Datasheet VSP3100Y-2K, VSP3100Y Datasheet (Burr Brown)

Download

Page 1

14-Bit, 10MHz

CCD/CIS SIGNAL PROCESSOR

VSP3100

DESCRIPTION

The VSP3100 is a complete CCD/CIS image processor which operates from a single +5V supply.

This complete image processor includes three Correlated Double Samplers (CDS) and Programmable Gain Amplifiers (PGA) to process CCD signals.

These three channel inputs also allow Contact Image Sensor (CIS) inputs.

The VSP3100 is an interface compatible with the VSP3000 which is 12-bit one-chip product.

The VSP3100 can be operated from 0°C to +85°C and is available in an LQFP-48 package.

FEATURES

● INTEGRATED TRIPLE-CORRELATED

DOUBLE SAMPLER

● OPERATION MODE SELECTABLE:

1-Channel, 3-Channel, 10MSPS (typ), CCD/CIS Mode

● PROGRAMMABLE GAIN AMPLIFIER:

0dB to +13dB

● SELECTABLE OUTPUT MODES:

Normal/Demultiplexed

● OFFSET CONTROL RANGE: ±400mV

● +3V, +5V Digital Output

● LOW POWER: 450mW (typ)

● LQFP-48 SURFACE-MOUNT PACKAGE

International Airport Industrial Park • Mailing Address: PO Box 11400, Tucson, AZ 85734 • Street Address: 6730 S. Tucson Blvd., Tucson, AZ 85706 • Tel: (520) 746-1111

Twx: 910-952-1111 • Internet: http://www.burr-brown.com/ • Cable: BBRCORP • Telex: 066-6491 • FAX: (520) 889-1510 • Immediate Product Info: (800) 548-6132

For most current data sheet and other product

information, visit www.burr-brown.com

RINP

INN

Clamp

GINP

Clamp

CDS

PGA

BINP

Clamp

10-Bit

DAC

10-Bit

DAC

10-Bit

DAC

MUX

Timing Generator

Reference

Circuit

Digital Output

Control

R G B

Offset

R G B

Gain

Control

Configuration

Port

14-Bit

A/D

P/S WRT RD SCLK SD

REFP REFN

DRV

B0-B13 (A0-A2, D0-D9)

VSP3100

CK1CLP CK2

ADCCK

REF

TP0

VSP3100

Page 2

VSP3100

SPECIFICATIONS

At TA = full specified temperature range, VCC = +5V, f

ADCCK

= 6MHz, f

CK1

= 2MHz, f

CK2

= 2MHz, PGA gain = 1, normal output mode, no output load, unless otherwise

specified.

VSP3100Y

PARAMETER CONDITIONS MIN TYP MAX UNITS RESOLUTION 14 Bits

CONVERSION CHARACTERISTICS

1-, 3-Channel CDS Mode 10 MSPS 1-, 3-Channel CIS Mode 10 MSPS

DIGITAL INPUTS

Logic Family CMOS Convert Command Start Conversion Rising Edge of ADCCK Clock High Level Input Current (V

= VCC) 20 µA Low Level Input Current (VIN = 0V) 20 µA Positive-Going Threshold Voltage Pins 18, 19, 20, 21, 22, 24 3.80 V Negative-Going Threshold Voltage Pins 18, 19, 20, 21, 22, 24 1.25 V Positive-Going Threshold Voltage Pins 12, 14, 15, 16 2.20 V Negative-Going Threshold Voltage Pins 12, 14, 15, 16 0.80 V Input Capacitance 5pF

ANALOG INPUTS

Full-Scale Input Range 0.5 3.5 Vp-p Input Capacitance 10 pF Input Limits AGND – 0.3 V

+ 0.3 V External Reference Voltage Range 0.25 0.3 V Reference Input Resistance 800 Ω

DYNAMIC CHARACTERISTICS

Integral Non-Linearity (INL) ±4.0 LSB Differential Non-Linearity (DNL) 0.5 LSB No Missing Codes Guaranteed Bits Output Noise Gain = 0dB, Input Grounded 0.5 LSBs rms

PSRR 0.04 % FSR DC ACCURACY

Zero Error Gain = 0dB 0.8 % FS Gain Error Gain = 0dB 1.5 % FS

DIGITAL OUTPUTS

Logic Family TTL/HCT Logic Coding Straight Offset Binary Digital Data Output Rate, Max Normal Mode 10 MHz

Demultiplexed Mode 10 MHz

DRV

Supply Range +2.7 +5.3 V

Output Voltage, V

DRV

= +5V Low Level IOL = 50µA +0.1 V High Level IOH = 50µA +4.6 V Low Level I

= 1.6mA +0.4 V

High Level IOH = 0.5mA +2.4 V

Output Voltage, V

DRV

= +3 Low Level I

= 50µA +0.1 V

High Level IOH = 50µA +2.5 V

Ouput Enable Time Output Enable = LOW 20 40 ns 3-State Enable Time Output Enable = HIGH 2 10 ns Output Capacitance 5pF Data Latency 7 Clock Cycles Data Output Delay C

= 15pF 12 ns

POWER SUPPLY REQUIREMENTS

Supply Voltage: V

4.7 5 5.3 V

Supply Current: ICC (No Load) 3-Ch Mode 90 mA

1-Ch Mode 75 mA

Power Dissipation (No Load) 3-Ch Mode 450 mW

1-Ch Mode 375 mW

Thermal Resistance,

100 °C/W

SPECIFIED TEMPERATURE RANGE 0 to +85 °C

NOTE: (1) SNR = 20log (full-scale voltage/rms noise).

