Electrical Characteristics (Continued)
1. Calculation Of Gain & Torque Limit Current
FAN8420D3
VM
EC
ECR
+
Gm
−
Current / Voltage
Convertor
−
Vin
+
Absolute
Values
Negative
Feedback loop
R1
−
+ Driver
+
+
Vmax
−
VM
Max. output current limiting
0.355 is GM times R1 and is a fixed value within IC.
Gain
=
0----.--3---5---5--
RS
[
A
⁄
V
]
VM
IO
RS
−
VS
Output
Current sense
+
CS1 (Pin 28)
Power
Transistors
U IO
V
W
Commutation
Distributor
H1 H2 H3
Vmax (see above block diagram) is set at 350mV.
Itl = -V----m-----a----x- = -3---5---0----[--m------V----]
RS
RS
Rev. 1.0.1
7
Oct. 2000.