ETC WT8045

WT8045
Synchronous
Signal
Discriminator
and
Power Saving Detector for Green Monitor

May 4, 1995
DESCRIPTION
The WT8045 is a silicon monolithic circuit designed for synchronous signal processing and power
saving detection of multi-sync display monitors, which can cope with many kinds of PC's and
workstations.
It can be applied to display monitors supporting standard IBM VGA, VESA super VGA and IBM
8514/A video modes. It can also be used in other high-end display monitors supporting non-standard
video modes with user-defined horizontal/vertical frequency ranges.
The WT8045 incorporates many functional circuits, including horizontal/vertical frequency
discrimination, display mode selection, and synchronous pulse polarity and power saving detection,
into this single chip IC.
WT8045 is more convenient for you to shrink the PC board size and to reduce the material and labor
cost with fewer components.
FEATURES
•
Accepting two separated H&V synchronous signals with positive/ negative polarity.
•
Support VESA VGA (640X480, 640X400, 640X350), VESA SVGA (800X600), European
SVGA (800X600), VESA new SVGA (800X600), XGA (1024X768) and 1280x1024.
•
Capable of processing horizontal frequency between 25KHZ to 80KHZ.
•
Standard IBM video mode control outputs (1024X768, 640X480, 640X400, 640X350).
•
Five non-standard horizontal frequency control outputs in predefined frequency range.
•
Power saving mode - It can detect the conditions of monitor to decide which one will be selected
as following: ON/STANDBY/SUSPEND/OFF mode.
•
Fixed polarity outputs on both horizontal and vertical synchronous signals.

Weltrend Semiconductor, Inc.
2F., No. 24, Industry E. 9th Rd.
Science-Based Industrial Park
Hsin-Chu, Taiwan, R.O.C.
Tel: 886-35-780241
Fax: 886-35-770419
1
WT8045
Synchronous
Signal
Discriminator
and
Power Saving Detector for Green Monitor

•
Power supply voltage: DC 5 volts; but for those pins with open-drain structure, such like the
mode select control output and frequency discrimination control output pins, can be connected to
12 volts through pull-high resistor.
APPLICATION
•
Auto size control for Multi-Sync Display Monitors
ORDERING INFORMATION
Part No.
WT8045N24P1
WT8045N24P3
WT8045N24P4
WT8045N24P5
WT8045N24P6
WT8045N24P7
WT8045N24P8
WT8045N28P1
WT8045N28P2
WT8045N28P3
WT8045N28P4
WT8045N28P5
WT8045N28P6
WT8045N28P7
WT8045N28P8
WT8045N32
Package
P-DIP 24L
P-DIP 24L
P-DIP 24L
P-DIP 24L
P-DIP 24L
P-DIP 24L
P-DIP 24L
P-DIP 28L (skinny)
P-DIP 28L (skinny)
P-DIP 28L (skinny)
P-DIP 28L (skinny)
P-DIP 28L (skinny)
P-DIP 28L (skinny)
P-DIP 28L (skinny)
P-DIP 28L (skinny)
P-DIP 32L
Note
V * 128
Without Mute
Without Mute
V*1
With Mute
Without Mute
With Mute
V * 128 Without Mute
V * 128 Without Mute
V * 1 Without Mute
V * 128 With Mute
V * 1 With Mute
V * 1 Without Mute
V * 128 With Mute
V * 1 With Mute
--

Weltrend Semiconductor, Inc.
2F., No. 24, Industry E. 9th Rd.
Science-Based Industrial Park
Hsin-Chu, Taiwan, R.O.C.
Tel: 886-35-780241
Fax: 886-35-770419
2
WT8045
Synchronous
Signal
Discriminator
and
Power Saving Detector for Green Monitor

PIN CONFIGURATION
WT8045N24P3
WT8045N24P1
OSCin
OSCout
1
2
24
23
VDD
1024x768(56.5K)
1
24
OSCout
2
23
1024x768(56.5K)
3
22
1024x768 (NI)
OSCin
VDD
HSin
3
22
1024x768 (NI)
HSin
VSin
4
21
1024x768 (I)
VSin
4
21
1024x768 (I)
5
20
800x600(48K)
H_out
5
20
800x600(48K)
6
19
800x600(37.5K)
7
18
800x600(35.2K)
H_out
6
19
800x600(37.5K)
V_out
7
18
800x600(35.2K)
F43.5K
F36.2K
8
17
640x480
F36.2K
8
17
640x480
F33K
9
16
640x400
F33K
9
16
640x400
QV128
10
15
640x350
Vss
10
15
640x350
QVRC
11
14
QH
PM1
11
14
QH
13
QHRC
PM3
12
13
QHRC
V_out
F43.5K
Vss
12
WT8045N24P4
WT8045N24P5
OSCin
1
24
VDD
OSCout
2
23
1024x768 (I)
HSin
3
22
VSin
4
Hout
1
24
VDD
OSCout
2
23
1024x768(56.5K)
800x600(37.5K)
HSin
3
22
1024x768 (NI)
21
NC
VSin
4
21
1024x768 (I)
5
20
800x600(35.2K)
H_out
5
20
800x600(48K)
Vout
6
19
640x480(31.5K)
V_out
6
19
800x600(37.5K)
F36.2K
7
18
640x400(31.5K)
F43.5K
7
18
800x600(35.2K)
F33K
8
17
640x480
(37.5K/72Hz)
F36.2K
8
17
640x480
NC
9
16
640x350
(31.5K/37.5K)
F33K
9
16
640x400
NC
10
15
NC
QV1
10
15
640x350
VSS
11
14
PM3
QVRC
11
14
QH
12
13
PM2
Vss
12
13
QHRC
PM1
OSCin