Page 3

VSP3100

The information provided herein is believed to be reliable; however, BURR-BROWN assumes no responsibility for inaccuracies or omissions. BURR-BROWN assumes no responsibility for the use of this information, and all use of such information shall be entirely at the user’s own risk. Prices and specifications are subject to change without notice. No patent rights or licenses to any of the circuits described herein are implied or granted to any third party. BURR-BROWN does not authorize or warrant any BURR-BROWN product for use in life support devices and/or systems.

Supply Voltage

(2)

.............................................................................................................. +6.5V

Supply Voltage Differences

(3)

................................................................................... ±0.1V

GND Voltage Differences

(4)

........................................................................................ ±0.1V

Digital Input Voltage................................................. –0.3V to (V

+ 0.3V)

Analog Input Voltage................................................ –0.3V to (V

+ 0.3V)

Input Current (any pins except suppplies) ...................................... ±10mA

Operating Temperature ........................................................ 0°C to +85°C

Storage Temperature...................................................... –55°C to +150°C

Junction Temperature .................................................................... +150°C

Lead Temperature (soldering) ....................................................... +150°C

Package Temperature (IR Reflow, peak, 10s)............................... +260°C

Package Temperature (IR Reflow, peak, 5s) ................................. +235°C

NOTES: (1) Stresses above these ratings may cause permanent damage. Exposure to absolute maximum conditions for extended periods may degrade device reliability. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those specified is not implied. (2) V

CC, VDRV

. (3) Among VCC. (4) Among AGND.

ABSOLUTE MAXIMUM RATINGS

(1)

ELECTROSTATIC DISCHARGE SENSITIVITY

This integrated circuit can be damaged by ESD. Burr-Brown recommends that all integrated circuits be handled with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage.

ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be more susceptible to damage because very small parametric changes could cause the device not to meet its published specifications.

PRODUCT PACKAGE

VSP3100Y DEM-VSP3100Y

DEMO BOARD ORDERING INFORMATION

PACKAGE SPECIFIED DRAWING TEMPERATURE PACKAGE ORDERING TRANSPORT

PRODUCT PACKAGE NUMBER RANGE MARKING NUMBER

(1)

MEDIA

VSP3100Y LQFP-48 340 0°C to +85°C VSP3100Y VSP3100Y 250-Piece Tray

""""VSP3100Y VSP3100Y/2K Tape and Reel

NOTE: (1) Models with a slash (/) are available only in Tape and Reel in the quantities indicated (e.g., /2K indicates 2000 devices per reel). Ordering 2000 pieces of “VSP3100Y/2K” will get a single 2000-piece Tape and Reel.

PACKAGE/ORDERING INFORMATION

Page 4

VSP3100

Top View LQFP

PIN DESCRIPTIONS

PIN DESIGNATOR TYPE DESCRIPTION PIN DESIGNATOR TYPE DESCRIPTION

1 CM AO Common-Mode Voltage 2 REFP AO Top Reference 3 AGND P Analog Ground 4 INN AI Red/Green/Blue Channel Reference Input 5 RINP AI Red Channel Analog Input 6 AGND P Analog Ground 7 GINP AI Green Channel Analog Input 8 AGND P Analog Ground

9 BINP AI Blue Channel Analog Input 10 AGND P Analog Ground 11 V

P Analog Power Supply, +5V

12 CLP DI Clamp Enable:

“High” = Enable, “Low” = Disable

13 V

P Analog Power Supply, +5V 14 ADCCK DI Clock for A/D Converter Digital Data Output 15 CK1 DI Sample Reference Clock 16 CK2 DI Sample Data Clock 17 AGND P Analog Ground 18 RD DI Read Signal for Registers 19 WRT DI Write Signal for Registers 20 P/S DI Parallel/Serial Port Select

“High” = Parallel Port, “Low” = Serial Port 21 SD DI Serial Data Input 22 SCLK DI Serial Data Shift Clock 23 V

P Analog Power Supply, +5V

24 OE DI Output Enable

PIN CONFIGURATION

25 B0 (D0) LSB DIO A/D Output (Bit 0) and Register Data (Bit 0) 26 B1 (D1) DIO A/D Output (Bit 1) and Register Data (Bit 1) 27 B2 (D2) DIO A/D Output (Bit 2) and Register Data (Bit 2) 28 B3 (D3) DIO A/D Output (Bit 3) and Register Data (Bit 3) 29 B4 (D4) DIO A/D Output (Bit 4) and Register Data (Bit 4) 30 B5 (D5) DIO A/D Output (Bit 5) and Register Data (Bit 5) 31 B6 (D6) DIO A/D Output (Bit 6) and Register Data (Bit 6) 32 B7 (D7) DIO A/D Output (Bit 7) and Register Data (Bit 7) 33 B8 (D8) DIO A/D Output (Bit 8) and Register Data (Bit 8)

