Intersil ISL98001CQZ-170 Triple video digitizer with digital pll Datasheet

ISL98001
Key Features
®
Data Sheet
March 8, 2006
FN6148.3
Triple Video Digitizer with Digital PLL
Features
The ISL98001 3-channel, 8-bit Analog Front End (AFE)
contains all the functions necessary to digitize analog YPbPr
video signals and RGB graphics signals from DVD players,
digital VCRs, video set-top boxes, and personal computers.
This product family’s conversion rates support HDTV
resolutions up to 1080p and PC monitor resolutions up to
UXGA and QXGA, while the front end's programmable input
bandwidth ensures sharp, clear images at all resolutions.
• 140MSPS, 170MSPS, 210MSPS, 240MSPS, and
275MSPS maximum conversion rates
To maximize performance with the widest variety of video
sources, the ISL98001 features a fast-responding digital PLL
(DPLL), providing extremely low jitter with PC graphics signals
and quick recovery from VCR head switching with video
signals. Integrated HSYNC and SOG processing eliminate the
need for external slicers, sync separators, Schmitt triggers,
and filters.
• 0.35Vp-p to 1.4Vp-p video input range
• Glitchless Macrovision®-compliant sync separator
• Extremely fast recovery from VCR head switching
• Low PLL clock jitter (250ps p-p @ 170MSPS)
• 64 interpixel sampling positions
• Programmable bandwidth (100MHz to 780MHz)
• 2 channel input multiplexer
• RGB 4:4:4 and YUV 4:2:2 output formats
• 5 embedded voltage regulators allow operation from
single 3.3V supply and enhance performance, isolation
Glitchless, automatic Macrovision®-compliance is obtained
by a digital Macrovision® detection function that detects and
automatically removes Macrovision® from the HSYNC
signal.
• Completely independent 8-bit gain/10-bit offset control
• Pb-free plus anneal available (RoHS compliant)
Applications
Ease-of-use is also emphasized with features such as the
elimination of PLL charge pump current/VCO range
programming and single-bit switching between RGB and
YPbPr signals. Automatic Black Level Compensation
(ABLC™) eliminates part-to-part offset variation, ensuring
perfect black level performance in every application.
• Digital TVs
• Projectors
• Multifunction monitors
• Digital KVM
• RGB graphics processing
The ISL98001 is fully backwards compatible (hardware and
software) with the X980xx family of AFEs.
Simplified Block Diagram
Offset
DAC
Voltage
Clamp
RGB/YPbPrIN1
RGB/YPbPrIN2
ABLC™
3
PGA
3
+
8 bit ADC
8 or 16
x3
RGB/YUVOUT
HSYNCOUT
VSYNCOUT
SOGIN1/2
HSYNCIN1/2
VSYNCIN1/2
Sync
Processing
Digital PLL
HSOUT
PIXELCLKOUT
AFE Configuration and Control
1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 1-888-468-3774 | Intersil (and design) is a registered trademark of Intersil Americas Inc.
Copyright Intersil Americas Inc. 2005, 2006. All Rights Reserved
All other trademarks mentioned are the property of their respective owners.
ISL98001
Ordering Information
MAXIMUM
PIXEL RATE (MHz)
TEMPERATURE
RANGE (°C)
ISL98001CQZ-140
140
0 to 70
128 MQFP
MDP0055
ISL98001CQZ-170
170
0 to 70
128 MQFP
MDP0055
ISL98001CQZ-210
210
0 to 70
128 MQFP
MDP0055
ISL98001CQZ-240
240
0 to 70
128 MQFP
MDP0055
ISL98001CQZ-275
275
0 to 70
128 MQFP
MDP0055
PART NUMBER (Note)
PACKAGE
(Pb-free)
PKG. DWG. #
NOTE: Intersil Pb-free plus anneal products employ special Pb-free material sets; molding compounds/die attach materials and 100% matte tin plate
termination finish, which are RoHS compliant and compatible with both SnPb and Pb-free soldering operations. Intersil Pb-free products are MSL
classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020.
Block Diagram
VCLAMP
RIN1
Offset
DAC
10
ABLC™
VIN+
8
RIN2
+
VCLAMP
GIN1
RGBGND1
Offset
DAC
10
8
8
VIN+
PGA
VIN-
GIN2
+
8 bit ADC
8
RGBGND2
VCLAMP
BIN1
Offset
DAC
10
ABLC™
VIN+
VIN-
BIN2
PGA
+
RP[7:0]
RS[7:0]
ABLC™
8 bit ADC
8
Output Data Formatter
PGA
VIN-
8 bit ADC
8
8
8
8
GP[7:0]
GS[7:0]
BP[7:0]
BS[7:0]
DATACLK
SOGIN1
SOGIN2
HSYNCIN1
HSYNCIN2
DATACLK
Sync
Processing
VSYNCIN1
AFE Configuration
and Control
HSOUT
VSOUT
VSYNCIN2
HSYNCOUT
VSYNCOUT
CLOCKINV
XTALIN
Digital PLL
XTALOUT
SCL
SDA
SADDR
XCLKOUT
Serial
Interface
2
FN6148.3
March 8, 2006
ISL98001
Absolute Maximum Ratings
Thermal Information
Voltage on VA, VD, or VX
(referenced to GNDA = GNDD = GNDX). . . . . . . . . . . . . . . . . 4.0V
Voltage on any Analog Input Pin
(referenced to GNDA). . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to VA
Voltage on any Digital Input Pin
(referenced to GNDD). . . . . . . . . . . . . . . . . . . . . . . -0.3V to +6.0V
Current into any Output Pin . . . . . . . . . . . . . . . . . . . . . . . . . . ±20mA
ESD Classification
Human Body Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2000V
Machine Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200V
Thermal Resistance
θJA (°C/W)
MQFP Package . . . . . . . . . . . . . . . . . . . . . . . . . . . .
30
Maximum Biased Junction Temperature . . . . . . . . . . . . . . . . . . 125°C
Storage Temperature . . . . . . . . . . . . . . . . . . . . . . . .-65°C to +150°C
Recommended Operating Conditions
Temperature (Commercial) . . . . . . . . . . . . . . . . . . . . . 0°C to +70°C
Supply Voltage. . . . . . . . . . . . . . . . . . . . . . . . . VA = VD = VX = 3.3V
CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation of the
device at these or any other conditions above those indicated in the operational sections of this specification is not implied.
Electrical Specifications
SYMBOL
Specifications apply for VA = VD = VX = 3.3V, pixel rate = 140MHz for ISL98001-140, 170MHz for
ISL98001-170, 210MHz for ISL98001-210, 240MHz for ISL98001-240, 275MHz for ISL98001-275,
fXTAL = 25MHz, TA = 25°C, unless otherwise noted
PARAMETER
COMMENT
MIN
TYP
MAX
UNIT
FULL CHANNEL CHARACTERISTICS
Conversion Rate
Per Channel
ISL98001-140
10
140
MHz
ISL98001-170
10
170
MHz
ISL98001-210
10
210
MHz
10
240
MHz
10
275
MHz
ISL98001-240
To achieve rated 240/275MHz
speeds, see the Initialization
section on page 26.
ISL98001-275
ADC Resolution
8
Missing Codes
DNL
(FullChannel)
INL
(FullChannel)
Bits
Guaranteed monotonic
None
Differential Non-Linearity
ISL98001-140
±0.5
+1.0/-0.9
LSB
ISL98001-170
±0.5
+1.0/-0.9
LSB
ISL98001-210
±0.6
+1.0/-0.9
LSB
ISL98001-240
±0.6
+1.1/-0.9
LSB
ISL98001-275
±0.7
+1.2/-0.9
LSB
ISL98001-140
±1.1
±2.75
LSB
ISL98001-170
±1.1
±3.25
LSB
ISL98001-210
±1.25
±3.25
LSB
ISL98001-240
±1.5
±3.5
LSB
ISL98001-275
±1.6
±3.75
LSB
Integral Non-Linearity
Gain Adjustment Range
±6
dB
Gain Adjustment Resolution
8
Bits
±1
%
Gain Matching Between Channels
Percent of full scale
Full Channel Offset Error,
ABLC™ enabled
ADC LSBs,
over time and temperature
Offset Adjustment Range
(ABLC™ enabled or disabled)
ADC LSBs (See ABLC™
applications information section)
3
±0.125
±127
±0.5
LSB
LSB
FN6148.3
March 8, 2006
ISL98001
Electrical Specifications
SYMBOL
Specifications apply for VA = VD = VX = 3.3V, pixel rate = 140MHz for ISL98001-140, 170MHz for
ISL98001-170, 210MHz for ISL98001-210, 240MHz for ISL98001-240, 275MHz for ISL98001-275,
fXTAL = 25MHz, TA = 25°C, unless otherwise noted (Continued)
PARAMETER
COMMENT
MIN
TYP
MAX
UNIT
0.7
1.4
VP-P
±0.01
±1
µA
ANALOG VIDEO INPUT CHARACTERISTICS (RIN1, GIN1, BIN1, RIN2, GIN2, BIN2)
Input Range
0.35
Input Bias Current
DC restore clamp off
Input Capacitance
5
pF
Programmable
780
MHz
Input Threshold Voltage
Programmable - see register
listing for details
0 to
-0.3
V
Hysteresis
Centered around threshold
40
mV
5
pF
0.4 to
3.2
V
240
mV
Full Power Bandwidth
INPUT CHARACTERISTICS (SOGIN1, SOGIN2)
VIH/VIL
Input Capacitance
INPUT CHARACTERISTICS (HSYNCIN1, HSYNCIN2)
VIH/VIL
Input Threshold Voltage
Programmable - see register
listing for details
Hysteresis
Centered around threshold
voltage
RIN
Input Impedance
1.2
kΩ
CIN
Input Capacitance
5
pF
DIGITAL INPUT CHARACTERISTICS (SDA, SADDR, CLOCKINVIN, RESET)
VIH
Input HIGH Voltage
VIL
Input LOW Voltage
I
Input Leakage Current
2.0
V
0.8
RESET has a 70kΩ pullup to VD
Input Capacitance
V
±10
nA
5
pF
SCHMITT DIGITAL INPUT CHARACTERISTICS (SCL, VSYNCIN1, VSYNCIN2)
VT+
Low to High Threshold Voltage
VT-
High to Low Threshold Voltage
I
1.45
V
0.95
Input Leakage Current
Input Capacitance
V
±10
nA
5
pF
DIGITAL OUTPUT CHARACTERISTICS (DATACLK, DATACLK)
VOH
Output HIGH Voltage, IO = 16mA
VOL
Output LOW Voltage, IO = -16mA
2.4
V
0.4
V
DIGITAL OUTPUT CHARACTERISTICS (RP, GP, BP, RS, GS, BS, HSOUT, VSOUT, HSYNCOUT, VSYNCOUT)
VOH
Output HIGH Voltage, IO = 8mA
VOL
Output LOW Voltage, IO = -8mA
RTRI
Pulldown to GNDD when Three-state
2.4
V
0.4
RP, GP, BP, RS, GS, BS only
56
V
kΩ
DIGITAL OUTPUT CHARACTERISTICS (SDA, XCLKOUT)
VOH
Output HIGH Voltage, IO = 4mA
VOL
Output LOW Voltage, IO = -4mA
XCLKOUT only; SDA is open-drain
2.4
V
0.4
V
POWER SUPPLY REQUIREMENTS
VA
Analog Supply Voltage
3
3.3
3.6
V
VD
Digital Supply Voltage
3
3.3
3.6
V
VX
Crystal Oscillator Supply Voltage
3
3.3
3.6
V
4
FN6148.3
March 8, 2006
ISL98001
Electrical Specifications
SYMBOL
Specifications apply for VA = VD = VX = 3.3V, pixel rate = 140MHz for ISL98001-140, 170MHz for
ISL98001-170, 210MHz for ISL98001-210, 240MHz for ISL98001-240, 275MHz for ISL98001-275,
fXTAL = 25MHz, TA = 25°C, unless otherwise noted (Continued)
PARAMETER
IA
Analog Supply Current
ID
Digital Supply Current
IX
Crystal Oscillator Supply Current
PD
Total Power Dissipation
COMMENT
MIN
TYP
With grayscale ramp input
MAX
UNIT
200
mA
200
mA
1.4
2
mA
ISL98001-140
With grayscale ramp input
0.95
1.10
W
ISL98001-170
With grayscale ramp input
1.05
1.15
W
ISL98001-210
With grayscale ramp input
1.10
1.20
W
ISL98001-240
With grayscale ramp input
1.15
1.25
W
ISL98001-275
With grayscale ramp input
1.20
1.30
W
Standby Mode
ADCs, PLL powered down
50
80
mW
250
450
ps p-p
AC TIMING CHARACTERISTICS
PLL Jitter
Sampling Phase Steps
5.6° per step
64
Sampling Phase Tempco
Sampling Phase
Differential Nonlinearity
Degrees out of 360°
±1
ps/°C
±3
°
HSYNC Frequency Range
10
150
kHz
Crystal Frequency Range
23
25
27
MHz
fXTALIN
Frequency Range with External 3.3V Clock
Signal Driving XTALIN
23
25
33.5
MHz
tSETUP
DATA Valid Before Rising Edge of
DATACLK
15pF DATACLK load, 15pF DATA
load (Note 1)
1.3
ns
tHOLD
DATA Valid After Rising Edge of DATACLK 15pF DATACLK load, 15pF DATA
load (Note 1)
2.0
ns
fXTAL
AC TIMING CHARACTERISTICS (2-WIRE INTERFACE)
fSCL
SCL Clock Frequency
0
Maximum Width of a Glitch on SCL that Will 2 XTAL periods min
be Suppressed
80
400
kHz
ns
tAA
SCL LOW to SDA Data Out Valid
tBUF
Time the Bus Must be Free Before a New
Transmission Can Start
1.3
µs
tLOW
Clock LOW Time
1.3
µs
tHIGH
Clock HIGH Time
0.6
µs
tSU:STA
Start Condition Setup Time
0.6
µs
tHD:STA
Start Condition Hold Time
0.6
µs
tSU:DAT
Data In Setup Time
100
ns
tHD:DAT
Data In Hold Time
0
ns
tSU:STO
Stop Condition Setup Time
0.6
µs
160
ns
tDH
Data Output Hold Time
5 XTAL periods plus SDA’s RC
time constant
4 XTAL periods min
See
comment
µs
NOTE:
