Read Harman Kardon AVR 135 (serv.man3) Service Manual online
R
×
5VL
14
OPERATION
FIG. 1 Block Diagram
Operation Diagram
Step 1. Output Voltage is equal to Power Source Voltage (V
DD
).
Step 2. When Input Voltage to Comparator reaches the state of Vref
≥
V
DD
·(Rb+Rc)/(Ra+Rb+Rc)at Point A (Detected Voltage –V
DET
), the output of Com-
parator is reserved, so that Output Voltage becomes GND.
Step 3. In the case of CMOS Output, Output Voltage becomes unstable when Supply Voltage (V
DD
) is smaller than Minimum Operating Voltage. In the
case of Nch Open Drain Output, a pulled-up voltage is output.
Step 4. Output Voltage becomes equal to GND.
Step 5. When Input Voltage to Comparator reaches the state of Vref
≤
V
DD
·(Rb)/(Ra+Rb) at Point B (Released Voltage +V
DET
), the output of Comparator is reserved,
so that Output Voltage becomes equal to Supply Voltage (V
DD
)
FIG. 2 Operation Diagram
Step
Step 1
Step 2
Step 3
Step 4
Step 5
Comparator(+)Pin
Input Voltage
I
II
II
II
I
Comparator Output
H
L
Indefinite
L
H
Tr. 1
OFF
ON
Indefinite
ON
OFF
Output Tr.
Pch
ON
OFF
Indefinite
OFF
ON
Nch
OFF
ON
Indefinite
ON
OFF
I.
Rb
+
Rc
Ra
+
Rb
+
Rc
·V
DD
II.
Rb
Ra
+
Rb
·V
DD
GND
OUT
V
DD
Ra
Rb
Rc
Tr.1
Vref
Pch
Nch
–
+
Detector Threshold Hysteresis
t
PLH
1
2
3
4
5
A
B
· In R
×
5VL
××
A, Nch Tr. drain is con-
nected to OUT pin.
· In R
×
5VL
××
C, Nch Tr. drain and
Pch Tr. drain are connected to
OUT pin.
Released Volage +V
DET
Supply Volage
Detected Volage –V
DET
(V
DD
)
Minimum Operating Volage
GND
Output Volage
(OUT)
GND
Click on the first or last page to see other AVR 135 (serv.man3) service manuals if exist.