EV1050 Datasheet, PDF (4/9 Pages) CML Microcircuits – User Manual

Evaluation Kit User Manual for FX105A
EV1050
1.3 Quick Start
This section provides instructions for users who wish to experiment immediately with the
evaluation kit. A fuller description of the kit and its use appears later in this document.
1.3.1 Setting-Up
THE EV1050 COMES PRE-CONFIGURED FOR OPERATION AT 5.0V.
To select 3.0V operation, short circuit JP1 with an insulated jumper socket.
WHEN THE SWITCHES (SW1 TO SW4) ARE SET TO USE THE FIXED VALUE RESISTORS,
THE EV1050 DETECTS A 440 Hz SIGNAL WITH A 6% (APPROX.) BANDWIDTH.
The default settings in the spreadsheet reflect the fixed component values used in the EV1050.
1.3.2 Operation
Apply an input signal between testpoint TP9 and V_SS. The detect output can be monitored at
testpoints TP1 or TP2 and is indicated by LED D2.
Select R1V with switch SW1 to adjust fo.
Select R2V with switch SW2 and RVV with switch SW4 to adjust the bandwidth.
Select RWV with switch SW3 to adjust the response and de-response times.
For all switches, setting the paddle away from the prototype area selects variable resistors and
setting the paddle towards prototype area selects fixed resistors. Please refer to the FX105A
data sheet for further information on the operation of this integrated circuit and for details of the
circuit design equations which govern the choice of component values.
1.3.3
Spreadsheet
An Excel spreadsheet has been included with this kit to simplify the selection of component
values. The design requirements should be entered into column "B" in the area shaded green on
the spreadsheet. The calculations will be automatically updated and intermediate results are
shown in the non-shaded area of column "B".
A convenient value for C1A and C1B is chosen (these values should be identical) and the
corresponding value of R1 is read from column "F" in the same row. Column "G" indicates
whether this choice of values is "OK" or "out of range". In the latter case, the FX105A will
probably still operate, but the actual component values may require adjustment from the
calculated spreadsheet values.
The choice of component values for (C2A, C2B, RV) and (C3A, C3B, RW) is made in the same
way. Note that it is not necessary to use the same row for (C2A, C2B, RV) and (C3A, C3B, RW)
as was used for (C1A, C1B, R1). The value of R2 is shown in column "B".
The choice of C4 is made by reading the value in column "K" on the same row as was used for
choosing the (C2A, C2B, RV) values.
This spreadsheet can only approximate to the actual component values required. Please note
that some device parameters (particularly V_TH) can vary from one silicon batch to another, and in
turn will cause a variation in detector performance. Component values should be carefully
chosen to optimise this performance spread.
© 1998 Consumer Microcircuits Limited
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UM1050/2