1. Setup and hold times are specified for a 170MHz DATACLK rate.
5
FN6148.3
March 8, 2006
ISL98001
tHIGH
tF
SCL
tLOW
tR
tSU:DAT
tSU:STA
SDA IN
tHD:DAT
tHD:STA
tSU:STO
tAA
tDH
tBUF
SDA OUT
FIGURE 1. 2-WIRE INTERFACE TIMING
DATACLK
DATACLK
tHOLD
tSETUP
Pixel Data
FIGURE 2. DATA OUTPUT SETUP AND HOLD TIMING
The HSYNC edge (programmable leading or trailing) that the DPLL is locked to.
The sampling phase setting determines its relative position to the rest of the AFE’s output signals
HSYNCIN
tHSYNCin-to-HSout = 7.5ns + (PHASE/64 +8.5)*tPIXEL
Analog
Video In
P0
P1
P2
P3
P4
P5
P6
P7
P8
P9
P10
P11
P12
DATACLK
8 DATACLK Pipeline Latency
RP/GP/BP[7:0]
D0
D1
D2
D3
RS/GS/BS[7:0]
Programmable
Width and Polarity
HSOUT
FIGURE 3. 24-BIT OUTPUT MODE
6
FN6148.3
March 8, 2006
ISL98001
The HSYNC edge (programmable leading or trailing) that the DPLL is locked to.
The sampling phase setting determines its relative position to the rest of the AFE’s output signals
HSYNCIN
tHSYNCin-to-HSout = 7.5ns + (PHASE/64 +8.5)*tPIXEL
Analog
Video In
P2
P1
P0
P3
P4
P5
P6
P7
P8
P9
P10
P11
P12
DATACLK
8.5 DATACLK Pipeline Latency
GP[7:0]
G0 (Yo)
G1 (Y1)
G2 (Y2)
RP[7:0]
B0 (Uo)
R1 (V1)
B2 (U2)
BP[7:0]
Programmable
Width and Polarity
HSOUT
FIGURE 4. 24-BIT 4:2:2 OUTPUT MODE (FOR YUV SIGNALS)
The HSYNC edge (programmable leading or trailing) that the DPLL is locked to.
The sampling phase setting determines its relative position to the rest of the AFE’s output signals
HSYNCIN
tHSYNCin-to-HSout = 7.5ns + (PHASE/64 +10.5)*tPIXEL
Analog
Video In
P0
P2
P1
P3
P4
P5
P6
P7
P8
P9
P10
P11
P12
DATACLK
RP/GP/BP[7:0]
D0
D2
RS/GS/BS[7:0]
D1
D3
Programmable
Width and Polarity
HSOUT
FIGURE 5. 48-BIT OUTPUT MODE
7
FN6148.3
March 8, 2006
ISL98001
The HSYNC edge (programmable leading or trailing) that the DPLL is locked to.
The sampling phase setting determines its relative position to the rest of the AFE’s output signals
HSYNCIN
tHSYNCin-to-HSout = 7.5ns + (PHASE/64 +8.5)*tPIXEL
Analog
Video In
P0
P1
P2
P3
P4
P5
P6
P7
P8
P9
P10
P11
DATACLK
RP/GP/BP[7:0]
D0
RS/GS/BS[7:0]
D2
D1
Programmable
Width and Polarity
HSOUT
FIGURE 6. 48-BIT OUTPUT MODE, INTERLEAVED TIMING
8
FN6148.3
March 8, 2006
ISL98001
RS2
RS3
RS4
104
103
GNDD
110
RS1
VD
111
105
RP7
112
RS0
RP6
113
106
RP5
114
107
RP4
115
VCORE
RP3
116
GNDD
RP2
117
108
RP1
118
109
GNDD
RP0
DATACLK
121
119
DATACLK
122
120
VD
HSOUT
125
GNDD
VSOUT
126
123
HSYNCOUT
127
124
VSYNCOUT
128
Pin Configuration (MQFP, ISL98001CQZ-xxx)
NC
1
102
RS5
NC
2
101
RS6
GNDA
3
100
RS7
VBYPASS
4
99
VD
GNDA
5
98
GNDD
VA
6
97
GP0
RIN1
7
96
GP1
GNDA
8
95
GP2
VBYPASS
9
94
GP3
GNDA
10
93
GP4
VA
11
92
GP5
GIN1
12
91
GP6
RGBGND1
13
90
GP7
SOGIN1
14
89
VD
GNDA
15
88
GNDD
VBYPASS
16
87
GS0
GNDA
17
86
GS1
VA
18
85
GS2
BIN1
19
84
GS3
VA
20
83
GS4
GNDA
21
82
GS5
RIN2
22
81
GS6
GNDA
23
80
GS7
GIN2
24
79
VCORE
RGBGND2
25
78
GNDD
SOGIN2
26
77
VD
GNDA
27
76
GNDD
BIN2
28
75
BP0
VA
29
74
BP1
51
52
53
54
55
56
57
58
59
60
61
62
63
64
VCORE
GNDD
VD
BS7
BS6
BS5
BS4
BS3
BS2
BS1
BS0
NC
VREGOUT
VREGIN
GNDD
65
50
38
49
GNDD
VX
SCL
66
SDA
37
48
VD
GNDX
47
67
SADDR
36
XCLKOUT
BP7
GNDA
46
68
45
35
RESET
BP6
VA
VSYNCIN2
69
44
34
VSYNCIN1
BP5
HSYNCIN2
43
70
GNDD
33
42
BP4
HSYNCIN1
VPLL
71
41
32
CLOCKINVIN
BP3
GNDD
40
BP2
72
39
73
31
XTALIN
30
XTALOUT
GNDA
VCOREADC
9
FN6148.3
March 8, 2006
ISL98001
Pin Descriptions
SYMBOL
MQFP PIN #(s)
RIN1
7
Analog input. Red channel 1. DC couple or AC couple through 0.047µF.
GIN1
12
Analog input. Green channel 1. DC couple or AC couple through 0.047µF.
BIN1
19
Analog input. Blue channel 1. DC couple or AC couple through 0.047µF.
RGBGND1
13
Analog input. Ground reference for the R, G, and B inputs of channel 1 in the DC coupled configuration.
Connect to the same ground as channel 1's R, G, and B termination resistors. This signal is not used in the
AC-coupled configuration, but the pin should still be tied to GNDA.
SOGIN1
14
Analog input. Sync on Green. Connect to GIN1 through a 0.01µF capacitor in series with a 500Ω resistor.
HSYNCIN1
33
Digital input, 5V tolerant, 240mV hysteresis, 1.2kΩ impedance to GNDA. Connect to channel 1's HSYNC
signal through a 680Ω series resistor.
VSYNCIN1
44
Digital input, 5V tolerant, 500mV hysteresis. Connect to channel 1's VSYNC signal.
RIN2
22
Analog input. Red channel 2. DC couple or AC couple through 0.047µF.
GIN2
24
Analog input. Green channel 2. DC couple or AC couple through 0.047µF.
BIN2
28
Analog input. Blue channel 2. DC couple or AC couple through 0.047µF.
RGBGND2
25
Analog input. Ground reference for the R, G, and B inputs of channel 2 in the DC coupled configuration.
Connect to the same ground as channel 1's R, G, and B termination resistors. This signal is not used in the
AC-coupled configuration, but the pin should still be tied to GNDA.
SOGIN2
26
Analog input. Sync on Green. Connect to GIN1 through a 0.01µF capacitor in series with a 500Ω resistor.
HSYNCIN2
34
Digital input, 5V tolerant, 240mV hysteresis, 1.2kΩ impedance to GNDA. Connect to channel 2's HSYNC
signal through a 680Ω series resistor.
VSYNCIN2
45
Digital input, 5V tolerant, 500mV hysteresis. Connect to channel 2's VSYNC signal.
CLOCKINVIN
41
Digital input, 5V tolerant. When high, changes the pixel sampling phase by 180 degrees. Toggle at frame rate
during VSYNC to allow 2x undersampling to sample odd and even pixels on sequential frames. Tie to DGND
if unused.
RESET
46
Digital input, 5V tolerant, active low, 70kΩ pullup to VD. Take low for at least 1µs and then high again to reset
the ISL98001. This pin is not necessary for normal use and may be tied directly to the VD supply.
