ELM701
Electrical Characteristics
All values are for operation at 25°C and a 3V supply, unless otherwise noted. For further information, refer to note 1 below.
Characteristic
Minimum Typical
Maximum Units
Conditions
Supply Voltage, VDD
VDD rate of rise
3.0
3.0
5.5
V
see note 2
0.05
V/ms
During operation, see note 3
Between chirps
Average Supply Current, IDD
0.60
2
2.0
14
mA
µA
Output Series Resistance
Notes:
see note 4
470
4700
W
1. This integrated circuit is produced with a Microchip Technology Inc.’s PIC12C5XX as the core embedded
microcontroller. For further device specifications, and possibly clarification of those given, please refer to the
appropriate Microchip documentation.
2. This spec must be met in order to ensure that a correct power on reset occurs. It is quite easily achieved
using most common types of supplies, but may be violated if one uses a slowly varying supply voltage, as
may be obtained through direct connection to solar cells, or some charge pump circuits.
3. Internal integrated circuit current only. This does not include the piezo element currents.
4. A series resistor must be used to limit the current peaks due to the relatively large capacitance (~50nF) of a
piezo element. Maximum size is determined by the desired volume level.
Example Application
The ELM701 is usually connected as
shown at the right. Pins 2 to 5 are simply connected
to the nearest supply pin so that they aren’t left
floating, and a series resistor is connected in line
with one of the piezo connections.
Piezo
Element
4.7KW
8
7
2
6
5
4
For a permanent type of installation, it would be
a good idea to also connect a switch in series with
one of the battery leads. Although the chip has a lot
of initial appeal, you will probably want to be able to
disable it after a while. Making the batteries
accessible for easy removal is another method that
could be used.
701
+
3V
1
3
3 of 3
ELM701DSB
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