WOLFSON WM8143-10

WM8143-10
10-bit/6MSPS CCD Signal Processor
Production Data June 1998 Rev 3f
Description
Features
The WM8143-10 integrates the analogue signal
conditioning required by CCD sensors with a 10-bit ADC.
The WM8143-10 requires minimal external circuitry and
provides a cost-effective sensor to digital domain system
solution.
•
•
•
•
•
•
•
•
•
•
Each of the three analogue conditioning channels
includes reset level clamp, CDS, fine offset level shifting
and programmable gain amplification. The three channels
are multiplexed into the ADC. The output from the ADC is
fed to the output bus pins OP[9:0] via a 10/8 bit
multiplexer, enabled by the OEB signal.
The flexible output architecture allows ten-bit data to be
accessed either on a ten-bit bus or via a time-multiplexed
eight-bit bus. The WM8143-10 can be configured for
pixel-by-pixel or line-by-line multiplexing operation. Reset
level clamp and/or CDS features can be optionally
bypassed. The device configuration is programmed either
via a simple serial interface or via an eight-bit parallel
interface.
Reset level clamp
Correlated double sampling (CDS)
Fine offset level shifting
Programmable gain amplification
10-bit ADC with maximum 6 MSPS
Simple clocking scheme
Control by serial or parallel interface
Time multiplexed eight-bit data output mode
32 pin TQFP package
Interface compatible with WM8144-10 and
WM8144-12
Applications
•
•
•
•
•
Flatbed scanners
Sheet feed scanners
Film scanners
CCD sensor interfaces
Contact image sensor (CIS) interfaces
The serial/parallel interfaces of the WM8143-10 are
control compatible with those of the WM8144-10 and
WM8144-12.
Block Diagram
VRLC
VRU
VRT
VRB
VMID
VSMP
MCLK
RLC
AGND
DGND
DVDD
AVDD
MUX
CL
RS
TIMING CONTROL
VS
VMID
OFFSET
S/H
RINP
+
PGA
+
S/H
WM8143-10
CDS
5-BIT REG
8-BIT +
SIGN DAC
VMID
OFFSET
S/H
GINP
+
PGA
+
S/H
M
U
X
OEB
10-bit
ADC
10/8
MUX
OP[9:0]
CDS
5-BIT REG
8-BIT +
SIGN DAC
VMID
OFFSET
S/H
BINP
+
PGA
+
S/H
CDS
5-BIT REG
8-BIT +
SIGN DAC
VMID
CONFIGURABLE
SERIAL/PARALLEL
CONTROL INTERFACE
SDI / DNA
SCK / RNW
SEN / STB
NRESET
Production Data datasheets
contain final specifications current
on publication date. Supply of
products conforms to Wolfson
Microelectronic's terms and
conditions.
Wolfson Microelectronics
Lutton Court, Bernard Terrace, Edinburgh, EH8 9NX, UK
Tel: +44 (0) 131 667 9386 Fax: +44 (0) 131 667 5176
email: [email protected]
www: http://www.wolfson.co.uk
1998 Wolfson Microelectronics Ltd.
WM8143-10
Production Data
SDI/DNA
SEN/STB
OEB
RINP
GINP
BINP
VRLC
VMID
23
22
21
20
19
18
17
Ordering Information
24
Pin Configuration
DEVICE
25
16
VRT
RLC
26
15
VRB
VSMP
27
14
VRU
MCLK
28
13
AGND
DGND
29
12
AVDD
nc
30
11
NRESET
nc
31
10
OP[9]
DVDD
32
9
OP[8]
1
2
3
4
5
6
7
8
OP[0]
OP[1]
OP[2]
OP[3]
OP[4]
OP[5]
OP[6]
OP[7]
PACKAGE
o
WM8143-10CFT/V
SCK/RNW
WM8143-10
TEMP. RANGE
0 - 70 C
32 Pin TQFP
Absolute Maximum Ratings
Analogue Supply Voltage .......... AGND - 0.3V, AGND +7V Operating Temperature Range, TA .......... 0°C to +70°C
Digital Supply Voltage ...............DGND - 0.3V, DGND +7V Storage Temperature.......................... -50°C to +150°C
Digital Inputs .......................... DGND - 0.3V, DVDD +0.3V Lead Temperature (soldering 10 seconds) ....... +260°C
Digital Outputs ....................... DGND - 0.3V, DVDD +0.3V
Reference Inputs ....................AGND - 0.3V, AVDD +0.3V
RINP, GINP, BINP..................AGND - 0.3 V, AVDD +0.3V
Absolute Maximum Ratings are stress ratings only. Permanent damage to the device may be caused by continuously
operating at or beyond these limits. Device functional operating limits and guaranteed performance specifications are
given under Electrical Characteristics at the test conditions specified
ESD Sensitive Device. This device is manufactured on a CMOS process. It is therefore generically
susceptible to damage from excessive static voltages. Proper ESD precautions must be taken during
handling and storage of this device.
As per JEDEC specifications A112-A and A113-A, this product requires specific storage conditions
prior to surface mount assembly. It has been classified as having a Moisture Sensitivity Level of 2
and as such will be supplied in vacuum-sealed moisture barrier bags.
