Datasheet MLX90255BA
Linear Optical Array
Features and Benefits
128 x 1 Sensor-Element Organization (1 Not Connected, 1 dummy, 128 real, 1 dummy
and 1 Dark Pixel)
385 Dots-Per-Inch (DPI) Sensor Pitch
High Linearity and Uniformity for 256 Gray-Scale (8-Bit) Applications
High Sensitivity: 1.7V @ 10µW/cm² @ 0.7ms integration time
Special Gain Compensation for use with single LED light source
Output Referenced to Ground
Low Image Lag
Single 5V Supply
Replacement for Texas Instruments TSL1301 & TSL1401 and MLX90255AA
Operation to 1MHz
Applications
Position Sensing
Electrical Power Assist Steering (EPAS)
Spectrometer Applications
Ordering Information
Part No.
Temperature Suffix
Package
LA
Option
-BA
Temperature Range
MLX90255
MLX90255
K
K
-40°C to 125°C Automotive
-40°C to 125°C Automotive
JA
-BA
Functional Diagram
Description
The MLX90255BA linear sensor array consists
of a 128 x 1 array of photodiodes, associated
charge amplifier circuitry and a pixel data-hold
function that provides simultaneous-integration
start and stop times for all pixels. The pixels
measure 200µm (H) by 66 µm (W) and 8 µm
spacing between pixels. Operation is simplified
by internal control logic that requires only a
serial-input (SI) signal and a clock.
4
3
Pixel 1
Pixel 2
Pixel 132
Integrator Reset
The sensor consists of 128 photodiodes
arranged in a linear array. Light energy falling on
a photodiode generates photocurrent, which is
integrated by the active integration circuitry
associated with that pixel. During the integration
period, a sampling capacitor connects to the
output of the integrator through an analog
switch. The amount of charge accumulated at
each pixel is directly proportional to the light
intensity and the integration time. The output
and reset of the integrators is controlled by a
132-bit shift register and reset logic. An output
cycle is initiated by clocking in a logic 1 on SI.
This causes all 132 sampling capacitors to be
disconnected from their respective integrators
and starts an integrator reset period.
Sample
Switching Logic
External
Load
Hold
Q1
Q2
Q132
132-Bit Shift Register
2
1
5
(continued on page 4)
MLX90255BA Linear Optical Array
3901090255
Page 1
Rev 1.2 08-Aug-01