AMC8500 Datasheet, PDF (20/27 Pages) List of Unclassifed Manufacturers – TWO PHASE VARIABLE SPEED FAN MOTOR CONTROLLER

Preliminary Specification
aMC8500
Figure 36- Thermistor Sensing Thermostatic Temperature Regulator
12 V
12
3
4
5
R4
R2
R3
7
H
8
R1
T
R5
10 k
@ 25°C
9
β = 3694
R7
6
R6
H
10
Reference
Op Amp
Oscillator
R
Under Voltage
Lockout
Hall Amplifier
Non-Overlap
Commutation
Fault Timer
Power Down
Kick Start
Min Speed
Comp
PWM Comp
PWM
Logic
Digital
Detector
H
SN
M
N
S
16
1
Motor
Drives
Thermal
Shutdown
Current
Limit
Latch
R
Q
S
10 μA
Current Limit
Comp
15
13
2
10 nF
11
14
Application Requirements
Speed Transition
Temperature °C
Minimum
Speed
Setting
Min to Max Max to Min
%on
30
28
35
35
30
35
38
35
0
40
38
30
45
40
30
Thermistor
R1
Ω
10000
10000
10000
10000
10000
Closest Standard 1.0% Resistor Values
Linearization
Threshold
Hysteresis
R2
R3
R4
R5
Ω
8060
7500
6340
5760
4990
Ω
1020
1020
1020
1050
1050
Ω
1000
1100
1070
1100
1130
Ω
158000
66500
113000
180000
73200
Min Speed
R6
R7
Ω
1070
1070
-
1070
1070
Ω
1130
1130
-
1270
1270
Thermostatic control can be accomplished by configuring the Op Amp as a non-inverting voltage comparator. The above table shows
five different application examples with the calculated resistor values. In applications 1, 2, 4, and 5, the motor will switch from the
programmed minimum setting to maximum speed as the sensor temperature rises above the required transition temperature. A
controlled amount of positive feedback shifts the transition temperatures to provide thermal hysteresis as the sensor cools. In the third
application requirement, the motor speed switches between zero and full speed. In this case the minimum speed set input is not
required and the comparator must be disabled by connecting Pin 6 to Pin 14. Note that the total Reference load current must exceed 2.0
mA in order to disable the automatic power down feature.
© Andigilog, Inc. 2006
- 20 -
www.andigilog.com
August 2006 - 70A04018