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db12348e_V3.11_preliminary_2017-07-06

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AS89010

V3.11

1 GENERAL DESCRIPTION

The ASIC AS89010 is a low noise sensor interface application specific standard product (ASSP) and suitable

for coupling of multi-channel optical sensors or sensors using current output. It converts input currents of

for example photodiodes (both polarities) to a digital output and realizes a continuous or triggered

measurement via current integration. Optional the integration time and sensitivity can be controlled by

external programming to extend the internal functions and parameters. The four signal channels convert

directly and simultaneously the input currents to a digital representation of the measured average. The

channels may be divided into three signal channels and one dummy channel for compensation of parasitic

currents. This ASIC is especially suitable for signal conditioning of photodiodes of array sensors like color

or other optical sensors with maximum of 4 channels per chip1. A configurable conversion gain factor and

integration time support a dynamic range2 of 1 - 2.68E+08 and achieves an accuracy of up to 16 bit signal

resolution with sensitivity up to 20 fA/LSB.

The internal reference generations offers a high reliability. The converter is insensitive to a 50 Hz/60 Hz

external disturbances and was especially designed to accommodate high accuracy at high sensitivity

offering high robustness. Automatic Power down (sleep function) between subsequent measurements offers

operation with very low current c60onsumption. Further, it offers a wide range of reference currents

(1.25 nA to 5 µA), integration times (1 ms to 1 s), synchronized mode and other control modes adjustable

by user programming. The conversion data can be accessed via 16 bit/400 kHz fast I²C Interface with

programmable slave addresses. Measurement of actual integration time for a full triggered measurement

can be performed.

AS89010’s supported operating modes depending on required performance:

▪

CMD Mode – single measurement and conversion (controlled via I²C bus),

▪

CONT Mode - continuous measurement and conversion (periodically recurring measuring cycles)

until “Stop” controlled via I²C bus,

▪

SYN[x] modes - synchronized measurement and conversion:

–

[SYNS Mode] synchronization of start,

–

[SYND Mode] synchronization of start and stop of measuring cycle on the falling edge of the

SYN pin.

The settings for the input current range and integration time are not affected by alternative modes. Further

the converter supports functions like Power down and Standby. It represents a low power solution and is

also suitable for mobile applications.

Based on the high flexibility the AS89010 is suitable as converter for a width range of multi-channel sensors

with current output. The device achieves a high dynamic range especially in (back) light applications and

in measurements of integral intensity of pulsed light. The combination of ams Sensors Germany’s color

sensors with AS89010 is excellently suited for photometry applications (brightness, color coordinate and/or

color temperature), for determining current values for control of spectrally mixed LED light sources or as

sensors for display and (back)light calibration and mobile devices for light measurement. The sensor signal

IC is available in SMD housing or can be supplied as a bare die.

1 Upon consideration of that I²C address more ASICs may be used in parallel to a sensor to convert more than 4 sensor channels. In that

case special operating notes must be considered.

2

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