uP PROGRAMMABLE FILTERS:          MAX260          MAX261         MAX262
-----------------------------------------------------------------------------
Filter type                       Universal       Universal      Universal
-----------------------------------------------------------------------------
Clock/Center freq ratio, approx   100-200         100-200        40-140
CLK/fc ratio - Mode 2 only        71-142          71-142         28-100
-----------------------------------------------------------------------------
Max Center Frequency              7.5 KHz         30 KHz         75 KHz
for Q > 8
-----------------------------------------------------------------------------
Q Register ( A,B independent )    7 bits          7 bits         7 bits
-----------------------------------------------------------------------------
Clock Ratio Register              6 bits          6 bits         6 bits
( A and B independent )
-----------------------------------------------------------------------------
Independent A,B mode selection    Yes             Yes            Yes
-----------------------------------------------------------------------------
Independent A and B Clock         Yes             Yes            Yes
-----------------------------------------------------------------------------
Uncommitted op amps               None            1              1
-----------------------------------------------------------------------------
Crystal or RC Clock               Yes             Yes            Yes
-----------------------------------------------------------------------------
***
PIN PROGRAMMABLE FILTERS:                MAX 263              MAX264
-----------------------------------------------------------------------------
Filter type                              Universal            Universal
-----------------------------------------------------------------------------
Clock/Center Freq. Ratio                 100-200              40-140
CLK/fc Ratio - Mode 2 only               71-142               28-100
-----------------------------------------------------------------------------
Max Center Frequency for Q > 8           30 KHz               75 KHz
for high Q
-----------------------------------------------------------------------------
Q Register ( A,B same value )            7 bits                7 bits
-----------------------------------------------------------------------------
Clock Ratio Register                     5 bits                5 bits
( A and B same value )
-----------------------------------------------------------------------------
Independent A and B mode selection       No                    No
-----------------------------------------------------------------------------
Independent A and B Clock                Yes                   Yes
-----------------------------------------------------------------------------
Crystal or RC Clock                      Yes                   Yes
-----------------------------------------------------------------------------
***
RESISTOR PROGRAMMABLE FILTERS:           MAX 265              MAX266
-----------------------------------------------------------------------------
Filter type                              Universal            Universal
-----------------------------------------------------------------------------
Clock/Center freq. Ratio                 100-200              40-140
( Can be changed with resistors )
-----------------------------------------------------------------------------
Max Center Frequency for Q > 8           30 KHz               75 KHz
-----------------------------------------------------------------------------
Q Setting ( A,B independent )      Set with resistors   Set with resistors
-----------------------------------------------------------------------------
Clock ratio pin setting,                 6 bits                6 bits
same both sides, further
independently modifiable with resistors
-----------------------------------------------------------------------------
Independent A and B Clock                Yes                   Yes
-----------------------------------------------------------------------------
Uncommitted op amps                      2                     2
-----------------------------------------------------------------------------
On-chip crystal or RC oscillator         Yes                   Yes
-----------------------------------------------------------------------------
***
PROGRAMMABLE BANDPASS FILTERS:        MAX 267              MAX268
-----------------------------------------------------------------------------
Filter type                           Bandpass only        Bandpass only
-----------------------------------------------------------------------------
Clock/Center Freq. Ratio              100-200              40-140
-----------------------------------------------------------------------------
Max Center Frequency for Q > 8        30 KHz               75 KHz
-----------------------------------------------------------------------------
Q Register ( A and B Same Value )     7 bits                7 bits
-----------------------------------------------------------------------------
Clock Ratio Register                  5 bits                5 bits
( A and B Same Value )
-----------------------------------------------------------------------------
Uncommitted op amps                   1                     1
-----------------------------------------------------------------------------
Crystal or RC Clock                   Yes                   Yes
-----------------------------------------------------------------------------
***

