FAIRCHILD FMS9874KGC100

www.fairchildsemi.com
FMS9874
Graphics Digitizer
3x8-Bit, 108Ms/s Triple Video A/D Converter with Clamps
Features
•
•
•
•
•
•
•
•
1600 x 1200/75Hz. ADC sampling clock can be derived from
either an external source or incoming horizontal sync signal
using the internal PLL. Output data is 24-bit RGB. Setup and
control is via registers, accessible through an SMBus/I2C compatible serial port.
3-channels
108 Ms/s conversion rate
Programmable Clamps
500ps PLL clock jitter
Adjustable Gain and offset
Internal Reference Voltage
I2C/SMBus compatible Serial Port
100-pin package
Input amplitude range is 500–1000mV with either DC or AC
coupling. Lower reference of AC coupled inputs is established with input clamps that are either internally generated
or externally provided.
Applications
Common to the three channels are clamp pulses, a bandgap
reference voltage and clocks derived from a PLL or an external
source. Digital data levels are 2.5–3.3 volt CMOS compliant.
• Flat panel displays and projectors
• RGB Graphics Processing
Description
As a fully integrated analog interface, the FMS9874 can directly
digitize RGB graphics with resolutions up to 1024 x 768/85Hz
and 1280 x 1024/60Hz; or using alternate pixel sampling,
Power can be derived from a single +3.3 Volt power supply.
Package is a 100-lead MQFP. Performance specifications are
guaranteed over 0°C to 70°C range.
Block Diagram
RIN
Clamp
Gain &
Offset
A/D
Converter
DR7-0
GIN
Clamp
Gain &
Offset
A/D
Converter
DG7-0
BIN
Clamp
Gain &
Offset
A/D
Converter
DB7-0
VREFIN
SCK
CLAMP
INVSCK
XCK
HS
HSIN
COAST
LPF
PLL
SDA
SCL
A0
A1
PWRDN
Control
Timing
Generator
PXCK
ACSIN
SYNC
STRIPPER
Reference
VREFOUT
ICLAMP
DCK
DCK
HSOUT
DCSOUT
REV. 1.5 11/10/00
PRODUCT SPECIFICATION
Architectural Overview
Three separate digitizer channels are controlled by common
timing signals derived from the Timing Generator. A/D clock
signals can be derived from either a PLL or an external clock
XCK. With the PLL selected, A/D clocks track the incoming
horizontal sync signal connected to the HSIN input. Setup is
controlled by registers that are accessible through the serial
interface.
Conversion Channels
Typical RGB graphics signals, RIN, GIN, BIN are ground referenced with 700mV amplitude. If a sync signal is embedded
then the usual format is sync on green with the sync tip at
ground, the black level elevated to 300mV and peak green at
1000mV.
AC coupled video signals must be level shifted to establish
the lower level of the conversion range by clamping to the
black level of the back porch (see Figure 1). Clamp pulses
are derived from internal Timing and Control logic or from
the external CLAMP input.
RIN, GIN, BIN
ICLAMP
Figure 1. Clamping to the back-porch
Gain and Offset
Gain and Offset registers serve two functions: adjustment of
contrast and brightness by setting RGB values in tandem;
matching the gain and offsets between channels, by setting
RGB values individually to obtain the same output levels.
A/D conversion range can be matched to the amplitude of the
incoming video signal by programming Gain Registers GR,
GG and GB, which vary sensitivity (LSB/volt) over a 2:1
range. Incoming video signal amplitudes varying from 0.5 to
1.0 volt can be accommodated.
Input offset voltage of each converter is programmable in 1
LSB steps through the 6-bit OSR, OSG and OSB registers.
Range of adjustment is equivalent to –31 to +32 LSB.
A/D Converter
Each A/D converter digitizes the analog input into 8-bit data
words. Latency is 5–51/2 clock cycles, depending upon the
state of CHINV.
2
FMS9874
VREFIN is the source of reference voltage for the three A/D
converters. VREFIN can be connected to either the internal
bandgap voltage, VREFOUT or an external voltage.
Output Data Configuration
Output data number format for each channel is binary:
00 corresponds to the lowest input; FF corresponds to the
highest input.
Timing and Control
Timing and Control logic encompasses the Timing Generator,
PLL and Serial Interface.
Timing Generator
All internal clock and synchronization signals are generated
by the Timing Generator. Master Clock source is either the
PLL or the external clock input, XCK. Bit XCKSEL selects
the Master Clock source. Two clocks are generated.
Sampling clock, SCK is supplied to all three A/D converters.
Phase of SCK can be adjusted in 32 11.25 degree phase
increments using the 5-bit PHASE register.
DCK is the output data clock. DCK and DCK are supplied as
outputs for synchronizing data transfer from the digitizer
outputs.
Horizontal sync applied to the input, HSIN is propagated by
the Timing and Control to the HSOUT output with a delay
that aligns leading and trailing edges with the output data.
Phase Locked Loop
With a horizontal sync signal connected to the HSIN input
pin, the PLL generates a high frequency internal clock signal,
PXCK that is fed to the Timing and Control logic. Frequency
of PXCK is set by the register programmable PLL divide ratio,
PLLN.
COAST is an input that disables the PLL lock to the horizontal
sync input, HSIN. If HSIN is to be disregarded for a period
such as the vertical sync interval, COAST allows the VCO
frequency to be maintained. Missing horizontal sync pulses
during the vertical interval can cause tearing at the top of a
picture, if COAST is not used.
Two pixels per clock mode is set by programming the PLL
to half the pixel rate. By toggling the INVCK pin between
frames, even and odd pixels can be read on alternate frames.
Serial Interface
Registers are accessed through an I2C/SMBus compatible
serial port. Four serial addresses are pin selectable.
REV. 1.5 11/10/00
FMS9874
PRODUCT SPECIFICATION
Pin Assignments
75
74
73
72
71
70
69
68
67
66
65
64
63
62
61
60
59
58
57
56
55
54
53
52
51
100-Lead MQFP (KG)
50
49
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
No.
Name
No.
Name
No.
Name
No.
Name
1
GND
26
GND
51
DB7
76
DR7
2
RIN
27
GND
52
DB6
77
DR6
3
VDDA
28
HSIN
53
DB5
78
DR5
4
GND
29
COAST
54
DB4
79
DR4
5
VDDA
30
GND
55
DB3
80
DR3
6
GND
31
VDDP
56
DB2
81
DR2
7
ACSIN
32
XCK
57
DB1
82
DR1
8
GIN
33
LPF
58
DB0
83
DR0
9
VDDA
34
NC
59
GND
84
GND
10
GND
35
GND
60
VDDO
85
VDDO
11
VDDA
36
VDDP
61
GND
86
DCK
12
GND
37
GND
62
VDDO
87
DCK
13
BIN
38
VDDP
63
DG7
88
HSOUT
14
VDDA
39
GND
64
DG6
89
DCSOUT
15
GND
40
GND
65
DG5
90
GND
16
VDDA
41
GND
66
DG4
91
VDDO
17
GND
42
NC
67
DG3
92
GND
18
INVSCK
43
NC
68
DG2
93
GND
19
CLAMP
44
NC
69
DG1
94
GND
20
SDA
45
NC
70
DG0
95
VDDA
21
SCL
46
NC
71
GND
96
PWRDN
22
A0
47
NC
72
VDDO
97
VREFOUT
23
A1
48
NC
73
NC
98
VREFIN
24
VDDP
49
GND
74
NC
99
VDDA
25
VDDP
50
VDDO
75
NC
100
VDDA
REV. 1.5 11/10/00
3
PRODUCT SPECIFICATION
FMS9874
Pin Descriptions
Pin Name
Pin No.
Type/Value
Pin Function Description
Converter Channels
RIN, GIN, BIN
2, 8, 13
Input
Analog Inputs.
