MLX75031 Datasheet, PDF (17/67 Pages) Melexis Microelectronic Systems – Optical Gesture & Proximity Sensing IC

MLX75031
Optical Gesture & Proximity Sensing IC
with Integrated LED Drivers
Datasheet
8.2. Ambient Light Sensor
8.2.1. Normal Operation
The ambient light detection system of the MLX75031 consists of two independent channels C & D and an
on-chip controllable dedicated ground pin GNDAMB. GNDAMB is internally set to GNDA in normal
operation. An external photodiode is connected in between each channel and GNDAMB. The Base-Emitter
diode of a bipolar transistor generates a logarithmic transfer function from the incoming photocurrent to an
internal voltage. Please refer to the MLX75031 EMC guidelines to improve the EMC resistance of the
ambient channels
8.2.2. Logarithmic Transfer Function
Following graphs show the input current to output ADC value characteristic of each ambient channel.
REVISION 001 – JANUARY, 2013
39010xxxxx
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