PAS302BCW-22S
CMOS Image Sensor IC
PAS302BCW-22S CMOS VGA DIGITAL IMAGE SENSOR
General Description
The PAS302BCW-22S is a highly integrated CMOS active-pixel image sensor that has a VGA resolution of 644H x 484V. The PAS302BCW-22S outputs 8-bit RGB raw data through a parallel data bus and is available in 22-pin CSP package. The PAS302BCW-22S can be programmed to set the exposure time for different luminance condition via I 2 CTM serial control bus. By programming the internal register sets, it can perform on-chip frame rate adjustment, offset correction DAC and programmable gain control.
Features
VGA(644 x 484 pixels) resolution, ~1/4” Lens Bayer-RGB color filter array Output format: 8-bit parallel RGB raw data On-chip 10-bit pipelined A/D converter On-chip programmable gain amplifier 4-bit color gain amplifier (x1~x2) 4-bit global gain amplifier (x1~x2) Digital gain stage Continuous variable frame time(1/2sec~1/30sec) Continuous variable exposure time
IC
2 TM
Key Specification
Supply Voltage Resolution Array diagonal Pixel Size Chief Ray Angle Frame rate System clock Pixel clock Sensitivity Color filter Exposure Time Scan Mode S/N Ratio 2.5V ~ 3.3V 644(H) x 484(V) 4.5mm (~1/4”Optic) 5.6µmx5.6µm 20∘ ~ 22∘ ~30 fps Up to 48 MHz Up to 12MHz 1.56 V/Lux-Sec RGB Bayer Pattern ~ Frame time to Line time Progressive > 45 dB
Interface
Support flash light timing Single 2.5V / 3.3V supply voltage < 15mA(~30 fps) power dissipation 2µA power dissipation when power down mode Window-Of-Interest (WOI) Sub-sampling Defect compensation Pin-to-pin compatible to OV7648 Note1: Only two decoupling capacitors needed Note2: Good sensitivity compared to competitors Package
22-pin lead-free CSP
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PixArt Imaging Inc.
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PAS302BCW-22S
CMOS Image Sensor IC
1. Pin Assignment
PX7 PX9 RESET VDDQ HSYNC
15
PX8
13
VSSD
11
SYSCLK
9
PXCLK
7
VSYNC
14
PX6
12
10
-- Top View --
8
6
VDDD
16
PX5
PAS302BCW-22S
PX3 SCL VDDA
5
VREF
17
PX4
19
PX2
21
SDA
2
VSSA
4
PWDN
18
20
22
1
3
Figure 1.1. PAS302BCW-22S pin assignment Pin No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 Name VSSA VDDA PWDN VREF VDDD VSYNC HSYNC PXCLK VDDQ SYSCLK RESET VSSD PX9 PX8 PX7 PX6 PX5 PX4 PX3 PX2 SCL SDA
Type
GND PWR IN IN PWR OUT OUT OUT PWR IN IN GND OUT OUT OUT OUT OUT OUT OUT OUT IN I/O
Description
Analog ground Analog VDD. Power Down (chip power down when high) Internal voltage reference Digital VDD. Vertical synchronization signal Horizontal synchronization signal Pixel clock output Sensor VDD, 2.5V ~ 3.3V Master clock input Resets all registers to their default values (chip reset when high) Digital ground Digital data out Digital data out Digital data out Digital data out Digital data out Digital data out Digital data out Digital data out I 2 CTM clock. I 2 CTM data. Internal pull high resister is 10KΩ.
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PAS302BCW-22S
CMOS Image Sensor IC
2. Block Diagram
Front Gain Color Gain CG Global Gain GG
The PAS302BCW-22S is a 1/4” CMOS imaging sensor with 644x488 physical pixels. The active region of sensor array is 644x484 as shown in Fig. 2.1. The sensor array is covered with Bayer pattern color filters and micro-lens. The first pixel location is programmable in 2 direction (X and Y) and the default value is at the left-down side of sensor array. After a programmable exposure time, the signals of image are sampled first with CDS (Correlated Double Sampling) block to improve S/N ratio and reduce fixed pattern noise. Three analog gain stages are implemented before signals are transferred to 10-Bit ADC. The front gain stage (FG) can be programmed to fit the saturation level of sensor to the full-range input of ADC. The programmable color gain stage (CG) is used to balance the luminance response difference between B, G and R color. The global gain stage (GG) is programmed to adapt the gain to the image luminance. After three gain stages, the signals will be digitized by the on-chip 10-Bit ADC. After the image data have been digitized, further adjustment to the signal can be applied before the data is output to next stage.