Weltrend Semiconductor, Inc.
2F., No. 24, Industry E. 9th Rd.
Science-Based Industrial Park
Hsin-Chu, Taiwan, R.O.C.
Tel: 886-35-780241
Fax: 886-35-770419
3
WT8045
Synchronous
Signal
Discriminator
and
Power Saving Detector for Green Monitor

WT8045N24P6
WT8045N24P7
1
24
1024x768(56.5K)
OSCout
2
23
1024x768(56.5K)
1024x768 (NI)
HSin
3
22
1024x768 (NI)
VSin
4
21
1024x768 (I)
H_out
5
20
800x600(48K)
V_out
6
19
800x600(37.5K)
F43.5K
7
18
800x600(35.2K)
F36.2K
8
17
640x480
640x400
F33K
9
16
640x400
640x350
Vss
10
15
640x350
P52K
11
14
PM3
PM1
12
13
PM2
1
24
OSCout
2
23
HSin
3
22
VSin
4
21
1024x768 (I)
H_out
5
20
800x600(48K)
V_out
6
19
800x600(37.5K)
F43.5K
7
18
800x600(35.2K)
F36.2K
8
17
640x480
F33K
9
16
10
15
Mute
11
14
QH
PM3
12
13
QHRC
OSCin
Vss
VDD
OSCin
WT8045N24P8
OSCin
OSCout
HSin
1
2
3
24
23
22
VDD
WT8045N32
VDD
OSCin
1
32
VDD
OSCout
2
31
1024x768(56.5K)
1024x768 (NI)
1024x768(56.5K)
HSin
3
30
1024x768 (NI)
VSin
4
29
1280x1024(64K)
5
28
1024x768 (I)
H_out
VSin
4
21
1024x768 (I)
V_out
6
27
800x600(48K)
H_out
5
20
800x600(48K)
F43.5K
7
26
800x600(37.5K)
V_out
6
19
800x600(37.5K)
F36.2K
8
25
800x600(35.2K)
7
18
9
24
QV128
10
23
640x400
QVRC
11
22
Vss
12
21
640x350
QH
QHRC
F43.5K
800x600(35.2K)
F36.2K
8
17
640x480
F33K
9
16
640x400
10
15
640x350
Vss
P52K
PM1+PM2
11
12
14
13
PM3
Mute
F33K
SELPIN
640x480
13
20
-QH
14
19
PM3
F52K
15
18
PM2
F60K
16
17
PM1

Weltrend Semiconductor, Inc.
2F., No. 24, Industry E. 9th Rd.
Science-Based Industrial Park
Hsin-Chu, Taiwan, R.O.C.
Tel: 886-35-780241
Fax: 886-35-770419
4
WT8045
Synchronous
Signal
Discriminator
and
Power Saving Detector for Green Monitor

WT8045N28P1
OSCin
1
28
VDD
OSCout
2
27
1024x768(56.5K)
HSin
3
26
1024x768 (NI)
VSin
4
25
1024x768 (I)
H_out
5
24
800x600(48K)
V_out
6
23
800x600(37.5K)
F43.5K
7
22
800x600(35.2K)
F36.2K
8
21
640x480
F33K
9
20
640x400
QV128
10
19
640x350
QVRC
11
18
QH
Vss
12
17
QHRC
F52K
13
16
PM3
PM1
14
15
PM2
WT8045N28P3
OSCin
OSCout
HSin
28
VDD
2
27
1024x768(56.5K)
3
26
1024x768 (NI)
1
VSin
4
25
1024x768 (I)
H_out
5
24
800x600(48K)
V_out
6
23
800x600(37.5K)
F43.5K
7
22
800x600(35.2K)
F36.2K
8
21
640x480
F33K
9
20
640x400
QV1
10
19
640x350
QVRC
11
18
QH
Vss
12
17
QHRC
F52K
13
16
PM3
14
15
PM2
PM1

Weltrend Semiconductor, Inc.
2F., No. 24, Industry E. 9th Rd.
Science-Based Industrial Park
Hsin-Chu, Taiwan, R.O.C.
Tel: 886-35-780241
Fax: 886-35-770419
5
WT8045
Synchronous
Signal
Discriminator
and
Power Saving Detector for Green Monitor

