Dual SPM/Security Detector/Generator
CMX641A
Package
D2
Package
P4
Signal
Description
Pin No.
22
Pin No.
22
Name
Type
This is a dual function pin differing between
Fixed Bandwidth Operating state and Enhanced
Features Operating state.
This pin has an internal pullup on chip so that
the default modes are Detect 12kHz (Fixed
Bandwidth Operating state, Fixed Sensitivity
mode) or TX Tone = 12kHz (Enhanced Features
Operating state).
SYSTEM
SELECT
I/P
(Fixed Bandwidth Operating state).
In the Fixed Sensitivity mode, this pin selects
the system frequency. High (logic ‘1’) = 12kHz;
Low (logic ‘0’) = 16kHz.
In the Controlled Sensitivity mode, this pin may
be tied to V
DD
or may be left unconnected.
Future functions of this pin, if tied low, are
reserved.
(Enhanced Features Operating state).
This pin selects 12kHz or 16kHz as the transmit
frequency at the TONE OP pin. When high
(logic ‘1’), the Tx tone at the TONE OP pin is
12kHz. When low (logic ‘0’), the Tx tone is
16kHz.
TX TONE
SELECT
I/P
23
23
TONE OP
O/P
Operates in Enhanced Features Operating state
only. A 12kHz or 16kHz transmit tone appears
at this pin under the control of the TONE ASK
and the TX TONE SELECT pin.
In Fixed Bandwidth Operating state, this pin is
unused and should be left unconnected.
24
24
V
DD
POWER
The positive supply rail. Critical levels and
voltages within the CMX641A are dependent
upon this supply. This pin should be decoupled
to V
SS
by a capacitor mounted close to the
device pins.
Notes:
I/P
O/P
BI
=
=
=
Input
Output
Bidirectional
(Note also that SYSTEM SELECT/TX TONE SELECT,
ENHANCED FEATURES and PRESET LEVEL/TONE ASK
pins should never be simultaneously driven low - to V
SS
).
©
2002 Consumer Microcircuits Limited
7
D/641A/5
CMLMICRO [ CML MICROCIRCUITS ]