XTALIN
39
Analog input. Connect to external 24.5MHz to 27MHz crystal and load capacitor (See crystal spec for
recommended loading). Typical oscillation amplitude is 1.0VP-P centered around 0.5V.
XTALOUT
40
Analog output. Connect to external 24.5MHz to 27MHz crystal and load capacitor (See crystal spec for
recommended loading). Typical oscillation amplitude is 1.0VP-P centered around 0.5V.
XCLKOUT
47
3.3V digital output. Buffered crystal clock output at fXTAL or fXTAL/2. May be used as system clock for other
system components.
SADDR
48
Digital input, 5V tolerant. Address = 0x4C when tied low. Address = 0x4D when tied high.
SCL
50
Digital input, 5V tolerant, 500mV hysteresis. Serial data clock for 2-wire interface.
SDA
49
Bidirectional Digital I/O, open drain, 5V tolerant. Serial data I/O for 2-wire interface.
RP[7:0]
112-119
3.3V digital output. Red channel, primary pixel data. 56K pulldown when three-stated.
RS[7:0]
100-107
3.3V digital output. Red channel, secondary pixel data. 56K pulldown when three-stated.
GP[7:0]
90-97
3.3V digital output. Green channel, primary pixel data. 56K pulldown when three-stated.
GS[7:0]
80-87
3.3V digital output. Green channel, secondary pixel data. 56K pulldown when three-stated.
BP[7:0]
68-75
3.3V digital output. Blue channel, primary pixel data. 56K pulldown when three-stated.
BS[7:0]
55-62
3.3V digital output. Blue channel, secondary pixel data. 56K pulldown when three-stated.
DATACLK
121
3.3V digital output. Data clock output. Equal to pixel clock rate in 24-bit mode, one half of pixel clock rate in
48-bit mode.
DATACLK
122
3.3V digital output. Inverse of DATACLK.
HSOUT
125
3.3V digital output. HSYNC output aligned with pixel data. Use this output to frame the digital output data.
This output is always purely horizontal sync (without any composite sync signals).
10
DESCRIPTION
FN6148.3
March 8, 2006
ISL98001
Pin Descriptions (Continued)
SYMBOL
MQFP PIN #(s)
DESCRIPTION
VSOUT
126
3.3V digital output. Artificial VSYNC output aligned with pixel data. VSOUT is generated 8 pixel clocks after
the trailing edge of HSOUT. This signal is usually not needed.
HSYNCOUT
127
3.3V digital output. Buffered HSYNC (or SOG or CSYNC) output. This is typically used for measuring HSYNC
period. This output will pass composite sync signals and Macrovision signals if present on HSYNCIN or
SOGIN.
VSYNCOUT
128
3.3V digital output. Buffered VSYNC output. For composite sync signals, this output will be asserted for the
duration of the disruption of the normal HSYNC pattern. This is typically used for measuring VSYNC period.
VA
6, 11, 18, 20, 29, Power supply for the analog section. Connect to a 3.3V supply and bypass each pin to GNDA with 0.1µF.
35
GNDA
3, 5, 8, 10, 15,
17, 21, 23, 27,
30, 36
Ground return for VA and VBYPASS.
VD
54, 67, 77, 89,
99, 111, 124
Power supply for all digital I/Os. Connect to a 3.3V supply and bypass each pin to GNDD with 0.1µF.
GNDD
32, 43, 51, 53,
66, 76, 78, 88,
98, 108, 110,
120, 123
Ground return for VD, VCORE, VCOREADC, and VPLL.
VX
38
Power supply for crystal oscillator. Connect to a 3.3V supply and bypass to GNDX with 0.1µF.
GNDX
37
Ground return for VX.
VBYPASS
4, 9, 16
VREGIN
65
3.3V input voltage for VCORE voltage regulator. Connect to a 3.3V source and bypass to GNDD with 0.1µF.
VREGOUT
64
Regulated output voltage for VPLL, VCOREADC and VCORE; typically 1.9V. Connect only to VPLL, VCOREADC
and VCORE and bypass at input pins as instructed below. Do not connect to anything else - this output can
only supply power to VPLL, VCOREADC and VCORE.
VCOREADC
31
Internal power for the ADC’s digital logic. Connect to VREGOUT through a 10Ω resistor and bypass to GNDD
with 0.1µF.
VPLL
42
Internal power for the PLL’s digital logic. Connect to VREGOUT through a 10Ω resistor and bypass to GNDD
with 0.1µF.
VCORE
52, 79, 109
NC
1, 2, 63
Bypass these pins to GNDA with 0.1µF. Do not connect these pins to each other or anything else.
Internal power for core logic. Connect to VREGOUT and bypass each pin to GNDD with 0.1µF.
Reserved. Do not connect anything to these pins.
11
FN6148.3
March 8, 2006
ISL98001
Register Listing
ADDRESS
0x00
0x01
0x02
0x03
REGISTER (DEFAULT VALUE)
Device ID
(read only)
SYNC Status
(read only)
SYNC Polarity
(read only)
HSYNC Slicer (0x33)
BIT(S)
SOG Slicer (0x16)
Note: Due to normal device-to-device
variation in slicer levels, SOG Slicer settings
of 0 (0mV), 1 (20mV), and 2 (40mV) may not
be functional. The minimum recommended
SOG Slicer setting is 3 (60mV).
Device Revision
1 = initial silicon, 2 = second revision, etc.
7:4
Device ID
1 = ISL98001
0
HSYNC1 Active
0: HSYNC1 is Inactive
1: HSYNC1 is Active
1
HSYNC2 Active
0: HSYNC2 is Inactive
1: HSYNC2 is Active
2
VSYNC1 Active
0: VSYNC1 is Inactive
1: VSYNC1 is Active
3
VSYNC2 Active
0: VSYNC2 is Inactive
1: VSYNC2 is Active
4
SOG1 Active
0: SOG1 is Inactive
1: SOG1 is Active
5
SOG2 Active
0: SOG2 is Inactive
1: SOG2 is Active
6
PLL Locked
0: PLL is unlocked
1: PLL is locked to incoming HSYNC
7
CSYNC Detect at
Sync Splitter
0: Composite Sync signal not detected
1: Composite Sync signal is detected
0
HSYNC1
Polarity
0: HSYNC1 is Active High
1: HSYNC1 is Active Low
1
HSYNC2
Polarity
0: HSYNC2 is Active High
1: HSYNC2 is Active Low
2
VSYNC1
Polarity
0: VSYNC1 is Active High
1: VSYNC1 is Active Low
3
VSYNC2
Polarity
0: VSYNC2 is Active High
1: VSYNC2 is Active Low
4
HSYNC1
Trilevel
0: HSYNC1 is Standard Sync
1: HSYNC1 is Trilevel Sync
5
HSYNC2
Trilevel
0: HSYNC2 is Standard Sync
1: HSYNC2 is Trilevel Sync
7:6
N/A
Returns 0
2:0
HSYNC1 Threshold
000 = lowest (0.4V) All values referred to
011 = default (1.6V) voltage at HSYNC input
111 = highest (3.2V) pin, 240mV hysteresis
Reserved
Set to 00
6:4
HSYNC2 Threshold
See HSYNC1
7
Disable Glitch Filter
0: HSYNC/VSYNC Glitch Filter Enabled (default)
1: HSYNC/VSYNC Glitch Filter Disabled
SOG1 and SOG2
Threshold
0x0 = lowest (0mV)
0x6 = default (120mV) 20mV step size
0xF = highest (300mV)
4
SOG Filter
Enable
0: SOG low pass filter disabled
1: SOG low pass filter enabled, 14MHz corner
(default)
5
SOG Hysteresis
Disable
0: 40mV SOG hysteresis enabled
1: 40mV SOG hysteresis disabled (default)
Reserved
Set to 00.
3:0
7:6
12
DESCRIPTION
3:0
3
0x04
FUNCTION NAME
FN6148.3
March 8, 2006
ISL98001
Register Listing (Continued)
ADDRESS
0x05
REGISTER (DEFAULT VALUE)
Input configuration (0x00)
BIT(S)
FUNCTION NAME
DESCRIPTION
0
Channel Select
0: VGA1
1: VGA2
1
Input Coupling
0: AC coupled (positive input connected to clamp DAC
during clamp time, negative input disconnected from
outside pad and always internally tied to appropriate
clamp DAC).
1: DC coupled (+ and - inputs are brought to pads and
never connected to clamp DACs). Analog clamp
signal is turned off in this mode.
2
RGB/YPbPr
0: RGB inputs
Base ABLC target code = 0x00 for R, G, and B)
1: YPbPr inputs
Base ABLC target code = 0x00 for G (Y)
Base ABLC target code = 0x80 for R (Pr) and B (Pb)
0x06
3
Sync Type
0: Separate HSYNC/VSYNC
1: Composite (from SOG or CSYNC on HSYNC)
4
Composite Sync
Source
0: SOGIN
1: HSYNCIN
Note: If Sync Type = 0, the multiplexer will pass
HSYNCIN regardless of the state of this bit.
5
COAST CLAMP
enable
0: DC restore clamping and ABLC™ suspended
during COAST.
1: DC restore clamping and ABLC™ continue during
COAST.
6
Sync Mask Disable
0: Interval between HSYNC pulses masked
(preventing PLL from seeing Macrovision and any
spurious glitches).
1: Interval between HSYNC pulses not masked
(Macrovision will cause PLL to lose lock).
7
HSYNCOUT Mask
Disable
0: HSYNCOUT signal is masked (any Macrovision,
sync glitches on incoming SYNC are stripped from
HSYNCOUT).
1: HSYNCOUT signal is not masked (any Macrovision,
sync glitches on incoming SYNC appear on
HSYNCOUT).
If Sync Mask Disable = 1, HSYNCOUT is not masked.
Red Gain
Channel gain, where:
gain (V/V) = 0.5 + [7:0]/170
7:0
Red Gain (0x55)
0x07
7:0
Green Gain
0x55: gain = 1.0V/V
(0.7VP-P input = full range of ADC)
Green Gain (0x55)
0x08
0x00: gain = 0.5V/V
(1.4VP-P input = full range of ADC)
7:0
Blue Gain
0xFF: gain = 2.0V/V
(0.35VP-P input = full range of ADC)
Blue Gain (0x55)
13
FN6148.3
March 8, 2006
ISL98001
Register Listing (Continued)
ADDRESS
REGISTER (DEFAULT VALUE)
0x09
BIT(S)
FUNCTION NAME
7:0
Red Offset
7:0
Green Offset
7:0
Blue Offset
Red Offset (0x80)
0x0A
Green Offset (0x80)
0x0B
Blue Offset (0x80)
0x0C
0x0D
Offset DAC Configuration (0x00)
AFE Bandwidth (0x2E)
DESCRIPTION
ABLC™ enabled: digital offset control. A 1LSB change
in this register will shift the ADC output by 1 LSB.
ABLC™ disabled: analog offset control. These bits go
to the upper 8-bits of the 10-bit offset DAC. A 1LSB
change in this register will shift the ADC output
approximately 1 LSB (Offset DAC range = 0) or
0.5LSBs (Offset DAC range = 1).