B0: Demiltiplexed Mode A/D Output (Bit 0) when Demultiplexed Output Mode

34 B9 (D9) DIO A/D Output (Bit 9) and Register Data (Bit 9)

B1: Demiltiplexed Mode A/D Output (Bit 1) when Demultiplexed Output Mode

35 B10 (A0) DIO A/D Output (Bit 10) and Register Address (Bit 0)

B2: Demiltiplexed Mode A/D Output (Bit 2) when Demultiplexed Output Mode

36 B11 (A1) DIO A/D Output (Bit 11) and Register Address (Bit 1)

B3: Demiltiplexed Mode A/D Output (Bit 3) when Demultiplexed Output Mode

37 B12 (A2) DIO A/D Output (Bit 12) and Register Address (Bit 2)

B4: Demiltiplexed Mode A/D Output (Bit 4) when Demultiplexed Output Mode

38 B13 MSB DO A/D Output (Bit 13)

B5: Demiltiplexed Mode A/D Output (Bit 5) when Demultiplexed Output Mode 39 AGND P Analog Ground 40 AGND P Analog Ground 41 V

DRV

P Digital Output Driver Power Supply

42 V

P Analog Power Supply, +5V

43 V

P Analog Power Supply, +5V 44 AGND P Analog Ground 45 TP0 AO A/D Converter Input Monitor Pin (single-ended output)

46 V

REF

AIO Reference Voltage Input/Output

47 V

P Analog Power Supply, +5V 48 REFN AO Bottom Reference

36 35 34 33 32 31 30 29 28 27 26 25

B11 (A1) B10 (A0) B9 (D9) B8 (D8) B7 (D7) B6 (D6) B5 (D5) B4 (D4) B3 (D3) B2 (D2) B1 (D1) B0 (D0) LSB

REFN

VCCV

REF

TP0

AGND

VCCVCCV

DRV

AGND

B13 MSB

B12 (A2)

ADCCK

CK1

CK2

AGND

WRT

P/S

SCLK

1 2 3 4 5 6 7 8

9 10 11 12

REFP

AGND

INN

RINP

AGND

GINP

AGND

BINP

AGND

CLP

48 47 46 45 44 43 42

41 40 39 38

13 14 15 16 17 18 19 20 21 22 233724

VSP3100Y

Page 5

VSP3100

TIMING DIAGRAMS

Timing Specifications: VCC = +5V supply and normal output mode with the specified temperature range, unless otherwise noted.

SYMBOL PARAMETER MIN TYP MAX UNITS

CK1W-1

CK1 Pulse Width 20 40 ns

CK1P-1

1-Channel Mode Conversion Rate 100 166 ns

CK2W-1

CK2 Pulse Width 20 40 ns

CK1CK2-1

CK1 Falling to CK2 Rising 15 ns

CK2CK1-1

CK2 Falling to CK1 Rising 40 ns

CK1ADC

CK1 Rising to ADCCK Falling 20 ns

ADCCK2-1

ADCCK Falling to CK2 Falling 15 ns

ADCW

ADCCK Pulse Width 41 83 ns

ADCP

ADCCK Period 83 166 ns

Sampling Delay 10 ns

SET

ADCCK Rising to CK1 Rising 10 ns

CNV

Conversion Delay 40 ns

1-Channel CCD Mode Timing

CCD Output

CK1

CK2

ADCCK

CK1P-1

SET

CK1ADC

ADCCK2-1

CK1CK2-1

CK2CK1-1

CK2W-1

CNV

ADCW

ADCP

ADCW

CK1W-1

Pixel 1

Pixel 2

SYMBOL PARAMETER MIN TYP MAX UNITS

CK1W-1

CK1 Pulse Width 20 40 ns

CK1P-1

1-Channel Mode Conversion Rate 100 166 ns

ADCW

ADCCK Pulse Width 41 83 ns

ADCP

ADCCK Period 83 166 ns

Sampling Delay 10 ns

SET

ADCCK Falling to CK1 Rising 10 ns

CNV

Conversion Delay 40 ns

1-Channel CIS Mode Timing

CIS Output

CK1

ADCCK

CK1P-1

SET

CNV

ADCW

ADCP

CK1W-1

SET

Pixel 1

Pixel 1 Pixel 2

Pixel 2

Page 6

VSP3100

TIMING DIAGRAMS (Cont.)

Timing Specifications: VCC = +5V supply and normal output mode with the specified temperature range, unless otherwise noted.

SYMBOL PARAMETER MIN TYP MAX UNITS

CK1W-3

CK1 Pulse Width 20 125 ns

CK1P-3

3-Channel Mode Conversion Rate 300 500 ns

CK2W-3

CK2 Pulse Width 20 125 ns

CK1CK2-3

CK1 Falling to CK2 Rising 15 ns

CK2CK1-3

CK2 Falling to CK1 Rising 70 ns

ADCCK2-3

ADCCK Falling to CK2 Falling 5 ns

ADCW

ADCCK Pulse Width 41 83 ns

ADCP

ADCCK Period 83 166 ns

Sampling Delay 10 ns

SET

ADCCK Rising to CK1 Rising 10 ns

CNV

Conversion Delay 40 ns

3-Channel CCD Mode Timing

ADCP

ADCW

SET

CK1CK2-3

CK2CK1-3

CNV

CK2W-3

ADCW

ADCCK2-3

CK1W-3

CK1P-3

(R)

(G)

(B) Pixel 1 (R)

Pixel 1 (R/G/B) Pixel 2 (R/G/B)

Pixel 1 (G) Pixel 1 (B)

CCD Output

CK1

CK2

ADCCK

Page 7

VSP3100

TIMING DIAGRAMS (Cont.)

Timing Specifications: VCC = +5V supply and normal output mode with the specified temperature range, unless otherwise noted.

