MC44302A 데이터 시트보기 (PDF) - Motorola => Freescale
부품명
상세내역
제조사
MC44302A Datasheet PDF : 28 Pages
| |||
Pin No.
10
MC44302A
PIN FUNCTION DESCRIPTION (continued)
Equivalent Internal Circuit
Description
VCC
3.0 k PAL 1
PAL 2
VCC
V1
10 Video Mode Switch
Video Mode Switch
A dc voltage at this input selects the proper video AGC and sound
demodulation technique for PAL, SECAM, and NTSC. With PAL
1 selected, AGC is keyed on the sync pulse by the horizontal PLL
which is locked to the flyback or video sync pulse present at Pin 17.
V2 The FM sound IF and detector is active. The PAL 2 selection is
identical to PAL 1 with the addition of sound muting when the
acquisition circuit is unlocked or vertical sync is absent. With
SECAM selected, the video level is established by both, a long
time constant peak white detector, and a back porch keyed AGC
that corrects for transmitted black level errors while maintaining
fast AGC response. The AM sound detector is active. With NTSC
selected, AGC and sound muting is the same as in PAL 1 mode.
The FM and AM detectors are both active with the FM output at
Pin 27 and the AM output at Pin 24. Refer to Table 2.
2.4 k SECAM
5.1 k NTSC
11
To Tuner AFT Input. AFT Output
AFT Ouput 11
3.3 IO must be externally With detent type tuners, the automatic fine tuning output can be
limited < 4.0 mA.
used to directly control the tuner local oscillator varactor. The
VCC
varactor control input must be high impedance in order to maintain
high AFT loop gain with acceptable dynamic response. This
VCC
output has a linear sink and source current range of 0 to 500 µA,
0 to ±500 µA
or ±2.0 mA
and is digitally switched to ±2.0 mA for large frequency errors. The
capacitor from Pin 11 to ground limits the bandwidth of the tuner
Digital Slew
20 Variable
Reference
Clamp Voltage
local oscillator loop. Digital phase–locked loop tuning systems
can also be controlled with the addition of a varactor diode used
to shift the PLL reference oscillator. Refer to Figures 6, 24, and 25.
Rate Control
12
VCC
12 AFT Mode Switch
VCC
VCC 24 k
5.1 k
AFT Mode Switch
This input is used to activate the output of the AFT control amplifier
that appears at Pin 11, and to select the control voltage polarity
versus IF frequency. This feature allows the AFT output to work
with all types of varactor tuned local oscillators. With the AFT
Mode Switch input connected to VCC, Pin 11 is placed in a
sourcing mode when the IF carrier frequency is below nominal.
With the AFT Mode Switch input grounded, Pin 11 is placed in a
sinking mode when the IF carrier frequency is below nominal. With
the AFT Mode Switch input disconnected, Pin 11 is internally
clamped to one half of VCC, refer to Figures 6 and 25.
24 k
13
VCC VCC
VCC
To Tuner
10 k
13
AGC Input
RF AGC
Output
RF AGC Output
This output is designed to control a reverse AGC tuner. As the
antenna signal level increases, the voltage at Pin 13 decreases,
causing a gain reduction in the tuner RF stage. An external pull–up
resistor must be added if one is not provided in the tuner. Pin 13
is guaranteed to sink a minimum of 1.0 mA. Note that when
operating with a tuner that requires in excess of 5.6 V, current will
flow into Pin 13 due to conduction of the upper internal clamp
diode.
20
MOTOROLA ANALOG IC DEVICE DATA
Share Link: 