WINBOND W6662CF

Preliminary W6662CF
SCANNER ANALOG FRONT END
1. GENERAL DESCRIPTION
The W6662 is a highly integrated CCD/CIS analog front end signal processor. It provides the
components required for all necessary front-end signal process of a CCD/CIS scanner, including a 3channel input clamp circuit for correlated double sampling (short as CDS) mode, a multiplexer to mux
3-channel inputs to a correlated double sampling (CDS) circuit, a programmable offset adjusted and
gain controlled amplifier, a 12-bit analog-to-digital converter.
CDS or S&H (sample and hold) of operation modes can be chosen. The device configuration is
programmed via 3-wire or 4-wired interface, operation modes, offset and gain value of each channel
can be programmed.
2. FEATURES
• 12-bit A/D Converter
• No Missing Code Guaranteed
• Three channels analog input with clamp circuit individually
• Integrated Correlated Double Sampler (CDS)
• Supports Contact Image Sensors (CIS)
• Accept CCD/CIS sensor with three channel or single channel analog out
• External offset voltage input for CIS reference voltage
• Built-in bandgap reference circuit for CDS mode and A/D Converter
• Integrated 6-bit Programmable Gain Amplifier (PGA) with 3-channel register selected
• Integrated 8-bit offset adjustment with 3-channel register selected
• 3 MHz sampling rate of offset/gain adjustment circuit
• Three-wired or four-wired Serial Interface programmable
• Registers readback capability
• Low power CMOS device
• Power down mode supported
• 3/5V digital I/O pin
• Packageed in 48-pin QFP
Applications:
Flatbed Scanners
Sheetfeed Scanners
Film Scanners
-1-
Publication Release Date: December 1998
Revision A1
Preliminary W6662CF
DOUT11
DOUT10
DOUT9
AVDD
45
OEN
VRDT
46
AVSS
VRDT
47
AVDD
VRDB
48
NC
VRDB
3. PIN CONFIGURATION
44
43
42
41
40
39
38
37
36
1
VREF
2
35
AVSS
VINR
3
34
DOUT8
AVSS
4
33
DOUT7
VING
5
32
DOUT6
AVSS
6
VINB
7
AVSS
8
NC
9
W6662CF
Winbond
VRDC
NC
31
DOUT5
30
DOUT4
29
DOUT3
28
DOUT2
20
21
22
23
SDO/SMS
19
SDI/SDIO
18
25
24
SCLK
17
SEL1
16
SEL0
15
DRVDD
PAOUTN
14
NC
12
13
DRVSS
DOUT0
PAOUT
ADCCLK
DOUT1
26
CDSCK2
27
11
AVDD
CDSCK1
10
CISREF
SEN
Fig. 3-1 Pin Assignments.
4. BLOCK DIAGRAM
CISREF
VREF
VRDC
VRDB VRDT
Bandgap Reference Circuit
OEN
CDS
VINR
Clamp
MUX
VING
Clamp
CDS
Process
Gain/Offset
Adjust
12-bit
ADC
I/P MUX
Ctrl
Weak
Drive
DAC
VINB
MUX
MUX
R
R
G
G
B
B
Clamp
Configuration
Register
ADCCLK
Fig. 4 The Block Diagram of W6662 Device.
-2-
PAOUT
PAOUTN
SCLK
Serial
I/O port
control
Gain
Offset
Registers Registers
CDSCK1 CDSCK2 SEL0 SEL1
DOUT[11:0]
SEN
SDI/SDIO
SDO/SMS
Preliminary W6662CF
5. PIN DESCRIPTIONS
PIN
NAME
TYPE
DESCRIPTION
10, 37, 44
AVDD
AP
Analog Power Supply.
4, 6, 8, 35, 42
AVSS
AP
Analog Ground.
45, 46
VRDT
AO
Voltage Reference Decoupling (Top).
47, 48
VRDB
AO
Voltage Reference Decoupling (Bottom).
1
VRDC
AO
Voltage Reference Decoupling (Center).
2
VREF
AO
Internal Reference Output.
3
VINR
AI
Analog Input, Red Channel.
5
VING
AI
Analog Input, Green Channel.
7
VINB
AI
Analog Input, Blue Channel.
11
CISREF
AI
Reference Voltage Input when CIS input.
12
PAOUT
AO
PGA Output, low speed analog monitor output for test only.