SYMBOL PARAMETER MIN TYP MAX UNITS

CK1W-3

CK1 Pulse Width 20 125 ns

CK1P-3

3-Channel Mode Conversion Rate 300 500 ns

ADCCK1

ADCCK Falling to CK1 Falling 5 ns

ADCW

ADCCK Pulse Width 41 83 ns

ADCP

ADCCK Period 83 166 ns

Sampling Delay 10 ns

SET

ADCCK Falling to CK1 Rising 10 ns

CNV

Conversion Delay 40 ns

3-Channel CIS Mode Timing

CIS Output

CK1

ADCCK

CK1P-3

SET

ADCWtADCW

ADCP

CK1W-3

ADCCK1

CNV

SET

Pixel 1 (R/G/B) Pixel 2 (R/G/B)

(R)

(G)

(B) Pixel 1

(R)

Pixel 1

(G)

Pixel 1

(B)

Timing for Parallel Port Writing

SYMBOL

PARAMETER MIN TYP MAX UNITS

Parallel Ready Time 20 ns

WRT Pulse Width 30 50 ns

Data Valid Time 30 ns

Address Setup Time 20 50 ns

Data Setup Time 30 50 ns

Timing for Reading

SYMBOL

PARAMETER MIN TYP MAX UNITS

Parallel Ready Time 20 ns

Data Setup Time 30 50 ns

Address Setup Time 20 50 ns

Readout Delay 20 ns

Data Hold Time 1 ns

Valid

Stable

D9-D0

A2-A0

P/S

WRT

tDAt

Valid

D7-D0

Stable

Valid

A2-A0

P/S

Page 8

VSP3100

TIMING DIAGRAMS (Cont.)

Timing Specifications: VCC = +5V supply and normal output mode with the specified temperature range, unless otherwise noted.

Timing for Serial Port Writing

SYMBOL PARAMETER MIN TYP MAX UNITS

WRT Pulse Width 30 50 ns

Data Valid Time 30 ns

Data Ready Time 15 50 ns

SCK

Serial Clock Pulse Width 30 50 ns

SCKP

Serial Clock Period 60 100 ns

Serial Ready Time 100 200 ns

WRT Pulse Setup Time 50 ns

P/S

SCLK

A2-A0

A2 A1

Valid

A0 D9 D1 D0

WRT

SCKtSCK

SCKP

• • •

Timing for A/D Output (Normal Operation Mode)

SYMBOL

PARAMETER MIN TYP MAX UNITS

OES

A/D Output Enable Setup Time

20 ns

OER

Output Enable Time 20 40 ns

3-State Enable Time 2 10 ns

OEW

OE Pulse Width 100 ns

DOD

Data Output Delay 12 ns

OEP

Parallel Port Setup Time 10 ns

Timing for A/D Output (

Demultiplexed Operation Mode

)

Data n+1

(Hi-Z)(Hi-Z)

Data n+2

(n+2) (n+1) (n)

Data n (14-Bit)

ADCCK

DOUT

P/S

DOD

OES

OEP

OEW

OER

NOTE: It is Inhibit Operation Mode that OE sets “Low” during P/S = “High” period.

n (B0-B5)

(Hi-Z)

NOTE: It is Inhibit Operation Mode that OE sets “Low” during P/S = “High” period.

n+1 (B6-B13)

(n+1)

(n)

n (B6-B13)

ADCCK

DOUT

P/S

DODH

DODL

DODH

OES

OEP

OEW

OER

SYMBOL

PARAMETER MIN TYP MAX UNITS

OES

A/D Output Enable Setup Time

20 ns

OER

Output Enable Time 20 40 ns

3-State Enable Time 2 10 ns

OEW

OE Pulse Width 100 ns

DODH

Data Output Delay, High Byte

12 ns

DODL

Data Output Delay, Low Byte

12 ns

OEP

Parallel Port Setup Time 10 ns

Page 9

VSP3100

Digital Data Output Sequence; 1-ch CCD Mode (B-ch: D4 = 1 and D5 = 0)

TIMING DIAGRAMS (Cont.)

Timing Specifications: VCC = +5V supply and normal output mode with the specified temperature range, unless otherwise noted.

CCD Output

CK1

CK2

ADCCK

CDS Output

A/D Input

A/D Output (Normal Mode)

Pixel (n)

• • •

Pixel (n+1) Pixel (n+7)

CNV

SET

(n) (n+1) (n+6) (n+7)

B (n+1) B (n+6) B (n+7)

B (n)

Digital Data Output Sequence; 1-ch CIS Mode (B-ch: D4 = 1 and D5 = 0)

CIS Output

CK1

ADCCK

S/H Output

A/D Input

A/D Output (Normal Mode)

Pixel (n)

• • •

Pixel (n+1) Pixel (n+7)

CNV

SET

(n) (n+1) (n+6) (n+7)

B (n+1) B (n+6) B (n+7)

B (n)

Page 10

VSP3100

Digital Data Output Sequence; 3-ch CCD Mode, R > G > B Sequence

TIMING DIAGRAMS (Cont.)

Timing Specifications: VCC = +5V supply and normal output mode with the specified temperature range, unless otherwise noted.

