Circuit Design

When I trying to debug the circuit board which designed for digital power using XMC1302T38-0032. I meet such error. “ Connecting to target...ERROR: Could not connect to target. Target connection failed. GDBServer will be closed...Restoring target state and closing J-Link connection... ” Finically I found the problem is because BMI (Boot Mode Index) is not right for debug. When XMC1000 device is just out of the factory, its default BMI value is ASC Bootstrap Load Mode. So I change the BMI to User Mode (debug) SWD0 (SWDIO=P0.14, SWDCLK=P0.15). The I can sue DAVE4 to debug the boards. I use the XMC42_OBD build in on XMC1000 boot kit to debug my board. The method to change BMI is. 1) click the tool icon as below.   2) On the pop up window, you can get or set BMI as below. 3) Set the BMI So I suggest before design your own board, try to under stand the BMI options first. Thus, you could design a board could use.

Recently, I am trying to design a high side current sensor circuit in my power system. But I am suffering occasionally broken of the sensor chip. And I realize that the proper protection of this circuit is quite important. Here is a protection circuit came from Ti Design. The original file could be found here .

A digital potentiometer (also called a resistive digital-to-analog converter or informally a digipot ) is a digitally-controlled electronic component that mimics the analog functions of a potentiometer . It is often used for trimming and scaling analog signals by microcontrollers . It Can be divided to Volatile version and Non Volatile version. Volatile Version will reset when lost power. The non-volatile version can keep the set when lost power. Manufacturer Part #: Optional Digital Interface Package Price for 100($) Voltage MCP4024T-103E/OT MCP402X （2.1k, 5k, 10k, 50k） Serial (2-Wire, CS and U/D) SOT-23-5 60 3.3 V, 5 V DS4301U-200+ 200k Up/Down USOP-8 67 2.4 V to 5.5 V MCP4141-103E/MS MCP414X/MCP416X MCP424X/MCP426X Serial (4-Wire, SPI) MSOP-8 61 2.5 V, 3.3 V, 5 V MCP4541-103E/MS MCP454X/MCP456X MCP464X/MCP466X Serial (2-Wire, I2C) MSOP-8 61 2.5 V, 3.3 V, 5 V CAT5140ZI-50-GT3 50k, 100k Serial (...

BSS214N H6327 (20V, 1.5A,  106mOhms) (SOT23-3),  Infineon Technologies ,  ($56 for 1000Pcs ) BSS806N H6327 (20V, 2.3A,  41mOhms) (SOT23-3),  Infineon Technologies ,  ($78 for 1000Pcs ) DMG2302UK-7 (20V, 2.8A,  61mOhms) (SOT23-3), Diodes Incorporated ,  ($72 for 1000Pcs ) DMN2041L- 7 (20V, 6.4A,  20mOhms) (SOT23-3),  Diodes Incorporated ,  ($90 for 1000Pcs ) NTR3C21NZT1G (20V, 3.6A,  18mOhms) (SOT23-3), ON Semiconductor ,  ($108 for 1000Pcs ) FDC637BNZ (20V, 6.2A,  24mOhms) (SSOT-6),  ON Semiconductor ,  ($114 for 1000Pcs )

For 5% resistor (Ohms) 1.0 　　 5.6 　　 33 　　 160 　　 820 　　 3.9K 　　 20K 　　 100K 　　 510K 　　 2.7M 1.1 　　 6.2 　　 36 　　 180 　　 910 　　 4.3K 　　 22K 　　 110K 　　 560K 　　 3M 1.2 　　 6.8 　　 39 　　 200 　　 1K 　　 4.7K 　　 24K 　　 120K 　　 620K 　　 3.3M 1.3 　　 7.5 　　 43 　　 220 　　 1.1K 　　 5.1K 　　 27K 　　 130K 　　 680K 　　 3.6M 1.5 　　 8.2 　　 47 　　 240 　　 1.2K 　　 5.6K 　　 30K 　　 150K 　　 750K 　　 3.9M 1.6 　　 9.1 　　 51 　　 270 　　 1.3K 　　 6.2K 　　 33K 　　 160K 　　 820K 　　 4.3M 1.8 　　 10 　　 56 　　 300 　　 1.5K 　　 6.6K 　　 36K 　　 180K 　　 910K 　　 4.7M 2.0 　　 11 　　 62 　　 330 　　 1.6K 　　 7.5K 　　 39K 　　 200K 　　 1M 　　 5.1M 2.2 　　 12 　　 68 　　 360 　　 1.8K 　　 8.2K 　　 43K 　　 220K 　　 1.1M 　　 5.6M 2.4 　　 13 　　 75 　　 390 　　 2K 　　 9.1K 　　 47K 　　 240K 　　 1.2M 　　 6.2M 2.7 　　 15 　　 82 　　 430 　　 2.2K 　　 10K 　　 51K 　　 270K 　　 1.3M 　　 6.8M 3.0 　　 16 　　 91 　　 470 　　 2.4K 　　 11K 　　 56K 　　 300K 　　 1.5M 　　 7.5M 3.3 　　 18 　　 100 　　 510 　...