13
PAOUTN
AO
PGA Output (negative), low speed analog monitor output for
test only.
14
CDSCK1
DI
CDS Clock 1 (Schmitt Trigger Input), Reset Level Sampling
Clock.
15
CDSCK2
DI
CDS Clock 2 (Schmitt Trigger Input), Data Level Sampling
Clock.
16
ADCCLK
DI
A/D Converter Sampling Clock (Schmitt Trigger Input).
19
DRVDD
DP
Digital Driver Power Supply.
17
DRVSS
DP
Digital Driver Ground.
20
SEL0
DI
Channel Select bit 0.
21
SEL1
DI
Channel Select bit 1.
22
SCLK
DI
Clock Input of Serial Interface (Schmitt Trigger Input).
23
SDI/SDIO
DI/DO
24
SDO/SMS
DI, DO Serial Interface of Data Output, Serial Interface Mode
Select.
25
SEN
DI
Enable Signal of Serial Interface, Active Low.
26:34
DOUT[0:8]
DO
Data Output Bit, DOUT0 is LSB.
38:40
DOUT[9:11]
DO
Data Output Bit, DOUT11 is MSB.
41
OEN
DI
Output Enable, Active Low.
Serial Interface of Data Input or Serial Interface of Data
Input/Output.
Type: AP is Analog Power, AI is Analog Input, AO is Analog Output, DP is Digital Power, DI is Digital Input, DO is Digital
Output.
-3-
Publication Release Date: December 1998
Revision A1
Preliminary W6662CF
6. FUNCTIONAL DESCRIPTIONS
Figure 4 is the block diagram of W6662, it consists of three channel clamp circuit for CDS mode, a
multiplexer to mux 3-channel inputs and outputs to a correlated double sampling (CDS), a
programmable gain control and offset adjustment amplifier, a 12-bit analog-to-digital converter.
Bandgap reference circuit generate voltage reference signals for input signals clampping and
correlated sampling use (in CDS mode), for offset D/A converter and output A/D converter use. The
select signals SEL1 and SEL0 are used to select the offset registers and gain registers, the input
channels may be selected simultaneously.
6.1 Clamp Circuit
The capacitor between the output of CCD/CIS device and W6662 is used to block the DC voltage
(even as high voltage). The clamp circuit is used to remove unwanted common-mode voltage in the
input pixel data and to get a maximum input signal span when the input is driven by CCD device as
shown in Figure 6-1. The input pins of W6662 are clampped to a internal offset voltage while valid
pixel signal is input. The clamp switches at three channels of figure 6-1 are turn on whenever
CDSCK1 goes high. Figure 6-2 shows the waveform between output of CCD device and input of
W6662, the voltage change on the capacitor will be clampped.
The value of input capacitor is calculated as follows:
tCLP
CMAX =
(RON + RCCDS) × ln (VC/VCLPTolerance)
IBIAS × tC2I
CMIN =
dV
where
CMAX is the maximum capacitor value.
CMIN is the minimum capacitor value.
tCLP is the high pulse width of the CDSCK1 clock input.
RON is switch resistance during clampping and is equivalent to 5K.
RCCDS is the source resistance of CCD device.
VC is the voltage change on the input capacitor must be clampped.
VCLPTolerance is the tolerance voltage error at the end of clampping.
IBIAS is the input leakage current on the input of the W6662 device.
dV is the maximum voltage drift on the input of the W6662 device.
tC2I is the time stamp from the end of clampping point to the acture input data sampling point, equal
to tC2S + tSPD + tACD or may be approximated as conversion time tCVR.
-4-
Preliminary W6662CF
If input capacitor value is specified as CIN, the following is the equation to calculate how many lines
are required before the capacitor settles to the desired accuracy after power is up:
(RON + RCCDS) × CIN
LN =
PIXN × tCLP
ln (VOFS/VCLPTolerance )
where
LN is line number.
PIXN is the total pixel number in one line.
CIN is the input capacitor value, 0.01 µF is suggestion value.
VOFS is the internal offset voltage to be clampped on the input terminal of the input capacitor.
CCD Device
RCCDS
(Pixel n)
W6662
CIN
IBIAS
Output
signal
from CCD
Input to MUX
(Pixel n+1)
VC
VDATAn+1
VDATAn
t CLP
0.01uF
RON = 5K
VOFS
on when
CDSCK1= high
Input
signal
to W6662
VC
VDATAn
V CLPTolerance
V DATAn+1
VOFS
Fig. 6-2 CCD Input Clamp Waveform.