Digital Data Output Sequence; 3-ch CIS Mode, R > G > B Sequence

CCD Output

CK1

CK2

ADCCK

CDS Output

A/D Input

A/D Output (Normal Mode)

Pixel (n)

Pixel (n+1) Pixel (n+2)

SET

CNV

(n)

(n+1) (n+2)

R (n+1) G (n+1) B (n+1) R (n+2)

R (n) G (n) B (n)

R (n+1)

R (n) G (n) B (n)

CIS Output

CK1

ADCCK

S/H Output

A/D Input

A/D Output (Normal Mode)

Pixel (n)

Pixel (n+1)

Pixel (n+2)

SET

CNV

(n)

(n+1) (n+2)

R (n+1) G (n+1) B (n+1) R (n+2)

R (n) G (n) B (n)

R (n+1)

R (n) G (n) B (n)

Page 11

VSP3100

TYPICAL PERFORMANCE CURVES

At TA = +25°C, VCC = +5V supply, t

ADCCK

= 6MHz, f

CK1

= 2MHz, f

CK2

= 2MHz, PGA Gain = 1, normal output mode, no load, unless otherwise specified.

PGA TRANSFER FUNCITON

SAMPLE QUALITY, N = 100

PGA Gain Setting

Gain

5.0

4.5

4.0

3.5

3.0

2.5

2.0

1.5

1.0

0.5 0

5 1015202530350

POWER DISSIPATION vs POWER SUPPLY

1 CH MODE

Power Supply Voltage (V)

Power Dissipation (mW)

500

450

400

350

300

250

200

5 5.34.7

POWER DISSIPATION vs POWER SUPPLY

3 CH MODE

Power Supply Voltage (V)

Power Dissipation (mW)

500

450

400

350

300

250

200

5 5.34.7

Page 12

VSP3100

THEORY OF OPERATION

VSP3100 can be operated in one of the following four modes:

(1) 1-Channel CCD (2) 1-Channel CIS (3) 3-Channel CCD (4) 3-Channel CIS

1-CHANNEL CCD MODE

In this mode, the VSP3100 processes only one CCD signal (D3 of the Configuration Register sets to “1”). The CCD signal is AC-coupled to RINP, GINP, or BINP (depending on D4, D5 of the Configuration Register). The CLP signal enables internal biasing circuitry to clamp this input to a proper voltage, so that internal CDS circuitry can work properly. The VSP3100 input may be applied as a DCcoupled input, which needs to be level-shifted to a proper DC level.

The CDS takes two samples of the incoming CCD signals. The CCD reset signal is taken on the falling edge of CK1 and the CCD information is taken on the falling edge of CK2. These two samples are then subtracted by the CDS and the result is stored as a CDS output.

In this mode, only one of the three channels is enabled. Each channel consists of a 10-bit Offset DAC (range from –400mV to +400mV). A 3-to-1 analog MUX is inserted between the CDSs and a high-performance 14-bit analog-todigital converter. The outputs of the CDSs are then multiplexed to the A/D converter for digitization. The analog MUX is not cycling between channels in this mode. Instead, it is connected to a specific channel, depending on the contents of D4 and D5 in the Configuration Register.

The VSP3100 allows two types of output modes:

1) Normal (D7 of Configuration Register sets to “0”).

2) Demultiplexed (D7 of Configuration Register sets to “1”). As specified in the “1-Channel CCD Mode” timing diagram,

the rising edge of CK1 must be in the HIGH period of ADCCK, and at the same time, the falling edge of the CK2 must be in the LOW period of ADCCK. Otherwise, the VSP3100 will not function properly.

1-CHANNEL CIS MODE

In this mode, the VSP3100 operates as a 1-channel sampler and digitizer. Unlike CDS modes, the VSP3100 takes only one sample on the falling edge of the CK1. Since only one sample is taken, CK2 is grounded in this operation. The input signal is DC coupled in most cases. Here, VSP3100 inputs are differential input. Using the Red channel as an example, RINP is the CIS input signal, and INN is the CIS common reference signal input. The same applies to the Green channel (GINP and INN) and Blue channel (BINP and INN).

In this mode, CDS becomes CIS (act like sample-and-hold). Each channel consists of a 10-bit Offset DAC (range from –400mV to +400mV).

A 3-to-1 analog MUX is inserted between the CISs and a high-performance, 14-bit A/D converter. The outputs of the CIS are then multiplexed to the A/D converter for digitization. The analog MUX is not cycling between channels in this mode. Instead, the analog MUX is connected to a specific channel, depending on the contents of D4 and D5 in the Configuration Register.

The VSP3100 allows two types of output modes:

1) Normal (D7 of Configuration Register sets to “0”).

2) Demultiplexed (D7 of Configuration Register sets to “1”). As specified in the “1-Channel CIS Mode” timing diagram,

the active period of both CK1 (t

CK1B

) and CK2 (t

CK2B

) must be in the LOW period of ADCCK. If it is in the HIGH period of ADCCK, the VSP3100 will not function properly.

3-CHANNEL CCD MODE

In this mode, the VSP3100 can simultaneously process triple output CCD signals. CCD signals are AC coupled to the RINP, GINP, and BINP inputs. The CLP signal enables internal biasing circuitry to clamp these inputs to a proper voltage so that internal CDS circuitry can work properly. VSP3100 inputs may be applied as a DC-coupled inputs, which need to be level-shifted to a proper DC level.

The CDSs take two samples of the incoming CCD signals. The CCD reset signals are taken on the falling edge of CK1 and the CCD information is taken on the falling edge of CK2. These two samples are then subtracted by the CDSs and the results are stored as a CDS output.