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Row Decoder
SCL
Sensor Array 644x484
FG
10-Bit A/D DAC2
3-Bit x2 ~ x4
DAC1
4-Bit x1 ~ x2
4-Bit x1 ~ x2
CDS Column Decoder
Timing Generator & Control Logic
Companding
Digital Gain Stage
Defect Compensation
PX(9 : 2)
SDA
SYSCLK
Figure 2.1. PAS302BCW-22S sensor block diagram
VSYNC
HSYNC
PXCLK
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PAS302BCW-22S
CMOS Image Sensor IC
3. Function Description 3.1 Defect Compensation
The Defect Compensation block can detect the possible defect pixel and replace it with average output of like-colored pixels from near side of defect pixel. There is no limitation capability of defect pixel number. This function can be programmed to enable/disable by user.
3.2 Companding Curves
The companding function which means compressing and expanding is used to simulate the gamma curve and do non-linear transformation before the data is output. There are 4 curves selected by setting Register Compand_Sel as shown in Fig. 3.1. This function can be programmed to enable/disable by user.
O/P ( 10-Bit) 11,1111,1111
3
2
1
0
without companding
00,0xxx,xxxx 00,1xxx,xxxx
010
011
10,xxxx,xxxx
11,xxxx,xxxx
I/P ( 10-Bit)
Figure 3.1 Companding curves programmed by Compand_EnH and Compand_Sel.
3.3 Power Down Mode
The PAS302BCW-22S can be powered down by setting register “Sw_PwrDn” = 1 or by enable Pwdn pin. The register value will sustain in the power down mode. PAS302BCW-22S supports 2 power down modes: Software power down:Set register “Sw_PwrDn” = 1 to power down all the internal block except I 2 CTM . Hardware power down:Pull Pwdn pin to high to power down the chip. The chip will go into standby mode.
3.4 Reset Mode
The PAS302BCW-22S can be reseted by setting register “Sw_Reset” = 1 or by enable Reset pin. PAS302BCW-22S supports 2 reset modes: Software reset:Set register “Sw_Reset” = 1 to reset all the I 2 CTM registers. Hardware reset:Pull Reset pin to high to reset the full chip.
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PAS302BCW-22S
CMOS Image Sensor IC
4. Output Format 4.1 Physical Sensor Array
644 - Column
Dark Line Dark Line Dark Line Dark Line
GRGRGRGR BGBGBGBG GRGRGRGR GRGRGRGR BGBGBGBG GRGRGRGR
488 - Row
644 X 484 Active Pixels
BGBGBGBG GRGRGRGR BGBGBGBG
BGBGBGBG GRGRGRGR BGBGBGBG
Figure 4.1 Physical Sensor Array
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PAS302BCW-22S
CMOS Image Sensor IC
4.2 Output Timing
VGA mode ( 644 x 488 ) pixel readout: H_Start[9:0] = 0, V_Start[8:0] = 0, Nov_By2[7:0] = 87, H_Size[9:0] = 643, V_Size[8:0]= 487,
NovSize = Nov_By2 *2 +1 = 175 Pixclks( default ) Line-time = NovSize + 644 = 819 Pixclks( default ) Hsync GRGR NovSize Pixclk B GB G Valid pixel = 644 Pixclks B GBG GRGR
Figure 4.2 Inter-line timing ( default )
If Mask_Dark[3] = 0,
Frame Time = LPF + 1 = 488 Line ( default ) Vsync Hsync Dark Dark Dark Dark Dark
Dark Line = 4 Line
Valid Line = 484 Line
Figure 4.3 Inter-frame timing (LPF default setting = 487, Mask_Dark[3] =0)
If Mask_Dark[3] = 1,
Frame Time = LPF + 1 = 488 Line ( default ) Vsync Hsync Dark Line = 4 Line Valid Line = 484 Line
Figure 4.4 Inter-frame timing (LPF default setting = 487, Mask_Dark[3] =1)
4.3 Hardware Windowing
Users are allowed to define window size as well as window location in PAS302BCW-22S, Window size can range from 20x14 to 644x484. The location of window can be anywhere in the sensor array. Window location and size is defined by register H_Start, V_Start, H_Size and V_Size; the H_Start defines the starting column while V_Start defines the starting row of the window; the H_Size define the column width of the window and V_Start define the row depth of the window.
4.4 Sub-sampling
PAS302BCW-22S can be programmed to output image in QVGA and QQVGA size by setting Registers Skip_Digital or Skip_Analog. In QVGA sub-sampling mode, both vertical and horizontal pixels are sub-sampling at 1/2, while in QQVGA sub-sampling mode, both vertical and horizontal pixels are sub-sampling at 1/4. The maximum sub-sampling rate is 1/16.
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PAS302BCW-22S
CMOS Image Sensor IC
5. I 2 CTM Bus
PAS302BCW-22S supports I 2 CTM bus transfer protocol and acts as slave device. The 7 bits unique slave address is 1000000 and the bus supports receiving / transmitting speed up to 400kHz.