WT8045N28P5
WT8045N28P4
OSCin
1
28
VDD
OSCout
2
27
1024x768(56.5K)
OSCin
1
28
VDD
OSCout
2
27
1024x768(56.5K)
HSin
3
26
1024x768 (NI)
1024x768 (I)
VSin
4
25
1024x768 (I)
HSin
3
26
1024x768 (NI)
VSin
4
25
H_out
5
24
800x600(48K)
H_out
5
24
800x600(48K)
V_out
6
23
800x600(37.5K)
V_out
6
23
800x600(37.5K)
F43.5K
7
22
800x600(35.2K)
F43.5K
7
22
800x600(35.2K)
F36.2K
8
21
640x480
F36.2K
8
21
640x480
F33K
9
20
640x400
F33K
9
20
640x400
QV128
10
19
640x350
QV1
10
19
640x350
QVRC
11
18
QH
QVRC
11
18
QH
QHRC
Vss
12
17
QHRC
Vss
12
17
F52K
13
16
PM3
F52K
13
16
PM3
PM1
+PM2
14
15
Mute
PM1
+PM2
14
15
Mute
Note: The Hout and Vout pin of N28P1, N28P3, N28P4 and N28P5 are negative pulse.

Weltrend Semiconductor, Inc.
2F., No. 24, Industry E. 9th Rd.
Science-Based Industrial Park
Hsin-Chu, Taiwan, R.O.C.
Tel: 886-35-780241
Fax: 886-35-770419
6
WT8045
Synchronous
Signal
Discriminator
and
Power Saving Detector for Green Monitor

ABSOLUTE MAXIMUM RATINGS
ITEM
Digital Supply Voltage
Horizontal Sync. Input Voltage
Vertical Sync. Input Voltage
Power Dissipation
Operating Temperature Range
Storage Temperature Range
SYMBOL
VDD
VHS
VALUE
5.5
VDD(5)+0.3
UNIT
V
VPP
VVS
PD
VDD(5)+0.3
300
VPP
mW
TOPT
TSTG
0¡ 7
ã0
-40¡ ã
125
¢ J
¢ J
RECOMMENDED OPERATING CONDITIONS
ITEM
Digital Supply Voltage
Supply Current (Standby)
Synchronous Input Voltage Low
Synchronous Input Voltage High
Horizontal Synchronous Frequency
Range
Vertical Synchronous Frequency
Range
Crystal Clock Frequency
Open Drain Pull High Voltage
Resistance of Monostable for Hsin
Capacitance of Monostable for Hsin
Resistance of Monostable for Vsin
Capacitance of Monostable for Vsin
SYMBOL
MIN.
TYP.
MAX.
UNIT
VDD(5)
IP
VIL
4.5
5
5.5
13
V
mA
VPP
VIH
FH
2.4
4
25
¡ Ð
FV
50
¡ Ð
FCLK
VOH
RH
3.5764
3.58
CH
RV
¡ Ð
10
100
CV
¡ Ð
100
10
0.8
5.5
80
(for N32)
120
VPP
KHz
Hz
3.5836
12
MHz
V
100
K£ [
pF
¡ Ð
500
¡ Ð
K£ [
pF

Weltrend Semiconductor, Inc.
2F., No. 24, Industry E. 9th Rd.
Science-Based Industrial Park
Hsin-Chu, Taiwan, R.O.C.
Tel: 886-35-780241
Fax: 886-35-770419
7
WT8045
Synchronous
Signal
Discriminator
and
Power Saving Detector for Green Monitor

ELECTRICAL CHARACTERISTICS
(VDD=5V, TOPT=25°C, Crystal=3.58MHz)
ITEM
SYMBOL
F33K
Discrimination of H.
F36.2K
Synchronous Frequency
F43.5K
F52K
F60K
Output Low (H-out, V-out),
VOL1
when IOL = 4mA
MIN.
TYP.
MAX.
UNIT
32.9
36.1
43.4
51.9
59.9
¡ Ð
¡ Ð
33.1
36.3
43.6
52.1
60.1
0.4
KHz
KHz
KHz
KHz
KHz
VPP
¡ Ð
¡ Ð
Output High (H-out, V-out),
when IOH = -400£ gA
VOH1
VPP
Open Drain Output Low
when IOL = 6mA
VOL2
0.4
VPP
Output Sink Current (H-out, V-out)
when VOL1 = 0.4V
Output Drive Current (H-out, V-out)
when VOH1 = 2.4V
Open Drain Sink Current
when VOL2 = 0.4V
Open Drain Sink Current
when VOL2 = 5V
IOL1
4
mA
¡ IWOH1¡ W
400
£ g
A
2.4
IOL2
10
mA
IOL2
40
mA