Recommended Operating Conditions
PARAMETER
Supply Voltage
Operating Temperature Range
Input Common Mode Range
SYMBOL
TEST
CONDITIONS
AVDD, DVDD
MIN
4.75
TYP
MAX
5.25
TA
0
70
VCMR
0.5
4.5
Wolfson Microelectronics
2
UNIT
V
o
C
V
PD Rev 3f June 98
WM8143-10
Production Data
Electrical Characteristics
Test Characteristics
AVDD = DVDD = 4.75V to 5.25V, AGND = DGND = 0V … TA = 0oC to +70oC, MCLK = 12MHz, unless otherwise stated
PARAMETER
SYMBOL
TEST
CONDITIONS
MIN
Supply Current - Active
Supply Current - Standby
TYP
MAX
UNIT
100
140
mA
7
15
mA
Digital Inputs
High Level Input Voltage
VIH
Low Level Input Voltage
VIL
0.2*DVDD
V
High Level Input Current
IIH
1
µA
Low Level Input Current
IIL
1
µA
0.8*DVDD
Input Capacitance
V
5
pF
Digital Outputs
High Level Output Voltage
VOH
IOH = 1mA
Low Level Output Voltage
VOL
IOL= 1mA
High Impedance Output
Current
IOZ
DVDD-0.75
V
DGND+0.75
V
1
µA
Input Multiplexer
CDS Mode Full Scale Input
Range (VVS-VRS)
x denotes the
channel selected
Channel to Channel Gain
Matching
Input Video Set-up Time
Input Video Hold Time
Reset Video Set-up Time
2
Gx
Vp-p
1
%
tVSU
10
ns
tVH
15
ns
tRSU
CDS Mode only
10
ns
tRH
CDS Mode only
15
ns
Reference Voltage – Top
VRT
VRU = 5V
3.47
3.5
3.53
V
Reference Voltage – Bottom
VRB
VRU = 5V
1.47
1.5
1.53
V
DAC Reference Voltage
VMID
VRU = 5V
2.47
2.5
2.53
Reset Video Hold Time
Reference String
R.L.C. Switching Impedance
Reset Level Clamp Options
VRLC
VRU=5V Voltage set
by register
configuration
V
Ω
500
1.46
1.5
1.54
V
2.46
2.5
2.54
V
3.46
3.5
3.54
V
Impedance VRT to VRB
250
500
750
Ω
Impedance VRU to AGND
1000
1500
2000
Ω
8-Bit DACs
Resolution
8
Zero Code Voltage
Full Scale Voltage Error
VMID +20
mV
0
20
mV
Wolfson Microelectronics
3
Bits
VMID -20
PD.Rev 3f June 98
WM8143-10
Production Data
Test Characteristics
AVDD = DVDD = 4.75V to 5.25V, AGND = DGND = 0V … TA = 0oC to +70oC, MCLK = 12MHz, unless otherwise stated
PARAMETER
SYMBOL
TEST
CONDITIONS
MIN
TYP
MAX
UNIT
Differential Non Linearity
DNL
0.1
0.5
LSB
Integral Non Linearity
INL
0.25
1
LSB
10-bit ADC performance including CDS, PGA and Offset Functions
NO MISSING CODES GUARANTEED
Resolution
AVDD = DVDD = 5V
10
Bits
Maximum Sampling Rate
AVDD = DVDD = 5V
6
MSPS
Zero Scale Transition Error
Voltage at VINP
DAC Code = 000H,
AVDD = DVDD = 5V,
measured relative to
VRB
± 25
±100
mV
Full Scale Transition Error
Voltage at VINP
DAC Code = 000H,
AVDD = DVDD = 5V,
measured relative to
VRT
± 25
±100
mV
+1
LSB
Differential Non Linearity
DNL
AVDD = DVDD = 5V
PGA Gain
Monotonicity Guaranteed
Red Channel Max Gain
Gr
Mode 1
7
7.5
Times
Green Channel Max Gain
Gg
AVDD = DVDD = 5V
7.5
8
Times
Blue Channel Max Gain
Gb
7.5
8
Times
MCLK Period
tPER
83.3
ns
MCLK High
tCKH
37.5
ns
MCLK Low
tCKL
37.5
ns
Data Set-up Time
tDSU
10
ns
Switching Characteristics
Data Hold Time
tDH
Output Propagation Delay
tPD
Output Enable Time
Output Disable Time
10
IOH=1mA, IOL=1mA
ns
75
ns
tPZE
50
ns
tPEZ
25
ns
Serial Interface
SCK Period
tSPER
83.3
ns
SCK High
tSCKH
37.5
ns
SCK Low
tSCKL
37.5
ns
SDI Set up Time
tSSU
10
ns
tSH
10
ns
Set up Time - SCK to SEN
tSCE
20
ns
Set up Time - SEN to SCK
tSEC
20
ns
SDI Hold Time
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WM8143-10
Production Data
Test Characteristics
AVDD = DVDD = 4.75V to 5.25V, AGND = DGND = 0V … TA = 0oC to +70oC, MCLK = 12MHz, unless otherwise stated
PARAMETER
SEN Pulse Width
SYMBOL
TEST
CONDITIONS
tSEW
MIN
TYP
MAX
50
UNIT
ns
Parallel Interface
RNW Low to OP[9:2] Tri-state
tOPZ
Address Setup Time to STB
Low
tASU
0
ns
DNA Low Setup Time to STB
Low
tADLS
10
ns
Strobe Low Time
tSTB
50
ns
Address Hold Time from STB
High
tAH
10
ns
DNA Low Hold Time from
STB High
tADLH
10
ns
Data Setup Time to STB Low
tDSU
0
ns
DNA High Setup Time to STB
Low
tADHS
10
ns
Data Hold Time from STB
High
tDH
10
ns
Data High Hold Time from
STB High
tADHH
10
ns
tOPD
0
ns
RNW High to OP[9:2] Output
20
Wolfson Microelectronics
5
ns
PD.Rev 3f June 98
WM8143-10
Production Data
Pin Description
PIN
NAME
TYPE
1
OP[0]
Digital OP
Tri-state digital 10-bit bi-directional bus. There are four modes:
DESCRIPTION
2
OP1]
Digital OP
Tri-state:
when OEB = 1
3
OP[2]
Digital IO
Output ten-bit:
ten bit data is output from bus
4
OP[3]
Digital IO
Output 8-bit multiplexed:
5
OP[4]
Digital IO
data output on OP[9:2] at 2 * ADC
conversion rate
6
OP[5]
Digital IO
Input 8-bit:
7
OP[6]
Digital IO
control data is input on bits OP[9:2] in
parallel mode when SCK/RNW = 0.