DR7-0
76–83
Output
Red Channel A Data Output.
DG7-0
63–70
Output
Green Channel A Data Output.
DB7-0
51–58
Output
Blue Channel A Data Output.
Timing Generator
CLAMP
19
Input
External Clamp Input.
INVSCK
18
Input
Invert Sampling Clock. Inverts SCK, the internal clock sampling the
analog inputs. Supports Alternate Pixel Sampling mode for capture
pixel rates up to 216Ms/s.
XCK
32
Input
External Clock input. Enabled if register bit, XCKSEL = H. Replaces
PXCK clock generated by PLL. If unused, connect to ground through a
10kΩ resistor.
DCK
86
Output
Output Data Clock. Clock for strobing output data to external logic.
DCK
87
Output
Output Data Clock Inverted. Inverted clock for strobing output data to
external logic.
HSOUT
88
Output
Horizontal Sync Output. Reconstructed HSYNC delayed by
FMS9874 latency and synchronized with DCK. Leading edge is
synchronized to start of data output. Polarity is always active HIGH.
Phase Locked Loop
HSIN
28
Schmitt
Horizontal Sync input. Schmitt trigger threshold is 1.5V. A 5V source
should be clamped at 3.3V or current limited to prevent overdriving
ESD protection diodes.
COAST
29
Input
PLL Coast. Maintain frequency of PLL output clock PXCK,
disregarding HSIN. If horizontal sync is missing during the vertical sync
interval, PXCK clock frequency can be maintained by asserting
COAST.
LPF
33
Passive
PLL Low Pass Filter. Connect recommended PLL filter to LPF pin.
(see Figure 13.)
Sync Stripper
ACSIN
7
Analog Composite Sync Input. Input to sync stripper with 150mV
threshold.
DCSOUT
89
Digital Composite Sync Output. Output from sync stripper.
Control
4
SDA
20
Bi-directional Serial Port Data. Bi-directional data.
SCL
21
Input
Serial Port Clock. Clock input.
A0
22
Input
Address bit 0. Lower bit of serial port address.
A1
23
Input
Address bit 1. Upper bit of serial port address.
PWRDN
96
Input
Power Down/Output Control. Powers down the FMS9874 and
tri-states the outputs.
REV. 1.5 11/10/00
PRODUCT SPECIFICATION
FMS9874
Pin Descriptions
Pin
Name
Pin No.
Pin Function Description
Power and Ground
VDDA
3, 5, 9, 11, 14, 16, 95, 99, 100 ADC Supply Voltages. Provide a quiet noise free voltage.
VDDP
24, 25, 31, 36, 38
PLL Supply Voltage. Most sensitive supply voltage. Provide a very
quiet noise free voltage.
VDDO
50, 60, 62, 72, 85, 91
GND
1, 4, 6, 10, 12, 15, 17, 26, 27,
30, 35, 37, 39, 40, 41, 49, 59,
61, 71, 84, 90, 92, 93, 94
VREFIN
98
Voltage Reference Input. Common reference input to RGB
converters. Connect to VREFOUT, if internal reference is used.
VREFOUT
97
Voltage Reference Output. Internal band-gap reference output. Tie to
ground through a 0.1µF capacitor.
Digital Output Supply Voltage. Decouple judiciously to avoid
propagation of switching noise.
Ground. Returns for all power supplies. Connect ground pins to a
solid ground plane.
Addressable Memory
Register Map
Name
Address
Function
PLLN11-4
00
PLL divide ratio, MSBs. PLLN + 1 = total number of
pixels per horizontal line.
69 (1693)
PLLN3-0
01
PLL divide ratio, LSBs. PLLN + 1 = total number of pixels
per horizontal line. PLLN3-0 stored in the four upper
register bits 7-4.
D0 (1693)
PLLN3–0
Default (hex)
X X X X
GR7-0
02
Gain, red channel. Adjustable from 70 to 140%.
80
GG7-0
03
Gain, green channel. Adjustable from 70 to 140%.
80
GB7-0
04
Gain, blue channel. Adjustable from 70 to 140%.
80
OSR5-0
05
Offset, red channel. OSR5-0 stored in the six upper
register bits 7-2.Default value is decimal 32.
80
OSR5–0
OSG5-0
06
Offset, green channel. OSR5-0 stored in the six upper
register bits 7-2. Default value is decimal 32.
OSG5–0
OSB5-0
07
80
X X
Offset, blue channel. OSR5-0 stored in the six upper
register bits 7-2. Default value is decimal 32.
OSB5–0
80
X X
CD7-0
08
Clamp delay. Delay in pixels from trailing edge of
horizontal sync.
80
CW7-0
09
Clamp width. Width of clamp pulse in pixels.
80
CONFIG 1
0A
Configuration Register No. 1
F4
PHASE7-0
0B
Sampling clock phase. PHASE4-0 stored in upper
register bits 7-3. PHASE sets the sampling clock phase in
11.25° increments. Default value is decimal 16.
10
PHASE4–0
5
X X
X X X
REV. 1.5 11/10/00
PRODUCT SPECIFICATION
FMS9874
Name
Address
Function
Default (hex)
PLLCTRL
0C
CONFIG 2
0D
Configuration Register No. 2
00
0E
Reserved
0X
0F
Reserved
00
PLL Control
24
Register Definitions
Configuration Register 1 (0A)
Bit no.
Name
Type
Description
1
XCKSEL
R/W
External Clock Select. Select internal clock source.
0: Internal PLL
1: XCK input.
2
XCLAMPOL
R/W
External Clamp Polarity. Select clamp polarity.
0: Active L.
1: Active H.
3
XCLAMP
R/W
External Clamp Select. Select clamp source.
0: Internally generated by PLL referenced to HSIN.
1: External CLAMP input.
4
COASTPOL
R/W
Coast Polarity. Select COAST input polarity.
0: Active L.
1: Active H.
5
HSPOL
R/W
HSIN Polarity. Select horizontal sync input polarity. PLL is locked to selected
edge:
0: Falling edge.
1: Rising edge.
6
—
R/W
0: Default must be 0.
7
—
R/W
0: Default must be 0.
0
PLL Configuration Register (0C)
6
Bit no.
Name
Type
Description
1-0
—
4-2
IPUMP2-0
R/W
Charge Pump Current. Selects Charge Pump current (µA). (see Table 5.
Charge Pump Current Codes)
000: 50
001: 100
010: 150
011: 250
100: 350
101: 500
110: 750
111: 1500
6-5
FVCO1-0
R/W
VCO Frequency Range. Selects VCO frequency range (MHz).
00: 20–90
01: 20–90
10: 80–108
11: —
7
—
R/W
Reserved.
0: Run.
1: (reserved).
REV. 1.5 11/10/00
FMS9874
PRODUCT SPECIFICATION
Configuration Register 2 (0D)
Bit no.
Name
Type
Description
0
—
—
Reserved. Set to 0.
3-1
REV
R
Revision Number. Die revision number.
4
OUTPHASE
W
Output Data Phase. In the alternate pixel mode, selects either odd (1, 3, 5, …)
or even (2, 4, 6 ….) samples following the HSYNC leading edge to be emitted
from output data ports.
0: Even samples
1: Odd samples
7-5
-
R/W
Reserved. Set to 00.
Functional Description
Clamps
There are two major sections within the FMS9874 Digitizer:
If the incoming signals are not ground referenced, a clamp
must be used to set the incoming video range relative to
ground. Prior to each A/D converter, each channel includes a
clamp that allows a capacitively coupled input to be referenced
to the A/D converter bottom reference voltage when the
clamp pulse is active. Source of the clamp signal is determined by the XCLAMP bit.
1.
Analog-to-digital Converter Channels, one for each
channel, RGB and the voltage reference.
2.