Weltrend Semiconductor, Inc.
2F., No. 24, Industry E. 9th Rd.
Science-Based Industrial Park
Hsin-Chu, Taiwan, R.O.C.
Tel: 886-35-780241
Fax: 886-35-770419
8
WT8045
Synchronous
Signal
Discriminator
and
Power Saving Detector for Green Monitor

MONO_STABLE DYNAMIC ELECTRICAL CHARACTERISTICS
(Ta=25°C; Input tr,tf=20ns, CL=50PF)
ITEM
Input H_SYNC Pulse Width
Input V_SYNC Pulse Width
Output Pulse Transition Time
Output Pulse Propagation Delay
Output Pulse Width Adjust Range
MIN.
0.558
0.0384
¡ Ð
¡ Ð
10
TYP.
¡ Ð
¡ Ð
100
300
¡ Ð
H_MONO_STB:
31KHz¡ Ð37.5KHz
31KHz¡ Ð48KHz
31KHz¡ Ð57KHz
31KHz¡ Ð64KHz
V_MONO_STB:
(50Hz¡ Ð120Hz)*128
6.4KHz¡ Ð15.36KHz
(50Hz¡ Ð80Hz)*128
6.4KHz¡ Ð10.2KHz
(50Hz¡ Ð120Hz)*1
Typical Pulse width Variation as a
function of Temperature at 75¢ Jto
24 ¢ J
Typical Pulse Width Variation as a
function of Supply Voltage at
4.75V to 5.25V
Output Low (Sink) Current
Output Voltage Low-Level
Output Voltage High-Level
Output Jitter (Hout & Vout)
MAX.
4
0.125
200
600
90
UNITS
£ g
s
ms
ns
ns
¢ M
26.66
20.83
17.54
15.62
£
£
£
£
65.10
£ g
s
97.66
£ g
s
ms
10
sg
s
g
s
g
s
g
¡ Ð
¡ Ð
¡ Ó
2
¢ M
¡ Ð
¡ Ð
¡ Ó
2
¢ M
1
¡ Ð
4.95
¡ Ð
0
6
0.05
¡ Ð
5
mA
V
V
ns
Hin & Vin Rise time and Fall time = 200ns

Weltrend Semiconductor, Inc.
2F., No. 24, Industry E. 9th Rd.
Science-Based Industrial Park
Hsin-Chu, Taiwan, R.O.C.
Tel: 886-35-780241
Fax: 886-35-770419
9
WT8045
Synchronous
Signal
Discriminator
and
Power Saving Detector for Green Monitor


Weltrend Semiconductor, Inc.
2F., No. 24, Industry E. 9th Rd.
Science-Based Industrial Park
Hsin-Chu, Taiwan, R.O.C.
Tel: 886-35-780241
Fax: 886-35-770419
10
WT8045
Synchronous
Signal
Discriminator
and
Power Saving Detector for Green Monitor

APPLICATION INFORMATION
Name
Struncure
of
Terminal
Function
OSCin
A clock generating circuit is built into the chip. So if a resonator is I
connected to OSCin/OSCout, a clock signal can be obtained
OSCout
Refer to OSCin pin
O
Hsin
Input terminal of horizontal synchronous signal
I, TTL
compatible
Vsin
Input terminal of vertical synchronous signal
I, TTL
compatible
H_OUT
Output pin, fixed negative polarity of original H_SYNC signal with I, TTL
same pulse width (but, positive for N28P2, N28P6,N28P7 and compatible
N28P8)
V_OUT
Output pin, fixed negative polarity of original V_SYNC signal with O, TTL
same pulse width (but, positive for N28P2, N28P6,N28P7 and compatible
N28P8)
F43.5k
>43.5k then active low, <43.5k then high
O, open drain
F36.2k
>36.2k then active low, <36.2k then high
O, open drain
F33k
>33k then active low, <33k then high
O, open drain
QV
Output pin, fixed positive polarity of vertical signal; pulse width O, open drain
depend upon RV & CV.
QVRC
Input pin, connected to Vdd through RV & to ground through CV I
Vss
Ground
SELPIN
Input pin, to select which one of H_SYNC or V_SYNC appears on I,
the output pin of QV; N.C. selects the V-SYNC on the output, (N.C.-no
grounding selects the H_SYNC.
connection)
-QH
Output pin, fixed negative polarity of horizontal signal; pulse width O, open drain
depend upon RH & CH.
F52k
>52k then active low, <52k then high
O, open drain
F60k
>60k then active low, < 60k then high
O, open drain
PM1
Indicate in STAND-BY mode
O, open drain

Weltrend Semiconductor, Inc.
2F., No. 24, Industry E. 9th Rd.
Science-Based Industrial Park
Hsin-Chu, Taiwan, R.O.C.
Tel: 886-35-780241
Fax: 886-35-770419
11
WT8045
Synchronous
Signal
Discriminator
and
Power Saving Detector for Green Monitor