8
OP[7]
Digital IO
9
OP[8]
Digital IO
10
OP[9]
Digital IO
11
NRESET
Digital IP
12
AVDD
Analogue supply
13
AGND
Analogue supply
14
VRU
Analogue IP
15
VRB
Analogue OP
16
VRT
Analogue OP
ADC reference voltages. The ADC reference range is applied between VRT (full
scale) and VRB (zero level). VRU can be used to derive optimal reference
voltages from an external 5V reference
17
VMID
Analogue OP
Buffered mid-point of ADC reference string.
18
VRLC
Analogue OP
Selectable analogue output voltage for RLC
19
BINP
Analogue IP
Blue channel input video
20
GINP
Analogue IP
Green channel input video
21
RINP
Analogue IP
Red channel input video
22
OEB
Digital IP
Output tri-state control:
all outputs enabled when OEB=0
23
SEN/STB
Digital IP
Serial interface:
enable, active high
Parallel interface:
strobe, active low
MSB of the output word is OP[9], LSB is OP[0]
Reset input, active low. This signal forces a reset of all internal registers and
selects whether serial control bus or parallel control bus is used ( see
SEN/STB)
Positive analogue supply (5V)
Analogue ground (0V)
Latched on NRESET rising edge: If low then device control is by serial
interface, if high then device control is by parallel interface
24
SDI/DNA
Digital IP
25
SCK/RNW
Digital IP
Serial interface:
serial interface input data signal
Parallel interface:
high = data, low = address
Serial interface:
serial interface clock signal
Parallel interface:
high = OP[9:2] is output bus
low = OP[9:2] is input bus
26
RLC
Digital IP
Selects whether reset level clamp is applied on a pixel-by-pixel basis. If RLC is
required on each pixel then this pin can be tied high
27
VSMP
Digital IP
Video sample synchronisation pulse. This signal is applied synchronously with
MLCK to specify the point in time that the input is sampled. The timing of
internal multiplexing between the R, G and B channels is derived from this
signal
28
MCLK
Digital IP
Master clock. This clock is applied at eight, six, three or two times the input pixel
rate depending on the operational mode. MCLK is divided internally to define the
ADC sample rate and to provide the clock source for digital logic
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PD Rev 3f June 98
WM8143-10
Production Data
PIN
NAME
TYPE
29
DGND
Digital supply
30
nc
Reserved, pin must be left unconnected
31
nc
Reserved, pin must be left unconnected
32
DVDD
Digital supply
DESCRIPTION
Digital ground (0V)
Positive digital supply (5V)
Typical Performance
o
AVDD = DVDD = 5V, TA = 25 C
WM8143-10 DNL
2
1.5
1
LSB's
0.5
0
-0.5
-1
-1.5
-2
0
256
512
768
1024
ADC Code
PGA Gain Code
PGA Gain Code vs Actual Gain
8.25
8
7.75
7.5
7.25
7
6.75
6.5
6.25
6
5.75
5.5
5.25
5
4.75
4.5
4.25
4
3.75
3.5
3.25
3
2.75
2.5
2.25
2
1.75
1.5
1.25
1
0.75
0.5
0.25
0
RED
GREEN
BLUE
0
1
2
3
4
5
6
7
8
9
Actual Gain
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WM8143-10
Production Data
System Description
COLOUR CCD
SENSOR
BUFFERING
FOR CCD
RED
RINP
OP[9:0]
PARALLEL
DATA I/O
WM8143-10
OEB
SDI/DNA
SCK/RNW
SEN/STB
NRESET
GREEN
GINP
VSMP
MCLK
RLC
BLUE
CONTROL/SERIAL
DATA IN
ANALOGUE
INTERFACE TIMING
BINP
Figure 1 System Diagram
The digital interface to the WM8143-10 can be divided
into three distinct sections: -
The WM8143-10 signal processing IC interfaces
typically via buffering and AC coupling to the output of
CCD image sensors. The WM8143-10 also interfaces
to CIS image sensors via DC coupling.
•
•
•
Analogue output signals from the image sensor are
sampled, amplified and offset-corrected by the IC
before being converted into digital form by an on-board
high-speed 10-bit resolution analogue to digital
converter. Figure 1 illustrates a typical system
implementation where the three colour outputs from the
CCD image sensor are buffered and AC coupled to the
analogue inputs of the WM8143-10.
Parallel Data I/O
Digital Control/Serial Timing
Analogue Interface Timing
These sections are constructed for ease of use by the
system designer and are described in detail on the
following pages of this datasheet.