Timing and Control comprising the PLL, Timing
Generator, Sync Stripper and Serial Interface.
A/D Converter Channels
Each of the three RGB channels consists of:
1.
A clamp to set the lower reference level of an AC
coupled input.
2.
Gain and offset stages to tune the converter to input
signal levels.
3.
An Analog-to-Digital Converter to digitize the analog
input.
Analog Inputs
Input signal range is 500 to 1000mV to support conversion of
single-ended signals with a typical amplitude of 700mV p-p.
With the clamp active, each input accommodates a negative
300mV excursion.
Inputs are optimized for a source resistance of 37.5 to 75Ω.
To reduce noise sensitivity, the ultra-wide 500MHz input
bandwidth may be reduced by adding a small series inductor
prior to the 75Ω terminating resistor. See Applications Section.
REV. 1.5 11/10/00
Internal clamp timing is generated by the Timing and Control Block. Position and width of the internal clamp pulse,
ICLAMP are programmable through registers CD and CW.
External clamp input is selected by register bit XCLAMP
and the external clamp polarity selected through register bit
XCLAMPOL. To disable the clamp for DC coupled inputs,
set XCLAMP = 1 with either of these conditions:
1.
XCLAMPOL = 0 with input CLAMP = H.
2.
XCLAMPOL = 1 with input CLAMP = L.
Best performance will be achieved with the clamp set active
for most of the black signal level interval between the trailing
edge of horizontal sync and the start of active video. Insufficient
clamping can cause brightness changes at the top of the image
and slow recovery from large changes in Average Picture
Level (APL). Recommended value of CD is 0x10 to 0x20 for
most standard video sources.
Analog-to-Digital Converter
Figure 2 is a block diagram of the ADC core with gain and
offset functions. G7-0, OS5-0, RGBIN and PD7-0 generically
refer to the gain and offset register values, analog input and
parallel data output of any RGB channel.
7
PRODUCT SPECIFICATION
FMS9874
VREF
Gain
Register
G7-0
Offset
Register
OS5-0
D/A
IBIAS + IOFFSET
Current
D/A
A/D Core
RGBIN
VOS
+
Track &
Hold
-
PD7-0
A/D
RLEVEL
SCK
Figure 2. A/D Converter Architecture
Core of the ADC block is a high speed A/D encoder with
differential inputs. Within the A/D converter core are the
following elements:
1.
Differential track and hold.
2.
Differential analog-to-digital converter.
Setting the gain register value G7-0 (GR7-0, GG7-0, GB7-0),
establishes the gain D/A converter voltage which is the A/D reference voltage. Increasing video gain reduces the contrast of the
picture since the number of output codes is reduced. Conversion
range is defined by the gain setting according to Table 1.
255 + G 7–0 500
V OS = ( OS 5–0 – 31 ) •• ----------------------------- •• --------255
255
D/A converter gain tracks A/D gain with 1 LSB of offset corresponding to 1LSB of gain. Increasing the offset of a video
signal increases brightness of the picture. Data output from
the A/D converter is:
D 7–0 = S •• V IN – ( OS 5–0 – 31 )
Impact of the offset values OSR5-0, OSG5-0, and OSB5-0 is
shown in Table 2.
Table 1. Gain Calibration
G7-0
Conversion Range (mV)
0
500
66h
700
OS5-0
Equivalent Offset (bits)
1000
0
-31d
1Fh
0
FFh
32d
FFh
A/D Converter sensitivity is:
255
255
•
S = --------- •• ----------------------------- LSB ⁄ mV
500 255 + G 7 – 0
Offset is set through the Single-Ended to Differential Amplifier
which translates the ground referenced input to a differential
voltage centered around A/D common mode bias voltage.
The 6-bit Offset D/A converter injects a current into RLEVEL
with two components:
1.
IBIAS to establish the A/D common mode voltage.
2.
IOFFSET to set the offset from the common mode level.
8
Voltage offset from the common mode voltage at the inverting input of the Track and Hold is:
Table 2. Offset Calibration
Sampling Clock PHASE Adjustment
Picture quality is strongly impacted by the PHASE4-0 value.
If PHASE is not set correctly, any section of an image consisting of vertical lines may exhibit tearing.
Figure 3 shows how an analog input, RINGINBIN is sampled
by the rising edge of SCK after a delay PHASE from the rising edge of either PXCK or XCK. SCK can be delayed up to
32 steps in 11.25° increments by adjusting the register value,
PHASE4-0.
Output data, DCK and DCK are delayed in tandem with
SCK relative to PXCK or XCK. There is a 5-61/2 clock
latency between the data sample Sn and the corresponding
data out DA7-0.
REV. 1.5 11/10/00
FMS9874
PRODUCT SPECIFICATION
PHASE
PXCK/XCK
SCK
VIN
Sn
DCK
DA
Figure 3. Internal Sampling Clock, SCK Timing
Ideally, incoming pixels would be trapezoidal with fast risetimes and the sampling edge of the A/D clock, SCK would
be positioned along the level section of the incoming pixel
waveform as shown in Figure 4. There is a narrow zone of
uncertainly where sampling during pixel rise time would
cause an error in the value of the A/D data output, D7-0,
which is shown as a value, 0-255.
Zones of Uncertainty
sampling clock jitter. To avoid corruption of the image, setting the value PHASE7-0 is critical. PHASE4-0 should be
trimmed to position the sampling edge of SCK within the
zone of serendipity.
Zones of Uncertainty
RIN, GIN, BIN
SCK
RIN, GIN, BIN
SCK
D7-0
D7-0
Figure 6. Improper Pixel Sampling
Voltage References
Figure 4. Ideal Pixel Sampling
In practice, high-resolution pixels have long rise-times. As
shown in Figure 5, there are narrow zones of serendipity when
the pixel amplitude is level. Samples are valid in these zones.
Zones of Serendipity
RIN, GIN, BIN
SCK
D7-0
Figure 5. Acceptable Pixel Sampling
Referring to Figure 6, when the sample clock, SCK has some
jitter, if the sampling edge occurs anywhere within the zone
of uncertainty where the pixel rise time is steep, there will be
amplitude modulation of the digitized data, D7-0, due to the
REV. 1.5 11/10/00
An on-chip voltage reference is generated from a bandgap
source. VREFOUT is the buffered output of this source that
can be connected to VREFIN to supply a voltage reference
that is common to the three converter channels.
VREFIN, with a nominal voltage of 1.25V, is the source of the
differential reference voltages for each A/D converter.
Reference voltages supplied to the differential inputs of the
comparators in the A/D converters are derived from VREFIN.
Digital Data Outputs
Input horizontal sync HSIN and outgoing data, D[7..0] are
resynchronized to the delayed sample clock, SCK. Output
timing characteristics are defined in Figure 4. Latency of the
first pixel, N varies according to the mode:
1.
Normal.
2.
Alternate pixel sampling.
Levels are 3.3 volt CMOS with the output supply variable
between 2.5 and 3.3 V. PWRDN = L sets the outputs
high-impedance. PWRDN = H enables the outputs.
9
PRODUCT SPECIFICATION
FMS9874
HSIN
PHASE
N
PXCK/XCK
SCK
RGBIN
S0
DCK
tDH
DCK
tDO
D[7..0]
D0
HSOUT
Figure 7. Output Timing
Figures 8 through 10 depict data output timing relative to the
sampling clock and inputs for all modes. Timing is referenced
to the leading edge of HSIN when the first sample is taken at
the rising edge of SCK. Register bit OUTPHASE, determines
if odd or even samples are directed to the data ports.
1.
HSOUT is always active HIGH.
2.
Only the leading edge of HSOUT is active or selected by
the HSPOL register bit.
3.
HSOUT is aligned with DCK.
P0
P1
P2
Trailing edge is linked to HSIN.
5.