PM2
Indicate in SUSPEND mode
Struncure
of
Terminal
O, open drain
PM3
Indicate in OFF mode
O, open drain
QHRC
Input pin, connected to Vdd through RH & to ground through CH.
I
QH
Output pin, fixed positive polarity of horizontal signal; pulse width O, open drain
depend upon RH & CH
640¡ Ñ
350
Mode select control output, if IBM VGA 640¡ Ñ
350 mode, or VESA O, open drain
VGA 640¡ Ñ350 mode. Then active "low", else open state output
640¡ Ñ
480
VESA VGA mode 640¡ Ñ480 (37.5k/72Hz)
640¡ Ñ
400
If IBM VGA 640¡ Ñ400 mode, or VESA VGA 640¡ Ñ
400 mode then O, open drain
active "low" (640¡ Ñ400, 31.5k, for N24P4)
640¡ Ñ
480
If IBM VGA 640¡ Ñ480 mode, or VESA VGA 640¡ Ñ
480 mode then O, open drain
active "low" (640¡ Ñ480, 31.5k, for N24P4)
800¡ Ñ
600
VESA super VGA mode
Name
Function
O, open drain
O, open drain
(H_SYNC = 35.2k, V_SYNC = 56Hz)
800¡ Ñ
600
European super VGA mode
O, open drain
(H_SYNC = 37.5k, V_SYNC = 60Hz)
800¡ Ñ
600
VESA new super VGA mode
O, open drain
(H_SYNC = 48k, V_SYNC = 72Hz)
1024¡ Ñ
IBM 8512/A interlace mode
768(I)
(H_SYNC = 35.5k, V_SYNC = 86Hz)
1280¡ Ñ
1280¡ Ñ1024 mode control output
1024
(H_SYNC = 64k, V_SYNC = 60Hz)
1024¡ Ñ
IBM 8514/A non-interlace mode
768(NI)
(H_SYNC = 48.5k, V_SYNC = 60Hz)
1024¡ Ñ
XGA 1024¡ Ñ768 mode Hsync freq. 57kHz
768(57k)
(H_SYNC = 56.5k, V_SYNC = 72Hz)
Vdd
5 Volts power supply
O, open drain
O, open drain
O, open drain
O, open drain

Weltrend Semiconductor, Inc.
2F., No. 24, Industry E. 9th Rd.
Science-Based Industrial Park
Hsin-Chu, Taiwan, R.O.C.
Tel: 886-35-780241
Fax: 886-35-770419
12
WT8045
Synchronous
Signal
Discriminator
and
Power Saving Detector for Green Monitor

APPLICATION DESCRIPTION
DPMS (Display Power Management Signaling) Detection
As per DPMS proposal version 1.0P, revision 0.54P, WT8045 provides Monitor Power
Management Detection Circuit for the convenience of monitor designers in designing power
saving monitors, or the so called "Green Monitors". Please refer to the table 1 as below for
power states defined in the DPMS.
DPMS requires at least 5 seconds delay before transition from ON state to any power saving
state, to avoid unintentionally entering a power saving state during display resolution changes
and timing mode changes. And it can be done instantaneously, for the transition between any
power saving state.
Table 1 Display Power Management Summary
Signals
State
On
Horizontal
Pulses
Vertical
Pulses
Video
Active
Stand-by
Suspend
Off
No Pulses
Pulses
Blanked
Pulses
No Pulses Blanked
No Pulses No Pulses Blanked
DPMS
Compliance
Requirement
Mandatory
Power
Savings
Recovery
Time
None
Optional
Mandatory
Mandatory
Minimal
Substantial
Maximum
Not
Applicable
Short
Longer
System
Dependent
* "No-Pulse" represents the frequency of Hsin or Vsin less than or equal to 10Hz, but
"Pulses" represents that frequency of Hsin greater than or equal to 10KHz and Vsin
greater than or equal to 40Hz

Weltrend Semiconductor, Inc.
2F., No. 24, Industry E. 9th Rd.
Science-Based Industrial Park
Hsin-Chu, Taiwan, R.O.C.
Tel: 886-35-780241
Fax: 886-35-770419
13
WT8045
Synchronous
Signal
Discriminator
and
Power Saving Detector for Green Monitor