Page 13

VSP3100

In this mode, three CDSs are used to process three inputs simultaneously. Each channel consists of a 10-bit Offset DAC (range from –400mV to +400mV). A 3-to-1 analog MUX is inserted between the CDSs and a high-performance, 14-bit A/D converter. The outputs of the CDSs are then multiplexed to the A/D converter for digitization. The analog MUX is switched at the falling edge of CK2, and can be programmed to cycle between the Red, Green, and Blue channels. When D6 of the Configuration Register sets to “0”, the MUX sequence is Red > Green > Blue. When D6 of the Configuration Register sets to “1”, the MUX sequence is Blue > Green > Red.

MUX resets at the falling edge of CK1. In the case of a Red > Green > Blue sequence, it resets to “R”, and in the case of a Blue > Green > Red sequence, it resets to “B”.

The VSP3100 allows two types of output modes:

1) Normal (D7 of Configuration Register sets to “0”).

2) Demultiplexed (D7 of Configuration Register sets to “1”). As specified in the “3-Channel CCD Mode” timing diagram,

the falling edge of CK2 must be in the LOW period of ADCCK. If the falling edge of CK2 is in the HIGH period of ADCCK (in the timing diagram, ADCCK for sampling B-channel), the VSP3100 will not function properly.

3-CHANNEL CIS MODE

In this mode, the VSP3100 is operated as 3-channel samplers and a digitizer. Unlike CCD modes, VSP3100 takes only one sample on the falling edge of CK1 for each input. Since only one sample is taken, CK2 is grounded in this operation. The input signals are DC coupled in most cases. Here, the VSP3100 inputs allow differential inputs. Using the Red channel as an example, RINP is the CIS input signal, and INN is the CIS common reference signal input. The same applies to the Green channel (GINP and INN) and Blue channel (BINP and INN).

In this mode, three CDSs become CISs (act like sample-andhold) to process three inputs simultaneously. Each channel consists of a 10-bit Offset DAC (range from –400mV to

+400mV). A 3-to-1 analog MUX is inserted between the CISs and a high-performance, 14-bit A/D converter. The outputs of the CIS are then multiplexed to the A/D converter for digitization. The analog MUX is switched at the falling edge of CK2, and can be programmed cycling between the Red, Green, and Blue channels. When D6 of the Configuration Register sets to “0”, the MUX sequence is Red > Green > Blue. When D6 of the Configuration Register sets to “1”, the MUX sequence is Blue > Green > Red.

MUX resets at the falling edge of CK1. In the case of a Red > Green > Blue sequence, it resets to “R”, and in the case of a Blue > Green> Red sequence, it resets to “B”.

The VSP3100 allows two types of output modes:

1) Normal (D7 of Configuration Register sets to “0”).

2) Demultiplexed (D7 of Configuration Register sets to “1”). As specified in the “3-Channel CIS Mode” timing diagram,

the falling edge of CK1 must be in the LOW period of ADCCK. If the falling edge of CK1 is in the HIGH period of ADCCK (in the timing diagram, ADCCK for sampling B-channel), the VSP3100 will not function properly.

DIGITAL OUTPUT FORMAT

The Digital Output Format is shown in Table I. The VSP3100 can be operated in one of the following two digital output modes:

(1) Normal output. (2) Demultiplexed (B13-based Big Endian Format). In Normal mode, the VSP3100 outputs the 14-bit data by B0

(pin 25) through B13 (pin 38) simultaneously. In Demultiplexed mode, VSP3100 outputs the high byte

(upper 8 bits) by B6 (pin 31) through B13 (pin 38) at the rising edge of ADCCK “HIGH”, then outputs the low byte (lower 6 bits) by B8 (pin 33) through B13 (pin 38) at the falling edge of ADCCK.

An 8-bit interface can be used between the VSP3100 and the Digital Signal Processor, allowing for a low-cost system solution.

BIT B13 B12 B11 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 B0

High Byte B13 B12 B11 B10 B9 B8 B7 B6 Low Low Low Low Low Low Low Byte B5 B4 B3 B2 B1 B0 Low Low Low Low Low Low Low Low

TABLE I. Digital Output Format.

Page 14

VSP3100

DIGITAL OUTPUTS

The digital outputs of the VSP3100 are designed to be compatible with both high-speed TTL and CMOS logic families. The driver stage of the digital outputs is supplied through a separate supply pin, V

DRV

(pin 41), which is not connected to the analog supply pins (VCC). By adjusting the voltage on V

DRV

, the digital output levels will vary respectively. Thus, it is possible to operate the VSP3100 on a +5V analog supply while interfacing the digital outputs to 3V logic. It is recommended to keep the capacitive loading on the data lines as low as possible (typically less than 15pF). Larger capacitive loads demanding higher charging current surges can feed back to the analog portion of the VSP3100 and influence the performance. If necessary, external buffers or latches may be used, providing the added benefit of isolating the VSP3100 from any digital noise activities on the bus, coupling back high-frequency noise. In addition, resistors in series with each data line may help minimize the surge current. Their use depends on the capacitive loading seen by the converter. As the output levels change from low to high and high to low, values in the range of 100Ω to 200Ω will limit the instantaneous current the output stage has to provide for recharging the parasitic capacitances.