Fig. 6-1 Equivalent Circuit of Clampping.
6.2 MUX and Channel Select
The analog input signal may be three channels or single channel and is specified in configuration
register. Three channel input or single channel input are described as follows:
The three channel input is used for red, green and blue analog signal input, selected by SEL1 and
SEL0 signals. The channel select signals SEL1 and SEL0 may be 01, 10, 11 and listed as follows:
SEL1 = 0, SEL0 = 1 is red channel input selected, red channel of gain register and offset register also
selected.
SEL1 = 1, SEL0 = 0 is green channel input selected, green channel of gain register and offset register
also selected.
SEL1 = 1, SEL0 = 1 is blue channel input selected, blue channel of gain register and offset register
also selected.
SEL1 = 0, SEL0 = 0 is reserved.
The one channel input is used for black and white CCD/CIS sensor or multiplexed color CCD/CIS
sensor output. Any channel input of red, green or blue can be used, other un-used analog input must
tight to VSS in S & H mode. The channel select signals SEL1 and SEL0 is used to select offset
register and gain register only and may be 01, 10, 11, described as follows:
-5-
Publication Release Date: December 1998
Revision A1
Preliminary W6662CF
SEL1 = 0, SEL0 = 1 is red channel of gain register and offset register selected.
SEL1 = 1, SEL0 = 0 is green channel of gain register and offset register selected.
SEL1 = 1, SEL0 = 1 is blue channel of gain register and offset register selected.
SEL1 = 0, SEL0 = 0 is reserved.
6.3 CDS vs S&H Mode
"CDS" stands for "correlated double sampling". It is used to reduce noise generated in CCD source
and to decrease the sampling error which induced from clampping voltage error. CDS takes two step
to sample a CCD's output pixel. In the first step, the reset level of CCD output is sampled and hold by
S/H1 at the falling edge of CDSCK1 signal. In the second step, the data signal of CCD output is
sampled and hold by S/H2 at the falling edge of CDSCK2 signal. The CDS output voltage is obtained
from the voltage difference of the outputs of S/H1 and S/H2.
In S&H mode, the data signal of CIS output is sampled and hold by S/H1 at the falling edge of
CDSCK2 signal and the output voltage is obtained from the voltage difference of the outputs of S/H1
and CISREF pin. Figure 6-3 shows the equivalent circuits of CDS and S&H mode processing.
From
I/P
MUX
+
S/H1
CDSCK1
S/H2
(a) CDS Mode.
From
I/P
MUX
CDSCK2
+
S/H1
CDSCK2
From
CISREF
pin
-
To
Gain/Offset
Adjust
-
To
Gain/Offset
Adjust
(b) S&H Mode.
Fig. 6-3 The Equivalent Circuit of CDS and S&H Mode.
6.4 Gain/Offset Adjustment
The analog input signal after CDS or S&H processed is amplified by PGA gain adjustment and then
shifted by offset value. The offset value will not affected by the PGA gain adjustment.
-6-
Preliminary W6662CF
PGA Gain Adjustment
"PGA" stands for "programmable gain amplifier", it can provide analog gain for "not enough level for
A/D converter" input signals. The gain value is converted from PGA_code of gain register and is
selected by channel select SEL1 and SEL0. The gain formula is:
PGA_code
analog gain = 1 +
12
PGA_code = 0−63 and the gain = 1−6.25.
Offset Adjustment
The analog signal level can be shifted by offset level and to get maximum linear region. The offset
level is converted from offset value by internal D/A converter and the offset value is selected by
channel select SEL1 and SEL0.
The mapping between offset register code and offset value is as follows:
OFFSET REGISTER
1111 1111 (LSB)
:
:
1000 0001
1000 0000
0000 0000
0000 0001
:
:
0111 1111
OFFSET VALUE
+200 mV
:
:
+1.6 mV
0.0 mV
0.0 mV
-1.6 mV
:
:
-200 mV
6.5 Analog Monitor
The analog differential signal of PAOUT and PAOUTN is used to monitor the output waveform after
gain and offset adjustment process. The CCD or CIS pixel rate must operate below or equal 1MHz
and at most one probe loading on the PAOUT and PAOUTN to get a correct voltage output. In normal
operation, the PAOUT and PAOUTN must be turned off by writting a specified bit on the configuration
register to avoid the interference of noise and extra capacitance loading.