If MSIN does not terminate before mid-line, HSOUT is
forced low. A 50% duty cycle indicates that HSPOL is
incorrectly set.
HS is the internal sync pulse generated from HSYNC. SCK
is the internal A/D converter sampling clock.
Note the timing of the HSOUT waveform:
RGBIN
4.
P3
P4
P5
P6
Output data transitions are synchronized with the falling
edge of DCK. Output data should be strobed on the rising
edge of DCK. A 5 to 5.5 clock cycle delay must be flushed
before valid data is available.
P7
HSIN
PXCK
HS
5 PIPE DELAY
SCK
DATACK
D7-0
D0
D1
D2
D3
D4
D5
D6
D7
HSOUT
Figure 8. Normal Mode
10
REV. 1.5 11/10/00
FMS9874
PRODUCT SPECIFICATION
P0 P1 P2 P3 P4 P5 P6 P7
RGBIN
HSIN
PXCK
HS
5.5 PIPE DELAY
SCK
DATACK
D1
D7-0
D3
D5
D7
HSOUT
Figure 9. Alternate Pixel Sampling Mode, (Even Pixels)
RGBIN
P0 P1 P2 P3 P4 P5 P6 P7
HSIN
PXCK
HS
5 PIPE DELAY
SCK
DATACK
D0
D7-0
D2
D4
D6
HSOUT
Figure 10. Alternate Pixel Sampling Mode, (Odd Pixels)
Alternate Pixel Sampling Mode
A logic H on the CKINV pin inverts the sampling phase of
SCK. In the Alternate Pixel Sampling Mode:
1.
The PLL is run at half rate. SCK, DCK and DCK are
half rate.
2.
CKINV is toggled between frames.
O
O
O
O
O
O
O
O
O
O
O
E
E
E
E
E
E
E
E
E
E
E
O
O
O
O
O
O
O
O
O
O
O
E
E
E
E
E
E
E
E
E
E
E
O
O
O
O
O
O
O
O
O
O
O
E
E
E
E
E
E
E
E
E
E
E
O
O
O
O
O
O
O
O
O
O
O
E
E
E
E
E
E
E
E
E
E
E
O
O
O
O
O
O
O
O
O
O
O
E
E
E
E
E
E
E
E
E
E
E
O
O
O
O
O
O
O
O
O
O
O
E
E
E
E
E
E
E
E
E
E
E
On one frame, even pixels are sampled. On the other, odd
pixels are sampled.
Alternate Pixel Sampling is similar to interlacing used in
broadcast video, except that the columns of pixels are interlaced instead of lines.
O1 E1 O1E1 O1 E1O1E1O1E1O1E1O1E1
O1 E1 O1E1 O1 E1O1E1O1E1O1E1O1E1
O1 E1 O1E1 O1 E1O1E1O1E1O1E1O1E1
O1 E1 O1E1 O1 E1O1E1O1E1O1E1O1E1
O1 E1 O1E1 O1 E1O1E1O1E1O1E1O1E1
O1 E1 O1E1 O1 E1O1E1O1E1O1E1O1E1
O1 E1 O1E1 O1 E1O1E1O1E1O1E1O1E1
O1 E1 O1E1 O1 E1O1E1O1E1O1E1O1E1
O1 E1 O1E1 O1 E1O1E1O1E1O1E1O1E1
O1 E1 O1E1 O1 E1O1E1O1E1O1E1O1E1
O1 E1 O1E1 O1 E1O1E1O1E1O1E1O1E1
Figure 12. Odd Pixels from Frame 1
Figure 11. Odd and Even Pixels in a Frame
REV. 1.5 11/10/00
11
PRODUCT SPECIFICATION
FMS9874
O1 E2 O1 E2 O1E2 O1E2 O1E2 O1E2 O1 E2
O1 E2 O1 E2 O1E2 O1E2 O1E2 O1E2 O1 E2
O1 E2 O1 E2 O1E2 O1E2 O1E2 O1E2 O1 E2
O1 E2 O1 E2 O1E2 O1E2 O1E2 O1E2 O1 E2
O1 E2 O1 E2 O1E2 O1E2 O1E2 O1E2 O1 E2
O1 E2 O1 E2 O1E2 O1E2 O1E2 O1E2 O1 E2
O1 E2 O1 E2 O1E2 O1E2 O1E2 O1E2 O1 E2
O1 E2 O1 E2 O1E2 O1E2 O1E2 O1E2 O1 E2
O1 E2 O1 E2 O1E2 O1E2 O1E2 O1E2 O1 E2
O1 E2 O1 E2 O1E2 O1E2 O1E2 O1E2 O1 E2
O1 E2 O1 E2 O1E2 O1E2 O1E2 O1E2 O1 E2
Figure 13. Even Pixels from Frame 2
O1 E2 O1 E2 O1 E2 O1 E2 O1 E2 O1 E2
O1 E2 O1 E2 O1 E2 O1 E2 O1 E2 O1 E2
O1 E2 O1 E2 O1 E2 O1 E2 O1 E2 O1 E2
O1 E2 O1 E2 O1 E2 O1 E2 O1 E2 O1 E2
O1 E2 O1 E2 O1 E2 O1 E2 O1 E2 O1 E2
O1 E2 O1 E2 O1 E2 O1 E2 O1 E2 O1 E2
O1 E2 O1 E2 O1 E2 O1 E2 O1 E2 O1 E2
O1 E2 O1 E2 O1 E2 O1 E2 O1 E2 O1 E2
O1 E2 O1 E2 O1 E2 O1 E2 O1 E2 O1 E2
O1 E2 O1 E2 O1 E2 O1 E2 O1 E2 O1 E2
O1 E2 O1 E2 O1 E2 O1 E2 O1 E2 O1 E2
O1 E2 O1 E2 O1 E2 O1 E2 O1 E2 O1 E2
O1 E2 O1 E2 O1 E2 O1 E2 O1 E2 O1 E2
Figure 14. Subsequent Output
Combining Frames 2 and 3
Timing and Control
Phase Locked Loop
2.
Internal sampling clock SCK.
O3 E2
O3 E2
O3 E2
O3 E2
O3 E2
O3 E2
O3 E2
O3 E2
O3 E2
O3 E2
O3 E2
Figure 15. Combined Frames
2 and 3
Values of IPUMP and FVCO for Standard VESA timing
parameters are shown in Table 3. Timing of many computer
video outputs does not comply with VESA recommendations.
PLLN should be optimized to avoid vertical noise bars on the
displayed image.
Two clock types originate in the PLL:
Data clocks DCK and DCK.
O3 E2
O3 E2
O3 E2
O3 E2
O3 E2
O3 E2
O3 E2
O3 E2
O3 E2
O3 E2
O3 E2
The PLL consists of a phase comparator, charge pump VCO
and ÷N counter, with the charge pump connected through the
LPF pin to an external filter. These elements must be programmed to match the incoming video source to be captured.
Timing and Control logic encompasses the PLL, Timing
Generator and Sync Stripper.
1.
O3 E2 O3 E2 O3 E2 O3 E2
O3 E2 O3 E2 O3 E2 O3 E2
O3 E2 O3 E2 O3 E2 O3 E2
O3 E2 O3 E2 O3 E2 O3 E2
O3 E2 O3 E2 O3 E2 O3 E2
O3 E2 O3 E2 O3 E2 O3 E2
O3 E2 O3 E2 O3 E2 O3 E2
O3 E2 O3 E2 O3 E2 O3 E2
O3 E2 O3 E2 O3 E2 O3 E2
O3 E2 O3 E2 O3 E2 O3 E2
O3 E2 O3 E2 O3 E2 O3 E2
DCK and DCK are used to strobe data from the FMS9874 to
following digital circuits. SCK is the ADC sample clock
which has adjustable phase controlled through the PHASE
register. DCK and DCK are phase aligned with SCK.