5.1 I 2 CTM Bus Overview
There are only two lines SDA (serial data) and SCL (serial clock) carry information between the devices which are connected by I 2 CTM bus. Normally both SDA and SCL lines are open collector structure and pulled high by external pull-up resistors. Only the master can initiate a transfer (start), generate clock signals, and terminate a transfer (stop). Start Condition : A high to low transition of the SDA line while SCL is high defines a start condition. Stop Condition : A low to high transition of the SDA line while SCL is high defines a stop condition. Valid Data: The data on the SDA line must be stable during the high period of the SCL clock. Within each byte, MSB is always transferred first. Read/write control bit is the LSB of the first byte. Both the master and slave can transmit and receive data from the bus. Acknowledge : The receiving device should pull down the SDA line during high period of the SCL clock line when a byte was transferred completely by transmitter. When in the case of that a master received data from a slave, the master does not generate an acknowledgment on the last byte to indicate the end of a master read cycle.
SDA
SCL
S Start Condition
P Stop Condition
Figure 5-1: Start and Stop Conditions
SDA
DATA STABLE
DATA CHANGE ALLOWED
SCL
Figure 5-2: Valid Data
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PAS302BCW-22S
CMOS Image Sensor IC
5.2 Data Transfer Format
5.2.1 Master transmits data to slave (write cycle)
S : Start A : Acknowledge by slave P : Stop RW : The LSB of 1st byte to decide whether current cycle is read or write cycle. If RW=1 that means read cycle, if RW=0 that means write cycle. SUBADDRESS : The address values of PAS302BCW-22S internal control registers (Please refer to PAS302BCW-22S register description)
1ST BYTE 2ND BYTE n BYTEs + A
S
SLAVE ID (7 BIT)
RW
A
SUBADDRESS (8 BIT)
A
DATA
A
DATA
A
P
MSB
LSB=0
During the write cycle, the master generates start condition and then places the 1st byte data that combined slave address (7 bits) with a read/write control bit on SDA line. After slave(PAS302BCW-22S) issues acknowledgment, the master places 2nd byte (sub-address) data on SDA line. And then following the slave’s( PAS302BCW-22S) acknowledgment, the master places the 8 bits data on SDA line and transmit to PAS302BCW-22S control register (address was assigned by 2nd byte). After PAS302BCW-22S issue acknowledgment, the master can generate a stop condition to end this write cycle. In the condition of multi-byte write, the PAS302BCW-22S sub-address will be increased automatically after each DATA byte has been transferred. The Data and A cycles are repeated until last byte write. Every control registers value inside PAS302BCW-22S can be programming via this way. (Please refer to Figure 5.3.)
5.2.2
Slave transmits data to master (read cycle)
The sub-address was assigned by previous write cycle The sub-address is automatically increased after each byte read Am : Acknowledged by master Note: there is no acknowledgment from master after last byte read
1ST BYTE SLAVE ADDRESS (7 BITS)
2ND BYTE
n BYTE
S
RW
A
DATA (8 BIT)
Am
DATA
Am
DATA
1
P
NO ACK IN LAST BYTE
During read cycle, the master generates start condition and then place the 1st byte data that combine slave address (7 bits) with a read/write control bit to SDA line. After slave issue acknowledgment, 8 bits DATA was placed on SDA line by PAS302BCW-22S. The 8 bit data was read from PAS302BCW-22S internal control register that address was assigned by previous write cycle. Following the master acknowledgment, the PAS302BCW-22S place the next 8 bits data (address is increased automatically) on SDA line and then transfer to master serially. The
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PAS302BCW-22S
CMOS Image Sensor IC
DATA and Am cycles are repeated until the last byte read. After last byte read, Am is no longer generated by master but instead of keeping SDA line as high. The slave (PAS302BCW-22S) must releases SDA line back to master to generate STOP condition. (Please refer to Figure 5.3.)