The way WT8045 implements VESA DPMS
As shown on Table 2, WT8045 use PM1 to represent Stand-by State, PM2 as Suspend State and
PM3 as OFF State. When H_SYNC / V_SYNC signals transition from ON State to any one of
the three power saving states, WT8045 will delay 5.9 seconds to meet the VESA DPMS
requirement: the minimum 5 seconds delay to avoid unintentionally entering a power saving
state during display resolution and timing mode changes. If during this delay time period,
H_SYN and V_SYN signals return to ON State, then all three power management pins (PM1,
PM2 and PM3) will remain ON state. If power management state of H_SYNC and V_SYNC
prolong for more than 5.9 seconds, then these three power management pins will change to the
corresponding states. While changing from any power saving state back to ON State will take
about 0.368 second for H_SYNC / VSYNC pulse checking. And transition between any power
saving state will be done immediately.
Table 2: The truth table of Power Saving Detector
MODE
ON
STAND_BY
SUSPEND
OFF
OVERRIDE
Hsin
Pulses
No Pulses
Pulses
No Pulses
No Pulses
Manually
Vsin
Pulses
Pulses
No Pulses
No Pulses
No Pulses
PWR ON
PM1
1
0
0
0
1
PM2
1
1
0
0
1
PM3
1
1
1
0
1
OVERRIDE mode:
To initial override, both horizontal and vertical sync signals shall be in the no pulses condition
when the display is maintained during the entire time override is required. As soon as pulses are
detected on horizontal and vertical sync signal. The display shall enter DPMS operation.
Three power management pins are open drain structure and active low. If you do not need all
those three power saving states in your design. You can just short two or three pins of the pins
PM1/PM2/PM3. for example, by shorting pin PM1 and pin PM2, you will have only two power
saving states, that is OFF and Suspend states, so you have three states total, including ON State.
Please refer to Application Circuit 2.

Weltrend Semiconductor, Inc.
2F., No. 24, Industry E. 9th Rd.
Science-Based Industrial Park
Hsin-Chu, Taiwan, R.O.C.
Tel: 886-35-780241
Fax: 886-35-770419
14
WT8045
Synchronous
Signal
Discriminator
and
Power Saving Detector for Green Monitor

Mono_Stable Circuit
WT8045 includes two sets of Mono_Stable Circuits, one uses H_SYNC as trigger signal, the
other uses either H_SYNC or V_SYNC as trigger signal (this only can be done on 32 pin
package, for 24 pin and 28 pin packages the trigger signal is fixed to H_SYNC); for N24p4
package, there is no mono-stable circuit. Please refer to the figure as below:
H-SYNC
vcc
T
Rx/Cx
SWITCH
V-SYNC
T
QH
QH-
Q
SELECT=OPEN
QV
SELECT=L
QH
vcc
Rx/Cx
SELECT
Q-
The Mono_Stable Circuit is triggered by positive edge, no matter H_SYNC or V_SYNC is used
as trigger signal. Please refer to the timing chart as below:
Trigger Pulse
positive
negative
Q
Q-
The output of Mono_Stable Circuit is open drain structure, and can be pulled up to +12V
maximum.

Weltrend Semiconductor, Inc.
2F., No. 24, Industry E. 9th Rd.
Science-Based Industrial Park
Hsin-Chu, Taiwan, R.O.C.
Tel: 886-35-780241
Fax: 886-35-770419
15
WT8045
Synchronous
Signal
Discriminator
and
Power Saving Detector for Green Monitor

In case of using output pulse of V_MONO_STABLE as voltage source, in order to prevent the
problem of slow response time, causing from the low frequency on vertical synchronous signal,
WT8045 internally increases the vertical signal frequency to 128 times the original frequency,
that is from 50Hz - 120 Hz to 6.4KHz - 15.36KHz. Then WT8045 uses this increased frequency
as the input signal of MONO_STABLE, so the leading edge of the signal of the increased
frequency will trigger the MONO_STABLE circuit.
An external resistor (Rx) and an external capacitor (Cx) control the timing and accuracy of the
circuit. Adjustment of Rx and Cx provides a wide range of output pulse widths from the Q and
Q-bar terminals. The delay time from trigger input to output transition is independent of Rx and
Cx.
The minimum value of external resistor Rx is 10k ohms. The typical value of external capacitor
Cx is 100 pF. The time period (T) for this multi-vibrator can be calculated with the formula: T ≈
1.1 Rx • Cx.
H/V Frequency Divisions and Video Modes
Figure 1 illustrates the typical frequency ranges of H and V sync signals for display monitors.
The operating video modes are determined by the H and V frequencies, and occasionally, by
their polarities. The typical video modes of display monitors include the IBM VGA, VESA VGA,
European VGA/super VGA, VESA super VGA, IBM 8514/A, XGA, and 1280x 1024.
WT8045 can determine 13 standard video modes for 32 pin package (refer to Table 3) according
to H and V frequencies and polarities. These standard video modes include the IBM VGA,
VESA VGA, VESA super VGA and IBM 8514/A. This provides the users with the capability to
adjust the screen size for different modes.
WT8045 pre-sets the discriminating points both on H and V frequencies. The discriminating
points for H sync are 33KHz, 36.2KHz, 43.5KHz, 52KHz and 60KHz (for 32 pin). These
discriminating points will be able to identify various video modes as shown in Fig. 1. WT8045
also provides the flexibility for users to define these discriminating points through mask option.