Wolfson Microelectronics
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PD Rev 3f June 98
WM8143-10
Production Data
Table 1 illustrates the PGA Gains Register codes
required for typical gains. (See Typical Performance
Graphs). The typical gain may also be calculated using
the following equation:
Device Description
S/H, Offset DACs and PGA
Each analogue input (RINP, GINP, BINP) of the
WM8143-10 consists of a sample and hold, a
programmable gain amplifier, and a DC offset
correction block. The operation of the red input stage is
summarised in Figure 2.
Typical Gain = 0.5+(Code∗0.25).
CODE
TYPICAL
CODE
TYPICAL
00000
GAIN
0.5
10000
GAIN
4.5
00001
0.75
10001
4.75
00010
1
10010
5
00011
1.25
10011
5.25
Figure 2 Operation of Red Input Stage
00100
1.5
10100
5.5
The sample/hold block can operate in two modes of
operation, CDS (Correlated Double Sampling) or Single
Ended.
00101
1.75
10101
5.75
00110
2
10110
6
In CDS operation the video signal processed is the
difference between the voltage applied at the RINP
input when RS occurs, and the voltage at the RINP
input when VS occurs. This is summarised in Figure 3.
00111
2.25
10111
6.25
01000
2.5
11000
6.5
01001
2.75
11001
6.75
01010
3
11010
7
01011
3.25
11011
7.25
01100
3.5
11100
7.5
01101
3.75
11101
7.75
Figure 3 Video Signal Processed in CDS mode
01110
4
11110
8
When using CDS the actual DC value of the input
signal is not important, as long as the signal extremes
are maintained within 0.5 volts of the chip power
supplies. This is because the signal processed is the
difference between the two sample voltages, with the
common DC voltage being rejected.
01111
4.25
11111
8.25
RINP
+
S/H
GAIN=G
VS
+
VADC
-
S/H
VOFFSET
VMID
+
VMID
RS
VRS
VVS
RS
VS
Table 1 Typical Gain
The DC value of the gained signal can then be trimmed
by the 8 bit plus sign DAC. The voltage output by this
DAC is shown as VOFFSET in Figure 2. The range of the
DAC is (VMID/2) or 1.5*(VMID/2) if the DAC_RANGE bit
in Set-up Register 4 is set.
In Single Ended operation, the VS and RS control
signals occur simultaneously, and the voltage applied
to the reset switch is fixed at VMID. This means that the
voltage processed is the difference between the voltage
applied to RINP when VS/RS occurs, and VMID. When
using Single Ended operation the DC content of the
video signal is not rejected.
The output from the offset DAC stage is referenced to
the VMID voltage. This allows the input to the ADC to
maximise the dynamic range, and is shown
diagrammatically in Figure 2 by the final VMID addition.
The Programmable Gain Amplifier block multiplies the
resulting input voltage by a value between 0.5 and 8.25
which can be programmed independently for each of
the three input channels via the serial (or parallel)
interface.
Wolfson Microelectronics
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WM8143-10
Production Data
For the input stage, the final analogue voltage applied
to the ADC can be expressed as:
VADC = G * (VVS − VRS) + [(1 − 2 * DSIGN) *
DAC_CODE
255
*
VMID
2
dependent on the type of sampling selected and the
polarity of the input video signal.
] + VMID
MCLK
Where VADC is the voltage applied, to the ADC
G is the programmed gain
VVS is the voltage of the video sample.
VRS is the voltage of the reset sample,
DSIGN is the Offset DAC sign bit
DAC_CODE is the offset DAC value.
VMID is the WM8143-10 generated VMID voltage.
VSMP
VS
CL
00
RS
CL
01
(default)
The ADC has a lower reference of VRB (typically 1.5 V)
and an upper reference of VRT (typically 3.5 V). When
an ADC input voltage is applied to the ADC equal to
VRB the resulting code is 000(hex). When an ADC input
voltage is applied to the ADC equal to VRT the resulting
code is 3FF(hex).
RS
CL
10
RS
CL
11
RS
Reset Level Clamp
Both CDS and Single Ended operation can be used
with Reset Level Clamping. A typical input
configuration is shown in Figure 4.
Figure 5 Reset Sample and Clamp Timing
For CDS operation it is important to match the clamp
voltage to the amplitude and polarity of the video
signal. This will allow the best use of the wide input
common-mode range offered by the WM8143-10. If the
input video is positive going it is advisable to clamp to
VCL (Lower clamp voltage). If the video is negative
going it is advisable to clamp to VCU (Upper clamp
voltage). Regardless of where the video is clamped the
offset DAC is programmed to move the ADC output
corresponding to the reset level to an appropriate value
to maximise the ADC dynamic range. For Single Ended
operation it is recommended that the clamp voltage is
set to VCM (middle clamp voltage).
WM8143-10
RINP
S/H
+
Cin
Gain=G
VS
S/H
-
RS
VRLC
VMID
Figure 4 Typical Input Configuration Using Reset
VIDEO INPUT
Level Clamping
The position of the clamp relative to the video sample
is shown diagramatically in Figure 6 and is
programmable by CDSREF1-0 (see Table 6). By
default, the reset sample occurs on the fourth MCLK
rising edge after VSMP. The relative timing between the
reset sample (and CL) and video sample can be altered
as shown in Figure 5. When the clamp pulse is active
the voltage on the WM8143-10 side of Cin, i.e. RINP,
will be forced to be equal to the VRLC clamp voltage.