SDA
SCL 1-7 S Start Condition Address R/W ACK from Receiver Data ACK from Receiver Data 8 9 1-7 8 9 1-7 8 9 P Stop ACK from Condition Receiver
Figure 5.3 Data Transfer Format
5.3 I 2 CTM Bus Timing
SDA tf tLOW SCL S tHD;STA tHD;DAT tSU;STA Sr tSU;STO P S tr tSU;DAT tf tHD;STA tSP tr tBUF
tHIGH
Figure 5.4 I 2 CTM Bus Timing
5.4 I 2 CTM Bus Timing Specification
PARAMETER SCL clock frequency Hold time (repeated) START condition. After this period, the first clock pulse is generated. Low period of the SCL clock HIGH period of the SCL clock Set-up time for a repeated START condition Data hold time. For I 2 CTM bus device Data set-up time Rise time of both SDA and SCL signals(note) Fall time of both SDA and SCL signals(note) Set-up time for STOP condition Bus free time between a STOP and START Capacitive load for each bus line
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STANDARD-MODE SYMBOL
UNIT kHz µs µs µs µs µs ns ns ns µs µs pF 9
fscl tHD:STA tLOW tHIGH tSU;STA tHD;DAT tSU;DAT tr tf tSU;STO tBUF Cb
MIN. 10 4.0 4.7 0.75 4.7 0 250 30 30 4.0 4.7 1
MAX. 400 3.45 N.D. N.D. 15
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PAS302BCW-22S
Noise margin at LOW level for each VnL connected device (including hysteresis) Noise margin at HIGH level for each VnH connected device (including hysteresis) Note: It depends on the "high" period time of SCL. 0.1 VDD 0.2 VDD
CMOS Image Sensor IC
-
V V
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PAS302BCW-22S
CMOS Image Sensor IC
6. Electrical Characteristics
Absolute Maximum Ratings Ambient Storage Temperature VDDD Supply Voltages ( with respect to Ground ) VDDA VDDMA VDDQ All Input / Output Voltages ( with respect to Ground ) Lead Temperature, Surface-mount process ESD Rating, Human Body model DC Electrical Characteristics ( VDD = 2.5V ± 4% , Ta = 0℃ ~ 70℃ ) Symbol Parameter Min. Typ. Type :PWR VDDA VDDD VDDQ IDD DC Supply voltage – Analog DC Supply voltage – Digital DC Supply voltage – I/O Operating Current 2.4 2.4 2.4 2.5 2.5 15 2 0.7 x VDDQ 0.3 x VDDQ 10 0.9 x VDDQ 0.1 x VDDQ Min. Typ. Max. 48 12 2.6 2.6 3.3 V V V mA µA V V pF V V -40℃ ~ +125℃ 3V 3V 4V 4V -0.3V to VDDQ + 1V +230℃ 2000V
Max.
Unit
IPWDN Power Down current Type :IN & I/O Reset and SYSCLK VIH VIL CIN VOH VOL Input voltage HIGH Input voltage LOW Input capacitor Output voltage HIGH Output voltage LOW
Type : OUT & I/O for PXD0:7, PXCK, H/VSYNC & SDA, load 10pf, 1.2kΩ,2.5volts
AC Operating Condition Symbol Parameter SYSCLK PXCK Master clock frequency Pixel clock output frequency
Unit MHz MHz
Sensor Characteristics Parameter Sensitivity Signal to Noise Ratio Dynamic Range Temperature Range Operation Stable Image
Typ. 1.56 > 45 60 -10 ~ 70
Unit V/Lux-Sec dB dB ℃
Note
0 ~ 50
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PAS302BCW-22S
VDDQ
PXCLK
HSYNC
VSYNC
VREF
Version 2.4, 20 Sep. 2005
C2 JP1
9
8
7
6
5
4
VREF
VDDQ
PXCLK
SY SCLK PWDN VDDA VSSA SDA SCL PX5 PX4 PX3 PX2 21 SCL 22 SDA 1 2 0.1U PWDN 3 C1
HSYNC
VSYNC
VDDD
PX7
15
16
PX6
17
18
19
20
PX7
PX6
PX5
PX4
PX3
PX2
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0.1U
PX8 PX6 PX4 PX2
PX9 PX7 PX5 VDDQ PX3 PXCLK HSY NC SCL RESET
7. Reference Circuit Schematic
U1 VSY NC SY SCLK SDA
10
SY SCLK
PWDN
RESET
11
RESET
1 3 5 7 9 11 13 15 17 19 21
2 4 6 8 10 12 14 16 18 20 22 SENSOR BOARD INTERFACE
12
VSSD
PX9
13
PAS302BCW
PX9
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PX8
14
PX8
Notes: VDDQ is 2.5V to 3.3V sensor power. C1 should close to sensor VDDA and AGND. C2 should close to sensor VREF and AGND.
CMOS Image Sensor IC
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PAS302BCW-22S
CMOS Image Sensor IC
8. Package Specification
Dimensions Package Body Dimension X Package Body Dimension Y Package Height Ball Height Package Body Thickness Thickness of Glass surface to wafer Ball Diameter Pin Pitch X axis Pin Pitch Y axis Edge to Pin Center Distance along X Edge to Pin Center Distance along Y Symbol A B C C1 C2 C3 D J1 J2 S1 S2 Min. 4310 4130 740 130 605 395 270 537.5 447.5 Typ. 4335 4155 800 160 640 415 300 800 800 567.5 477.5 Max. 4360 4180 860 190 675 435 330 597.5 507.5 Unit µm µm µm µm µm µm µm µm µm µm µm
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PAS302BCW-22S
CMOS Image Sensor IC
9. Recommended Lens and Holder
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PAS302BCW-22S
CMOS Image Sensor IC
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