0x00 = min DAC value or -0x80 digital offset,
0x80 = mid DAC value or 0x00 digital offset,
0xFF = max DAC value or +0x7F digital offset
0
Offset DAC Range
0: ±½ ADC fullscale (1 DAC LSB ~ 1 ADC LSB)
1: ±¼ ADC fullscale (1 DAC LSB ~ ½ ADC LSB)
1
Reserved
Set to 0.
3:2
Red Offset DAC
LSBs
5:4
Green Offset DAC
LSBs
These bits are the LSBs necessary for 10-bit manual
offset DAC control.
Combine with their respective MSBs in registers 0x09,
0x0A, and 0x0B to achieve 10-bit offset DAC control.
7:6
Blue Offset DAC
LSBs
0
Unused
Value doesn’t matter
3:1
AFE BW
3dB point for AFE lowpass filter
000b: 100MHz
111b: 780MHz (default)
7:4
Peaking
0x0: Peaking off
0x1: Moderate peaking
0x2: Maximum recommended peaking (default)
Values above 2 are not recommended.
14-bit HTOTAL (number of active pixels) value
The minimum HTOTAL value supported is 0x200.
HTOTAL to PLL is updated on LSB write only.
0x0E
PLL Htotal MSB (0x03)
5:0
PLL Htotal MSB
0x0F
PLL Htotal LSB (0x20)
7:0
PLL Htotal LSB
0x10
PLL Sampling Phase (0x00)
5:0
PLL Sampling Phase Used to control the phase of the ADC’s sample point
relative to the period of a pixel. Adjust to obtain
optimum image quality. One step = 5.625° (1.56% of
pixel period).
0x11
PLL Pre-coast (0x04)
7:0
Pre-coast
Number of lines the PLL will coast prior to the start of
VSYNC.
0x12
PLL Post-coast (0x04)
7:0
Post-coast
Number of lines the PLL will coast after the end of
VSYNC.
14
FN6148.3
March 8, 2006
ISL98001
Register Listing (Continued)
ADDRESS
0x13
REGISTER (DEFAULT VALUE)
PLL Misc (0x04)
BIT(S)
FUNCTION NAME
DESCRIPTION
0
PLL Lock Edge
HSYNC1
0: Lock on trailing edge of HSYNC1 (default)
1: Lock on leading edge of HSYNC1
1
PLL Lock Edge
HSYNC2
0: Lock on trailing edge of HSYNC2 (default)
1: Lock on leading edge of HSYNC2
2
Reserved
Set to 0
3
CLKINVIN Pin
Disable
0: CLKINVIN pin enabled (default)
1: CLKINVIN pin disabled (internally forced low)
5:4
CLKINVIN Pin
Function
00: CLKINV (default)
01: External CLAMP (See Note)
10: External COAST
11: External PIXCLK
Note: the CLAMP pulse is used to
- perform a DC restore (if enabled)
- start the ABLC™ function (if enabled), and
- update the data to the Offset DACs (always).
In the default internal CLAMP mode, the ISL98001
automatically generates the CLAMP pulse. If External
CLAMP is selected, the Offset DAC values only
change on the leading edge of CLAMP. If there is no
internal clamp signal, there will be up to a 100ms
delay between when the PGA gain or offset DAC
register is written to, and when the PGA or offset DAC
is actually updated.
6
XCLKOUT Frequency 0: XCLKOUT = fCRYSTAL (default)
1: XCLKOUT = fCRYSTAL/2
7
Disable XCLKOUT
0 = XCLKOUT enabled
1 = XCLKOUT is logic low
Pixel after HSYNCIN trailing edge to begin
DC restore and ABLC™ functions. 13-bits.
Set this register to the first stable black pixel following
the trailing edge of HSYNCIN.
0x14
DC Restore and ABLC™ starting pixel MSB
(0x00)
4:0
DC Restore and
ABLC™ starting
pixel (MSB)
0x15
DC Restore and ABLC™ starting pixel LSB
(0x03)
7:0
DC Restore and
ABLC™ starting
pixel (LSB)
0x16
DC Restore Clamp Width
(0x10)
7:0
DC Restore clamp
width (pixels)
Width of DC restore clamp used in AC-coupled
configurations. Has no effect on ABLC™. Minimum
value is 0x02 (a setting of 0x01 or 0x00 will not
generate a clamp pulse).
0x17
ABLC™ Configuration (0x40)
0
ABLC™ disable
0: ABLC™ enabled (default)
1: ABLC™ disabled
1
Reserved
Set to 0.
3:2
ABLC™ pixel width
Number of black pixels averaged every line for
ABLC™ function
00: 16 pixels [default]
01: 32 pixels
10: 64 pixels
11: 128 pixels
6:4
ABLC™ bandwidth
ABLC™ Time constant (lines) = 2(5+[6:4])
000 = 32 lines
100 = 512 lines (default)
111 = 4096 lines
Reserved
Set to 0.
7
15
FN6148.3
March 8, 2006
ISL98001
Register Listing (Continued)
ADDRESS
0x18
REGISTER (DEFAULT VALUE)
Output Format (0x00)
0x19
HSOUT Width (0x10)
0x1A
Output Signal Disable (0x00)
0x1B
0x1C
Power Control (0x00)
PLL Tuning (0x49)
16
BIT(S)
FUNCTION NAME
DESCRIPTION
0
Bus Width
0: 24-bits: Data output on RP, GP, BP only; RS, GS, BS
are all driven low (default).
1: 48-bits: Data output on RP, RP, GP, GS, BS, BS.
1
Interleaving
(48-bit mode only)
0: No interleaving: data changes on same edge of
DATACLK (default).
1: Interleaved: Secondary databus data changes on
opposite edge of DATACLK from primary databus.
2
Bus Swap
(48-bit mode only)
0: First data byte after trailing edge of HSOUT
appears on RP, GP, BP (default).
1: First data byte after trailing edge of HSOUT
appears on RS, GS, BS (primary and secondary
busses are reversed).
3
UV order
(422 mode only)
0: U0 V0 U2 V2 U4 V4 U6 V6… (default)
1: U0 V1 U2 V3 U4 V5 U6 V7… (X980xx)
4
422 mode
0: Data is formatted as 4:4:4 (RGB, default).
1: Data is decimated to 4:2:2 (YUV), blue channel is
driven low.
5
DATACLK
Polarity
0: HSOUT, VSOUT, and Pixel Data changes on falling
edge of DATACLK (default).
1: HSOUT, VSOUT, and Pixel Data changes on rising
edge of DATACLK.
6
VSOUT Polarity
0: Active High (default)
1: Active Low
7
HSOUT Polarity
0: Active High (default)
1: Active Low
HSOUT Width
HSOUT width, in pixels. Minimum value is 0x01 for 24bit modes, 0x02 for 48-bit modes.
0
Three-state RP[7:0]
1
Three-state RS7:0]
2
Three-state GP[7:0]
3
Three-state GS7:0]
0 = Output byte enabled
1 = Output byte three-stated
These bits override all other I/O settings
Output data pins have 56kΩ pulldown resistors to
GNDD.
4
Three-state BP[7:0]
5
Three-state BS[7:0]
6
Three-state
DATACLK
0 = DATACLK enabled
1 = DATACLK three-stated
7
Three-state
DATACLK
0 = DATACLK enabled
1 = DATACLK three-stated
0
Red
Power-down
0 = Red ADC operational (default)
1 = Red ADC powered down
1
Green
Power-down
0 = Green ADC operational (default)
1 = Green ADC powered down
2
Blue
Power-down
0 = Blue ADC operational (default)
1 = Blue ADC powered down
3
PLL
Power-down
0 = PLL operational (default)
1 = PLL powered down
7:4
Reserved
Set to 0.
7:0
Reserved
Use default setting of 0x49 for all PC and video modes
except signals coming from an analog VCR. Set to
0x4C for analog videotape compatibility.
7:0
FN6148.3
March 8, 2006
ISL98001
Register Listing (Continued)
ADDRESS
REGISTER (DEFAULT VALUE)
BIT(S)
FUNCTION NAME
DESCRIPTION
0x1D
Red ABLC Target (0x00)
7:0
Red ABLC Target
This is a 2's complement number controlling the target
code of the Red ADC output when ABLC is enabled.
In RGB mode, the Red ADC output will be servoed to
0x00 + the number in this register (-0x00 to +0x7F).
In YPbPr mode, the Red ADC output will be servoed
to 0x80 + the number in this register (-0x80 to +0x7F).
Note: This register does NOT disable the digital offset
adder. Both functions can be used simultaneously.
0x1E
Green ABLC Target (0x00)
7:0
Green ABLC Target
This is a 2's complement number controlling the target
code of the Green ADC output when ABLC is enabled.
In RGB and YPbPr modes, the Green ADC output will
be servoed to 0x00 + the number in this register
(-0x00 to +0x7F).
Note: This register does NOT disable the digital offset
adder. Both functions can be used simultaneously.
0x1F
Blue ABLC Target (0x00)
7:0
Blue ABLC Target
This is a 2's complement number controlling the target
code of the Blue ADC output when ABLC is enabled.
In RGB mode, the Blue ADC output will be servoed to
0x00 + the number in this register (-0x00 to +0x7F).
In YPbPr mode, the Blue ADC output will be servoed
to 0x80 + the number in this register (-0x80 to +0x7F).
Note: This register does NOT disable the digital offset
adder. Both functions can be used simultaneously.
0x23
DC Restore Clamp (0x18)
3:0
Reserved
Set to 1000
6:4
DC Restore Clamp
Impedance
DC Restore clamp's ON resistance.
Shared for all three channels
0: Infinite (clamp disconnected) (default)
1: 1600Ω
2: 800Ω
3: 533Ω
4: 400Ω
5: 320Ω
6: 267Ω
7: 228Ω
Reserved
Set to 0.
7
17
FN6148.3
March 8, 2006
ISL98001
Register Listing (Continued)
ADDRESS
0x25
0x2B
REGISTER (DEFAULT VALUE)
Sync Separator Control (0x00)
Crystal Multiplier (0x14)
BIT(S)
DESCRIPTION
0
Three-state Sync
Outputs
0: VSYNCOUT, HSYNCOUT, VSOUT, HSOUT are active
(default).
1: VSYNCOUT, HSYNCOUT, VSOUT, HSOUT are in
three-state.
1
COAST Polarity
0: Coast active high (default)
1: Coast active low
Set to 0 for internal VSYNC extracted from CSYNC.
Set to 0 or 1 as appropriate to match external VSYNC
or external COAST.
2
HSOUT Lock Edge
0: HSOUT's trailing edge is locked to selected
HSYNCIN's lock edge. Leading edge moves
backward in time as HSOUT width is increased
(X980xx default).
1: HSOUT's leading edge is locked to selected
HSYNCIN's lock edge. Trailing edge moves forward in
time as HSOUT width is increased.
3
Reserved
Set to 0
4
VSYNCOUT Mode
0: VSYNCOUT is aligned to HSYNCOUT edge,
providing “perfect” VSYNC signal (default).
1: VSYNCOUT is “raw” integrator output.
5
Reserved
Set to 0
6
Reserved
Set to 0
7
VSOUT Mode
0: VSOUT is output on VSOUT pin (default).
1: COAST (including pre- and post-coast COAST) is
output on VSOUT pin.