The VRLC clamp voltage is programmable to three
different levels via the serial interface. The voltage to
which the clamp voltage should be programmed is
CLAMP PULSE
Figure 6 Position of Clamp Relative to Video Input
A reset level clamp is activated if the RLC pin is high
on an MCLK rising edge (Figure 7). By default this
initiates an internal clamp pulse three MCLK pulses
later (shown as CL in Figure 5). The relationship
between CL and RS is fixed. Therefore altering the RS
position also alters the CL position (Figure 5). Table 6
shows the three possible voltages to which the reset
level can be clamped.
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WM8143-10
Production Data
to 4 MSPS. This is achieved by altering the
MCLK:VSMP ratio to 3:1. In this mode, the timing of
RS and CL must be fixed (refer to Table 3). The
sampled video data will pass through the internal
pipeline and emerge on the OP[9:0] bus.
MCLK
VSMP
RLC
Input video
1
X
X
0
r,g,b
X
r,g,b
RLC on this pixel
X
0
X
Max. Speed Monochrome Mode (Mode 4)
r,g,b
No RLC on this pixel
Figure 12 summarises the timing relationships. This
mode allows the maximum sample rate to be increased
to 6 MSPS. This is achieved by altering the
MCLK:VSMP ratio to 2:1. The latency through the
device is identical to modes 1 and 2. CDS is not
available in this mode.
Figure 7 RLC Timing
Video Sampling Options
The WM8143-10 can interface to CCD sensors using
six basic modes of operation (summarised in Table 3).
Mode configurations are controlled by a combination of
control bits and timing applied to MCLK and VMSP
pins. The default operational mode is mode 1: colour
with CDS enabled.
Slow Colour Mode (Mode 5)
Figure 13 summarises the timing relationships. This
mode is identical to Mode 1 except that the MCLK to
VSMP ratio is 8 : 1 and the maximum sample rate is
1.5 MSPS. To obtain a ratio of 4:4 between the video
sample position and the reset sample position, Setup
Register 3 CDSREF1-0 control bits b[5:4] should be set
to 10. The first three of the four output words are valid.
Colour Mode Definitions (Mode 1)
Figure 9 summarises the timing relationships. MCLK is
applied at twice the required ADC conversion rate.
Synchronisation of sampling and channel multiplexing
to the incoming video signal is performed by the VSMP
pulse (active high). The three input channels (R,G,B)
are sampled in parallel on the rising edge of MCLK
following a VSMP pulse. The sampled data is
multiplexed into a single data stream at three times the
VSMP rate, passes through the internal pipeline and
emerges on the OP[9:0] bus. Both Correlated Double
Sampling (CDS) and Single Ended Sampling modes of
operation are available.
Slow Monochrome Mode (Mode 6)
Figure 14 summarises the timing relationships. This
mode is identical to mode 2 except that the MCLK to
VSMP ratio is 8 : 1 and the maximum sample rate is
1.5 MSPS. To obtain a ratio of 4:4 between the video
sample position and the reset sample position, Setup
Register 3 CDSREF 1-0 control bits b[5:4] should be
set to 10. The first of the four output words is the only
valid output.
Monochrome Mode Definitions
Input Impedance
One input channel is continuously sampled on the
rising edge of MCLK following a VSMP pulse. The user
can specify which input channel (R,G,B) is to be
sampled by writing to the WM8143-10 internal control
registers. There are four separate monochrome modes
with different maximum sample rates and CDS
availability.
The input impedance of the WM8143-10 is dependent
upon the sampling frequency of the input signal and the
gain that the PGA is set to. This is due to the effective
capacitance of the ‘sample and hold’ circuits (Figure 8).
S/H
Monochrome Mode (Mode 2)
RINP/VMID
PGA
C
Figure 10 summarises the timing relationships. The
timing in this mode is identical to mode 1 except that
one input channel is sampled three times (due to the
multiplexer being held in one position) and passes
through the device as three separate samples. The last
two samples can be ignored at the output OP[9:0].
VMID
VS/RS
Figure 8 Input Impedance S/H Circuit
When the VS/RS control is activated the switch closes
and the effective impedance of the input is 1/CF where
the value of C changes from 0.3pF for minimum gain to
Fast Monochrome Mode (Mode 3)
Figure 11 summarises the timing relationships. This
mode allows the maximum sample rate to be increased
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Production Data
9.6pF for maximum gain and F is the sample frequency
in Hz. Table 2 illustrates the maximum and minimum
input impedance at different frequencies.
SAMPLING
FREQUENCY
(MHz)
IMPEDANCE
(MΩ
Ω ) MIN.
GAIN
IMPEDANCE
(KΩ
Ω ) MAX.
GAIN
0.5
6.6
208
1
3.3
104
2
1.6
52
4
0.8
26
6
0.5
17
Table 2 Effects of Frequency on Input Impedance
Calibration
To achieve optimum performance of the WM8143-10, a
calibration procedure must be implemented. This is
achieved by using a combination of the gain and offset
functions to amplify and shift the input signal so that it
lies within and maximises the input ADC range.
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MODE
DESCRIPTION
CDS
AVAILABLE
MAX.
SAMPLE
RATE
SENSOR INTERFACE
DESCRIPTION
TIMING
REQUIREMENTS
REGISTER
CONTENTS
WITH CDS
REGISTER
CONTENTS
WITHOUT
CDS*
1
Colour
Yes
2MSPS
Three input channels
(R, G, B) are sampled
in parallel at max.
2MSPS. The sampled
data is multiplexed
into a single data
stream before the
internal ADC, giving
an internal serial rate
of max. 6MSPS
MCLK max.
12MHz.
MCLK:
VSMP ratio
is 6:1
Setup Reg. 1:
03(H)
Setup Reg. 1:
01(H)
2
Monochrome
Yes
2MSPS
One input channel is
continuously sampled.
