal Circuit
Description
1
0.1
VCC
Gnd
ACC
External Filter used by ACC section. A single capacitor, that does not
have a critical value, typically 0.01
μ
F, filters the feedback loop of the
chroma automatic gain control amplifier.
2
40
100 nF
Gnd
1.0 k
20 k
20 k
14 k
Video Input 1 (Pin 40) and 2 (Pin 2)
Video inputs (Pin 2 = Video 2; Pin 40 = Video1); Intended for a
nominal 1.0 Vpp input level of composite video. Separate luma and
chroma components may also be used with these input pins for
S–VHS. The external circuit requirement is for a coupling capacitor of
0.01
μ
F and a series resistance not exceeding 1.0 k
. The input
selection and adaptation for Y and C is carried out in software.
3
Set
Iref
VCC
Gnd
8.0 k
20 k
V
Supply
0.01
2.2
μ
F
Reference Current
Master reference current used throughout the IC. This is programmed
by means of an external pull–up resistor, as on–board resistors are
not sufficiently accurate. The designated current is 70
μ
A. This pin
should be very well de–coupled to ground to avoid picking up
interference from the nearby I2C bus inputs. Nominal voltage at the
pin is 1.3 V.
4
Gnd
To MCU
150 k
70 k
I2C Clock
I2C bus clock input. This input can be taken straight into the IC, but in
a real TV application it may be prudent to fit a series current limiting
resistor near the pin in case of flash–over. A single pull–up resistor to
5.0 V is required. Although its value is associated with the
μ
P, taking
into account system capacitance at high data rates, a value of 4.7 k
,
giving optimal performance, is recommended.
5
Gnd
To MCU
180 k
70 k
I2C Data
I2C data input. Comments above for Pin 4 also apply to this pin.
6
0.082
μ
F
VCC
Gnd
Vertical Ramp
A current is used to charge an external capacitor connected to this
pin, developing a voltage sawtooth with a field period. The capacitor
value determines the ramp amplitude. 82 nF is the more convenient
value for symmetrical, linearity and parabola tilt adjustments.