PROGRAMMABLE GAIN AMPLIFIER

VSP3100 has one Programmable Gain Amplifier (PGA), and it is inserted between the CDSs and the 3:1 MUX. The PGA is controlled by a 5-bit of Gain Register and each channel (Red, Green, and Blue) has its own Gain Register.

The gain varies from 1 to 4.44 (0dB to 13dB), and the curve has log characteristics. Gain Register Code all “0” corresponds to minimum gain, and Code all “1” corresponds to maximum gain.

The transfer function of the PGA is:

Gain = 4/(4 – 0.1 • x)

where, x is the integer representation of the 5-bit PGA gain register.

Figure 1 shows the PGA transfer function plot.

INPUT CLAMP

The input clamp should be used for 1-channel and 3-channel CCD mode, and it will be enabled when both CLP and CK1 are set to HIGH.

Bit Clamp: the input clamp is always enabled. Line Clamp: enables during the dummy pixel interval at

every horizontal line, and disables during the effective pixel interval.

Generally, “Bit Clamp” is used for many scanner applications, however, “Line Clamp” is used instead of “Bit Clamp” when the clamp noise is impressive.

CHOOSING THE AC INPUT COUPLING CAPACITORS

The purpose of the Input Coupling Capacitor is to isolate the DC offset of the CCD array from affecting the VSP3100 input circuitry. The internal clamping circuitry is used to restore the necessary DC bias to make the VSP3100 input circuitry functional. Internal clamp voltage, V

CLAMP

, is set

when both the CLP pin and CK1 are set high. V

CLAMP

changes depending on the value of V

REF

. V

CLAMP

is 2.5V if

REF

is set to 1V (D1 of the Configuration Register set to

“0”), and V

CLAMP

is 3V if V

REF

is set to 1.5V (D1 of the

Configuration Register set to “1”).

FIGURE 1. PGA Transfer Plot.

PGA TRANSFER FUNCTION

PGA Gain Setting

5 10152025 310

Gain

4.5

4.0

3.5

3.0

2.5

2.0

1.5

1.0

PGA TRANSFER FUNCTION

PGA Gain Setting

5 10152025 310

Gain (dB)

Page 15

VSP3100

There are many factors that decide what size of Input Coupling Capacitor is needed. Those factors are CCD signal swing, voltage difference between the Input Coupling Capacitor, leakage current of the VSP3100 input circuitry, and the time period of CK1.

Figure 2 shows the equivalent circuit of the VSP3100 inputs.

CHOOSE C

MAX

AND C

MIN

As mentioned, a large CIN is better if there is enough time for the CLP signal to charge up CIN so that the input circuitry of the VSP3100 can work properly. Typically, 0.01µF to 0.1µF of CIN can be used for most cases.

In order to optimize CIN, the following two equations can be used to calculate the maximum (C

MAX

) and minimum (C

MIN

)

values of CIN:

MAX

= (t

CK1

• N)/[RSW • ln(VD/V

ERROR

)]

where t

CK1

is the time when both CK1 and CLP go HIGH, and N is the number of black pixels; RSW is the switch resistance of the VSP3100 (typically, driver impedance + 4kΩ); VD is the droop voltage of CIN; V

ERROR

is the voltage

difference between VS and V

CLAMP

MIN

= (I/V

ERROR

) • t

where I is the leakage current of the VSP3100 input circuitry (10nA is a typical number for this leakage current); t is the clamp pulse period.

PROGRAMMING VSP3100

The VSP3100 consists of 3 CCD/CIS channels and a 14-bit A/D. Each channel (Red, Green, and Blue) has its own 10-bit Offset and 5-bit Gain Adjustable Registers to be programmed by the user. There is also an 8-bit Configuration Register, on-chip, to program the different operation modes. Those registers are shown in Table II.

In this equivalent circuit, Input Coupling Capacitor CIN, and Sampling Capacitor C1, are constructed as a capacitor divider (during CK1). For AC analysis, OP inputs are grounded. Therefore, the sampling voltage, VS, (during CK1) is:

VS = (CIN/(CIN + C1)) • V

From the above equation, we know that a larger CIN makes VS close to VIN. In other words, input signal, VIN, will not be attenuated if CIN is large.

However, there is a disadvantage of using a large CIN. It will take longer for the CLP signal to charge up CIN so that the input circuitry of the VSP3100 can work properly.

AMP

CLP

4pF

CK1

CK2

4pF

CLAMP

CK1

FIGURE 2. Equivalent Circuit of VSP3100 Inputs.

TABLE II. On-Chip Registers.

ADDRESS POWER-ON A2 A1 A0 REGISTER DEFAULT VALUE

0 0 0 Configuration Register (8-bit) All “0s” 0 0 1 Red Channel Offset Register (10-bit) All “0s” 0 1 0 Green Channel Offset Register (10-bit) All “0s” 0 1 1 Blue Channel Offset Register (10-bit) All “0s” 1 0 0 Red Channel Gain Register (5-bit) All “0s” 1 0 1 Green Channel Gain Register (5-bit) All “0s” 1 1 0 Blue Channel Gain Register (5-bit) All “0s” 1 1 1 Reserved

Page 16

VSP3100

These registers can be accessed by the following two programming modes:

(1) Parallel Programming Mode using digital data output pins, with the data bus assigned as D0 to D9 (pins 25 to 34), and the address bus as A0 to A2 (pins 35 to 37). It can be used for both reading and writing operations. However, it cannot be used by the Demultiplexed mode (when D7 of the Configuration Register is set to “1”).

