SENSORS

IMAGEImage-sensor analog front-end ICsdeliver extra integration and flexibilityProduct OverviewThe WM8232, WM8233, WM8234 and WM8235 fromWolfson Microelectronics are 16-bit Analog Front-End (AFE)digitizer ICs capable of processing and digitizing the analogoutput signals from Charged Coupled Device (CCD) sensorsor Contact Image Sensors (CIS) at effective pixel samplerates of up to 210M Sample/s.The WM8234 has six channels with two ADCs and achievespixel sample rates up to 23M Sample/s per channel at a totaleffective conversion rate of 140M Sample/s.The WM8235 has nine channels with three ADCs andachieves pixel sample rates up to 23M Sample/s per channelat a total effective conversion rate of 210M Sample/s.IMAGE34Each device integrates multiple signal-processing channels,and implements functions including reset-level clamping,Correlated Double Sampling (CDS) and sample/hold,programmable gain, Automatic Gain Control (AGC) andoffset adjustment for each channel. The channel outputs aretime multiplexed, into an on-chip array of 16-bit high-speedADCs.Other integrated features include a 4-bit DAC for internalreference-level generation, automatic black-level calibrationto adjust the DC offset of the output data, and a sensortimingclock generator for CCD and CIS sensors. Thedevices also have a flexible output port that enablesdesigners to arrange digital output data in a variety offormats, and permit selection of either LVDS or CMOS outputarchitecture.The key difference between devices in the family lies inthe number of signal-processing channels provided. TheWM8232 and WM8233 have three and six channelsrespectively, with three ADCs, and achieve pixel sample ratesup to 35M Sample/s per channel.The variety of configurations available translates into higherscanning speeds at higher resolutions, for end-users, whileengineers can take advantage of the common flexiblearchitecture to simplify design-in and speed up time-tomarket.Features & Benefits3.3V single-supply operationSupply current: 320mA for WM8232/34, 380mA forWM8233and 400mA for WM8235Internally generated voltage referencesCompliant for spread-spectrum clock56-lead QFN package 7mm x 7mm for WM8234/35 and8mm x 8mm for WM8232/33ApplicationsDigital copiersUSB2.0-compatible scannersMulti-function printersHigh-speed CCD/CIS interfaceswww.FutureElectronics.com/Sensors