AN2018S Correlated Double Sampling IC Unit:mm 0.15 0.65 ■ Features 1.5±0.2 0.1±0.1 1.27 The AN2018S is used to reduce noise in CCD image sensor output signal. It performs correlated doublesampling on image signal sent from a CCD sensor to output clearer image signal. 5.0±0.3 0.4 0.4±0.25 ■ Overview 0.3 • Operating on low voltage (V CC=4.8V), consuming little current (ICC =12.7mA typ.) • Including a high-speed sampling circuit responding to 510-830H CCD • 6dB or 9dB fixed gain • 83-dB high S/N-ratio (at 6dB output) 4.2±0.3 6.5±0.3 8-Pin SOP Package (SOP008-P-0225) p ■ Pin Descriptions Pin No. Pin name 1 2 CDS output (9dB) 3 CCD signal input 4 VCC 5 Sampling pulse input (2) 6 Sampling pulse input (1) 7 GND 8 CDS output (6dB) Blanking pulse input ■ Block Diagram 6dB OUT GND SP1 SP2 8 7 6 5 + 6dB + – 9dB – BLK S/H BIAS S/H 50kΩ 1 2 3 4 9dB OUT BLK SIG.IN VCC ■ Absolute Maximum Ratings Parameter Symbol Rating Unit Supply voltage VCC 5.5 V Supply current ICC 18 mA mW Power dissipation PD 99 Operating ambient temperature Note 1) Topr –20 to +70 ˚C Storage temperature Note 1) Tstg –55 to +125 ˚C Note 1) Ta=25˚C except operating ambient temperature and storage temperature. ■Recommended Operating Range (Ta=25˚C) Parameter Operating supply voltage range Symbol Range VCC 4.5V to 5.1V ■ Electrical Characteristics (VCC=4.8V, Ta=25±2˚C) Parameter Symbol Supply current ICC Terminal voltage pin (3) V3 Terminal voltage pin (8) V8 Terminal voltage pin (1) V1 6dB amp. gain G1 9dB amp. gain G2 AMP frequency characteristics * fC Condition VCC=4.8V VCC=4.8V Pint, y=4.8V VCC=4.8V Pint, y=4.8V VCC=4.8V Pint, y=4.8V Input level=300mVP–P Input level=300mVP–P min CMR Sampling pulse threshold (1) VTH1 VCC=4.8V Sampling pulse threshold (2) VTH2 Blanking pulse high level VTHB VCC=4.8V VCC=4.8V V3=300mVP–P max Unit 12.7 16.2 mA 2.48 2.63 2.78 V 1.30 1.60 1.90 V 1.25 1.55 1.85 V 5.0 6.0 7.0 dB 7.8 9.0 10.2 dB VCC=4.8V V3=100mVP–P 10MHz VCC=4.8V V3=100mVP–P 10MHz AMP common mode rejection ratio * typ 9.2 –3.0 dB –35 dB 0.8 1.5 2.2 V 0.8 1.5 2.2 V 3.5 Note) The value in the above characteristics is not a guaranteed value, but reference one on design. * The characteristics are of the amplifier itself. V ■ Pin Descriptions Pin No. Pin name DC voltage (VCC=5V) Description Equivalent circuit VCC (4) 1 9dB OUT Black level: 1.55V •9-dB-amp. output CDS signal •Typical 1.55V DC output •90-Ω output impedance 8 GND (7) H 3.5V VCC (4) 50µA 2 BLK 1 33kΩ 1kΩ 1kΩ 50kΩ 63kΩ GND (7) L 0.5V VCC (4) 75µA 3 SIG.IN Black level: 2.6V 38kΩ 500Ω 3 200Ω 1kΩ 58kΩ •Blanking (Hclear) pulse input (from an AN2145 series only) •Active high •3.0V threshold voltage •50kΩ input impedance •Grounded or left open when not used •CCD signal input •CCD signal must be input through a capacitor. •The capacitor should preferably be 0.022µF. •2.6V typ. bias voltage GND (7) 4 VCC •Supply voltage 4.8V H 2.2V VCC (4) 300µA 5 SP2 5 28kΩ 1kΩ 20kΩ GND (7) L 0.8V H 2.2V VCC(4) 300µA 6 28kΩ 1kΩ SP1 6 20kΩ GND 8 6dB OUT •Sample-hold pulse input •Active high •1.5V threshold voltage •Sampling pulses are input in synchronization with the feed-through timing of CCD signal at Pine. GND (7) L 0.8V 7 •Sample-hold pulse input •Active high •1.5V threshold voltage •Sampling pulses are input in synchronization with the video timing of CCD signal at Pine. •Ground Black level: 1.6V Same as for Pinq. •6-dB-amp. output CDS signal Note) The above characteristics value, measured at VCC=5V, is not a guaranteed value, but reference one on design.