AMC8500 Datasheet, PDF (14/27 Pages) List of Unclassifed Manufacturers – TWO PHASE VARIABLE SPEED FAN MOTOR CONTROLLER

Preliminary Specification
aMC8500
Figure 26- Higher Voltage Reference
5
3.5 V
7
R1 8
R2 ₉
Reference
Op Amp
R2
V_O = V_Ref
+1
R1
V_{O Max} = V_DD - 1.7 V
V_O
The Op Amp can be used to gain up the Reference voltage in applications that require an additional regulated voltage source. This circuit
can supply up to 10 mA for powering additional circuitry or to provide a higher reference voltage. To insure that the Op Amp output
maintains regulation, the maximum programmed output voltage must be less than V_DD - 1.7 V.
Figure 27- Connections If Op Amp Is Not Required
5
Reference
7
Op Amp
8
9
5
Reference
7
Op Amp
8
9
5
Reference
7
Op Amp
8
9
Unity gain amplifier configuration with
the output forced low.
Comparator configuration with the
output forced high.
Comparator configuration with the
output forced low.
Figure 28- Connections To Disable Minimum Speed Set Or Digital Signal Speed Control Operation
Slope Select Grounded
Slope Select Open
Reference
5
Op Amp
7
8
9
6
Oscillator
R
1
Min Speed
Comp
PWM Comp
PWM
Logic
Digital
Detector
10
μA
Reference
5
Op Amp
7
8
9
6
Oscillator
R
1
Min Speed
Comp
PWM Comp
PWM
Logic
Digital
Detector
10
μA
11
14
11
14
If the end application does not require a programmed minimum speed or is to be controlled by a variable duty cycle digital pulse train, the
Minimum Speed Set comparator must be disabled by connecting Pin 6 directly to Pin 14.
© Andigilog, Inc. 2006
- 14 -
www.andigilog.com
August 2006 - 70A04018