ELM701
Solid State Mouse
Description
The ELM701 is a fun circuit for creating mouse-
like noises. Its very low current consumption makes
it an ideal candidate for battery-powered toys and
novelty items.
All of the logic required for circuit operation is
contained within this 8 pin integrated circuit.
Normally only a battery, a piezo element, and a
single resistor are all that are needed for a complete
circuit, although an on/off switch may be desireable.
The ELM701 uses pseudo-random number
generators to produce from one to four ‘chirps’ at
random intervals of up to about eight seconds. This
makes the noises seem more like a real (but fairly
active) rodent. Between these series of chirps, the
circuit reverts to low power mode in order to
conserve battery energy.
Features
• Low power CMOS design
• Wide supply range - 3.0 to 5.5 volt operation
• Low power mode between chirps saves batteries
• Pseudo-random intervals for more realistic sounds
• Push-pull piezo drive eliminates the need for an
external capacitor while providing high volume
• Only one external resistor required
Connection Diagram
PDIP and SOIC
(top view)
Applications
• Mousetrap bait
• Unique power on warning
• Voicing for toys
• Coffee machine or office desk item
• A fun plaything
V
DD
in1
in2
in3
1
2
3
4
8
7
6
5
V
SS
OUT1
OUT2
in4
Block Diagram
Random
Interval
Timer
Random
Chirp
Generator
7
Output
Drivers
6
Out1
Out2
ELM701DSB
Elm Electronics – Circuits for the Hobbyist
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