- SS-HQ1 Application Notes -
Ver.1.0.0 January 7, 2005
21
3.6.2. Countermeasures for Areas around Individual Devices
Countermeasures for the CCD and Surrounding Areas
1. To prevent noise from entering the CCD, be sure the ground pattern is sufficient and connect individual
LC filters to power supply pins VDD (+15V or +12V) and VL (-5.0V or -7.0V) to keep the power supply
separate from other circuits.
2. Noise may be generated if ringing is observed in the waveform of reset gate (RG) clock input, or if
overshoot or undershoot is observed in the waveform of horizontal register transfer clock input (H1 and
H2). To deal with it, insert a damping resistance of approximately 100 ohms in the signal line for
waveform adjustment.
3. In addition, be sure to connect a buffering transistor near the CCD signal output (VOUT) because it is
susceptible to noise and has low load driving capability.
4. For details, see the CCD data sheet and application circuit diagrams.
Countermeasures for the CXA2096N and Surrounding Areas
1. For the power supply of VCC (pins 5, 16, and 23), connect LC filters to prevent crosstalk from other
circuits causing interference. Additionally, connect bypass capacitors between each pin and ground.
2. PIN and DIN (pins 21 and 22) are input pins for the CCD signal, so make the signal lines from the CCD
as short as possible and surround them with a ground shield.
3. VRB and VRT (pins 7 and 8) are output pins for ADC reference voltage. Be sure to connect a
bypass capacitor near them because they are susceptible to noise.
We recommend connecting the capacitance of around 4.7 uF and around 0.1 uF in parallel.
4. To reduce horizontal clamp noise, increase the capacitance of the capacitor between AGCCLP (pin 13)
and the ground. However, caution is advisable because excessive capacitance may cause slower
startup and impair clamp operation. We recommend a capacitance of around 0.1 uF.
5. XRS, SHP, and SHD (pins 11, 17, and 18, respectively) are input pins for sample hold. Noise may be
generated if overshoot or undershoot is observed in the waveform. To deal with it, insert a damping
resistance of approximately 100 ohms in the signal lines for waveform adjustment.