Application Note DK90308 / DK90314 Evaluation Kit Scope The DK90308 and DK90314 provide a communications interface between the device and PC. All necessary components for implementing the three application circuits with the user’s bridge sensor are on board. This document describes the board itself and setup of the common application circuits for the DK90308 and DK90314 Evaluation kit. Applications Absolute Voltage Output Mode: The device uses an external FET to regulate the supply voltage. The supply voltage is supplied from J2 thru JP3 to VDD1, then the device regulates +5V on VDD using the onboard FET giving a stable output over varied supply voltage. Ratiometric Voltage Output Mode: In this application the output follows the supply voltage; this is used when the device output is tied to an A/D converter sharing the same supply and ground reference. A 4.5V to 5.2V supply voltage is supplied thru VDD and VDD1 tied together. JP3 must be open for this mode to avoid permanent damage to the chip. Current Output Mode: In Current Mode the device supplies a 4 to 20mA current range for use as a 2-wire analog sensor. VDD is regulated by the onboard FET from the supply (7V to 35V) thru VDD1. JP3 must be open to separate the interface circuit supply thru J2 from the device current supply thru VDD1. The device supply ground must be floating with respect to the interface circuit ground. DO NOT CONNECT CMN to GND. The DK90308 and DK90314 can also be used to communicate with the MLX90308 and MLX90314 in custom external circuits. For more information about the MLX90308 and MLX90314 consult the device datasheet. Related Melexis Products MLX90308 Programmable Sensor Interface MLX90314 Programmable Sensor Interface SW90308 Software for MLX90308CCC and MLX90314AB 90308CCC90314AB UsersManual.pdf 39011yyyyyzz Rev 1.3 Page 1 of 6 Jan-2008 Application Note DK90308 / DK90314 Evaluation Kit PC GND VDD1 VDD VCC Hardware Description Communications Interface Conne ctor REG JP1 Optional Sensor DUT SO16 JP2 JP4 IO2 S U P P L Y IO1 J3 JP3 TMP FLT O FC VBN VBP VMO CMN Component side view: Connector COM 12V GND VBN IO1 IO2 FLT VBP TMP OFC VDD VDD1 CMN VMO COMS VCC JP1 JP2 J3 JP4 JP3 39011yyyyyzz Rev 1.3 Function SO16W Pin No SERIAL connection to PC + 12V Power Connector General Ground Connector 15 Negative Bridge Input 7 Bidirectional I/O 1 Bidirectional I/O 2 Filter Pin 4 Positive Bridge Input 6 Temperature sensor Input 8 Offset Control Output 5 Regulated Supply Voltage 9 Unregulated Supply Voltage 10 Current Mode Negative Rail 14 Voltage Mode Output 12 Communication 16 Power Supply TSTB to GND (Jumper open) FLT to 39nF (Jumper closed) +12V Supply to VDD1 Absolute Voltage Mode (Jumper closed) Ratiometric Mode (Jumper open) VDD1 will be shorted to VDD Current Mode (Jumper Open) Shorten U5 pads to VBN (closed) Shorten U5 pads to VBP (closed) Page 2 of 6 Jan-2008 Application Note DK90308 / DK90314 Evaluation Kit Schematic 39011yyyyyzz Rev 1.3 Page 3 of 6 Jan-2008 Application Note DK90308 / DK90314 Evaluation Kit Typical Applications Absolute Voltage Output Mode 39011yyyyyzz Rev 1.3 Page 4 of 6 Jan-2008 Application Note DK90308 / DK90314 Evaluation Kit Ratiometric Voltage Output Mode 39011yyyyyzz Rev 1.3 Page 5 of 6 Jan-2008 Application Note DK90308 / DK90314 Evaluation Kit Current Output Mode TO com PC Reg 12V Power Supply Opt. Sens DUT SOI16 4-20 mA Output Current 7V-35V Supply Note : Don't tie CMN to GND ! Sensor Bridge Temp Res 39011yyyyyzz Rev 1.3 Page 6 of 6 Jan-2008