Weltrend Semiconductor, Inc.
2F., No. 24, Industry E. 9th Rd.
Science-Based Industrial Park
Hsin-Chu, Taiwan, R.O.C.
Tel: 886-35-780241
Fax: 886-35-770419
16
WT8045
Synchronous
Signal
Discriminator
and
Power Saving Detector for Green Monitor

The tolerance for H sync frequency discrimination is¡ Ó
0.1KHz. For instance, the 33KHz
discriminating point will be able to distinguish the H sync frequency that is either "less than or
equal to" 32.9KHz, or "greater than or equal to" 33.1KHz. There is an ambiguous region
between 32.9KHz and 33.1KHz.
WT8045 has two discriminating points, 64Hz and 78Hz, for the V sync signal as shown in Fig.1.
The tolerance is ¡ Ó0.4Hz. The discrimination results of V sync frequency are used internally for
mode selection.
Base on the package consideration, IBM VGA mode and VESA VGA mode (both have same
resolution: 640x480, 640x400, 640x350) are decoded on same open Drain structure output pins.
In case of these whole six modes decoding is needed, the horizontal frequency discrimination pin
F33k or F36.2k must take into consideration. The horizontal frequency of IBM VGA mode is
31.5kHz, and VESA IBM VGA mode is 37.5kHz. Using F33k or F36.2k pin can clearly identify
these two standard modes. The decoding circuit is attached on application section for reference.
Graphic Standard
IBM VGA
VESA Super VGA
IBM 8512/A Interlaced
VESA VGA
European Super VGA
VESA New Super VGA
IBM 8514/A Non-Interlaced
VESA New 1024X768
Work Station 1280X1024
Resolution
640X350
640X400
640X480
800X600
1024X768
640X350
640X400
640X480
800X600
800X600
1024X768
1024X768
1280X1024
Horizontal
31.5kHz
31.5kHz
31.5kHz
35.2kHz
35.5kHz
37.5kHz
37.5kHz
37.5kHz
37.5kHz
48.0kHz
48.5kHz
56.5kHz
64.0kHz
Vertical
70Hz
70Hz
60Hz
56Hz
86Hz
83Hz
83Hz
72Hz
60Hz
72Hz
60Hz
72Hz
60Hz
Polarities
+,-,+
-.-
+,-,+
-,-
Table 3: Graphic Standard and Frequencies

Weltrend Semiconductor, Inc.
2F., No. 24, Industry E. 9th Rd.
Science-Based Industrial Park
Hsin-Chu, Taiwan, R.O.C.
Tel: 886-35-780241
Fax: 886-35-770419
17
WT8045
Synchronous
Signal
Discriminator
and
Power Saving Detector for Green Monitor

Fv (Hz)
83.86
1024X768
640X350
(+,-)
640x400
(-,+)
800X600
78
640X350
(+,-)
640x400
(-,+)
70.72
640X480
(-,-)
1024X768
800X600
64
640X480
(-,-)
56.60
0
31.5
33
35
1280X1024
800X600
1024X768
38
48
36.2
43.5
52
56
64
Fh(KHz)
60
(58.5 for N28P2)
Figure 1: H/V Frequency Division and Video Mode
PIN
Mode
IBM
VGA
VESA
VGA
640X480
640X400
640X350
640X480
640X400
640X350
640X480
640X400
640X350
0
1
1
0
1
1
1
0
1
1
0
1
1
1
0
1
1
0
Table 4: IBM VGA/ VESA VGA Decoding Table

Weltrend Semiconductor, Inc.
2F., No. 24, Industry E. 9th Rd.
Science-Based Industrial Park
Hsin-Chu, Taiwan, R.O.C.
Tel: 886-35-780241
Fax: 886-35-770419
18
WT8045
Synchronous
Signal
Discriminator
and
Power Saving Detector for Green Monitor

Horizontal Frequency Discriminator
There are horizontal frequency discriminator pins on different type package: 33k, 36.2k (for
N24P4 package); 33k, 36.2k, 43.5k (for 24 pin); 33k, 36.2k, 43.5k, 52k (for 28 pin); 33k, 36.2k,
43.5k, 52k, 60k (for 32 pin); please refer to table 5 for the logical truth table of these pins. These
frequency discriminator pins output can be used for CS Capacitor Control directly as well as
other application.
Signa
l
Hsync
Hs<33k
36k>Hs>33k
43.5k>Hs>36k
52k>Hs>43.5k
60k>Hs>52k
F33k
F36k
F43.5k
F52k
F60k
1
0
0
0
0
1
1
0
0
0
1
1
1
0
0
1
1
1
1
0
1
1
1
1
1
Table 5: Truth table of Frequency discriminator
Mute function Timing Diagram

Weltrend Semiconductor, Inc.
2F., No. 24, Industry E. 9th Rd.
Science-Based Industrial Park
Hsin-Chu, Taiwan, R.O.C.
Tel: 886-35-780241
Fax: 886-35-770419
19
WT8045
Synchronous
Signal
Discriminator
and
Power Saving Detector for Green Monitor