                  THE FEATURES OF THIS PROGRAM
-----------------------------------------------------------------------------
Program PZ    Given the type of filter ( Chebyshev, Butterworth, elliptic ),
              cutoff or center frequency, passband ripple, Q, atttenuation,
              PZ will calculate the center frequencies , Q's, zeros and the
              number of stages needed.
-----------------------------------------------------------------------------
Program RP    For devices which use resistor programming, RP will calculate
              the values of the resistors, given the specs of the individual
              first or second order stages, worked out by PZ.
-----------------------------------------------------------------------------
Program RPCHECK   Given any set of programming resistors, the clock ratio and
              clock frequency, RPCHECK will calculate the actual performance
              of a stage for all of the modes. This might be used to test the
              sensitivity to resistor tolerances of a design out of RP.
-----------------------------------------------------------------------------
Program MPP   For digitally programmed filters MPP outputs the proper
              programming codes and describes the performance of the design
              when given the filter center frequencies and Q's.
-----------------------------------------------------------------------------
***
-----------------------------------------------------------------------------
Program FR    When a design of one or more double pole or single pole stages is
              completed using the above aids for setting up resistors and
              digital codes, FR will check the final assembly of stages when
              they are cascaded into one system. The output frequency response
              can be compared with that expected from PZ.
-----------------------------------------------------------------------------
Program BP    In the special case of bandpass filters, another mode of
              implementation is the multiple feedback technique using the
              special parts MAX 267/268. Program BP will calculate the
              resistor values and give the frequency response which can be
              compared with that expected from PZ. This method has the benefit
              of requiring only one clock frequency for all stages and allows
              for arbitrary gain.
-----------------------------------------------------------------------------
Program FV    The graphics program FV can be used directly from the menu or
              from inside Programs PZ, FR and BP. It will display on the screen
              graphical representations of gain, phase and group delay using as
              input data the files developed by PZ, FR and BP.
***
PROGRAM OUTPUT FILES ( Engineering reports and frequency response listings )

PZ      First run of PZ: report file is PZ1.R and frequency response files are
        PZ1A, PZ1B,. . . . . .PZ1I etc. for 9 possible runs
        Ninth run of PZ: summary file is PZ9.R and frequency response files are
        PZ9A, PZ9B,. . . . . .PZ9I

RP      First run report file is RP1.R and so on for 9 runs
        Ninth run report file is RP9.R

RPCHECK    First run report file is CHECK1.R and so on for 9 runs
           Ninth run report file is CHECK9.R

MPP     First run report file is MPP1.R and so on for 9 runs
        Ninth run report file is MPP9.R

FR      First run output files for different frequency response conditions
        are FR1A, FR1B  etc for 9 possible files to FR1I
        for 9 runs down to FR9A, FR9B, . . . . . . . FR9I

BP      First run gives BP1.R and then BP1A . . . . . BP1I
        Ninth run gives BP9.R and then BP9A . . . . . BP9I
***
NOTES ON OUTPUT FILES

As noted above the programs generate two types of files, report files and
frequency response files. The program names the files automatically starting
with '1' and 'A' and then successively going to 2, 3 ... and B, C, ....
Report files give design information and have a subscript ".R" while frequency
response files which can be used by the graphics package have no subscript.

AUTOMATIC RENAMING OF OUTPUT FILES

The program names the files automatically and always uses the same names.
Consequently any old files in the directory would be overwritten and lost if
the program did not rename them. However, the program does check to see if a
file of the same name exists and renames it by adding a letter to the end of
the name so that the name is unique in the directory.
Examples: PZ1.R may be renamed PZ1.RA;  BP1A may be renamed BP1A.C
The first letter which results in a unique name is appended for renaming.


***
BROWSING IN FILES

It is often necessary to use the output of one program as the input for another
one. For instance, the output of PZ in file PZ1.R would be needed to provide
the pole, zero, Q information for either MPP or RP. The existing output files
can be conveniently examined directly from the main menu by using the BROWSE
option which gives access to all files in the working directory. Data can
be noted by hand or the PRINT SCREEN feature of the keyboard may be used to
print the pertinent passages.

MISCELLANEOUS HINTS

In many cases where the user is asked for a Y/N answer to a question, the
negative option may be taken by pressing RETURN without typing a letter.
In almost all cases answers may be lower or uppercase without affecting the
result. In case the user wishes to abort a program, pressing CONTROL-BREAK
will return the user to DOS.
***
USE OF TITLES ON FILES

The first line of every output file is a main title which would normally be
the title of the overall project. This title also appears on the top of the
graphics display. The user gets the opportunity to make this title at the
startup of FILTER.

The second line of every output file has the date and time of the start of the
subprogram and the subtitle which can be written at the start of each
subprogram. The same first and second line titles, with the same time and date
will be on all files of the same run and can be used to connect the design
data to the proper frequency response data. The second line title helps to
identify files in the BROWSE option and in FV graphics.

FURTHER HELP

Each individual program has its own help file which may be invoked after
selecting the program.
***

