MX631
Features
•
•
•
•
•
DATABULLETIN
LOW VOLTAGE SPM DETECTOR
Detects 12 & 16kHz SPM Frequencies
Low Power (3.0 Volt
MIN
<1.0mA) Operation
High Speechband Rejection Properties
Tone-Follower and Packet Mode Outputs
Applications
•Complex and/or Simple Telephone Systems
•Call-Charge/-Logging Systems
MX631DW
16-Pin SOIC
MX631P
16-Pin PDIP
XTAL/CLOCK
XTAL/CLOCK
OSCILLATOR
XTAL
CLOCK
OUT
CLOCK IN
CLOCK
DIVIDERS
SYSTEM
V
SS
V
DD
TONE FOLLOWER
OUTPUT
SYSTEM
(12kHz/16kHz)
TONE
FOLLOWER
LOGIC
INPUT AMP
12kHz/16kHz
SIGNAL
IN (+)
AMP OUT
V
BIAS
Figure 1 - Functional Block Diagram
Description
The MX631 is a low-power, system-selectable
Subscriber Pulse Metering (SPM) detector that indicates
the presence of both 12kHz or 16kHz telephone call-
charge frequencies on a telephone line.
Deriving its input directly from the telephone line,
input amplitude/sensitivities are component adjustable
to the user's national ‘Must/Must-Not Decode’
specifications via an on-chip input amplifier, while the
12kHz and 16kHz frequency limits are accurately
defined by the use of an external 3.579545MHz
telephone-system Xtal or clock-pulse input.
The MX631, which demonstrates high 12kHz and
16kHz performance in the presence of both voice and
noise, can operate from either a single or differential
analog signal input from which it will produce two
individual logic outputs:
1. Tone Follower Output - A 'tone-following' logic
output producing a “Low” level for the period of a
correct decode and a “High” level for a bad decode
or N
OTONE
.
2. Packet (Cumulative Tone) Mode Output - To
respond and/or de-respond after a cumulative
40ms of good tone (orN
OTONE
) in any 48ms period.
This process will ignore small fluctuations or fades
of a valid frequency input and is available for
µProcessor
‘Wake-Up’, Minimum Tone detection,
N
OTONE
indication or transient avoidance.
This system (12kHz/16kHz) selectable integrated
circuit, which may be line-powered, is available in 16-pin
plastic DIP and SOIC surface mount packages.
© 1997 MX•COM, INC.
www.mxcom.com Tele: 800 638 5577 910 744 5050 Fax: 910 744 5054
Doc.# 20480087.003
4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA
All trademarks and service marks are held by their respective companies
+
-
SIGNAL
IN (-)
32
1
LEVEL DETECTOR
DIVIDER
PERIOD
MEASURE
PACKET MODE
OUTPUT
PACKET
TONE
LOGIC
+20dB
SYSTEM
CMLMICRO [ CML MICROCIRCUITS ]