The internal
multiplexer is held in
one position under
control of the user.
Identical to
Mode 1
Setup Reg. 1:
07(H)
Setup Reg. 3:
bits b[7-6]
define which
channel is
sampled
Setup Reg.
1:05(H)
Setup Reg. 3:
bits b[7-6]
define which
channel is
sampled
3
Fast
Monochrome
Yes
4MSPS
Identical to Mode 2
except that max.
sample rate is 4MSPS
MCLK max.
12MHz.
MCLK:
VSMP ratio
is 3:1
Identical to
Mode 2 plus
Setup Reg. 3:
bits b[5-4] must
be set to 00(H)
Identical to
Mode 2
4
Max. Speed
Monochrome
No
6MSPS
Identical to Mode 2
except that max.
sample rate is 6MSPS
MCLK max.
12MHz.
MCLK:
VSMP ratio
is 2:1
Not applicable
Setup Reg.
1:45(H)
Setup Reg. 3:
bits b[7-6]
define which
channel is
sampled
5
Slow Colour
Yes
1.5MSPS
Identical to Mode 1
except that max.
sample rate is
1.5MSPS
MCLK max.
12MHz.
MCLK:
VSMP ratio
is 8:1
Identical to
Mode 1
Identical to
Mode 1
6
Slow
Monochrome
Yes
1.5MSPS
Identical to Mode 2
except that max.
sample rate is
1.5MSPS
MCLK max.
12MHz.
MCLK:
Identical to
Mode 2
Identical to
Mode 2
VSMP ratio
is 8:1
* Only indicates relevant register bits
Table 3 WM8143-10 Mode Summary
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INPUT
Production Data
MCLK
SIGNALS
VSMP
Input r1,g1,b1
video
r2,g2,b2
3
2
INTERNALRS
SIGNALS
r4,g4,b4
r3,g3,b3
1
r5,g5,b5
4
5
3
2
5
4
VS
b0
ADC input
g1
r1
b1
r2
g2
b2
r3
g3
b3
r4
g4
b4
ADC sample
16.5 MCLK periods
OUTPUT
OP[9:0]
SIGNALS
g1
r1
b1
Figure 9 Default Timing in CDS Colour Mode (Mode 1)
MCLK
INPUT
SIGNALS
VSMP
Input r1,g1,b1
video
r2,g2,b2
r4,g4,b4
r3,g3,b3
2
3
r5,g5,b5
4
5
RS
INTERNAL
SIGNALS
1
3
2
5
4
VS
ADC input
X
X
r1
X
X
X
X
X
X
X
ADC sample
16.5 MCLK periods
OUTPUT
OP[9:0] *
X
X
X
X
X
X
r1
X
X
X
SIGNALS
* This example shows function when Red channel selected.
'X' indicates don't care
Figure 10 Default Timing in CDS Monochrome Mode (Mode 2)
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Production Data
MCLK
INPUT
SIGNALS
VSMP
Input video
n
n+1
RS
INTERNAL
SIGNALS
VS
n
ADC input
ADC sample
23.5 MCLK periods
OUTPUT
SIGNALS
n
OP[9:0]
* This example shows function when Red channel selected.
Figure 11 Default Timing in Fast CDS Monochrome Mode (Mode 3)
MCLK
INPUT
SIGNALS VSMP
Input video
INTERNAL
SIGNALS VS
ADC input
n
1
n
ADC sample
16.5 MCLK periods
OUTPUT
n
OP[9:0]
SIGNALS
* This example shows function when Red channel selected.
Figure 12 Default Timing in Max. Speed non-CDS Monochrome Mode (Mode 4)
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Production Data
MCLK
INPUT
SIGNALS
VSMP
Input r1,g1,b1
video
r2,g2,b2
r4,g4,b4
r3,g3,b3
3
2
r5,g5,b5
4
5
RS
INTERNAL
SIGNALS
1
3
2
4
5
VS
ADC input
b0
r1
g1
b1
X
r2
g2
b2
X
r3
g3
b3
X
r4
g4
b4
X
ADC sample
16.5 MCLK periods
OUTPUT OP[9:0]
SIGNALS
r1
g1
b1
X
'X' indicates an invalid output
Figure 13 Default Timing in Slow CDS Colour Mode (Mode 5)
INPUT
MCLK
SIGNALS
VSMP
Input r1,g1,b1
video
r2,g2,b2
3
2
INTERNAL RS
SIGNALS
r4,g4,b4
r3,g3,b3
1
r5,g5,b5
5
4
5
4
3
2
VS
ADC input
b0
r1
X
X
X
r2
X
X
X
r3
X
X
X
r4
X
X
X
ADC sample
16.5 MCLK periods
OUTPUT
OP[9:0]
SIGNALS
r1
X
X
X
This example shows function when Red channel selected. 'X' indicated invalid output.
Figure 14 Default timing in Slow Monochrome Mode (Mode 6)
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Production Data
It is expected that this would be achieved on system
power-up by attaching a simple RC network to the
NRESET pin. The RC network should delay the set-up
on the NRESET pin until the other conditions have
been established. This feature is only activated on a
hardware reset (using the NRESET pin). The software
reset does not sample SEN/STB.
Applications Recommendations
Output Data Interface
By default, data is output from the device as a ten-bit
wide word on OP[9:0]. Optionally, data can be output in
an eight-bit word format. Figure 15 shows this function.
Data is presented on pins OP[9:2] at twice pixel rate.