Crystal Multiplier
When using the ISL98001-240 or the ISL98001-275,
the value in this register may need to be changed to
achieve the maximum conversion rate (see the
Initialization section on page 26).
This register may also be adjusted to lower power
consumption at slower pixel rates (see the Reducing
Power Dissipation section for more information).
7:0
Technical Highlights
The ISL98001 provides all the features of traditional triple
channel video AFEs, but adds several next-generation
enhancements, bringing performance and ease of use to
new levels.
DPLL
All video AFEs must phase lock to an HSYNC signal,
supplied either directly or embedded in the video stream
(Sync On Green). Historically this has been implemented as
a traditional analog PLL. At SXGA and lower resolutions, an
analog PLL solution has proven adequate, if somewhat
troublesome (due to the need to adjust charge pump
currents, VCO ranges and other parameters to find the
optimum trade-off for a wide range of pixel rates).
As display resolutions and refresh rates have increased,
however, the pixel period has shrunk. An XGA pixel at a
60Hz refresh rate has 15.4ns to change and settle to its new
value. But at UXGA 75Hz, the pixel period is 4.9ns. Most
consumer graphics cards (even the ones with “350MHz”
18
FUNCTION NAME
DACs) spend most of that time slewing to the new pixel
value. The pixel may settle to its final value with 1ns or less
before it begins slewing to the next pixel. In many cases it
rings and never settles at all. So precision, low-jitter
sampling is a fundamental requirement at these speeds, and
a difficult one for an analog PLL to meet.
The ISL98001's DPLL has less than 250ps of jitter, peak to
peak, and independent of the pixel rate. The DPLL generates
64 phase steps per pixel (vs. the industry standard 32), for
fine, accurate positioning of the sampling point. The crystallocked NCO inside the DPLL completely eliminates drift due to
charge pump leakage, so there is inherently no frequency or
phase change across a line. An intelligent all-digital loop filter/
controller eliminates the need for the user to have to program
or change anything (except for the number of pixels) to lock
over a range from interlaced video (10MHz or higher) to
UXGA 60Hz (170MHz, with the ISL98001-170).
The DPLL eliminates much of the performance limitations and
complexity associated with noise-free digitization of high
speed signals.
FN6148.3
March 8, 2006
ISL98001
Automatic Black Level Compensation (ABLC™)
and Gain Control
Traditional video AFEs have an offset DAC prior to the ADC,
to both correct for offsets on the incoming video signals and
add/subtract an offset for user “brightness control” without
sacrificing the 8-bit dynamic range of the ADC. This solution
is adequate, but it places significant requirements on the
system's firmware, which must execute a loop that detects
the black portion of the signal and then servos the offset
DACs until that offset is nulled (or produces the desired ADC
output code). Once this has been accomplished, the offset
(both the offset in the AFE and the offset of the video card
generating the signal) is subject to drift - the temperature
inside a monitor or projector can easily change 50°C
between power-on/offset calibration on a cold morning and
the temperature reached once the monitor and the monitor's
environment have reached steady state. Offset can drift
significantly over 50°C, reducing image quality and requiring
that the user do a manual calibration once the monitor has
warmed up.
In addition to drift, many AFEs exhibit interaction between
the offset and gain controls. When the gain is changed, the
magnitude of the offset is changed as well. This again
increases the complexity of the firmware as it tries to
optimize gain and offset settings for a given video input
signal. Instead of adjusting just the offset, then the gain, both
have to be adjusted interactively until the desired ADC
output is reached.
The ISL98001 simplifies offset and gain adjustment and
completely eliminates offset drift using its Automatic Black
Level Compensation (ABLC™) function. ABLC™ monitors the
black level and continuously adjusts the ISL98001's 10-bit
offset DACs to null out the offset. Any offset, whether due to
the video source or the ISL98001's analog amplifiers, is
eliminated with 10-bit (1/4 of an ADC LSB) accuracy. Any drift
is compensated for well before it can have a visible effect.
Manual offset adjustment control is still available - an 8-bit
register allows the firmware to adjust the offset ±64 codes in
exactly 1 ADC LSB increments. And gain is now completely
independent of offset - adjusting the gain no longer affects the
offset, so there is no longer a need to program the firmware to
cope with interactive offset and gain controls.
Finally, there should be no concerns over ABLC™ itself
introducing visible artifacts; it doesn't. ABLC™ functions at a
very low frequency, changing the offset in 1/4 LSB
increments, so it can't cause visible brightness fluctuations.
And once ABLC™ is locked, if the offset doesn't drift, the
DACs won't change. If desired, ABLC™ can be disabled,
allowing the firmware to work in the traditional way, with
10-bit offset DACs under the firmware's control.
Changing the gain does not affect the DC offset, and the
weight of an Offset DAC LSB does not vary depending on
the gain setting.
The full-scale gain is set in the three 8-bit registers
(0x06-0x08). The ISL98001 can accept input signals with
amplitudes ranging from 0.35VP-P to 1.4VP-P.
The offset controls shift the entire RGB input range, changing
the input image brightness. Three separate registers provide
independent control of the R, G, and B channels. Their
nominal setting is 0x80, which forces the ADC to output code
0x00 (or 0x80 for the R (Pr) and B (Pb) channels in YPbPr
mode) during the back porch period when ABLC™ is enabled.
Functional Description
Inputs
The ISL98001 digitizes analog video inputs in both RGB
and Component (YPbPr) formats, with or without
embedded sync (SOG).
RGB Inputs
For RGB inputs, the black/blank levels are identical and equal
to 0V. The range for each color is typically 0V to 0.7V from
black to white. HSYNC and VSYNC are separate signals.
Component YPbPr Inputs
In addition to RGB and RGB with SOG, the ISL98001 has an
option that is compatible with the component YPbPr video
inputs typically generated by DVD players. While the
ISL98001 digitizes signals in these color spaces, it does not
perform color space conversion; if it digitizes an RGB signal,
it outputs digital RGB, while if it digitizes a YPbPr signal, it
outputs digital YCbCr, also called YUV.
The Luminance (Y) signal is applied to the Green Channel
and is processed in a manner identical to the Green input
with SOG described previously. The color difference signals
Pb and Pr are bipolar and swing both above and below the
black level. When the YPbPr mode is enabled, the black
level output for the color difference channels shifts to a mid
scale value of 0x80. Setting configuration register
0x05[2] = 1 enables the YPbPr signal processing mode of
operation.
TABLE 1. YUV MAPPING (4:4:4)
INPUT
SIGNAL
ISL98001
INPUT
CHANNEL
ISL98001
OUTPUT
ASSIGNMENT
OUTPUT
SIGNAL
Y
Green
Green
Y0Y1Y2Y3
Pb
Blue
Blue
U0U1U2U3
Pr
Red
Red
V0V1V2V3
Gain and Offset Control
To simplify image optimization algorithms, the ISL98001
features fully-independent gain and offset adjustment.
19
FN6148.3
March 8, 2006
ISL98001
Automatic Black Level
Compensation (ABLC™) Loop
DC Restoration
CLAMP
GENERATION
DC Restore
Clamp DAC
To
ABLC
Block
VCLAMP
Offset
DAC
Fixed
Offset
Offset
Control
Registers
10
10
0x00
ABLC™
10
8
8
ABLC™
Fixed
Offset
ABLC™
R(GB)IN1
VGA1
R(GB)GND1
8
VIN+
PGA
VIN-
Input
Bandwidth
8 bit ADC
8
8
To Output
Formatter
R(GB)IN2
Bandwidth
Control
VGA2
R(GB)GND2
FIGURE 7. VIDEO FLOW (INCLUDING ABLC™)
The ISL98001 can optionally decimate the incoming data to
provide a 4:2:2 output stream (configuration register
0x18[4] = 1) as shown in Table 2.
TABLE 2. YUV MAPPING (4:2:2)
INPUT
SIGNAL
ISL98001
INPUT
CHANNEL
ISL98001
OUTPUT
ASSIGNMENT
OUTPUT
SIGNAL
Y
Green
Green
Y0Y1Y2Y3
Pb
Blue
Blue
driven low
Pr
Red
Red
U0V0U2V2
There is also a “compatibility mode”, enabled by setting bit 3
of register 0x18 to a 1, that outputs the U and V data with the
format used by the previous generation (“X980xx”) series of
AFEs, shown in Table 3.
TABLE 3. YUV MAPPING (4:2:2)
INPUT
SIGNAL
ISL98001
INPUT
CHANNEL
ISL98001
OUTPUT
ASSIGNMENT
OUTPUT
SIGNAL
Y
Green
Green
Y0Y1Y2Y3
Pb
Blue
Blue
driven low
Pr
Red
Red
U0V1U2V3
Input Coupling
Inputs can be either AC-coupled (default) or DC-coupled (See
register 0x05[1]). AC coupling is usually preferred since it
allows video signals with substantial DC offsets to be accurately
digitized. The ISL98001 provides a complete internal
DC-restore function, including the DC restore clamp (See
Figure 7) and programmable clamp timing (registers 0x14,
0x15, 0x16, and 0x23).
HSYNC. If register 0x05[5] = 0 (the default), the clamp will not
be applied while the DPLL is coasting, preventing any clamp
voltage errors from composite sync edges, equalization pulses,
or Macrovision signals.
After the trailing edge of HSYNC, the DC restore clamp is
turned on after the number of pixels specified in the DC Restore
and ABLC™ Starting Pixel registers (0x14 and 0x15) has been
reached. The clamp is applied for the number of pixels
specified by the DC Restore Clamp Width Register (0x16). The
clamp can be applied to the back porch of the video, or to the
front porch (by increasing the DC Restore and ABLC™ Starting
Pixel registers so all the active video pixels are skipped).
If DC-coupled operation is desired, the input to the ADC will be
the difference between the input signal (RIN1, for example) and
that channel’s ground reference (RGBGND1 in that example).
SOG
For component YPbPr signals, the sync signal is embedded
on the Y channel’s video, which is connected to the green
input, hence the name SOG (Sync on Green). The horizontal
sync information is encoded onto the video input by adding
the sync tip during the blanking interval. The sync tip level is
typically 0.3V below the video black level.
To minimize the loading on the green channel, the SOG input
for each of the green channels should be AC-coupled to the
ISL98001 through a series combination of a 10nF capacitor
and a 500Ω resistor. Inside the ISL98001, a window
comparator compares the SOG signal with an internal 4-bit
programmable threshold level reference ranging from 0mV to
300mV below the minimum sync level. The SOG threshold
level, hysteresis, and low-pass filter is programmed via
register 0x04. If the Sync-On-Green function is not needed,
the SOGIN pin(s) may be left unconnected.
When AC-coupled, the DC restore clamp is applied every line,
a programmable number of pixels after the trailing edge of
20
FN6148.3
March 8, 2006
ISL98001
SYNC Processing
HSYNCOUT, set the HSYNCOUT Mask Disable bit (register
0x05 bit 7).
The ISL98001 can process sync signals from 3 different
sources: discrete HSYNC and VSYNC, composite sync on
the HSYNC input, or composite sync from a Sync-On-Green
(SOG) signal embedded on the Green video input. The
ISL98001 has SYNC activity detect functions to help the
firmware determine which sync source is available.