6.6 Internal Registers
The registers in the W6662 is configuration register, three channel offset registers and three channel
gain registers, these registers are addressed by A2, A1 and A0. The registers can be read or modified
through 3-wired or four-wired serial interface. During address phase, if SDO/SMS pin is low, threewired is selected, the three-wired interface are SEN, SCLK and SDIO signals, if SDO/SMS pin is
high, four-wired interface is selected, the four-wired interface are SEN, SCLK SDI and SDO signals.
Figure 6-4 shows the setting of the serial interface. For three-wired interface setting, the SDO/SMS
pin must connected to VSS. For four-wired interface, it only need to connect a pull high resistor on the
SDO/SMS pin. The signal format on the serial interface is listed as follows:
-7-
Publication Release Date: December 1998
Revision A1
Preliminary W6662CF
R/W
A0
A1
A2
--
--
--
--
D0
D1
D2
Address phase
D3
D4
Data phase
R/W is read (high) or write (low) command to access the register.
A0, A1 and A2 is the address select bits of the register.
D0 throuth D7 is the data bit of the register, D7 is MSB and D0 is LSB.
The address of the registers is:
A2
A1
A0
0
0
0
0
1
1
1
0
0
1
1
0
0
1
0
1
0
1
0
1
0
Configuration Register
Red PGA Register
Green PGA Register
Blue PGA Register
Red Offset Register
Green Offset Register
Blue Offset Register
REGISTER
1
1
1
Reserved
Configuration Register
The bit definition of configuration register is:
A. Configuration mode (wake up and configuration)
bit 0 = 0: 1.5V input span.
1: 3.0V input span.
bit 1 = 0: S&H mode.
1: CDS mode.
bit [3:2] = 0 0: Red channel input only.
0 1: Green channel input only.
1 0: Blue channel input only.
1 1: Three channels input and selected by SEL1 and SEL0 signals.
bit 4 = Reserved (must set to 0).
bit 5 = 0: PAOUT and PAOUTN enable.
1: PAOUT and PAOUTN disable.
bit 6 = Reserved (must set to 0).
bit 7 = 0.
-8-
D5
D6
D7
Preliminary W6662CF
B. Power down mode
bit [6:0] = don't care.
bit 7 = 1.
The CDSCK1, CDSCK2, ADCCLK and SCLK must hold at stable state after power down mode has
been configured to ensure the W6662 is in low power state. The system must wait at least 10 mS to
ensure that the device is power up completedly if the configuration register is programmed with bit 7
= 0.
PGA Registers
The mapping of PGA registers and PGA_code is:
bit [5:0] PGA_code, bit 5 is MSB, bit 0 is LSB.
bit [7:6] reserved (must set to 0).
The offset registers are described in PGA gain/offset adjustment section.
W6662
SCLK
chip select
SEN
SDIO
Micro-controller
or
System Controller
or
Core Chip
SMS
May drive another peripherals
(a). Three-wired Interface Mode Selected.
W6662
SCLK
chip select
SEN
SDI
Micro-controller
or
System Controller
or
Core Chip
SDO
DRVDD
(b). Four-wired Interface Mode Selected.
May drive another peripherals
Fig. 6-4 Configuration Serial Interface Modes.
-9-
Publication Release Date: December 1998
Revision A1
Preliminary W6662CF
7. ELECTRICAL CHARACTERISTICS
7.1 Maximum Ratings*
PARAMETER
SYMBOL
RATING
UNITS
Supply Voltage with respect to AVSS (at AVDD pin)
VAVDD
-0.3 to 6
V
Supply Voltage with respect to DRVSS (at DRVDD
pin)
VDRVDD
-0.3 to 6
V
-0.3 to VAVDD + 0.3
V
-0.3 to VDRVDD + 0.3
V
0 to 10
mA
TST
-65 to 150
°C
SYMBOL
RATING
UNIT
VAVDD
4.75 to 5.25
V
VDRVDD
3.0 to 5.25
V
TOP
0 to 70
°C
Voltage on any pin other than VAVDD supplies
Voltage on any pin other than VDRVDD supplies
Current at any pin other than supplies
Storage Temperature
* Exceeding these values may cause permanent damage.
