M-88L70 Datasheet, PDF (1/8 Pages) Clare, Inc. – 3V DTMF Receiver

M-88L70
3V DTMF Receiver
Features
• Operates between 2.7 and 3.6 volts
• Low power consumption
• Power-down mode
• Inhibit mode
• Central office quality and performance
• Inexpensive 3.58 MHz time base
• Adjustable acquisition and release times
• Dial tone suppression
• Functionally compatible with Clare’s M-8870
Applications
• Telephone switch equipment
• Mobile radio
• Remote control
• Paging systems
• PCMCIA
• Portable TAD
• Remote data entry
Description
The M-88L70 monolithic DTMF receiver offers small size,
low power consumption and high performance, with 3 volt
operation. Its architecture consists of a bandsplit filter
section, which separates the high and low group tones,
followed by a digital counting section which verifies the
frequency and duration of the received tones before
passing the corresponding code to the output bus.
Ordering Information
Part #
M-88L70-01P
M-88L70-01S
M-88L70-01T
Description
18-pin plastic DIP
18-pin SOIC
18-pin SOIC, Tape and Reel
Figure 1 Pin Connections
The M-88L70 is a full DTMF Receiver that integrates
both bandsplit filter and decoder functions into a single
18-pin DIP or SOIC package. Manufactured using
CMOS process technology, the M-88L70 offers low
power consumption (18 mW max), precise data handling
and 3V operation. Its filter section uses switched capaci-
tor technology for both the high and low group filters and
for dial tone rejection. Its decoder uses digital counting
techniques to detect and decode all 16 DTMF tone pairs
into a 4-bit code. External component count is minimized
by provision of an on-chip differential input amplifier,
clock generator, and latched tri-state interface bus.
Minimal external components required include a low-cost
3.579545 MHz color burst crystal, a timing resistor, and a
timing capacitor.
Figure 2 Block Diagram
DS-M88L70-R1
www.clare.com
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