Headswitching from Analog Videotape Signals
Occasionally this AFE may be used to digitize signals
coming from analog videotape sources. The most common
example of this is a Digital VCR (which for best signal quality
would be connected to this AFE with a component YPbPr
connection). If the digital VCR is playing an older analog
VHS tape, the sync signals from the VCR may contain the
worst of the traditional analog tape artifacts: headswitching.
Headswitching is traditionally the enemy of PLLs with large
capture ranges, because a headswitch can cause the
HSYNC period to change by as much as ±90%. To the PLL,
this can look like a frequency change of -50% to greater than
+900%, causing errors in the output frequency (and
obviously the phase) to change. Subsequent HSYNCs have
the correct, original period, but most analog PLLs will take
dozens of lines to settle back to the correct frequency and
phase after a headswitch disturbance. This causes the top of
the image to “tear” during normal playback. In “trick modes”
(fast forward and rewind), the HSYNC signal has multiple
headswitch-like discontinuities, and many PLLs never settle
to the correct value before the next headswitch, rendering
the image completely unintelligible.
Macrovision
The ISL98001 automatically detects the presence of
Macrovision-encoded video. When Macrovision is detected,
it generates a mask signal that is ANDed with the incoming
SOG CSYNC signal to remove the Macrovision before the
HSYNC goes to the PLL. No additional programming is
required to support Macrovision.
If desired (it is never necessary in normal operation), this
function can be disabled by setting the Sync Mask Disable
(register 0x05 bit 6) to a 1.
The mask signal is also applied to the HSYNCOUT signal.
When Sync Mask Disable = 0, any Macrovision present on
the incoming sync will not be visible on HSYNCOUT. If the
application requires the Macrovision pulses to be visible on
ACTIVITY 0x01[6:0]
&
POLARITY 0x02[5:0]
DETECT
HSYNCIN1
HSYNC1
SLICER
0x03[2:0]
0:
VGA1
VSYNCIN1
SOGIN1
HSYNCIN2
SOG
SLICER
0x1C
HSYNCIN
0x05[0]
HSYNC2
SLICER
0x03[6:4]
SOGIN
00, 10,
11:
HSYNCIN
0x05[4:3]
SYNC
TYPE
SYNC
SPLITTER
VSYNC
01:
SOGIN
1:
VGA2
VSYNCIN2
SOGIN2
HSYNCOUT
CSYNC
SOURCE
0x05[3]
VSYNCIN
COAST
GENERATION
0x11, 0x12, 0x13[2]
RP[7:0]
Pixel Data
from AFE
CLOCKINVIN
PLL
HS
0x0E through 0x13
PIXCLK
0: ÷1
XTALOUT
24
RS[7:0]
GP[7:0]
Output
Formatter
0x18,
0x19,
0x1A
GS[7:0]
BP[7:0]
BS[7:0]
DATACLK
DATACLK
0x13
[6]
÷2
VSYNCOUT
0:
VSYNCIN
SOG
SLICER
0x1C
XTALIN
1:
SYNC
SPLTR
HSOUT
VSOUT
1: ÷2
XTALCLOCKOUT
FIGURE 8. SYNC FLOW
21
FN6148.3
March 8, 2006
ISL98001
Intersil’s DPLL has the capability to correct large phase
changes almost instantly by maximizing the phase error gain
while keeping the frequency gain relatively low. This is done
by changing the contents of register 0x1C to 0x4C. This
increases the phase error gain to 100%. Because a phase
setting this high will slightly increase jitter, the default setting
(0x49) for register 0x1C is recommended for all other sync
sources.
PGA
The ISL98001’s Programmable Gain Amplifier (PGA) has a
nominal gain range from 0.5V/V (-6dB) to 2.0V/V (+6dB).
The transfer function is:
Table 4 shows the corner frequencies for different register
settings.
Register 0x0D[7:4] controls a programmable zero, allowing
high frequencies to be boosted, restoring some of the
harmonics lost due to excessive EMI filtering, cable losses, etc.
This control has a very large range, and can introduce high
frequency noise into the image, so it should be used judiciously,
or as an advanced user adjustment.
TABLE 5. PEAKING CORNER FREQUENCIES
0X0D[7:4] VALUE
ZERO CORNER FREQUENCY
0x0
Peaking disabled
V
GainCode
Gain  ---- = 0.5 + ---------------------------- V
170
0x1
800MHz
0x2
400MHz
where GainCode is the value in the Gain register for that
particular color. Note that for a gain of 1V/V, the GainCode
should be 85 (0x55). This is a different center value than the
128 (0x80) value used by some other AFEs, so the firmware
should take this into account when adjusting gains.
0x3
265MHz
0x4
200MHz
0x5
160MHz
0x6
135MHz
0x7
115MHz
0x8
100MHz
0x9
90MHz
0xA
80MHz
0xB
70MHz
0xC
65MHz
0xD
60MHz
0xE
55MHz
0xF
50MHz
The PGAs are updated by the internal clamp signal once per
line. In normal operation this means that there is a maximum
delay of one HSYNC period between a write to a Gain
register for a particular color and the corresponding change
in that channel’s actual PGA gain. If there is no regular
HSYNC/SOG source, or if the external clamp option is
enabled (register 0x13[5:4]) but there is no external clamp
signal being generated, it may take up to 100ms for a write
to the Gain register to update the PGA. This is not an issue
in normal operation with RGB and YPbPr signals.
Bandwidth and Peaking Control
Register 0x0D[3:1] controls a low pass filter allowing the
input bandwidth to be adjusted with three bit resolution
between its default value (0x0E = 780MHz) and its minimum
bandwidth (0x00, for 100MHz). Typically the higher the
resolution, the higher the desired input bandwidth. To
minimize noise, video signals should be digitized with the
minimum bandwidth setting that passes sharp edges.
TABLE 4. BANDWIDTH CONTROL
0x0D[3:0] VALUE
(LSB = “x” = “don’t care”)
AFE BANDWIDTH
000x
100MHz
001x
130MHz
010x
150MHz
011x
180MHz
100x
230MHz
101x
320MHz
110x
480MHz
111x
780MHz
22
Table 5 shows the corner frequency of the zero for different
peaking register settings. Values above 0x2 may cause
excessive noise, depending on the quality of the input signal
and the PCB environment.
Offset DAC
The ISL98001 features a 10-bit Digital-to-Analog Converter
(DAC) to provide extremely fine control over the full channel
offset. The DAC is placed after the PGA to eliminate
interaction between the PGA (controlling “contrast”) and the
Offset DAC (controlling “brightness”).
In normal operation, the Offset DAC is controlled by the
ABLC™ circuit, ensuring that the offset is always reduced
to sub-LSB levels (See the following ABLC™ section for
more information). When ABLC™ is enabled, the Offset
registers (0x09, 0x0A, 0x0B) control a digital offset added
to or subtracted from the output of the ADC. This mode
provides the best image quality and eliminates the need for
any offset calibration.
If desired, ABLC™ can be disabled (0x17[0] = 1) and the
Offset DAC programmed manually, with the 8 most
FN6148.3
March 8, 2006
ISL98001
TABLE 6. OFFSET DAC RANGE AND OFFSET DAC ADJUSTMENT
OFFSET
DAC RANGE
0X0C[0]
10-BIT
OFFSET DAC
RESOLUTION
ABLC™
0x17[0]
USER OFFSET CONTROL RESOLUTION
USING REGISTERS 0x09 - 0X0B ONLY
(8-BIT OFFSET CONTROL)
USER OFFSET CONTROL RESOLUTION
USING REGISTERS 0X09 - 0x0B AND
0X0C[7:2](10-BIT OFFSET CONTROL)
0
0.25 ADC LSBs
(0.68mV)
0
(ABLC on)
1 ADC LSB
(digital offset control)
N/A
1
0.125 ADC LSBs
(0.34mV)
0
(ABLC on)
1 ADC LSB
(digital offset control)
N/A
0
0.25 ADC LSBs
(0.68mV)
1
(ABLC off)
1.0 ADC LSB
(analog offset control)
0.25 ADC LSB
(analog offset control)
1
0.125 ADC LSBs
(0.34mV)
1
(ABLC off)
0.5 ADC LSB
(analog offset control)
0.125 ADC LSB
(analog offset control)
significant bits in registers 0x09, 0x0A, 0x0B, and the 2 least
significant bits in register 0x0C[7:2].
The default Offset DAC range is ±127 ADC LSBs. Setting
0x0C[0] = 1 reduces the swing of the Offset DAC by 50%,
making 1 Offset DAC LSB the weight of 1/8th of an ADC
LSB. This provides the finest offset control and applies to
both ABLC™ and manual modes.
Automatic Black Level Compensation (ABLC™)
ABLC is a function that continuously removes all offset
errors from the incoming video signal by monitoring the
offset at the output of the ADC and servoing the 10-bit
analog DAC to force those errors to zero. When ABLC is
enabled, the user offset control is a digital adder, with 8-bit
resolution (See Table 6).
When the ABLC function is enabled (0x17[0] = 0), the ABLC
function is executed every line after the trailing edge of
HSYNC. If register 0x05[5] = 0 (the default), the ABLC
function will be not be triggered while the DPLL is coasting,
preventing any composite sync edges, equalization pulses,
or Macrovision signals from corrupting the black data and
potentially adding a small error in the ABLC accumulator.
After the trailing edge of HSYNC, the start of ABLC is
delayed by the number of pixels specified in registers 0x14
and 0x15. After that delay, the number of pixels specified
by register 0x17[3:2] are averaged together and added to
the ABLC’s accumulator. The accumulator stores the
average black levels for the number of lines specified by
register 0x17[6:4], which is then used to generate a 10-bit
DAC value.
The default values provide excellent results with offset
stability and absolute accuracy better than 1 ADC LSB for
most input signals.
ADC
The ISL98001 features 3 fully differential, high-speed 8-bit
ADCs.
Clock Generation
A Digital Phase Lock Loop (DPLL) is employed to generate
the pixel clock frequency. The HSYNC input and the external
23
XTAL provide a reference frequency to the PLL. The PLL
then generates the pixel clock frequency that equal to the
incoming HSYNC frequency times the HTOTAL value
programmed into registers 0x0E and 0x0F.
The stability of the clock is very important and correlates
directly with the quality of the image. During each pixel time
transition, there is a small window where the signal is
slewing from the old pixel amplitude and settling to the new
pixel value. At higher frequencies, the pixel time transitions
at a faster rate, which makes the stable pixel time even
smaller. Any jitter in the pixel clock reduces the effective
stable pixel time and thus the sample window in which pixel
sampling can be made accurately.
Sampling Phase
The ISL98001 provides 64 low-jitter phase choices per pixel
period, allowing the firmware to precisely select the optimum
sampling point. The sampling phase register is 0x10.
HSYNC Slicer
To further minimize jitter, the HSYNC inputs are treated as
analog signals, and brought into a precision slicer block with
thresholds programmable in 400mV steps with 240mV of
hysteresis, and a subsequent digital glitch filter that ignores
any HSYNC transitions within 100ns of the initial transition.
This processing greatly increases the AFE’s rejection of
ringing and reflections on the HSYNC line and allows the
AFE to perform well even with pathological HSYNC signals.
Voltages given above and in the HSYNC Slicer register
description are with respect to a 3.3V sync signal at the
HSYNCIN input pin. To achieve 5V compatibility, a 680Ω
series resistor should be placed between the HSYNC source
and the HSYNCIN input pin. Relative to a 5V input, the
hysteresis will be 240mV*5V/3.3V = 360mV, and the slicer
step size will be 400mV*5V/3.3V = 600mV per step.