7.2 Recommended Operating Conditions
PARAMETER
Operation Voltage (referenced to AVSS pin)
Operation Voltage (referenced to DRVSS pin)
Operation Temperature
7.3 Power Supply Characteristics
PARAMETER
CONDITION
SYMBOL
Standby Supply Current
Power Supply
IDDQ
Operating Supply Current
(VDD = 5.0V)
IDD
MIN.
TYP‡
30
MAX.
UNITS
TEST
0.1
mA
Test 1
40
mA
Test 2
‡: Typical figure are at VDD = 5V and temperature = 25° C and are for design aid only, not guaranteed and not subject to
production testing.
Test 1: All input pins are VDD or VSS, include CDSCK1, CDSCK2, ADCCLK and SCLK, OEN and SEN are VDD, configure as
power down mode, output without loading.
Test 2: No analog input, CDS mode configured, 2 MHz pixel rate, PAOUT and PAOUTN disabled and output without loading.
7.4 Digital Characteristics
TYP‡
PARAMETER
CONDITION
SYM.
MIN.
Output High Sourcing Current
(VDRVDD = 5V)
IOH
0.5
mA
1
Output Low Sinking Current
(VDRVDD = 5V)
IOL
0.5
mA
2
High Level Input Voltage
(VDRVDD = 5V)
VIH
2.0
V
3
Low Level Input Voltage
(VDRVDD = 5V)
VIL
0.8
V
3
Schmitt Input High Threshold
Voltage
(VDRVDD = 5V)
VT+
2.2
V
4
- 10 -
MAX.
UNITS NOTES
Preliminary W6662CF
7.4 Digital Characteristics, continued
PARAMETER
Schmitt Input Low Threshold
Voltage
CONDITION
SYM.
MIN.
(VDRVDD = 5V)
VT-
0.8
Input Current
Iin
Input Capacitance
Cin
TYP‡
MAX.
UNITS NOTES
V
4
µA
1
10
pF
‡: Typical figure are at VDD = 5V and temperature = 25° C and are for design aid only, not guaranteed and not subject to
production testing.
Notes:
1: VOH = 0.9 VDRVDD.
2: VOL = 0.1 VDRVDD.
3. All digital input pin, CDSCK1, CDSCK2, ADCCLK and SCLK are exclusive.
4. CDSCK1, CDSCK2, ADCCLK and SCLK schmitt trigger input pins.
7.5 Analog Characteristics (measures from analog input to ADC output)
PARAMETER
SYM.
MIN.
SPS
3
TYP‡
MAX.
UNITS
TEST CONDITIONS
Analog to Digital Converter
Maximum Conversion Rate
MHz
Resolution
12
Bits
Integral Nonlinearity
INL
+/- 4
LSB
Differential Nonlinearity
DNL
+/- 1
LSB
Gain Error
ADGERR
2.7%
FSR
Note 1
Offset Error
ADOFERR
2.7%
FSR
Note 1
6.25
V/V
PGA & Offset DAC
PGA Gain Range
G
PGA Gain Resolution
GRES
Offset Range
OFS
Offset Resolution
1
64
-200
200
OFSRES
256
VREF
+/1.5%
steps
Note 2
mV
VAVDD = 5.0V
steps
Note 2
Bandgap Reference
Voltage Reference Tolerance
(VREF = 1.5V or 0.75V)
+/2.0%
VAVDD = 5.0V
Analog Input and Output
Linear Region of Analog Input
Vin
Input Capacitance
Cin
Input Leakage Current
IBIAS
0
3
10
pF
0.01
Total Output Noise at PGA
4
- 11 -
V
µA
LSB
Publication Release Date: December 1998
Revision A1
Preliminary W6662CF
7.5 Analog Characteristics (measures from analog input to ADC output), continued
PARAMETER
Signal to Noise Ratio
SYM.
TYP‡
MIN.
SNR
MAX.
57
UNITS
TEST CONDITIONS
dB
Note 3
from analog I/P to ADC O/P
‡: Typical figure are at VDD = 5V and temperature = 25° C and are for design aid only, not guaranteed and not subject to
production testing.
Notes:
1: 3V input span configured, PGA gain = 1, offset = 0 and measures from analog input to ADC output.
2: All steps of PGA gain and offset are monotonic.
3. 3V input span configured and analog 3V signal range.
7.5.1 Analog Characteristics (measures from ADC input to ADC output)
PARAMETER
SYM.
MIN.
