IL600 Rhopoint Components, IL600 Datasheet - Page 8

• Manufacturer Part Number: IL600
• Description: Passive-input Digital Isolators ? Cmos Outputs
• Manufacturer: Rhopoint Components

Calculating Limiting Resistor Value
Figure 1. IL600-Series Transfer Function
Figure 2. Limiting Resistor Calculation
Coil Current
V
V
Logic State
INH
INL
High
Low
mA
3.5
1.5
5
Equivalent Circuit
R1
I
COIL
85
Input
Coil
t
t
Example 1. In this case, T
R
resistance is:
(R1+R
Therefore:
R1 = 4440 Ω − 85 Ω = 4355 Ω
Example 2. At a maximum operating temperature of 85°C:
T
R
At T
R
Therefore, the recommended series resistor is:
R1 = (V
R1 = (5−0) − 97 = 903
Allowance should also be made for the temperature coefficient of the
current limiting resistor to ensure that I
maximum operating temperature.
MAX
COIL
COIL
COIL
MAX
= 85
= 85 + (85 − 25) x 0.2 = 85 + 12 = 97
= 85ºC, T
=85 Ω and I
= 85 + (T
8
COIL
0.005
I
= 85ºC:
INH
COIL
) = (V
Ω
−V
.
INL
MAX
NOM
) – R
INH
COIL
I
− T
COIL
= 25ºC, V
− V
minimum is specified as 5 mA. Total loop
NOM
COIL
INL
) = 22.2
) x TCR
NOM
Ω
IN
0.005
= 25ºC, V
High = 5 V, V
COIL
Ω
= 4440
COIL
IN
IL600 Series
High = 24V, V
is at least 5 mA at the
Ω
IN
Ω
Low = 0 V, and nominal
IN
Low = 1.8V,