APPLICATION CIRCUIT I

Weltrend Semiconductor, Inc.
2F., No. 24, Industry E. 9th Rd.
Science-Based Industrial Park
Hsin-Chu, Taiwan, R.O.C.
Tel: 886-35-780241
Fax: 886-35-770419
20
WT8045
Synchronous
Signal
Discriminator
and
Power Saving Detector for Green Monitor

APPLICATION CIRCUITII

Weltrend Semiconductor, Inc.
2F., No. 24, Industry E. 9th Rd.
Science-Based Industrial Park
Hsin-Chu, Taiwan, R.O.C.
Tel: 886-35-780241
Fax: 886-35-770419
21
WT8045
Synchronous
Signal
Discriminator
and
Power Saving Detector for Green Monitor

APPLICATION CIRCUIT III

Weltrend Semiconductor, Inc.
2F., No. 24, Industry E. 9th Rd.
Science-Based Industrial Park
Hsin-Chu, Taiwan, R.O.C.
Tel: 886-35-780241
Fax: 886-35-770419
22
WT8045
Synchronous
Signal
Discriminator
and
Power Saving Detector for Green Monitor

APPLICATION CIRCUIT IV

Weltrend Semiconductor, Inc.
2F., No. 24, Industry E. 9th Rd.
Science-Based Industrial Park
Hsin-Chu, Taiwan, R.O.C.
Tel: 886-35-780241
Fax: 886-35-770419
23
WT8045
Synchronous
Signal
Discriminator
and
Power Saving Detector for Green Monitor

DIP OUTLINE DIMENSIONS
N24
N28
SKINNY
N32
A
1250
1385
B
542
288
C
152
130
D
100
100
E
130
130
F
650
355
G
600
310
1650
542
154
100
130
650
600
¡ ¯Dimension in mil
¡ ¯1mm = 39.37 mil

Weltrend Semiconductor, Inc.
2F., No. 24, Industry E. 9th Rd.
Science-Based Industrial Park
Hsin-Chu, Taiwan, R.O.C.
Tel: 886-35-780241
Fax: 886-35-770419
24
WT8045
Synchronous
Signal
Discriminator
and
Power Saving Detector for Green Monitor

WT8045N28P6
WT8045N28P2
OSCin
1
28
VDD
OSCout
2
27
1024x768(56.5K)
OSCin
1
28
VDD
OSCout
2
27
1024x768(56.5K)
HSin
3
26
1024x768 (NI)
HSin
3
26
1024x768 (NI)
VSin
4
25
1024x768 (I)
VSin
4
25
1024x768 (I)
H_out
5
24
800x600(48K)
H_out
5
24
800x600(48K)
V_out
6
23
800x600(37.5K)
V_out
6
23
800x600(37.5K)
F43.5K
7
22
800x600(35.2K)
F43.5K
7
22
800x600(35.2K)
F36.2K
8
21
8
21
F33K
9
20
F33K
9
20
QV128
10
19
640x480(31.5K)
640x400
(31.5K/37.5K)
640x480(37.5K)
F36.2K
QVRC
11
18
QH
QV1
10
19
640x480(31.5K)
640x400
(31.5K/37.5K)
640x480(37.5K)
QVRC
11
18
QH
Vss
12
17
QHRC
Vss
12
17
QHRC
F52K
13
16
PM3
F52K
13
16
PM3
PM1
14
15
PM2
PM1
14
15
PM2
WT8045N28P8
WT8045N28P7
OSCin
OSCout
HSin
VSin
1
28
VDD
1
28
VDD
OSCout
2
27
1024x768(56.5K)
HSin
3
26
1024x768 (NI)
1024x768 (I)
VSin
4
25
1024x768 (I)
800x600(48K)
H_out
5
24
800x600(48K)
800x600(37.5K)
V_out
6
23
800x600(37.5K)
27
1024x768(56.5K)
3
26
1024x768 (NI)
4
25
2
OSCin
H_out
5
24
V_out
6
23
F43.5K
7
22
800x600(35.2K)
F43.5K
7
22
800x600(35.2K)
F36.2K
8
21
640x480(31.5K)
F36.2K
8
21
F33K
9
20
F33K
9
20
QV128
10
19
640x400
(31.5K/37.5K)
640x480(37.5K)
QV1
10
19
QVRC
11
18
QH
QVRC
11
18
640x480(31.5K)
640x400
(31.5K/37.5K)
640x480(37.5K)
QH
QHRC
Vss
12
17
QHRC
Vss
12
17
F52K
13
16
PM3
F52K
13
16
PM3
PM1
+PM2
14
15
Mute
PM1
+PM2
14
15
Mute
Note: The Hout and Vout pin of N28P2, N28P6, N28P7 and N28P8 are positive pulse.

Weltrend Semiconductor, Inc.
2F., No. 24, Industry E. 9th Rd.
Science-Based Industrial Park
Hsin-Chu, Taiwan, R.O.C.
Tel: 886-35-780241
Fax: 886-35-770419
25