SOG Slicer
The SOG input has programmable threshold, 40mV of
hysteresis, and an optional low pass filter that can be used to
remove high frequency video spikes (generated by overzealous
video peaking in a DVD player, for example) that can cause
FN6148.3
March 8, 2006
ISL98001
TABLE 7. SYNC SOURCE DETECTION TABLE
HSYNC
DETECT
VSYNC
DETECT
SOG
DETECT
TRILEVEL
DETECT
1
1
X
X
Sync is on HSYNC and VSYNC
1
0
X
X
Sync is composite sync on HSYNC. Set Input configuration register to CSYNC on
HSYNC and confirm that CSYNC detect bit is set.
0
0
1
0
Sync is composite sync on SOG. It is possible that trilevel sync is present but amplitude
is too low to set trilevel detect bit. Use video mode table to determine if this video mode
is likely to have trilevel sync, and set clamp start, width values appropriately if it is.
0
0
1
1
Sync is composite sync on SOG. Sync is likely to be trilevel.
0
0
0
X
No valid sync sources on any input.
RESULT
false SOG triggers. The SOG threshold sets the comparator
threshold relative to the sync tip (the bottom of the SOG pulse).
SYNC Status and Polarity Detection
The SYNC Status register (0x01) and the SYNC Polarity
register (0x02) continuously monitor all 6 sync inputs
(VSYNCIN, HSYNCIN, and SOGIN for each of 2 channels)
and report their status. However, accurate sync activity
detection is always a challenge. Noise and repetitive video
patterns on the Green channel may look like SOG activity
when there actually is no SOG signal, while non-standard
SOG signals and trilevel sync signals may have amplitudes
below the default SOG slicer levels and not be easily
detected. As a consequence, not all of the activity detect bits
in the ISL98001 are correct under all conditions.
Table 7 shows how to use the SYNC Status register (0x01)
to identify the presence of and type of a sync source. The
firmware should go through the table in the order shown,
stopping at the first entry that matches the activity indicators
in the SYNC Status register.
Final validation of composite sync sources (SOG or
Composite sync on HSYNC) should be done by setting the
Input Configuration register (0x05) to the composite sync
source determined by this table, and confirming that the
CSYNC detect bit is set.
The accuracy of the Trilevel Sync detect bit can be increased
by multiple reads of the Trilevel Sync detect bit. See the
Trilevel Sync Detect section for more details.
For best SOG operation, the SOG low pass filter (register
0x04[4] should always be enabled to reject the high
frequency peaking often seen on video signals.
HSYNC and VSYNC Activity Detect
Activity on these bits always indicates valid sync pulses, so
they should have the highest priority and be used even if the
SOG activity bit is also set.
SOG Activity Detect
The SOG activity detect bit monitors the output of the SOG
slicer, looking for 64 consecutive pulses with the same period
and duty cycle. If there is no signal on the Green (or Y)
24
channel, the SOG slicer will clamp the video to a DC level and
will reject any sporadic noise. There should be no false
positive SOG detects if there is no video on Green (or Y).
If there is video on Green (or Y) with no valid SOG signal,
the SOG activity detect bit may sometimes report false
positives (it will detect SOG when no SOG is actually
present). This is due to the presence of video with a
repetitive pattern that creates a waveform similar to SOG.
For example, the desktop of a PC operating system is black
during the front porch, horizontal sync, and back porch, then
increases to a larger value for the video portion of the
screen. This creates a repetitive video waveform very similar
to SOG that may falsely trigger the SOG Activity detect bit.
However, in these cases where there is active video without
SOG, the SYNC information will be provided either as
separate H and V sync on HSYNCIN and VSYNCIN, or
composite sync on HSYNCIN. HSYNCIN and VSYNCIN
should therefore be used to qualify SOG. The SOG Active bit
should only be considered valid if HSYNC Activity
Detect = 0. Note: Some pattern generators can output
HSYNC and SOG simultaneously, in which case both the
HSYNC and the SOG activity bits will be set, and valid. Even
in this case, however, the monitor should still choose
HSYNC over SOG.
TriLevel Sync Detect
Unlike SOG detect, the TriLevel Sync detect function does
not check for 64 consecutive trilevel pulses in a row, and is
therefore less robust than the SOG detect function. It will
report false positives for SOG-less video for the same
reasons the SOG activity detect does, and should therefore
be qualified with both HSYNC and SOG. TriLevel Sync
Detect should only be considered valid if HSYNC Activity
Detect = 0 and SOG Activity Detect = 1.
If there is a SOG signal, the TriLevel Detect bit will operate
correctly for standard trilevel sync levels (600mVP-P). In
some real-world situations, the peak-to-peak sync amplitude
may be significantly smaller, sometimes 300mVP-P or less.
In these cases the sync slicer will continue to operate
correctly, but the TriLevel Detect bit may not be set. Trilevel
detection accuracy can be enhanced by polling the trilevel
bit multiple times. If HSYNC is inactive, SOG is present, and
FN6148.3
March 8, 2006
ISL98001
the TriLevel Sync Detect bit is read as a 1, there is a high
likelihood there is trilevel sync.
CSYNC Present
If a composite sync source (either CSYNC on HSYNC or
SOG) is selected through bits 3 and 4 of register 0x05, the
CSYNC Present bit in register 0x01 should be set. CSYNC
Present detects the presence of a low frequency, repetitive
signal inside HSYNC, which indicates a VSYNC signal. The
CSYNC Present bit should be used to confirm that the signal
being received is a reliable composite sync source.
SYNC Output Signals
The ISL98001 has 2 pairs of HSYNC and VSYNC output
signals, HSYNCOUT and VSYNCOUT, and HSOUT and
VSOUT.
HSYNCOUT and VSYNCOUT are buffered versions of the
incoming sync signals; no synchronization is done. These
signals are used for mode detection
HSOUT and VSOUT are generated by the ISL98001’s logic
and are synchronized to the output DATACLK and the digital
pixel data on the output databus. HSOUT is used to signal
the start of a new line of digital data. VSOUT is not needed in
most applications.
Both HSYNCOUT and VSYNCOUT (including the sync
separator function) remain active in power-down mode. This
allows them to be used in conjunction with the Sync Status
registers to detect valid video without powering up the
ISL98001.
HSYNCOUT
HSYNCOUT is an unmodified, buffered version of the incoming
HSYNCIN or SOGIN signal of the selected channel, with the
incoming signal’s period, polarity, and width to aid in mode
detection. HSYNCOUT will be the same format as the incoming
sync signal: either horizontal or composite sync. If a SOG input
is selected, HSYNCOUT will output the entire SOG signal,
including the VSYNC portion, pre-/post-equalization pulses if
present, and Macrovision pulses if present. HSYNCOUT
remains active when the ISL98001 is in power-down mode.
HSYNCOUT is generally used for mode detection.
VSYNCOUT
VSYNCOUT is an unmodified, buffered version of the
incoming VSYNCIN signal of the selected channel, with the
original VSYNC period, polarity, and width to aid in mode
detection. If a SOG input is selected, this signal will output
the VSYNC signal extracted by the ISL98001’s sync slicer.
Extracted VSYNC will be the width of the embedded VSYNC
pulse plus pre- and post-equalization pulses (if present).
Macrovision pulses from an NTSC DVD source will lengthen
the width of the VSYNC pulse. Macrovision pulses from
other sources (PAL DVD or videotape) may appear as a
second VSYNC pulse encompassing the width of the
Macrovision. See the Macrovision section for more
25
information. VSYNCOUT (including the sync separator
function) remains active in power-down mode. VSYNCOUT
is generally used for mode detection, start of field detection,
and even/odd field detection.
HSOUT
HSOUT is generated by the ISL98001’s control logic and is
synchronized to the output DATACLK and the digital pixel
data on the output databus. Its trailing edge is aligned with
pixel 0. Its width, in units of pixels, is determined by register
0x19, and its polarity is determined by register 0x18[7]. As
the width is increased, the trailing edge stays aligned with
pixel 0, while the leading edge is moved backwards in time
relative to pixel 0. HSOUT is used by the scaler to signal the
start of a new line of pixels.
The HSOUT Width register (0x19) controls the width of the
HSOUT pulse. The pulse width is nominally 1 pixel clock
period times the value in this register. In the 48 bit output
mode (register 0x18[0] = 1), or the YPbPr input mode
(register 0x05[2] = 1), the HSOUT width is incremented in 2
pixel clock (1 DATACLK) increments (See Table 8).
TABLE 8. HSOUT WIDTH
HSOUT WIDTH (PIXEL CLOCKS)
REGISTER
0x19 VALUE
24-BIT MODE,
RGB
24-BIT MODE,
YPbPr
ALL 48-BIT
MODES
0
0
1
0
1
1
1
0
2
2
3
2
3
3
3
2
4
4
5
4
5
5
5
4
6
6
7
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6
VSOUT
VSOUT is generated by the ISL98001’s control logic and is
synchronized to the output DATACLK and the digital pixel
data on the output databus. Its leading and trailing edges are
aligned with pixel 7 (8 pixels after HSYNC trailing edge). Its
width, in units of lines, is equal to the width of the incoming
VSYNC (See the VSYNCOUT description). Its polarity is
determined by register 0x18[6]. This output is not needed in
most applications. Intersil strongly discourages using this
signal - use VSYNCOUT instead.
Crystal Oscillator
An external 22MHz to 27MHz crystal supplies the low-jitter
reference clock to the DPLL. The absolute frequency of this
crystal within this range is unimportant, as is the crystal’s
temperature coefficient, allowing use of less expensive,
lower-grade crystals.
FN6148.3
March 8, 2006
ISL98001
As an alternative to a crystal, the XTALIN pin can be driven
with a 3.3V CMOS-level external clock source at any
frequency between 22MHz and 33.5MHz. The ISL98001’s
jitter specification assumes a low-jitter crystal source. If the
external clock source has increased jitter, the sample clock
generated by the DPLL may exhibit increased jitter as well.
Reset
The ISL98001 has a Power On Reset (POR) function that
resets the chip to its default state when power is initially
applied, including resetting all the registers to their default
settings as described in the Register Listing. The external
RESET pin duplicates the reset function of the POR without
having to cycle the power supplies. The RESET pin does not
need to be used in normal operation and can be tied high.
Initialization
The ISL98001 initializes with default register settings for an
AC-coupled, 640x480 RGB input on the VGA1 channel, with
a 24-bit output. An input signal meeting these conditions will
be output on the databus without writing to any of the
configuration registers. The configuration registers will need
to be changed as required to support other resolutions,
different input channels, different sync sources, phase
optimization etc.
The ISL98001-275 and (under some conditions) the
ISL98001-240 require one additional register write to
operate at their maximum speed. The ISL98001 generates
an internal reference clock equal to the crystal frequency
times the value in register 0x2B (nominally 0x14 or 20
decimal). The typical value of this clock is therefore 500MHz
(25MHz * 20). The minimum value of this clock is 360MHz.