Reference for the PLL is the horizontal sync input, HSIN
with polarity selected by the HSPOL bit.
Modes marked 2X are 2X-oversampled modes where the
number of samples per horizontal line is doubled. To select
this mode, the Phase-locked Loop Divide Ratio value must
changed from PLL1x to:
PLL 2x = 2 • ( PLL 1x + 1 ) – 1
Frequency of the HSIN input is multiplied by the value PLLN
+ 1 derived from the PLLN11-4 and PLLN3-0 registers. PLLN
+ 1 should equal the number of pixels per horizontal line
including active and blanked sections. Typically blanking is
20–30% of active pixels. Divide ratios from 2–4095 are
supported. SCK, DCK and DCK run at a rate PLLN + 1
times the HSIN frequency.
Values of IPUMP and FVCO are set through the PLL
Configuration Register (0x0C). Recommended external filter
components are shown in Figure 16. RF quality ±10%
ceramic capacitors with X7R dielectric are recommended.
Table 3. Recommended IPUMP and FVCO values for Standard Display Formats1
Standard
Resolution
Refresh Rate
Horizontal
Frequency
Sample Rate
FVCO1-0
IPUMP2-0
VGA
640 X 480
60 Hz
72 Hz
75 Hz
85 Hz
31.5 kHz
37.7 kHz
37.5 kHz
43.3 kHz
25.175 MHz
31.500 MHz
31.500 MHz
36.000 MHz
01
01
01
01
100
100
100
100
2X
640 X 480
60 Hz
67 Hz
72 Hz
75 Hz
70 Hz
31.5 kHz
35 kHz
37.7 kHz
37.5 kHz
31.5 kHz
50 MHz
62.5 MHz
63 MHz
63 MHz
56.6 MHz
01
01
01
01
01
100
100
100
100
100
56 Hz
60 Hz
72 Hz
75 Hz
85 Hz
35.1 kHz
37.9 kHz
48.1 kHz
46.9 kHz
53.7 kHz
36.000 MHz
40.000 MHz
50.000 MHz
49.500 MHz
56.250 MHz
01
01
01
01
01
111
111
111
111
720 X 400
SVGA
12
800 X 600
REV. 1.5 11/10/00
FMS9874
PRODUCT SPECIFICATION
Table 3. Recommended IPUMP and FVCO values for Standard Display Formats1 (continued)
Standard
Resolution
Refresh Rate
Horizontal
Frequency
Sample Rate
FVCO1-0
IPUMP2-0
XGA
1024 X 768
60 Hz
70 Hz
75 Hz
80 Hz
85 Hz
48.4 kHz
56.5 kHz
60.0 kHz
64.0 kHz
68.3 kHz
65.000 MHz
75.000 MHz
78.750 MHz
85.500 MHz
94.500 MHz
01
01
10
111
111
111
SXGA
1280 X 1024
60 Hz
64.0 kHz
108.000 MHz
10
111
Notes:
1. VESA Monitor Timing Standards and Guidelines, September 17, 1998 and others.
COAST = H disables PLL lock to HSIN, while the VCO
frequency is retained. VCO frequency remains stable over
several lines without updates from HSIN. COAST can be
connected directly to the vertical sync signal or supplied by
the graphics controller.
VDDP
C1
0.18µF
C2
0.018µF
R1
1.5K
RMS Clock jitter is less than 3% of pixel period in all operating modes. At lower frequencies below 40MHz, the jitter
rises but can be reduced by over-sampling at a 2X clock rate.
See Performance section for jitter specifications and plots.
LPF
Figure 16. Schematic, PLL Filter.
Loop performance is established by setting:
COAST
1.
VCO frequency range through FVCO1-0. (see Table 4)
2.
Charge Pump Current through IPUMP2-0. (see Table 5)
3.
External loop filter component values.
COAST = H disables PLL lock to HSIN, while the VCO
frequency is retained. VCO frequency remains stable over
several lines without updates from HSIN. COAST can be
connected directly to the vertical sync signal or supplied by
the graphics controller.
Table 4. VCO Frequency Bands
FVCO2-0 Frequency Range (MHz) KVCO (MHz/V)
00
20–90
60
10
75–108
90
11
—
—
01
Table 5. Charge Pump Current Levels
Operation of COAST is depicted in Figure 17. HSOUT
polarity is always positive. When COAST = L, HSOUT
tracks HSIN (shown with postive polarity in Figure 1 ):
1.
HSOUT rising edge tracks HSIN delayed by a few pixels.
2.
HSOUT falling edge tracks the trailing edge of HSIN
with no delay.
IPUMP2-0
Current (µA)
000
50
When COAST = H, the PLL flywheels, disregarding the
incoming HSIN references, while the HSOUT waveform
depends upon the state of HSIN.
001
100
1.
010
150
a.) HSOUT rising edge remains locked to the PLL.
011
250
100
350
b.) HSOUT trailing edge falls after 50% of the HSOUT
period has expired.
101
500
110
750
a.) HSOUT rising edge remains locked to the PLL.
111
1500
b.) HSOUT falling edge is terminated by the trailing
edge of HSIN.
Setting SPHASE4-0 selects the sampling phase of SCK relative to PXCK in 32 steps of 11.25°. Phase of the output data,
DCK and DCK is slaved to the SCK phase.
REV. 1.5 11/10/00
2.
3.
If HSIN = H:
HSIN transitions:
If HSIN = L, then HSOUT = L
13
PRODUCT SPECIFICATION
FMS9874
HSIN
Trailing edge terminates HSOUT
COAST
HSOUT
50% Timeout
Figure 17.
Timing Generator
Serial Interface
Timing and Control logic generates:
Register access is via a 2-wire I2C/SMBus compatible interface. As a slave device, the 7-bit address is selected by the
A1-0 pins (see Table 6). Serial port pins SDA and SCL communicate with the host SMBus/I2C controller which act as a
master.
1.
Internal sampling clock, SCK.
2.
Output data clocks, DCK and DCK.
3.
Output horizontal sync, HSOUT.
4.
Internal clamp pulse, ICLAMP.
With HSPOL set correctly, ICLAMP delay follows the trailing edge of horizontal sync in (HSIN). Delay is set by the
CD register. Width of ICLAMP is set by the CW register.
Range of CD and CW values is 1–255 pixels.
Sync Stripper
Some video signals include embedded composite sync rather
than separate horizontal and vertical sync signals, typically
sync on green. Composite sync is extracted from Composite
Video at the ACSIN pin.
Since the serial control port is design to interface with 3.3V
logic, the pins must be protected by series connected 150Ω
resistors if SDA and SCL signals originate from 5V logic.
(See Applications Section)
Table 6. Serial Interface Address Codes
A1-0
7-Bit Address
00
4C
01
4D
10
4E
11
4F
When the ACSIN signal falls below a 150mV ground referenced threshold, sync is detected. Composite Sync Output,
DCSOUT reflects the ACSIN sync timing with non-inverted
CMOS digital levels.
Two signals comprise the bus: clock (SCL) and bi-directional
data (SDA). When receiving and transmitting data through
the serial interface, the FMS9874 acts as a slave, responding
only to commands by the I2C/SMBus master.
Power Down
Data received or transmitted on the SDA line must be stable
for the duration of the positive-going SCL pulse. Data on
SDA may change only when SCL = L. An SDA transition
while SCL = H is interpreted as a start or stop signal.
PWRDN = L minimizes FMS9874 power consumption.
Data outputs become high impedance. Clocks generation is
stopped. Register contents are maintained. Sync stripping
and the internal voltage reference function.
