- SS-HQ1 Application Notes -
Ver.1.0.0 January 7, 2005
44
Fig 6.3-1 SS-HQ1 CCD Drive Circuit Example (ICX404/405AK, ICX408/409AK) shows the drive circuit when
using 1/3 type CCD image sensors (ICX404/405AK, ICX408/409AK). Both Vsub voltage and RG voltage are
adjustment-free. Vsub is a voltage generated inside the CCD and is used to clamp the shutter pulse, so an
external clamping circuit is not required. The CXD3172AR SUB (36pin) output is input via capacitor to the
CCD’s SUB pin.
The CXD3172AR RG (19pin) is input to the CCD after its DC component is cut by a capacitor. But the high
clamp circuit is need.
Fig 6.3-2 SS-HQ1 CCD Drive Circuit Example (ICX206/207AK, ICX278/279AK) shows the drive circuit when
using 1/4 type CCD image sensors (ICX206/207AK, ICX278/279AK). Both Vsub voltage and RG voltage are
adjustment-free. Vsub is a voltage generated inside the CCD and is used to clamp the shutter pulse, so an
external clamping circuit is not required. The CXD3172AR SUB (pin 36) output is input via a capacitor to the
CCD’s SUB pin. The CXD3172AR RG (19pin) is input to the CCD after its DC component is cut by a capacitor.
Fig 6.3-3 SS-HQ1 CCD Drive Circuit Example (ICX226/227AK, ICX228/229AK) shows the drive circuit when
using 1/4 type CCD image sensors (ICX226/227AK, ICX228/229AK). Both Vsub voltage and RG voltage are
adjustment-free. Vsub is a voltage generated inside the CCD and is used to clamp the shutter pulse, so an
external clamping circuit is not required. The CXD3172AR SUB (pin 36) output is input via a capacitor to the
CCD’s SUB pin. The CXD3172AR RG (19pin) is input to the CCD after its DC component is cut by a capacitor.
Fig 6.3-4 SS-HQ1 CCD Drive Circuit Example (ICX254/255AK, ICX258/259AK) shows the drive circuit when
using 1/3 type CCD image sensors (ICX254/255AK, ICX258/259AK). Both Vsub voltage and RG voltage are
adjustment-free. Vsub is a voltage generated inside the CCD and is used to clamp the shutter pulse, so an
external clamping circuit is not required. The CXD3172AR SUB (pin 36) output is input via a capacitor to the
CCD’s SUB pin. The CXD3172AR RG (19pin) is input to the CCD after its DC component is cut by a capacitor.
6.3.2. Clock System Changes
In the internal synchronization mode, the composition which operates only by one X'tal is the basic system.
And it can be made to operate even if it does not constitute PLL.
And when it constitutes the clock system inputted into ECK/MCK using two VCO, it is necessary to constitute
PLL and to input into MCK. We recommend to use LC VCO or X'tal VCO properly according to a use to the
MCK VCO in that case. By exchanging ECK VCO, it corresponds to change of the number of CCD pixels, and
TV system (NTSC/PAL).
6.3.3. Frequency Response Changes
As mentioned above, the encoder clock (ECK) frequency differs according to the type of CCD image sensor
used. Therefore, the bandwidth and carrier frequency of the luminance signal output from CXD3172AR IOY
(pin 75) also differ.
In addition, the NTSC and PAL subcarrier frequencies differ from each other, making it necessary to also
change the characteristics of the BPF connected to the rear end of the CXD3172AR IOC (pin67).