Wanted to share info about PLL's
My study Material.. I think LD is why I Couldnt transmit.. Turns out technical error made that transmit on all channels at once... OOppps..
VCC or VDD.
---------- This is the +DC supply voltage which atually provides the
operating power to the chip, and is generally in the range of 4 to 8 Volt's.
GND or VSS.
---------- This is the DC power ground connection for the above.
NOTE:- A chip may be found one or more of its functional pins tied to
either of the above sources. This may be done to enable a specific
function by connecting that function to a logic 1 or 0, or to prevent an
unused function pin from "floating" unconnected to prevent a possible
change in it's logic state.
RI
---- Reference Oscillator Input. This is where the (usually) 10.240 MHz
crysal is connected. Crystal pins are sometimes called "X" by the manufacturer.
RO
---- Reference Oscillator Output. In most chips the crystal is simply
connected across RI and RO because the chip has an inbuilt oscillator circuit
which only requires some external capacitors. However, some chips such as the
PLL02A don't have the built in oscillator; that is why there is no RO pin and
an active transistor oscillator is required externally which connects to RI.
1/2R
------ A built-in divide by two circuit which provides an output of half the
10.240MHz reference oscillator frequency, or 5.12MHz. If used, it normally
connects to a trippler circuit to provide a 15.360MHz signal (5.12MHz * 3)
which can be used for loop mixing with the 16MHz VCO. This mixing provides a
low frequency signal input or downmix to the programmable divider.
RB
---- Buffered Output of the 10.240MHz Reference Oscillator. This signal, if
present, can be used for mixing with the 10.695MHz receiver first IF or mixing
with the 16MHz VCO during TX mode to provide the 455KHz second IF (RX) or the
direct on-channel TX Frequency.
Fin
----- Input to the programmable divider which is coming from the output of
the VCO. Sometimes called "PI"(Programmable Input) or "DI"(Divider Input) by
some manufacturers. This is the actual downmix signal or direct VCO signal in
the faster chip's which will be compared to the reference dividers output in
the Phase Detector. It is the change in the signals frequency which forces the
Phase Detector and VCO to correct until the loop lock's.
DO
---- Phase Detector output. Sometimes called "PO" or "PDout"(Phase Output)
or "EO"(Error Output) by some manufacturers. This is the output which results
from comparing RI and Fin. If the two inputs dont match exactly, this circuit
sends a DC correction output to the loop filter/VCO until the loop corrects
itself and locks up.
LD
---- Lock Detector. Sometimes called "LM"(Lock Monitor) by some
manufacturers. This is a second output of the phase detector which is used
to kill the transmitter (and sometimes the receiver) if the loop is not
locked and operating correctly. Some chips have more than one lock
detector and sometimes you will see LD1 and LD2 on the specifications.
When two lock detectors are used, their normal outputs are usually
opposite logic states. This is a convenient design feature which allows
the manufacturer some flexibility because he can have a choice of
inhibiting circuits ; some work with LOW outputs and some work with HIGH
outputs. Some radio's use both LD pins in their circuits.
MC
---- Misprogram Code Detector. The same idea as the Lock Detector,
this is found in the newer ROM Chip's. If you try to force an illegal
program code on the chip, this pin is activated and will kill the
transmitter, receiver, or in some cases, call up channel 9 or channel 19
instead.
T/R
----- Transmit/Receive switch. This is used to provide the 455KHz
offset for the receiver's second IF stage in dual conversion AM or FM
radio's. Pressing the Mike Button changes the pins logic state to its
opposite state from the RX mode. This shifts the ROM controlling the
programmable divider, and in some chips also shifts the output of the
reference divider from standard 5KHz steps to 2.5KHz steps. The T/R shift
is the reason you will see two different sets of 'N' codes and VCO
frequencies in a radio's service manual or SAMS FOTOFACTS.
NOTE:- Some manufacturers chip specification sheets show a bar (-)
above the pin functions, such as LM, T/R, etc. This bar is a digital logic
symbol which indicates what state ( 1 or 0 ) that pin is when activated.
FS ---- Frequency Select. This is a feature of some chips which
allows them to synthesize frequencies in either 10KHz CB steps, or 5KHz
steps. Remember, some older chips such as the PLL02A were intended for
other uses besides CB, such as VHF marine radio's, Aircraft radio's, etc.,
where the 5KHz channel spacing is common. In addition, this feature often
makes it easier to synthesize SSB frequencies as well as AM and FM
although the feature has not been used much for this. Depending on whether
the Chip has an internal pull-up or pull-down resistor here, it is
generally connected to produce 10KHz spacings in the older chips. The
newer chips having a T/R shift must use the 5KHz spacing when the T/R pin
is also used. IMPORTANT:- You can not use this function to get 5Khz
channel spacings, because the Programmable Divider must also change to
match the spacing.
AI,AO ------- Active Loop Filter Amplifier Input and Output. This
circuit, if present, is used to smooth out the digital waveform coming
from the phase detector, before it is applied to the VCO. This filter is
found in the newer CB-only chips. The older chips Eg(PLL02A) require
external passive filters using capacitors and resistors. In many radio's
you will find that these pins are connected either directly or through a
resistor so that they are placed in series between the phase detector
output pin and the VCO input.
FIL ----- Active Filter. Where using this designation in certain very
old chips when the exact specification sheets are not available but its
known from studying the chips that wiring in the radio that the pins are
in fact part of a loop filter.
T&Q ----- This is a wave shaping circuit found in a few NEC chips
(uPD2810, uPD2814, uPD2816, uPD2824). It adds design flexibility but is
often not even connected. This circuit consists of an input amplifier and
a "flip flop", and its purpose is to change a sine-wave input (T) to a
square wave output (Q) which is more compatible with a digital electronic
circuits.
P0..to..P10 ----------- Program select pins from the channel switch.
(Sometimes called "D" for "DATA" rather than "P" for "PROGRAM".) These
pins control the actual channel selection. They may control selection
through straight binary coding, BCD, or ROM. The sub numbers indicate the
weight or significance of each pin. For example if there were eight
programming pins, P1 to P8, P1 would be in the "least significant bit" and
P8 would be the "Most significant bit". The higher the sub number, the
greater the weight of the pin.
NC ----- No Connection. An unused pin. May actually be disconnected
inside the chip, or simply not be used for that particular radio's PLL
circuit.
* --- Special Remarks when necessary.