14
REV. 1.5 11/10/00
FMS9874
PRODUCT SPECIFICATION
SDA
tBUFF
tDHO
tSTAH
tDSU
tSTASU
tSTOSU
tDAL
SCL
tDAH
Figure 18. Serial Bus: Read/Write Timing
SDA
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
ACK
SCL
Figure 19. SerialBus: Typical Byte Transfer
SDA
A6
A5
A4
A3
A2
A1
A0
R/W\
ACK
SCL
Figure 20. Serial Bus: Slave Address with Read/Write Bit
There are five steps within an I2C/SMBus cycle:
Data Transfer via Serial Interface
1.
2.
3.
4.
5.
If a slave device, such as the FMS9874 does not acknowledge the master device during a write sequence, SDA
remains HIGH so the master can generate a stop signal. During a read sequence, if the master device does not acknowledge by bringing SDA = L, the FMS9874 interprets SDA =
H as “end of data.” SDA remains HIGH so the master can
generate a stop signal.
Start signal
Slave address byte
Pointer register address byte
Data byte to read or write
Stop signal
When the Serial Bus interface is inactive, SCL = H and SDA
= H. Communications are initiated by sending a start signal
(Figure 14, left waveform) that is a HIGH-to-LOW transition
on SDA while SCL is HIGH. A start signal alerts all slaved
devices that a data transfer sequence is imminent.
After a start signal, the first eight bits of data comprise a seven
bit slave address followed a single R/W bit (Read = H, Write
= L) to set the direction of data transfer: read from; or write
to the slave device. If the transmitted slave address matches
the address of the FMS9874 which set by the state of the
ADD pin, the FMS9874 acknowledges by pulling SDA
LOW on the 9th SCL pulse (see Figure 16). If the addresses
do not match, the FMS9874 does not acknowledge.
For each byte of data read or written, the MSB is the first bit
of the sequence.
REV. 1.5 11/10/00
To write data to a specific FMS9874 control register, three
bytes are sent:
1.
2.
3.
Write the slave address byte with bit R/W = L.
Write the pointer byte.
Write to the control register indexed by the pointer.
After each byte is written, the pointer auto-increments to
allow multiple data byte transfers within one write cycle.
Data is read from the control registers of the FMS9874 in a similar manner, except that two data transfer operations are required:
1.
2.
3.
4.
Write the slave address byte with bit R/W = L.
Write the pointer byte.
Write the slave address byte with bit R/W = H
Read the control register indexed by the pointer.
15
PRODUCT SPECIFICATION
After each byte is read, the pointer auto-increments to allow
multiple data byte transfers within one read cycle.
Preceding each slave write, there must be a start cycle.
Following the pointer byte there should be a stop cycle.
After the last read, there must be a stop cycle comprising
a LOW-to-HIGH transition of SDA while SCL is HIGH.
(see Figure 18, right waveform)
A repeated start signal occurs when the master device driving the serial interface generates a start signal without first
generating a stop signal to terminate the current communication. This is used to change the mode of communication
(read, write) between the slave and master without releasing
the serial interface lines.
Serial Interface Read/Write Examples
Examples below show how serial bus cycles can be linked
together for multiple register read and write access cycles.
For sequential register accesses, each ACK handshake initiates further SCL clock cycles from the master to transfer
the next data byte.
FMS9874
Read from one register
1. Start signal
2. Slave Address byte (R/W bit = LOW)
3. Pointer byte (= base address)
4. Stop signal (optional)
5. Start signal
6. Slave Address byte (R/W bit = HIGH)
7. Data byte from base address
8. Stop signal
Read from four registers
1. Start signal
2. Slave Address byte (R/W bit = LOW)
3. Pointer byte (= base address)
4. Stop signal (optional)
5. Start signal
6. Slave Address byte (R/W bit = HIGH)
7. Data byte from base address
8. Data byte from (base address + 1)
9. Data byte from (base address + 2)
10. Data byte from (base address + 3)
11. Stop signal
Write to one register
1. Start signal
2. Slave Address byte (R/W bit = LOW)
3. Pointer byte
4. Data byte to base address
5. Stop signal
Write to four consecutive registers
1. Start signal
2. Slave Address byte (R/W bit = LOW)
3. Pointer byte
4. Data byte to base address
5. Data byte to (base address + 1)
6. Data byte to (base address + 2)
7. Data byte to (base address + 3)
8. Stop signal
16
REV. 1.5 11/10/00
FMS9874
PRODUCT SPECIFICATION
Absolute Maximum Ratings
(beyond which the device may be damaged)1
Parameter
Min
Typ
Max
Unit
-0.5
4
V
-0.3
VDDA
V
-5.0
5.0
mA
-0.5
VDDA
V
-10.0
10.0
mA
Power Supply Voltages
VCC (Measured to GND)
Digital Inputs
Applied voltage (Measured to GND)2
Forced current
3, 4
Analog Inputs
Applied Voltage (Measured to GND)2
Forced current
3, 4
Digital Outputs
Applied voltage (Measured to GND)2
-0.5
V
Forced current
3, 4
-6.0
6.0
mA
Forced current
3, 4
-8.0
8.0
mA
1
second
Junction
150
°C
Lead Soldering (10 seconds)
300
°C
Vapor Phase Soldering (1 minute)
220
°C
150
°C
±150
V
Short circuit duration (single output in HIGH state to ground)
Temperature
Storage
-65
Electrostatic Discharge5
Notes:
1. Functional operation under any of these conditions is NOT implied. Performance and reliability are guaranteed only if
Operating Conditions are not exceeded.
2. Applied voltage must be current limited to specified range.
3. Forcing voltage must be limited to specified range.
4. Current is specified as conventional current flowing into the device.
5. EIAJ test method.
Operating Conditions
Parameter
Min
Nom
Max
Units
VDDA
ADC Power Supply Voltage
3.0
3.3
3.6
V
VDDP
PLL Power Supply Voltage
3.0
3.3
3.6
V
VDDO
Output Power Supply Voltage
2.2
3.3
3.6
V
TA
Ambient Temperature, Still Air
0
70
°C
500
mV p-p
A/D analog input range, min.
A/D analog input range, max.
REV. 1.5 11/10/00
1000
mV p-p
17
PRODUCT SPECIFICATION
FMS9874
Electrical Characteristics1
Parameter
Conditions
Min
Typ
Max
Unit
Power Supply Currents
IDDA
Supply current, ADC
current2,
Digital Output
Operating, 25°C
211
mA
Operating, 25°C
47
mA
IDDD
Supply
IDDP
Supply current, PLL
Operating, 25°C
30
mA
PD
Power dissipation
0 to 70°C
800
mW
IPD
Power-down current
0 to 70°C
23
mA
PDD
Powered-down disspation
0 to 70°C
10
mW
3
pF
Digital Inputs/Outputs
CI
Input Capacitance
25°C
IIH
Input Current, HIGH
0 to 70°C
IIL
Input Current, LOW
0 to 70°C
VIH
Input Voltage, HIGH
0 to 70°C
VIL
Input Voltage, LOW
0 to 70°C
IOHD
Output Current, HIGH, data
0 to 70°C
4
mA
IOHC
Output Current, HIGH, clock
0 to 70°C
8
mA
IOLD
Output Current, LOW, data
0 to 70°C
4
mA
IOLC
Output Current, LOW, clock
0 to 70°C
8
mA
VOH
Output Voltage, HIGH
IOH = max., 0 to 70°C
VOL
Output Voltage, LOW (VDD3)
IOL = max., 0 to 70°C
-1
µA
+1
2.5
µA
V
0.8
VDDO–0.1
V
V
0.1
V
Serial Bus I/O
VSMIH
Input Voltage, HIGH
0 to 70°C
VSMIL
Input Voltage, LOW
0 to 70°C
0.8
V
VSMOL
Output Voltage, LOW
ISMOL = max.
