NEC MultiSync V520 Service Manual

4. Horizontal deflection signal processing
LM1290:
1. Full-automatic synchronization from 22 kHz to 90 kHz. No component changeover nor external
adjustment is required.
2. DC control H phase and duty cycle.
3. The resistance corresponds to the frequency programmable down to VCO.
4. X-ray input invalid.
5. H-drive invalid due to low VCC (when VCC<9.5V). The H OUT transistor is protected as a result.
6. The capacitor protects the H output transistor during the change of the scanning mode, by means
of the programmable frequency ramming H VO/dt.
System Block Diagram
5
DISABLE
LATCH
4
H DRIVE
7
9
6
DUTY CNTL
12
H DRIVE
PD2
FILTER
FLYBACK
PD1 FILTER/
VCO IN
PD2
PD1
10
1
VCOS/H
V DETECT
H SYNC
3
FCV
2
11
1.8V
14
13
8
VOLTAGE
REFERENCE
X-RAY
SD
V
CC
V
GND
FVC
FILTER
H/HV
SYNC
H/HV POLARITY
f
MIN
PHASE CNTL
Typical Application LM1290
H
POLARITY
OUTPUT
H/HV
SYNC
INPUT
V
CC
DUTY
CYCLE
CONTROL
X-RAY
PROTECTION
FLYBACK
PULSE IN
H DRIVE
OUTPUT
H PHASE
CONTROL
V
CC
V
CC
f
MIN
H
/
HV
POLARITY
H
/
HV
SYNC
DUTY
CYCLE
X
-
RAY
FLYBACK
H DRIVE
V
CC
V
REF
PD
1
FILTER
/
VCO IN
FVC
FILTER
PHASE
PD2
FILTER
GND
LM
1290
20k
0.1
µ
F
50k
2k
10k
5k
1.2k
5k
3.3k
3.9k
0.1
µ
F
1
µ
F
1
µ
F
4.7nF
0.47
µ
F
100
µ
F
470
µ
F
0.1
µ
F
+
+
+
+
1
2
3
4
5
6
7
14
13
11
12
10
9
8
57

NEC MultiSync V520 Specifications

General

Brand	NEC
Model	MultiSync V520
Category	Monitor
Language	English