KAF-0400 Head (A2061)

© 2009-2014 Kevan Hashemi, Brandeis University HEP

Contents

Description
Operation
Modifications
Electronics
SchematicPCB

Description

The KAF-0400 Head is a LWDAQ device that provides clock signals for a KAF-0400 Sensor Head (A2063). The sensor head holds a single CCD image sensor of type KAF-0400, KAF-0401, KAF-0402, or KAF-0261.


Figure: The A2061B Top View, Enclosure Lid Removed. The flex cable connects to the sensor head. Its contacts face upwards within the flex connector housing. Pin one is marked with a blue stripe.

The A2061A provides a LWDAQ device socket in the form of a right-angle, shielded RJ-45. Connection to the A2063 is via the eight-way flex socket on the right side of the figure. For a bottom view of the board, see here.


Figure: The A2061A (Left) and A2063A (Right) Connected by a Flex Cable. The A2061A is hard to make because of close packing of its components. We replace it with the A2061B.

The KAF-0400 was the first version of Kodak's 768×512 pixel full-frame CCD. (Note that Kodak's image sensor division is now Truesense Imaging Inc, a subsiduary of ON Semiconductor.) The KAF-0400 was replaced by the KAF-0401E, which in turn was replaced by the KAF-0402. These sensors are pin-compatible, and we find that, despite slight differences in their specifications, they are interchangeable. They have 9μm square pixels and provide an active area 6.9 mm × 4.6 mm.


Figure: KAF-0400 Three-Second Exposure with Pin-Hole camera. The image is 800×520. The active area is outlined with a blue rectangle, and starts with column 20 in row 8. It ends with column 784 in row 516.

The image we obtain with the LWDAQ, contains 800 columns and 520 rows. Within this image, we recommend analysis boundaries 20, 8, 784, and 516 for left, top, right, and bottom edges respectively. These boundaries will enclouse only the active image pixels. The top rows tend to be filled with residual charge when the sensor is exposed to bright light, so we prefer to omit rows 0-7 from our analysis bounds.

VersionDescription
AKAF-0400 Head (original board, hard to assemble, reads KAF-0400, KAF-0401E, KAF-0402)
BKAF-0400 Head (fits in PPL enclosure, reads KAF-0400, KAF-0401E, KAF-0402, uses P206101D PCB)
CKAF-0261 Head (fits in PPL enclosure, reads KAF-0261, uses P206101D PCB)
Table: Versions of the KAF-0400 Head (A2061).

The A2061A and A2061B are compatible with the KAF-0400 Sensor Head (A2063) versions A and B. The A2061C is compatible with the KA-0261 Sensor Head (A2063C). In all cases, connection to the sensor head is with an eight-way flex cable. The A2063C differs from the A2063B in that three resistor values have been changed so as to modify the reset clock voltage for the KAF-0261.

The figure below is a 5-second x-ray exposure of a KAF-0261 by an A2061C with a 2.5-mm tungston ball in front of the image sensor. This sensor provides 520 × 520 active pixels each 20 μm square, for a total image area of 10.4 mm × 10.4 mm.


Figure: KAF-0261 X-Ray Exposure. When it arrives on our screen, the KAF-0261 image has 530 rows and 530 columns. Of these, 520 × 520 are active image pixels.

The dark current of the KAF-0261 is so low, we can expose to x-rays for several minutes. In this image we see the wires within a small thin-gap chamber (sTGC) along with some fiducial tungston balls, obtained over a 120-s exposure with 15-50 keV x-rays.

Operation

The A2061 complies with the LWDAQ Specification. The A2061A/B device type is 4 (KAF0400). The A2061C device type is 8 (KAF0261). Only four command bits are required to clear, expose, and read out the image sensor. These are VD2 and VD1, which operate the vertical clock phases of the image sensor, HD, which operates the horizontal clock phases, and DCEN, which enables 2 MPixel/s clocking of HD directly via the LWDAQ transmit logic signal.

DC16DC15DC14DC13DC12DC11 DC10DC9DC8DC7DC6DC5 DC4DC3DC2DC1
XXXXXX XXWAKELBXX V2DV1DHDDCEN
Table 1:Command Bit Allocation on the A2061. An "X" means the command bit serves no function.

