LX1973A EVALUATION BOARD USER GUIDE LX1973A AMBIENT LIGHT DETECTOR (R) TM Copyright (c) 2006 Rev. 1.0, 2006-09-14 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 1 LX1973A EVALUATION BOARD USER GUIDE INTRODUCTION TO PRODUCT The LX1973A Evaluation Board is available from Microsemi for evaluating the functionality and performance of the LX1973A ambient light sensor. The component sizes used on the evaluation board facilitate easy probing, however, in practice, smaller component sizes are recommended to minimize the circuit physical size. KEY FEATURES Nearly Perfect Best EyeTM Human Eye Spectral Response 25C Dark Current < 0.005 lux 5 Decades Compressed Output 10% Accuracy Over Temperature Very Low IR Sensitivity Highly Accurate & Repeatable Output Current vs. Light Scalable Output Voltage No Optical Filters Needed APPLICATIONS * * Auto Headlamp Control Auto Mirror Contrast Control PART SPECIFIC INFORMATION Part Number Product LX1973AIDU Ambient Light Detector, MSOP Standard Package LX1973AIDR Ambient Light Detector, MSOP Reverse Form Package Table 1 - PART INFORMATION IC EVALUATION BOARDS LX1973AIDU LX1973A EVAL KIT Table 2 - EVALUATION BOARD INFORMATION Copyright (c) 2006 Rev. 1.0, 2006-09-14 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 2 LX1973A EVALUATION BOARD USER GUIDE SCHEMATIC AND PCB LAYOUT FOR LXE PWR Q1 NDS0610 J4 640457-5 1 VCC GND AUTO OUT PWM 2 R47 5.11K 3 1 4 8 VDD 5 VSS 7 2 R48 4.99K NC 3 NC Part NC 6 NC 4 5 OUT D8 BAW56 NC U13 LX1973A SW10 R49 56.2K R50 51.1K R51 4.99K C24 4.7F C23 0.22F R53 100K R52 50K PWR Q2 2N7002 / SOT Figure 1 - LX1973A Evaluation Board Schematic Copyright (c) 2006 Rev. 1.0, 2006-09-14 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 3 LX1973A EVALUATION BOARD USER GUIDE Figure 2 - LX1973A Evaluation Board PCB Layout IC BLOCK DIAGRAM Figure 3 - Simplified Block Diagram Copyright (c) 2006 Rev. 1.0, 2006-09-14 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 4 LX1973A EVALUATION BOARD USER GUIDE and Pin 2 on connector J4 by using multimeter (Red lead to pin 1, black lead to pin 2) to verify +5V power is supplied to the board. LX1973A EVAL BOARD Schematic: The LX1973A Eval board schematic is shown in Figure 1. 2) Power on +3.3V to the AUTO pin to turn on the light sensor. The light sensor output should show on the scope. While observing the sensor output, power on / off the 3.3V. This demonstrates that the sensor output is controlled by the AUTO pin. PCB Layout: The LX1973A Eval board layout is shown in Figure 2. Connections: The LX1973A Evaluation Board has a 5-pin connector connecting to outside power and signals. The connection pin names and functions are listed below. Figure 4 is a suggested test connection diagram. 3) Change the light input (simply cover sensor with hand) while observing the scope, the waveform should change in conjunction to the light input change. Jumper Setting: Jumper SW10 is used to bypass the PWM effect, if you don't want to use PWM input, you can put the jumper cap on. Pin # Pin Name 1 VCC +5V Power Supply 2 GND Power Return 3 AUTO Sensor On/Off Control 4 OUT 5 4) Change TRIMPOT R52 value can change the sensor output circuit sensitivity and scale. The smaller the R52 value, the larger range the light sensor can sense, and the lower sensitivity the circuit will be. Function 5) Connect +3V PWM signal to pin 5. Adjust PWM duty cycle while observing the sensor output. The output amplitude should change with the PWM duty cycle change. Sensor Output 6) When the PWM duty cycle is 100%, it is equal to a +3V power to pin 5. If a +3V (or +3.3V) voltage is connected to pin 5, it sets the minimum output voltage of the sensor. PWM PWM Input Table 3 - Connector Pin Assignment Basic Test Steps: The following is a demonstration scenario that can be used to evaluate the LX1973A. Note: The LX1973A is very sensitive to light. Office lighting may saturate the device 1) Make connections as shown in Figure 4. Apply 5V power source to the board. Measure Pin 1 Copyright (c) 2006 Rev. 1.0, 2006-09-14 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 5 LX1973A EVALUATION BOARD USER GUIDE LX1973A TYPICAL TEST HOOKUP Figure 4 - LX1973A Eval Typical Test Hookup Copyright (c) 2006 Rev. 1.0, 2006-09-14 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 6 LX1973A EVALUATION BOARD USER GUIDE LX1973A EVALUATION BOARD BILL OF MATERIALS MISCELLANEOUS COMPONENTS Line Item Part Description Manufacturer & Part # 1 2 3 4 Microsemi IC - Ambient Light Sensor MOSFET P-CH 60V 120MA SOT-23 MOSFET N-CH 60V 300MA SOT-23 Diode Schottky 30V 100MA MICROSEMI FAIRCHILD PHILIPS 5 Conn Header rt. Angle 5position .100 AMP 640457-5 6 Trimpot cerm 50K OHM 25TRN TOP MURATA PV36W503C01B00 LX1973AIDU NDS0610 2N7002 T/R ST MICROELECTRONICS BAR43AFILM Reference Designators Qty U13 Q1 Q2 D8 1 1 1 1 J4 1 R52 1 Case Reference Designators Qty 0805 0805 C24 C23 1 1 Case Reference Designators Qty 0805 0805 0805 0805 0805 R47 R48,51 R49 R50 R53 1 2 1 1 1 Case MSOP-8 SOT-23 SOT-23 SOT-23 Through Hole Through Hole CAPACITORS Line Item 1 2 Part Description Capacitor, 4.7F, 16V, 20% Capacitor, 0.22F, 16V, 20% Part Description PANASONIC PANASONIC ECJ-2FF1C475Z ECJ-2VF1C224Z RESISTORS Line Item 1 2 3 4 5 Part Description Resistor, 5.11K, 1%, 1/8W Resistor, 4.99K, 1%, 1/8W Resistor, 10K, 1%, 1/8W Resistor, 51.1K, 1%, 1/8W Resistor, 100K, 1%, 1/8W Copyright (c) 2006 Rev. 1.0, 2006-09-14 Part Description PANASONIC PANASONIC PANASONIC PANASONIC PANASONIC ERJ-6ENF5111V ERJ-6ENF4991V ERJ-6ENF1002V ERJ-6ENF5112V ERJ-6ENF1003V Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 7