Datasheet MICS6814

Data Sheet
Power circuit and measurement circuit
Parameter
RED sensor/OX sensor/NH3 sensor
Symbol Typ Min Max Unit
Heating power P
H
76/43/66 71/30/60 81/50/73 mW
Heating voltage V
H
2.4/1.7/2.2 - - V
Heating current I
H
32/26/30 - - mA
Heating resistance
at nominal power
R
H
74/66/72 66/59/64 82/73/80
Ω
Rating Symbol Value / Range Unit
Maximum heater power dissipation P
H
88 mW
Maximum sensitive layer power dissipation Ps 8 mW
Voltage supplyHeating current Vsupply 4.9 – 5.1 V
Relative humidity range RH 5 – 95 %RH
Ambient operating temperature Tamb -30 – 85 °C
Storage temperature range Tsto -40 – 120 °C
Storage humidity range RHsto 5 - 95 %RH
MiCS-6814
1143 rev 8
MiCS-6814 with measurement circuit (top view)
The example above shows the principle to read a resistance
between 1 kOhms and 2MOhms with a 8bit A/D converter.
Depending on the application and on the precision of the
A/D converter, a single load resistor of 56 kOhms may be
sufficient. Rload must be 820 Ohms at the lowest in order
not to damage the sensitive layer.
MiCS-6814 with recommended supply circuit (top view)
R1 is 130 Ohms, R2 is 820 Ohms and R3 is 27 Ohms. These
resistors are necessary to obtain the right temperatures on
the three independent heaters while using a single 5 V
power supply. The resulting voltages are typically VhRED =
2.4 V, VhOX = 1.7 V and VhNH3 = 2.2 V.
Page 3 of 5