Controlling the WM8143-10
In mode 3, the output is spread over three MCLK
periods. The first two periods contain byte A data and
the third period has byte B data. Either of the two byte
A data periods are valid.
The WM8143-10 can be configured through a serial
interface or a parallel interface. Selection of the
interface type is by the SEN/STB pin which must be
tied high (parallel) or low (serial) as shown in Table 4.
Serial Interface
MCLK
OP[9:2]
A
The serial interface consists of three pins (refer to
Figure 16). A six-bit address is clocked in MSB first
followed by an eight-bit data word, also MSB first. Each
bit is latched on the rising edge of SCK. Once the data
has been shifted into the device, a pulse is applied to
SEN to transfer the data to the appropriate internal
register.
B
Figure 15 Eight-bit Multiplexed Bus Output
•
A =d9,d8,d7,d6,d5,d4,d3,d2 - First byte
•
B =d1,d0,X,X,PNS,CC1,CC0,ORNG - Second byte
•
PNS : This bit shows if the device is configured in
parallel or serial mode. 1 = Parallel, 0 = Serial.
•
CC1/CC0 : These bits show which channel the
current output was taken from. 00 = RED, 01 =
GREEN, 10 = BLUE.
•
ORNG : This bit indicates if the current output pixel
has exceeded the maximum or minimum range
during processing. 1 = out of range, 0 = within range.
•
Parallel Interface
The parallel interface uses bits [9:2] of the OP bus as
well as the STB, DNA and RNW pins (refer to Figure
17). Pin RNW must be low during a write operation.
The DNA pin defines whether the data byte is address
(low) or data (high). The data bus OP[9:2] is latched in
during the low period of STB.
Internal Register Definition
Table 5 summarises the internal register content. The
first 5 addresses in the table are used to program setup
registers and to provide a software reset feature (00H
is reserved). The remaining 3 entries in the table define
the address location of internal data registers. In each
case, a further three sub-addresses are defined for the
red, green and blue register. Selection between the red,
green and blue registers is performed by address bits
a1 and a0, as defined in the table. Setting both a1 and
a0 equal to 1 forces all three registers to be updated to
the same data value. Blank entries in Table 5 should be
programmed to zero.
X: This is an invalid output.
Control Interface Selection
WM8143-10 can be controlled via a serial or parallel
interface. The decision on which interface is to be used
is made on the sense of the SEN/STB pin on the rising
edge of the NRESET signal.
SEN/STB
CONDITION
MODE
0
NRESET rising edge
Serial Interface
1
NRESET rising edge
Parallel Interface
Table 4 WM8143-10 Interface Set-up
SCK
SDI
a5 a4 a3 a2 a1 a0 b7 b6 b5 b4
SEN
Address
b3 b2 b1 b0
Data Word
Figure 16 Serial Interface Timing
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Production Data
Figure 17 Parallel Interface Timing
STB
Address
OP[9:2]
Data
DNA
RNW
ADDRESS
<a5:a0>
DESCRIPTION
000000
Reserved
000001
Setup
DEFAULT
(HEX)
BIT
b7
03
b6
b5
b4
VSMP6M
b3
b2
b1
b0
MONO
CDS
ENADC
Register 1
000010
Setup
00
INVOP
MUXOP
Register 2
000011
Setup
11
CHAN[1]
CHAN[0] CDSREF[1] CDSREF[0]
RLC[1]
RLC[0]
Register 3
000100
Software
Reset
00
000101
Setup
Register 4
00
1000a1a0
DAC Values
00
1001a1a0
DAC Signs
00
1010a1a0
PGA Gains
00
DACRNG
DAC[7]
DAC[6]
DAC[5]
DAC[4]
DAC[3] DAC[2]
DAC[1]
DAC[0]
DSIGN
PGA[4]
ADDRESS LSB
DECODE
a1
a0
Red Register
0
0
Green Register
0
1
Blue Register
1
0
Red, Green and
Blue
1
1
PGA[3] PGA[2]
PGA[1]
PGA[0]
Table 5 Register Map Contents
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Production Data
REGISTER
BIT NO
BIT NAMES(S)
DEFAULT
DESCRIPTION
Setup Register 1
0
ENADC
1
ADC Standby Control: 0 = Standby, 1 = Active
Address ,<a5:a0>
000001
1
CDS
1
Correlated Double Sampling Mode:
0 = Single Ended Mode, 1 = CDS Mode
2
MONO
0
Mono/Colour Select:
0 = Colour, 1 = Monochrome Operation
6
VSMP6M
0
Required when operating in Mode 4:
0 = Other Modes, 1 = Mode 4