0.1
V
ISMOH
Output Current, HIGH
0 to 70°C
µA
ISMOL
Output Current, HIGH
0 to 70°C
mA
2.5
V
Analog Inputs
IB
Input bias current
0 to 70°C
EOS
Input Offset Voltage
0 to 70°C
7
1
µA
50
mV
Reference Output
Output Voltage
0 to 70°C
Temperature Coefficient
0 to 70°C
1.20
1.25 1.30
±50
V
ppm/°C
Notes:
1. Unless otherwise stated, 0 to 70°C
2. DCK, DCK load = 15 pF; data load = 5 pF.
18
REV. 1.5 11/10/00
FMS9874
PRODUCT SPECIFICATION
Switching Characteristics
Parameter
Conditions
Min.
Conversion rate
0 to 70°C
Data to clock skew
Typ.
Max.
Unit
10
108
Ms/s
0 to 70°C
-0.5
2.0
ns
0 to 70°C
15
110
kHz
Maximum PLL clock rate
0 to 70°C
108
Minimum PLL clock rate
0 to 70°C
Analog-to-Digital Converters
tSKEW
Timing Generator
HSIN input frequency
PLL
Jitter1
Sampling phase tempco
25°C
MHz
20
1.8
MHz
µs p-p
0 to 70°C
15
ps/°C
Serial Bus Interface
tDAL
SCL Pulse Width, LOW
0 to 70°C
4.7
µs
tDAH
SCL Pulse Width, HIGH
0 to 70°C
4.0
µs
tSTAH
SDA Start Hold Time
0 to 70°C
4.0
µs
tSTASU
SCL to SDA Setup Time (Stop)
0 to 70°C
4.7
µs
tSTOSU
SCL to SDA Setup Time (Start)
0 to 70°C
4.0
µs
tBUFF
SDA Stop Hold Time Setup
0 to 70°C
4.7
µs
tDSU
SDA to SCL Data Setup Time
0 to 70°C
250
ns
tDHO
SDA to SCL Data Hold Time
0 to 70°C
0
ns
Notes:
1. FVCO = 10, IPUMP = 110, PLLN = 137510.
System Performace Characteristics
Parameter
Conditions
Min
Typ1
Max
Unit
25°C
-1.4
±0.8
1.4
LSB
0 to 70°C
-2.5
2.5
LSB
25°C
-1.0
1.15
LSB
0 to 70°C
-1.0
1.25
LSB
Analog to Digital Converter
ELI
ELD
BW
Integral Linearity Error
Differential Linearity Error
±0.5
Missing Codes
0 to 70°C
Input full scale matching
0 to 70°C
5
0
%FS
Offset adjustment range
0 to 70°C
25
%FS
Gain tempco
25°C
280
ppm/°C
Analog bandwidth, full power
25°C
500
MHz
Transient response
25°C
2
ns
tOV
Over-voltage recovery time
25°C
1.5
ns
SNR
SNR without harmonics
45
dB
REV. 1.5 11/10/00
19
PRODUCT SPECIFICATION
FMS9874
System Performace Characteristics (continued)
Parameter
Conditions
Min
Typ1
Max
Unit
Phase Locked Loop
tPP
tRMS
Peak-to-peak PLL Jitter @
MHz
25.175
RMS PLL Jitter @ MHz
25°C
7.1
31.5
6.9
36
6.5
40
4.6
49.5
2.8
56.25
2.4
66
2.2
78.75
2.1
108
1.8
25.175
25°C
ns
900
31.5
700
36
600
40
600
49.5
400
56.25
300
66
300
78.75
250
108
250
ps
Thermal
θJC
Resistance, junction-to-case
θJA
Resistance, junction-to-ambient
°C/W
44
°C/W
Notes:
1. External pixel clock.
8.0
7.0
6.0
Jitter (ns)
5.0
RMS
4.0
P-P
3.0
2.0
1.0
0.0
0
20
40
60
80
100
120
Pixel Clock (MHz)
Figure 21. Pixel Clock Jitter vs. Frequency
20
REV. 1.5 11/10/00
FMS9874
PRODUCT SPECIFICATION
Applications Information
AC Coupled Digitizer
To minimize component count, use of the following on-chip
circuits is recommended:
Shown in Figure 22 is an implementation of a video digitizer
with AC coupled RGB inputs. Horizontal sync input, HS is
passed through a voltage divider which attenuates the 5.0 V
logic HIGH excursion to the 3.3 V HIGH input level of the
FMS9874. Vertical sync is also attenuated to make the
VSOUT level compatible with 3.3 V pixel processing
following the FMS9874.
Clamp.
3.
Voltage reference
Optimum PLL Configuration Register (address 0x0C) settings for typical graphics modes are listed in Table 3. Unless
otherwise indicated, all modes are compliant with VESA
specifications. For unlisted modes, values should be adjusted
to optimize performance.
Output data is three channel 24-bit pixels with a maximum
rate of 140Ms/s. Data is clocked out on the negative edge of
DCK. HSOUT defines the active video along a line, while
incoming vertical sync, VSIN is propagated as VSOUT to
the output data to synchronize handling of digitized frames
of output data.
By adjusting the values in the gain (GR, GG, GB) and offset
(OSR, OSG, OSB) registers, the input conversion range can
be matched to the incoming analog signals.
C1
.047µF
C2
.047µF
C3
.047µF
R3
75
VDDA
R1
75
U1
FMS9874
24
25
31
36
38
R2
75
VDDP
VDDP
VDDP
VDDP
VDDP
2
RIN
8
GIN
13
BIN
18
INVSCK
19
CLAMP
28
HSIN
29
COAST
32
XCK
33
LPF
SCL
20
SDA
SDA
21
SCL
COAST
22
R1
1.5K
C4
0.018µF
VDD
23
7
R7
10K
C8
0.1µF
51
52
53
54
55
56
57
58
BA7
BA6
BA5
BA4
BA3
BA2
BA1
BA0
BA[7..0]
DG7
DG6
DG5
DG4
DG3
DG2
DG1
DG0
63
64
65
66
67
68
69
70
GA7
GA6
GA5
GA4
GA3
GA2
GA1
GA0
GA[7..0]
DR7
DR6
DR5
DR4
DR3
DR2
DR1
DR0
76
77
78
79
80
81
82
83
RA7
RA6
RA5
RA4
RA3
RA2
RA1
RA0
RA[7..0]
DCK
86
DCK
DCK
87
DCK
HSOUT
88
HSOUT
DCSOUT
89
NC1
NC2
NC3
NC4
NC5
NC6
NC7
NC8
34
42
43
44
45
46
47
48
A0
A1
ACSIN
73
74
75
NC9
NC10
NC11
98
VREFIN
96
PWRDN
97
VREFOUT
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
R5
1.8K
C1
0.18µF
DB7
DB6
DB5
DB4
DB3
DB2
DB1
DB0
1
4
6
10
12
15
17
26
27
30
35
37
39
40
41
49
59
61
71
84
90
92
93
94
VDDP
R4
1K
VDDO
VDDP
3
5
9
11
14
16
95
99
100
RED
GREEN
BLUE
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Control is through the serial port with 150Ω resistors
inserted to allow interfacing with 5V logic. If the serial bus is
operates with 3.3V levels, these resistors are unnecessary.
50
60
62
72
85
91
2.
VDDO
VDDO
VDDO
VDDO
VDDO
VDDO
ADC sampling clock.
VDDA
VDDA
VDDA
VDDA
VDDA
VDDA
VDDA
VDDA
VDDA
1.
VSOUT
Figure 22. Schematic, VGA Digitizer, AC Coupled RGB
REV. 1.5 11/10/00
21
PRODUCT SPECIFICATION
FMS9874
Printed Wiring Board Design Guidelines
Digital I/O
Recommended strategy is to mount the FMS9874 over a
ground plane with carefully routed analog inputs and digital
outputs. All connections should be treated as transmission
lines to ensure that reflections due to mismatches are minimized and ground return currents do not interfere with critical
signals.
