ELM331
Absolute Maximum Ratings
Storage Temperature....................... -65°C to +150°C
Ambient Temperature with
Power Applied....................................-40°C to +85°C
Voltage on V
DD
with respect to V
SS
............ 0 to +7.5V
Voltage on any other pin with
respect to V
SS
........................... -0.6V to (V
DD
+ 0.6V)
Note:
Stresses beyond those listed here will likely damage
the device. These values are given as a design
guideline only. The ability to operate to these levels
is neither inferred nor recommended.
Electrical Characteristics
All values are for operation at 25°C and a 5V supply, unless otherwise noted. For further information, refer to note 1 below.
Characteristic
Supply Voltage, V
DD
V
DD
rate of rise
Average Supply Current, I
DD
Minimum
3.0
0.05
Typical
5.0
Maximum Units
5.5
V
V/ms
Conditions
see note 2
V
DD
= 5V, see note 3
V
DD
= 3V, see note 3
see note 4
see note 5
see note 6
1.0
0.6
2.0
300
500
V
SS
0.85 V
DD
470
2.4
2.4
mA
mA
sec
Frequency of measurements
Reset pin internal pullup resistance
R
1
C
or
R
2
C time constant
Input low voltage - reset pin
Input high voltage - reset pin
Output low voltage
Output high voltage
V
DD
- 0.7
600
500,000
0.15 V
DD
V
DD
0.6
KΩ
µs
V
V
V
V
Current (sink) = 8.7mA
Current (source) = 5.4mA
Notes:
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. Device only. Does not include any LED or drive currents.
4. If a measured resistance is determined to be out of limits, the frequency of measurements is increased to
provide visual feedback as well as a faster recovery.
5. The value of the pullup resistance is supply and temperature dependent.
6. One should also maintain R
1
and
R
2
to not less than about 5KΩ. When C is chosen, select the pin 5 current
limiting resistance so that R
LIM
C is less than 1msec, and R
LIM
is greater than 1KΩ.
ELM331DSB
Elm Electronics – Circuits for the Hobbyist
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