(2) Serial Programming Mode using a serial port, Serial Data (SD), the Serial Shift Clock (SCLK), and Write Signal (WRT) assigned.

It can be used only for writing operations; reading operations via the serial port are prohibited.

Table III shows how to access these modes.

Power-on default value is all “0s”, set to 3-channel CCD mode with 1V internal reference, R > G > B MUX sequence, and normal output mode.

For reading/writing to the Configuration Register, the address will be A2 = “0”, A1 =“0”, and A0 = “0”.

For Example:

A 3-channel CCD with internal reference V

REF

= 1V (2V full-scale input), R > G > B sequence and normal output mode will be D0 = “0”, D1 = “0”, D2 =“0”, D3 = “0”, D4 = “x (don’t care)”, D5 = “x (don’t care)”, D6 = “0”, and D7 = “0”.

For this example, bypass V

REF

with an appropriate capacitor

(for example, 10µF to 0.1µF) when internal reference mode is used.

Another Example:

A 1-channel CIS mode (Green channel) with an external

1.2V reference (2.4V full-scale input), Demultiplexed Output mode will be D0 = “1”, D1 = “x (don’t care)”, D2 = “1”, D3 = “1”, D4 = “0”, D5 = “1”, D6 = “x (don’t care)”, and D7 = “1”.

For this example, V

REF

will be an input pin applied with

1.2V.

OFFSET REGISTER

Offset Registers control the analog offset input to channels prior to the PGA. There is a 10-bit Offset Register on each channel. The offset range varies from –400mV to +400mV. The Offset Register uses a straight binary code. All “0s” corresponds to –400mV, and all “1s” corresponds to +400mV of the offset adjustment. The register code 200H corresponds to 0mV of the offset adjustment. The Power-on default value of the Offset Register is all ”0s”, so the offset adjustment should be set to –400mV.

PGA GAIN REGISTER

PGA Gain Registers control the gain to channels prior to the digitization by the A/D converter. There is a 5-bit PGA Gain Register on each channel. The gain range varies from 1 to

4.44 (from 0dB to 13dB). The PGA Gain Register is a straight binary code. All “0s” corresponds to an analog gain of 0dB, and all “1s” corresponds to an analog gain of 13dB. PGA Transfer function is log gain curve. Power-on default value is all “0s”, so that it sets the gain of 0dB.

BIT LOGIC ‘0’ LOGIC ‘1’

D0 CCD mode CIS mode D1 V

REF

= 1V V

REF

=1.5V D2 Internal Reference External Reference D3 3-channel Mode, 1-channel Mode,

D4 and D5 disabled D4 and D5 enabled

D4,D5 (disabled when 3-channel) D4 D5

1-channel mode, Red channel

1-channel mode, Green channel

1-channel mode, Blue channel

D6 MUX Sequence MUX Sequence

Red > Green > Blue Blue > Green >Red

D7 Normal output mode Demultiplexed output mode

TABLE IV. Configuration Register Design.

OE P/S MODE

0 0 Digital data output enabled, Serial mode enabled 0 1 Prohibit mode 1 0 Digital data output disabled, Serial mode enabled 1 1 Digital data output disabled, Parallel mode enabled

TABLE III. Access Mode for Serial and Parallel Port.

CONFIGURATION REGISTER

The Configuration Register design is shown in Table IV.

Page 17

VSP3100

OFFSET AND GAIN CALIBRATION SEQUENCE

When the VSP3100 is powered on, it will be initialized as a 3-Channel CCD, 1V internal reference mode (2V full-scale) with an analog gain of 1, and normal output mode. This mode is commonly used for CCD scanner applications. The calibration procedure is done at the very beginning of the scan.

To calibrate the VSP3100, use the following procedure:

1. Set the VSP3100 to the proper mode.

2. Set Offset to 0mV (control code: 00H), and PGA gain to 1 (control code: 200H).

3. Scan dark line.

4. Calculate the pixel offsets according to the A/D Converter output.

5. Readjust input Offset Registers.

6. Scan white line.

7. Calculate gain. It will be the A/D Converter full-scale divided by the A/D Converter output when the white line is scanned.

8. Set the Gain Register. If the A/D Converter output is not close to full-scale, go back to item 3. Otherwise, the calibration is done.

The calibration procedure is started at the very beginning of the scan. Once calibration is done, registers on the VSP3100 will keep this information (offset and gain for each channel) during the operation.

RECOMMENDATION FOR POWER SUPPLY AND GROUNDING

Proper grounding, bypassing, short lead length, and the use of ground planes are particularly important for high-frequency designs. Multi-layer PC boards are recommended for the best performance since they offer distinct advantages such as minimization of ground impedance, separation of signal layers by ground layers, etc.

It is recommended that analog and digital ground pins of the VSP3100 be joined together at the IC and connected only to the analog ground of the system. The VSP3100 has several analog supply pins (VCC), so the VSP3100 should be treated as an analog component, and all supply pins should be powered by the analog supply on your system. This will ensure the most consistent results since digital supply lines often carry high levels of noise that would otherwise be coupled into the converter and degrade the achievable performance.

As the result of the high operation speed, the converter also generates high-frequency current transients and noise that are fed back into the supply and reference lines. This requires that the supply and reference pins be sufficiently decoupled with ceramic capacitors.

Page 18

VSP3100

FIGURE 3. Demo Board Schematic (DEM-VSP3100).