SPS
3
TYP.
MAX.
UNITS
TEST CONDITIONS
Analog to Digital Converter
Maximum Conversion Rate
MHz
Resolution
12
Bits
Integral Nonlinearity
INL
+/- 1.5
LSB
Note
Differential Nonlinearity
DNL
+/- 1
LSB
Note
Note: This is measured on the engineer sample and do not subject to production testing.
7.6 Timing Characteristics
PARAMETER
SYM.
MIN.
TYP.
MAX.
UNITS
Conversion Rate
tCVR
332
nS
ADCCLK High pulse width
tADCH
166
nS
ADCCLK Low pulse width
tADCL
166
nS
Clamp pulse width
tCLP
40
nS
Sample data pulse width
tSPD
40
nS
Clamp to Sample
tC2S
20
nS
Sample data to ADC Convert
tS2AD
80
nS
ADC Convert to Clamp
tS2C
tS2AD+20
nS
Analog signal Capture Delay of
CDS clocks
tACD
10
nS
Clock Input Requirement
- 12 -
NOTES
Preliminary W6662CF
7.6 Timing Characteristics, continued
PARAMETER
SYM.
MIN.
TYP.
MAX.
UNITS
NOTES
Data Output
Digital Output Delay
tDOD
40
nS
Output Enable to Data Delay
tOED
20
nS
Output Disable to Data tri-state
tODZ
20
nS
3
ADCCLKcycles
24
MHz
Digital Output Latency
Serial Interface
Maximum SCLK Frequency
f SCLK
SEN to SCLK set-up time
tSES
10
nS
SCLK to SEN hold time
tSEH
10
nS
SDI input to SCLK set-up time
tSIS
15
nS
SCLK to SDI input hold time
tSIH
10
nS
SCLK falling to SDO output
enable time
tSOE
10
nS
SDO output delay time
tSOD
15
nS
SEN to SDO output tri-state
delay time
tSOZ
10
nS
Analog
input
(PIXn)
(PIXn+1)
(PIXn+2)
(PIXn+3)
(PIXn+4 )
tACD
tCLP
tACD
tCVR
CDSCK1
tS2C
tC2S
tSPD
CDSCK2
tS2AD
tADCL
ADCCLK
tDOD
tADCH
DOUT
(PIXn-5)
(PIXn-4)
Latency
(PIXn-3)
0
(PIXn-2)
1
(PIXn-1)
2
(PIXn)
3
Fig. 7-1 Timing of CDS Mode.
- 13 -
Publication Release Date: December 1998
Revision A1
Preliminary W6662CF
(PIXn+1)
(PIXn)
(PIXn+2)
(PIXn+3)
(PIXn+4)
Analog
input
tACD
CDSCK1
tSPD
tCVR
CDSCK2
tS2AD
tADCL
ADCCLK
tDOD
tADCH
(PIXn-5)
DOUT
(PIXn-4)
Latency
(PIXn-3)
(PIXn-2)
0
1
(PIXn-1)
2
(PIXn)
3
Fig. 7-2 Timing of S&H Mode.
ADCCLK
tDOD
high-Z
DOUT
tOED
tODZ
OEN
Fig. 7-3 Output Enable Timing.
SCLK
tSIH
tSIS
tSIS
tSIH
1/fSCLK
SDI/
SDIO
SEN
A0
A1
A2
D0
D1
D2
D3
D4
D5
D6
tSES
D7
tSEH
Fig. 7-4 Serial Interface Write Timing (3-wired or 4-wired Interface).
- 14 -
Preliminary W6662CF
SCLK
tSIH
tSIS
1/fSCLK
SDIO
(input)
A0
A1
A2
high-Z
tSOD
tSOE
tSIS
SDIO
(output)
D0
D1
D2
D3
D4
D5
D6
D7
high-Z
tSOZ
SEN
tSES
tSEH
Fig. 7-5 Serial Interface Read Timing in 3-Wired Interface (SMS = low).
SCLK
tSIH
tSIS
1/fSCLK
A0
SDI
A1
A2
tSOD
tSOE
tSIS
SDO
(output)
D0
D1
D2
D3
D4
D5
D6
D7
high-Z
(Note: SDO and SMS at the same pin)
SMS
(input)
tSOZ
D0
pull-high
D1
D2
D3
D4
D5
D6
D7
driven by SDO
SEN
tSES
tSEH
Fig. 7-6 Serial Interface Read Timing in 4-Wired Interface Mode.
