USERS MANUAL ISL29501-ST-EV1Z UG055 Rev 0.00 Sand Tiger User Guide October 7, 2015 Description Key Features The ISL29501-ST-EV1Z is a distance measurement reference Self contained measurement system design. It combines the ISL29501 chip with an OSRAM SFH Enables proximity detection and distance measurement 4550 IR emitting LED and OSRAM SFH 213FA photodiode. The Emitter DAC with programmable current up to 255mA circuit board is enclosed in an opaque plastic chassis designed to optically isolate components. Included is a USB flash drive Operates in continuous or single shot mode containing the evaluation software for a PC and related On-chip active ambient light rejection technical documents. Regulated power 2.7V to 3.3V USB or external supply The ISL29501-ST-EV1Z board also allows quick evaluation of 2 I C interface supporting 1.8V and 3.3V bus the ISL29501 performance for a 2m sensing system. References Specifications ISL29501 Datasheet This board has been configured and optimized for the following operating conditions: AN1966, ISL29501 Sand Tiger Optics Application Note AN1917, ISL29501 Layout Design Guide Micro USB 2.0 connection UG054, ISL29501 Evaluation Software User Guide V = 5V (USB Power) IN AN1967, Temperature and Ambient Light Data Collection I maximum = 225mA DD P optical maximum = 70mW Ordering Information Wavelength = 860nm PART NUMBER DESCRIPTION Optical duty cycle maximum = 50% ISL29501-ST-EV1Z ISL29501 Sand Tiger demonstration kit, Emission angle = 3 (EVB, USB cable, software, technical documentation) Coherent light - No USB 5V 2.7V TO 3.3V LDO DVCC EVCC C 1 EIR DVSS C 2 IR R 4 LED R 5 R R R EVSS 1 2 3 A1 A2 ISL29501 PDp SCL PD 8051 SDA HOST PDn IRQ CONTROLLER SS AVCC CEn C 3 VOUT AVSS AVDD RSET C 4 R 4 FIGURE 1. SAND TIGER BLOCK DIAGRAM UG055 Rev 0.00 Page 1 of 15 October 7, 2015ISL29501-ST-EV1Z MAGNITUDE CALIBRATION Functional Description Magnitude calibration is done after the emitter current and duty The ISL29501-ST-EV1Z is both a reference design and cycle settings are programmed. It is a dark (no light) calibration demonstration board that provides a single platform to that takes less than 1s to run. Run this calibration from the GUI. demonstrate the features of the ISL29501. The ISL29501-ST-EV1Z circuit board and supplied enclosure have CROSSTALK CALIBRATION been designed to deliver maximum electrical and optical Crosstalk is defined as a signal that reaches the ISL29501 chip performance. directly without bouncing off the target. This can be electrical or optical. At close range and large return signal values, crosstalk The system sends out light pulses through the emitter LED and has a minor impact on distance measurements. At the far end of receives returned light pulses that reflected off a target. The difference in phase of the emitted signal and the return signal is the distance range the crosstalk might exceed the signal, adding error to measurements. converted to distance by the ISL29501 and is graphed in the evaluation software. The magnitude of the return signal is For this calibration the user makes a distance measurement with graphed as well. This and additional data is available in chip the return signal blocked from reaching the photodiode. This can registers, see UG054, ISL29501 Evaluation Software User be done in two ways. The first is to cover the emitter or Guide for additional details. photodiode optically preventing any of the emitted signal from reaching the photodiode. The second is to point the board toward Operating Features infinity so there is no return signal. Care must be taken since small amounts of signal will be returned by objects up to 4 The ISL29501-ST-EV1Z demonstration board is shown in meters away. The emitting angle of the light is 3 so you must Figures 4 and 5. The hardware enable function is controlled by a be sure that there are no objects within this cone when doing this software switch, which can be overriden shorting J9 pins 1 and 2. calibration. See the schematic for details. A Power-Good (PG) LED indicates that the LDO is regulating properly. Since the chip sees none of the emitted signal anything received is crosstalk. Run this calibration from the GUI after running External Power Supply Magnitude calibration. For high current/high duty cycle setups USB power may not be DISTANCE CALIBRATION able to power the board. In the default condition, jumper J10 Variation in delay of emitters, photodiodes and the ISL29501 will shorts pins 1 and 2 to connect to USB power to the LDO. To power the board with an external power supply, remove this jumper and change the signal path delay. To compensate for this a reference connect the positive (+) terminal to J10-2 and the negative (-) to point at a known distance needs to be established. This J10-4. reference is calculated during distance calibration. The process involves making a distance measurement at a known distance. If you want to bypass the LDO and power the ISL29501 directly While it is not critical it is best to use a reference distance about with a power supply, remove the jumper on J10. Use J10-4 for 25% of the intended range. The GUI will write the correct your ground connection and apply the positive voltage to TP7. registers that establish the reference distance inside the chip. External Microprocessor It is important that there are no objects inside the 3 emitting angle other than the target. For debug of customer written software, it might be useful to 2 connect the Sand Tiger to a different microprocessor. The I C Once these calibration registers are written, all succeeding pins SCL and SDA are available on pins J4-4 and J4-3 distance will have this value subtracted real time from the respectively. The remaining support pins are available on measured value. Run this calibration from the GUI after running J5: SS - J5-4, IRQ - J5-3 and CEn - J5-2. The support pins are crosstalk calibration. See UG054, ISL29501 Evaluation generally connected to GP pins on the microprocessor. SCL and Software User Guide for details on how to run the calibrations in SCL are compatible with 1.8V microprocessors but unfortunately the GUI. the support pins require 3V signaling. Operating Range System Calibration The circuit board contains an LDO to convert the input voltage to Before meaningful measurements can be made the calibration the ISL29501 operating voltage range, 2.7V - 3.3V. By default the registers in the chip need to be loaded. This can be done in two board is configured for USB power but can be alternately ways. The first is to load a profile that contains data into the GUI. powered by an external power supply. The LDO resistors are This could be one of the Intersil provided profiles or one that was ratioed to create a 3.0V power rail. All other set-up conditions can saved previously by the user. See UG054, ISL29501 Evaluation be configured through the chip registers and evaluation software. Software User Guide for further details. The second is to calibrate the board directly. Calibrating Sand Tiger There are 3 separate standard calibrations that need to be executed in order to calibrate the system. These are magnitude, crosstalk and distance calibrations. UG055 Rev 0.00 Page 2 of 15 October 7, 2015