Functional Description

This manual is arranged in the following sections:

■ Operation

This general description of the operation and the functionalities is targeted at the user and application level.

■ Hardware Design

All information regarding hardware design aspects are covered here.

■ Instruction Set

Contains a detailed description of the data communication and the command set.

■ Optical Design Considerations

The chapter where the user finds some design guidelines for developing appropriate optics and illumination for the device.

1. Operation

1.1. Introduction

The epc600 chip is based on the 3D-TOF principle. Modulated light is sent out by a transmitter. This light is then reflected by the object to

be detected and the returning light is sampled by a photosensitive sensor. The receiver compares the phase difference between the emit-

ted and the received light and computes the time difference of the “time-of-flight”. This value multiplied by the speed of light (ca.

300'000km/sec) and divided by 2 corresponds directly to the distance.

epc600

device

Backscattered light with a time delay

dependent on the distance between

the object and the device

Object

Figure 10: The time-of-flight principle

1.2. General overview

The epc600 chip is designed to enable simple and cost effective system designs. Together with a tiny microprocessor and few external

components, a very low cost but fully functional TOF sensor system can be built (refer to Figure 11).

The epc600 system-on-chip contains:

■ A full data acquisition path with a power driver for the LED, the photo-receiver, the signal conditioning, the A/D converter and the signal

processing.

■ An on-chip controller managing the data acquisition and the data communication.

■ A 2-wire serial interface for the command and data communication.

■ A supply-voltage power management unit.

Microprocessor

IR LED

epc600

LED

SCLK

SDATA

< 180mA

CCD

SCLK

SDATA

2-wire interface

OUT

DIST

Figure 11: Basic application

The measurement functionality supports distance and ambient-light measurement with variable integration times and on-chip temperature

measurement for drift compensation.

The sensitivity of the system can be adjusted o n the fly to the object reflectivity, the object distance and the ambient-light conditions by

means of integration time. The longer the integration time, the higher the sensitivity.

In cases where the illumination power of the built-in driver is not sufficient, the epc600 chip can also be used with an external LED driver.

This allows longer operational ranges or faster measurements, resulting in a faster response time and a reduced ambient-light sensitivity.

© 2014 ESPROS Photonics Corporation

Characteristics subject to change without notice

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Datasheet epc600 - V1.3

www.espros.ch