Setup Register 2
Address ,<a5:a0>
000010
0
MUXOP
0
Eight Bit Output Mode: 0 = 10-bit, 1 = 8-bit Multiplexed
2
INVOP
0
Inverts ADC Output: 0 = Non-inverting, 1 = Inverting
Setup Register 3
Address ,<a5:a0>
000011
1-0
RLC1-0
01
Reset Level Clamp Voltage:
00 = 1.5V
01 = 2.5V
10 = 3.5V
11 = Reserved
5-4
CDSREF1-0
01
CDS Mode Reset Timing Adjust:
00 = Advance 1 MCLK Period
01 = Normal
10 = Retard 1 MCLK Period
11 = Retard 2 MCLK Periods
7-6
CHAN1-0
00
Monochrome Mode Channel Select:
00 = Red channel
01 = Green channel
10 = Blue channel
11 = Reserved
Setup Register 4
Address ,<a5:a0>
000101
1
DACRNG
0
Offset DAC Output Range:
0 = DAC Output Range = Vmid/2 = +/-1.25V
1 = DAC Output Range = 1.5 ∗(Vmid/2) = +/-1.875V
Table 6 Control Bit Descriptions
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Production Data
Detailed Timing Diagrams
MCLK
tDSU
tDSU
tDH
tDH
VSMP, RLC
tVSU
tVH
tVSU
tVH
tVSU
tVH
tVSU
tVH
tVSU
tVH
R,G,B Video Inputs
(Default Mode)
tVSU
tVH
tVSU
tVH
R,G,B Video Inputs
(CDSREF[1]=0,CDSREF[0]=0)
tRSU
R,G,B Video Inputs
(CDSREF[1]=0,CDSREF[0]=1)
tVSU
tRH
tVH
tRSU
R,G,B Video Inputs
(CDSREF[1]=1,CDSREF[0]=0)
tVSU
tVH
tRH
tRSU
R,G,B Video Inputs
(CDSREF[1]=1,CDSREF[0]=1)
tRH
tRSU
tRH
Figure 18 Detailed Video Input Timing - Modes 1 and 2
MCLK
tDSU
tDH
tDH
tDSU
VSMP, RLC
tVSU
tVSU
tVH
tVH
R,G,B Video Inputs
(CDSREF[1]=0,CDSREF[0]=0)
tRSU
tRH
Figure 19 Detailed Video Input Timing - Mode 3
MCLK
tDSU
tDH
VSMP, RLC
tVSU
R,G,B Video Inputs
RESET
tVH
tVSU
tVH
VIDEO
Figure 20 Detailed Video Input Timing - Mode 4
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Production Data
MCLK
tDSU
tDSU
tDH
tDH
VSMP, RLC
R,G,B Video Inputs
(CDSREF[1]=0,CDSREF[0]=0)
tVSU
tVH
tVSU
tVH
tRSU
R,G,B Video Inputs
(CDSREF[1]=0,CDSREF[0]=0)
tVSU
tRH
tVH
R,G,B Video Inputs
(CDSREF[1]=0,CDSREF[0]=0)
tRSU
tVSU
R,G,B Video Inputs
(CDSREF[1]=0,CDSREF[0]=0)
tRH
tVH
tRSU
tRH
tRSU
tVSU
tVH
tVSU
tVH
tVSU
tVH
tVSU
tVH
tRH
Figure 21 Detailed Video Timing - Modes 5 and 6
tCKH
tCKL
tPER
MCLK
tDH
tDSU
VSMP, RLC
tPD
OP[9:0]
RED
GREEN
BLUE
Figure 22 Detailed Digital Timing - Modes 1 and 2
tCKH
tCKL
tPER
MCLK
tDSU
VSMP, RLC
tDH
tDSU
tDH
tPD
t PD
OP[9:0]
Figure 23 Detailed Digital Timing – Mode 3
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WM8143-10
Production Data
tCKH
tCKL
tPER
MCLK
tD
H
tDS
U
VSMP, RLC
tD
H
tDS
U
tPD
t PD
OP[9:0]
Figure 24 Detailed Digital Timing – Mode 4
tCKH
tCKL
tPER
MCLK
tDSU
tDH
VSMP, RLC
tPD
OP[9:0]
X
RED
X
BLUE
GREEN
'X' Indicates Invalid
Output
Figure 25 Detailed Digital Timing – Modes 5 and 6
tSCKH
tSPER
tSCKL
SCK
tSH
tSSU
SDI
tSCE
tSEW
tSEC
SEN
Figure 26 Detailed Timing Diagram for Serial Interface
tSTB
STB
OP[9:2]
tASU
Data Out
Z
tSTB
tAH
Address In
tADLS
tDH
tDSU
Z
Data In
tADLH
tADHS
Data Out
tADHH
DNA
RNW
tOPZ
tOPD
Figure 27 Detailed Timing Diagram for Parallel Interface
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WM8143-10
Production Data
SEN/STB
OEB
RINP
GINP
BINP
VRLC
23
22
21
20
19
VMID
SDI/DNA
24
Applications Diagram
SCK/RNW
25
16
RLC
26
15
VSMP
27
MCLK
28
DGND
14
WM8143-10
VRU
AGND
AVDD
7
8
OP[6]
OP[7]
1
6
OP[8]
OP[5]
9
5
32
OP[4]
OP[9]
4
10
OP[3]
NRESET
31
3
30
nc
OP[2]
nc
11
OP[1]
OP[0]
+ 10µF
DGND
AVDD
12
DVDD
100nF
13
Note: AGND and DGND should
be starpointed as close as
possible to the AGND pins
100nF
VRB
29
2
DVDD
+ 10µ F
17
18
+ 22µ F
100nF
VRT
+ 10µF
+ 10µ F
+ 10µF
100nF
100nF
100nF
+ 10µF
100nF
AGND
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WM8143-10
Production Data
Package Dimensions
0.45
0.30
0.80 BSC
0.20 M
17
24
25
16
32
9
0.20
0.09
1
8
7.00 BSC
Gauge Plane
9.00 BSC
0.25
1.45
1.35
0.15
0.05
0o - 7o
0.75
0.45
Seating Plane
0.10
1.60MAX
DM002.a 32-pin TQFP
Notes:
A. All linear dimensions are in milimeters
B
The drawing is subject to change without notice
C
Falls within JEDEC MS-026. Refer to this specification for further details.
Last page of WM8143-10 Datasheet
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