This internal clock needs to be greater than 2 times the PLL
pixel rate. The nominal value of 500MHz therefore supports
pixel rates up to 250MHz. To achieve pixel rates of 275MHz,
or to work with lower frequency crystals, the multiplier in
register 0x2B must be programmed using Equation 1:
 f MAX_PIXELCLK
0x2B value = INT  2 ----------------------------------------- + 1
f CRYSTAL 

(EQ. 1)
For example, if the maximum pixel clock is 263MHz (QXGA),
and the crystal frequency is 24MHz, then register 0x2B
should be set to 1 + INT(2*263/24) = 1 + INT(21.917) = 1 +
21 = 22 = 0x16. Table 9 illustrates the compensation values
required to operate the ISL98001-275 at its maximum speed
of 275MHz. If lower maximum Pixel Clock frequencies are
needed, using the formula above to reduce the value of
register 0x2B will reduce power consumption.
TABLE 9. CRYSTAL MULTIPLIER FOR 275MHz PIXEL RATE
Crystal Frequency Range (MHz)
23 - 23.9
23.9 - 25
25.0 - 26.2
26.2 - 27
Register 0x2B Value
decimal
hex
24
0x18
23
0x17
22
0x16
21
0x15
Reducing Power Dissipation
It is possible to reduce the total power consumption of the
ISL98001 in applications where power is a concern. There are
several techniques that can be used to reduce power
consumption:
• Internal Digital Voltage Regulator. The ISL98001 features
a 3.3V to 1.9V voltage regulator (pins VREGIN and
VREGOUT) for the low voltage digital supply. This regulator
typically sources 100mA at 1.9V, dissipating up to 140mW in
heat. Providing an external, clean 1.8V supply to the VCORE,
VPLL, and VCOREADC will substantially reduce power
dissipation. The external 1.8V supply should ramp up after
(or at the same time as) the digital 3.3V (VD) supply.
• Internal Analog Voltage Regulator. The ISL98001 also
features a 3.3V to 1.9V voltage regulator for the low voltage
analog supply. This voltage appears on the VBYPASS pins.
Unlike the digital low voltage supply, there are no “in” and
“out” connections for this regulator. However, this internal
regulator can only source voltage, and can be effectively
bypassed by driving the VBYPASS pins with an external, clean
2.0V supply. The external 2.0V supply should ramp up after
(or at the same time as) the analog 3.3V (VA) supply.
• Buffering Digital Outputs. Switching 24 or 48 data output
pins into a capacitive bus can consume significant current.
The higher the capacitance on the external databus, the
higher the switching current. To minimize current
consumption inside the ISL98001, minimize bus capacitance
and/or insert data buffers such as the SN64AVC16827
between the ISL98001’s data outputs and the external
databus.
• Internal Reference Frequency. The crystal frequency is
multiplied by the value in register 0x2B to generate an
internal high frequency reference clock. For pixel rates up to
160MHz, this internal frequency should be set to 400MHz
±10% for minimum power consumption. For example, for a
33MHz frequency at XTALIN, register 0x2B should be set to a
value of 0x0C to minimize power. For pixel rates greater than
160MHz, the register 0x2B value should be set using
Equation 1 in the Initialization section on page 26.
Standby Mode
The ISL98001 can be placed into a low power standby mode
by writing a 0x0F to register 0x1B, powering down the triple
ADCs, the DPLL, and most of the internal clocks.
26
FN6148.3
March 8, 2006
ISL98001
To allow input monitoring and mode detection during powerdown, the following blocks remain active:
• Serial interface (including the crystal oscillator) to enable
register read/write activity
• Activity and polarity detect functions (registers 0x01 and
0x02)
• The HSYNCOUT and VSYNCOUT pins (for mode
detection)
EMI Considerations
There are two possible sources of EMI on the ISL98001:
Crystal oscillator. The EMI from the crystal oscillator is
negligible. This is due to an amplitude-regulated, low voltage
sine wave oscillator circuit, instead of the typical high-gain
square wave inverter-type oscillator, so there are no harmonics.
The crystal oscillator is not a significant source of EMI.
Digital output switching. This is the largest potential source of
EMI. However, the EMI is determined by the PCB layout and
the loading on the databus. The way to control this is to put
series resistors on the output of all the digital pins (as our demo
board and reference circuits show). These resistors should be
as large as possible, while still meeting the setup and hold
timing requirements of the scaler. We recommend starting with
22Ω. If the databus is heavily loaded (long traces, many other
part on the same bus), this value may need to be reduced. If
the databus is lightly loaded, it may be increased.
Intersil’s recommendations to minimize EMI are:
• Minimize the databus trace length
• Minimize the databus capacitive loading.
If EMI is a problem in the final design, increase the value of the
digital output series resistors to reduce slew rates on the bus.
This can only be done as long as the scaler’s setup and hold
timing requirements continue to be met.
ISL98001 Serial Communication
Overview
The ISL98001 uses a 2-wire serial bus for communication
with its host. SCL is the Serial Clock line, driven by the host,
and SDA is the Serial Data line, which can be driven by all
devices on the bus. SDA is open drain to allow multiple
devices to share the same bus simultaneously.
Communication is accomplished in three steps:
1)
The Host selects the ISL98001 it wishes to communicate
with.
2)
The Host writes the initial ISL98001 Configuration
Register address it wishes to write to or read from.
3)
The Host writes to or reads from the ISL98001’s
Configuration Register. The ISL98001’s internal address
pointer auto increments, so to read registers 0x00 through
27
0x1B, for example, one would write 0x00 in step 2, then
repeat step three 28 times, with each read returning the
next register value.
The ISL98001 has a 7-bit address on the serial bus. The
upper 6-bits are permanently set to 100110, with the lower
bit determined by the state of pin 48. This allows two
ISL98001s to be independently controlled while sharing the
same bus.
The bus is nominally inactive, with SDA and SCL high.
Communication begins when the host issues a START
command by taking SDA low while SCL is high (Figure 9).
The ISL98001 continuously monitors the SDA and SCL lines
for the start condition and will not respond to any command
until this condition has been met. The host then transmits the
7-bit serial address plus a R/W bit, indicating if the next
transaction will be a Read (R/W = 1) or a Write (R/W = 0). If
the address transmitted matches that of any device on the
bus, that device must respond with an ACKNOWLEDGE
(Figure 10).
Once the serial address has been transmitted and
acknowledged, one or more bytes of information can be
written to or read from the slave. Communication with the
selected device in the selected direction (read or write) is
ended by a STOP command, where SDA rises while SCL is
high (Figure 9), or a second START command, which is
commonly used to reverse data direction without
relinquishing the bus.
Data on the serial bus must be valid for the entire time SCL
is high (Figure 11). To achieve this, data being written to the
ISL98001 is latched on a delayed version of the rising edge
of SCL. SCL is delayed and deglitched inside the ISL98001
for three crystal clock periods (120ns for a 25MHz crystal) to
eliminate spurious clock pulses that could disrupt serial
communication.
When the contents of the ISL98001 are being read, the SDA
line is updated after the falling edge of SCL, delayed and
deglitched in the same manner.
Configuration Register Write
Figure 12 shows two views of the steps necessary to write
one or more words to the Configuration Register.
Configuration Register Read
Figure 13 shows two views of the steps necessary to read
one or more words from the Configuration Register.
FN6148.3
March 8, 2006
ISL98001
SCL
SDA
Start
Stop
FIGURE 9. VALID START AND STOP CONDITIONS
SCL from
Host
1
8
9
Data Output
from Transmitter
Data Output
from Receiver
Start
Acknowledge
FIGURE 10. ACKNOWLEDGE RESPONSE FROM RECEIVER
SCL
SDA
Data Stable
Data Change
Data Stable
FIGURE 11. VALID DATA CHANGES ON THE SDA BUS
28
FN6148.3
March 8, 2006
ISL98001
Signals the beginning of serial I/O
START Command
ISL98001 Serial Bus
R/W
0
A
This is the 7-bit address of the ISL98001 on the 2-wire bus. The
address is 0x4C if pin 48 is low, 0x4D if pin 48 is high. Shift this
value left to when adding the R/W bit.
0
1
0
0
1
1
A7
A6
A5
A4
A3
A2
A1
A0
D7
D6
D5
D4
D3
D2
D1
D0
(pin 48)
ISL98001 Serial Bus Address Write
ISL98001 Register Address Write
This is the address of the ISL98001’s configuration register that
the following byte will be written to.
ISL98001 Register Data Write(s)
This is the data to be written to the ISL98001’s configuration register.
Note: The ISL98001’s Configuration Register’s address pointer auto
increments after each data write: repeat this step to write multiple
sequential bytes of data to the Configuration Register.
(Repeat if desired)
Signals the ending of serial I/O
STOP Command
Signals from
the Host
SDA Bus
Signals from
the ISL98001
S
T Serial Bus
A
R Address
T
Register
Address
1 0 0 1 1 0A0
aaaaaaaa
A
C
K
S
T
O
P
Data
Write*
* The data write step may be repeated to write to the
ISL98001’s Configuration Register sequentially, beginning at
the Register Address written in the previous step.
dddddddd
A
C
K
A
C
K
FIGURE 12. CONFIGURATION REGISTER WRITE
29
FN6148.3
March 8, 2006
ISL98001
Signals the beginning of serial I/O
START Command
ISL98001 Serial Bus
R/W
0
1
0
0
1
1
A7
A6
A5
A4
A3
A
(pin 48)
0
ISL98001 Serial Bus Address Write
This is the 7-bit address of the ISL98001 on the 2-wire bus. The
address is 0x4C if pin 48 is low, 0x4D if pin 48 is high. R/W = 0,
indicating next transaction will be a write.
ISL98001 Register Address Write
A2
A1
A0
This sets the initial address of the ISL98001’s configuration
register for subsequent reading.
Ends the previous transaction and starts a new one
R/W
ISL98001 Serial Bus Address Write
START Command
ISL98001 Serial Bus
A
0
1
0
0
1
1
D7
D6
D5
D4
D3
(pin 48)
D2
D1
1
D0
SDA Bus
Signals from
the ISL98001
R
E
S
T Serial Bus
A Address
R
T
1 0 0 1 1 0A1
Register
Address
1 0 0 1 1 0A0
aaaaaaaa
A
C
K
This is the data read from the ISL98001’s configuration register.
Signals the ending of serial I/O
STOP Command
S
T Serial Bus
A
R Address
T
ISL98001 Register Data Read(s)
Note: The ISL98001’s Configuration Register’s address pointer
auto increments after each data read: repeat this step to read
multiple sequential bytes of data from the Configuration Register.
(Repeat if desired)
Signals from
the Host
This is the 7-bit address of the ISL98001 on the 2-wire bus. The
address is 0x4C if pin 48 is low, 0x4D if pin 48 is high. R/W = 1,
indicating next transaction(s) will be a read.
A
C
K
Data
Read*
S
T
O
AP
C
K
* The data read step may be repeated to read
from the ISL98001’s Configuration Register
sequentially, beginning at the Register
Address written in the two steps previous.
Adddddddd
C
K
FIGURE 13. CONFIGURATION REGISTER READ
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Intersil Corporation’s quality certifications can be viewed at www.intersil.com/design/quality
Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without
notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be accurate and
reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result
from its use. No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries.
For information regarding Intersil Corporation and its products, see www.intersil.com
30
FN6148.3
March 8, 2006
128-Lead Metric Quad Flat Pack (MQFP) Package
31
ISL98001
FN6148.3
March 8, 2006
All dimensions in mm.
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