- 15 -
Publication Release Date: December 1998
Revision A1
Preliminary W6662CF
8. APPLICATION CIRCUITS
8.1 System Application
Figure 8-1 is the application block diagram of scanner, the photo sensor may be CCD device or CIS
device with single channel or three-channel analog output. The ASIC is used to generate the request
signal of photo sensor, W6662, motor control and other mechanical/electric interface. The memory
buffer is used to temporary store the image data and the data will be transfered to the host through
EPP port or other interface as SCSI. If micro controller is included, some control sequence, photo
sensor calibration or image data procession can be completed without the aid of the host.
Memory
Buffer
to/from
other mechanical
control and senor
Photo
Sensor
W6662
Scanner
ASIC
Micro
Controller
(optional)
Fig. 8-1 System Application.
- 16 -
Host
Interface
Preliminary W6662CF
8.2. Decoupling Circuit
Figure 8-2 shows the decoupling capacitor request on the W6662 system board to reduce noise and
distortion, 0.1 µF capacitor must as near to the pin as possible. The analog power source and digital
power source (DRVDD) had better regulated by different regulator, the analog ground and digital
ground (DRVSS) must separated and must connected only at one point near the power supplier. All
the analog power pins must connected as short as possible and all the analog ground pins must
connected as short as possible on the PC board. Termination resistor must added near the W6662
chip on the CDSCK1, CDSCK2 and ADCCLK input pin.
(Analog Part)
(Digital Part)
VRDT
0.1uF
10uF
VRDT
+
0.1uF
VDRB
W6662
CDSCK1
(other pins are not shown)
Rterm
VRDB
0.1uF
0.1uF
CDSCK2
VRDC
Rterm
VREF
1uF
ADCCLK
+
0.1uF
0.1uF
DRVDD
AVDD
10uF
Rterm
CISREF
+
0.1uF
AVDD
DRVDD
AVSS
DRVSS
0.1uF
+
10uF
(near power source)
Fig. 8-2 Decoupling Capacitor Circuit of W6662 Device.
- 17 -
Publication Release Date: December 1998
Revision A1
Preliminary W6662CF
9. PACKAGE DIMENSIONS
48L QFP (10 x 10 x 2.0 mm footprint 5.0 mm)
HD
D
48
37
36
1
E HE
12
25
13
e
b
24
c
2
Seating Plane
See Detail F
A
y
θ
L
A1
L1
Dimension in inch
Symbol
A
A1
A2
b
c
D
E
e
HD
HE
L
L1
y
θ
Min.
Nom.
Max.
Dimension in mm
Min.
Nom.
0.004
0.008
0.012
Max.
2.30
0.90
0.10
0.078
0.20
0.30
2.00
0.010
0.013
0.018
0.25
0.33
0.004
0.006
0.008
0.10
0.15
0.390
0.394
0.398
9.9
10.00
10.1
0.390
0.394
0.398
9.9
10.00
10.1
.029
0.45
0.20
0.75
0.582
0.590
0.598
14.80
15.0
15.20
0.582
0.590
0.598
14.80
15.0
15.20
1.70
0.066
2.50
0.098
0.10
0.004
0
10
0
- 18 -
10
Detail F
Preliminary W6662CF
Headquarters
Winbond Electronics (H.K.) Ltd.
Rm. 803, World Trade Square, Tower II,
No. 4, Creation Rd. III,
123 Hoi Bun Rd., Kwun Tong,
Science-Based Industrial Park,
Kowloon, Hong Kong
Hsinchu, Taiwan
TEL: 852-27513100
TEL: 886-3-5770066
FAX: 852-27552064
FAX: 886-3-5792646
http://www.winbond.com.tw/
Voice & Fax-on-demand: 886-2-27197006
Winbond Electronics North America Corp.
Winbond Memory Lab.
Winbond Microelectronics Corp.
Winbond Systems Lab.
2727 N. First Street, San Jose,
CA 95134, U.S.A.
TEL: 408-9436666
FAX: 408-5441798
Taipei Office
11F, No. 115, Sec. 3, Min-Sheng East Rd.,
Taipei, Taiwan
TEL: 886-2-27190505
FAX: 886-2-27197502
Note: All data and specifications are subject to change without notice.
- 19 -
Publication Release Date: December 1998
Revision A1