The KAF-series image sensors require two vertical clock signals, φV1 and φV2, and two horizontal clock phases, φH1 and φH2, and one reset clock, φR. (For a detailed description and comparison of the KAF-series image sensor input voltages, see the A2063 Manual.) We are able to use the same vertical and horizontal clock phase voltages for all four sensors. But the φR must be modified to suit the KAF-0261. Thus the A2061C produces φR for the KAF-0261, but not for the KAF-0400, KAF-0401E, and KAF-0402. The change is accomplished by switching the values of R7, R40, and R38, as called for on the schematic.

To capture images from the KAF-0400, KAF-0401E, or KAF-0402, connect the A2061A to a KAF-0400 Sensor Head (A2063A or A2063B). If you are using a LWDAQ Driver (A2037E), you need firmware version 14 or higher. The LWDAQ Driver (A2037A) does not support these image sensors. All versions of the LWDAQ Driver (A2071E) firmware provide support. In the LWDAQ, select the Camera Instrument. Press the KAF-0400 button, which configures the Camera Instrument for KAF-0400 readout. There are similar buttons in the BCAM, Rasnik, and Dosimeter instruments, but you have to open the Info panel to see them. The Dosimeter Instrument always reads out a CCD image pixel-by-pixel from the image area, instead of transferring the image into a storage area line-by-line before reading it out pixel-by-pixel. The KAF-0400 has no storage area. The table below gives the Dosimeter Instrument parameters that use the KAF-0400 image area for radiation detection.

ParameterValueDescription
daq_device_type4Specifies KAF-0400 device LWDAQ hardware
daq_image_height520Number of rows
daq_image_width800Number of columns
daq_image_left20Left edge of active area
daq_image_top8Top edge of active area
daq_image_right784Right edge of active area
daq_image_bottom516Bottom edge of active area
Table: Dosimeter Instrument Parameters for KAF-0400 Image Capture.

To capture images from the KAF-0261, connect the A2061C to a KAF-0261 Sensor Head (A2063C). If you are using a LWDAQ Driver with Ethernet Interface (A2037E), you need firmware version 17 or higher. The LWDAQ Driver with VME Interface (A2037A) does not support the KAF-0261. If you are using the newer and faster LWDAQ Driver with Ethernet Interface (A2071E), you will need firmware version 5 or higher.

ParameterValueDescription
daq_device_type4Specifies KAF-0400 device LWDAQ hardware
daq_image_height520Number of rows
daq_image_width520Number of columns
daq_image_left20Left edge of active area
daq_image_top8Top edge of active area
daq_image_right516Right edge of active area
daq_image_bottom516Bottom edge of active area
Table: Dosimeter Instrument Parameters for KAF-0261 Image Capture.

The table above gives the Dosimeter Instrument parameters that use the KAF-0261 image area for radiation detection. You can configure the Camera, Dosimeter, BCAM, or Rasnik Instruments to capture with the KAF-0261 by pressing their KAF0261 buttons, which may be on the main panel or in the Info panel.

Modifications

A206101B: The A206101B circuit board has one error that requires modification as shown below.


Figure: Modification Required by the A206301B. Look for the black wire in the top left.

Resistor R50 must connect to OV, not U12-7. So we solder R50 off to one side and connect to 0V with a wire link.

A206101D: The A206101D layout has no errors. Both the A2063B and A2063C use this board, which fits in the PPL enclosure. The A2063C is identical to the A2063B except that resistors R7, R40, and R38 have different values, as show on the S2061_3 schematic.

Electronics

Note: All our schematics and Gerber files are distributed under the GNU General Public License.

Schematic

S2061_1: LVDS Transceiver and Power Switches
S2061_2: Command Receiver
S2061_3: Level Shifters
S2061_4: CCD Connection

PCB

A206101B.zip: Gerber files for the A206101B PCB of the A2061A.
A206101D.zip: Gerber files for the A206101D PCB of the A2061B/C.
A206101D.pdf: Multi-layer view of A206101D PCB.
A2061B: Assembly Instructions for A2061B.