Recommendations:
Analog Inputs
Recommendations:
1.
Keep analog trace lengths short to minimize crosstalk.
2.
Terminate analog inputs with 75Ω resistors, placed
close to the FMS9874 analog inputs, RIN, GIN and BIN.
By matching transmission line impedances, reflections
will be minimized.
3.
Layout traces as 75Ω transmission lines.
4.
Avoid running analog traces near digital traces. Due to
the wide input bandwidth (500MHz) digital noise can
easily leak into analog inputs.
5.
If necessary, limit bandwidth by adding a ferrite bead in
series with each RGB input as shown in Figure 23. A
Fair-Rite #2508051217Z0 is recommended. Further
bandwidth reduction using a shunt 10pF capacitor may
reduce snow (intensity noise) caused by HF noise riding
on the RGB input. Mismatches, reflections and noise
may cause ringing or distortion of the incoming video
signals.
6.
Locate the PLL filter clear of other signals.
7.
Bypass the reference with a 0.1µF capacitor to ground.
1.
Route digital I/O signals clear of analog inputs.
2.
Terminate clock lines to reduce reflections. Treat clock
lines as transmission lines.
3.
Scale the HSIN input to 3.3V, using a resistor network
or a series 1 kΩ resistor.
4.
Limit Serial Port inputs SDA and SDL with 150Ω resistors connected directly to the pins.
5.
If necessary terminate the HSIN input with 330/220Ω.
6.
If necessary, to reduce reflections, EMI or spikes add a
50–200Ω resistor at each data output pin.
7.
To minimize noise within the FMS9884A, restrict the
capacitive load at the digital outputs to < 10pF.
Power and Ground
A schematic of the recommended power distribution is
shown in Figure 24. Note that:
1.
Analog and digital circuits are layed out over a common
solid ground plane.
2.
Each FMS9874 pin is decoupled with a 0.1µF capacitor.
3.
A group of pins may be de-coupled through a common
capacitor if no pin is more than 5 mm from the capacitor.
4.
A separate regulated supply is used for the phase-locked
loop power supply, VDDP.
5.
Capacitors are attached to each PLL pin or pin-pair.
C1
47nF
L1
BEAD
RIN, GIN, BIN
R, G, B INPUT
R1
75
C2
10pF
Figure 23. RGB Input Filter Option
22
REV. 1.5 11/10/00
FMS9874
PRODUCT SPECIFICATION
VPLL
Pins 33, 34
U3
RC1117-3.3
L1
BEAD
2 OUT
4
OUT
C2
0.01µF
IN
3
ADJ/GND
C1
0.1µF
1
Pin 43
C3
0.1µF
Pin 48
C4
0.01µF
U2
RC1117-3.3
2 OUT
4 OUT
Pin 50
+ C6
10 µF
C5
0.1µF
IN
ADJ/GND
3
1
Power Input
C7
0.1µF
+ C8
10µF
L2
BEAD
VADC Pins
C10
C11
C12
C13
C14
C15
C16
C17
+ C26
10µF
0.1µF 0.1µF 0.1µF 0.1µF 0.1µF 0.1µF 0.1µF 0.1µF
U3
RC1117-3.3
L3
BEAD
VDD Pins
C18
C19
C20
C21
C22
C23
2 OUT
3
ADJ/GND IN
4
OUT
C24
0.1µF 0.1µF 0.1µF 0.1µF 0.1µF 0.1µF 0.1µF
+
C25
10µF
1
C9
0.1µF
Figure 24. Recommended Power Distribution
Physical placement of PLL power supply decoupling
components is critical. Bearing in mind the following
suggestions:
1.
All components should be placed in close proximity to
the FMS9874 pins.
2.
Routing through vias should be avoided, if possible.
3.
Each VDDP/GND pin pair: 24&25/26, 31/30, 36/35, and
38/37 should be decoupled with a 100–1000p/10µF pair
of capacitors (see Figure 24). If board space is limited,
use as many capacitor pairs as possible.
4.
2.
Calibrate Offset and Gain by first setting each input to
0mV. Then adjust OSR, OSG, and OSB to set each RGB
data output D7-0 = 0x00. Next with 700mV input, adjust
GR, GG and GB so that each RGB data output D7-0 =
(same value), typically 240 decimal.
3.
Clamp registers, CD and CW, should be programmed to
maximize the period of the clamp during the backporch,
while not encroaching into the sync or active video
periods.
4.
PHASE must be trimmed to minimize onscreen snow
(intensity noise) when a vertical grill pattern is displayed.
5.
FVCO must be set to encompass the incoming
frequency range.
6.
IPUMP must be set to minimize intensity noise.
Use Fair-rite 274 301 9447 bead.
Firmware
Best performance can be achieved by correctly setting the
FMS9874 registers. Here are some recommendations:
1.
If PLLN + 1 does not equal the number of pixels, there
will be irregular intensities on text and an interference
pattern on a vertical grill pattern.
Set the value of PLLN equal to the number of pixels to
be sampled minus one. With this setting, the number of
samples per horizontal line equals the number of pixels.
REV. 1.5 11/10/00
23
PRODUCT SPECIFICATION
FMS9874
Mechanical Dimensions
100-Lead MQFP (KG) Package
Notes:
Millimeters
Symbol
Notes
Min.
Typ.
Max
A
A1
A2
D
D1
D2
L
N
e
—
—
2.62
2.82
0.15
3.00
—
2.77
3, 5
1.03
4
b
0.17
2.67
17.20 BSC
14.00 BSC
12.00 BSC
0.73
0.88
100
0.50 BSC
—
1. All dimensions and tolerances conform to ANSI Y14.5M-1994.
2. Dimensions D1 and E1 do not include mold protrusion.
Allowable mold protrusion is 0.254mm per side.
3. "N" is the number of terminals, 25 per side.
4. Dimension "b" does not include dambar protrusion. Allowable
dambar protrusion shall be 0.08mm in excess of the "b"
dimension at the maximum material condition.
0.27
.40 Min.
0° Min.
0.13 R Min.
Datum Plane
.13/.30 R
e
D2
L
D1/2
Lead Detail
D
A2
See Lead Detail
Base Plane
A
A1
24
0–7°
1.60 Ref.
B
Seating Plane
-CLEAD COPLANARITY
ccc C
REV. 1.5 11/10/00
PRODUCT SPECIFICATION
FMS9874
Ordering Information
Product Number
Temperature Range
Screening
Package
Package Marking
FMS9874KGC100
0°C to 70°C
Commercial
100 Lead MQFP
9874KGC100
DISCLAIMER
FAIRCHILD SEMICONDUCTOR RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO
ANY PRODUCTS HEREIN TO IMPROVE RELIABILITY, FUNCTION OR DESIGN. FAIRCHILD DOES NOT ASSUME
ANY LIABILITY ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCT OR CIRCUIT DESCRIBED HEREIN;
NEITHER DOES IT CONVEY ANY LICENSE UNDER ITS PATENT RIGHTS, NOR THE RIGHTS OF OTHERS.
LIFE SUPPORT POLICY
FAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES
OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD SEMICONDUCTOR
CORPORATION. As used herein:
1. Life support devices or systems are devices or systems
which, (a) are intended for surgical implant into the body, or
(b) support or sustain life, and (c) whose failure to perform
when properly used in accordance with instructions for use
provided in the labeling, can be reasonably expected to
result in a significant injury of the user.
2. A critical component in any component of a life support
device or system whose failure to perform can be
reasonably expected to cause the failure of the life support
device or system, or to affect its safety or effectiveness.
www.fairchildsemi.com
11/10/00 0.0m 003
Stock#DS30009874
 2000 Fairchild Semiconductor Corporation