RZM001P02T2L  (-20V, -100mA, 40Ohms)(SOT-723-3, 1.1mm*1.1mm),  ROHM Semiconductor , ($41 for 1000pcs) RU1C001ZPTL  (-20V, -100mA, 2.5Ohms)( SOT-323FL-3, 1.9mm*2.0mm)  ROHM Semiconductor , ($46 for 1000pcs) RU1C002ZPTCL  (-20V, -200mA, 9.6Ohms,  Vgs-th -300mV ),   ROHM Semiconductor , ($46 for 1000pcs) RSC002P03T316  ()-20V. -250mA, 0.9Ohms ), (SOT-23-3, 2.3mm*2.8mm),  ROHM Semiconductor , ($52 for 1000pcs) BSS84-7-F  (-50V, -130mA, 10Ohms)(SOT-23-3, 2.3mm*2.8mm),  Diodes Incorporated , ($45 for 1000pcs) BSS84P H6327  (-60V, -170mA, 5.8Ohms)(SOT-23-3, 2.3mm*2.8mm),  Diodes Incorporated , ($47 for 1000pcs) DMP210DUFB4-7  (-20V, -200mA, 15Ohms) (X2-DFN1006-3, 0.95mm*0.55mm )  Diodes Incorporated , ($51 for 1000pcs) DMP3099L-7   (-30V, -3.8A, 0.065Ohms ) ((SOT-23-3, 2.3mm*2.8mm)  Diodes Incorporated , ($72 for 1000pcs)

RQ3C150BCTB (-20V, -30A, 4.8mOhms) (HSMT-8)  ROHM Semiconductor ,  ($448 for 1000Pcs ) DMP2008UFG-13 (-20V, -14A, 8mOhms) ( PowerDI3333-8 ),   Diodes Incorporated , ($213 for 1000Pcs ) DMP3017SFG-7 (-30V, -15.2A, 10mOhms)  PowerDI3333-8 ),   Diodes Incorporated , ($171 for 1000Pcs ) DMP3017SFG-13 (-30V, -11.5A, 8.5mOhms) ( PowerDI3333-8 ),   Diodes Incorporated , ($171 for 1000Pcs ) DMG7401SFG-7 (-30V, -9.5A, 9mOhms) ( PowerDI3333-8 ),   Diodes Incorporated , ($213 for 1000Pcs ) SSM6J511NU,LF (-12V, -14A, 6.5mOhms) (UDFN6B-6),  Toshiba , ($148 for 1000Pcs ) MCQ4407-TP (-30V, -12A, 7.8mOhms) (SOP-8),  Micro Commercial Components (MCC) , ($186 for 1000Pcs )

Some times the customer hope the output signal of the sensor should be a current signal. So I design a simple circuit to convert a voltage signal to current signal. Input voltage: 0-5V, output: 4-20mA

I am going to design a circuit that uses a battery as a power source. And an adapter as the input power. So I need a circuit that switches the power source automatically from battery to input power. And I do not want to add a chip to do this because it will increase the cost of the board. The simple circuit for that could be: The shortcoming of this circuit is that it will consume some power by the diode D1 when the adapter plugs in.  In order to overcome this, a P-MOSFET is used to replace it. The simulation showed it works well. I will test it later.

Recently, I am designing a circuit that needs to switch off a module from 12V by a 5V control signal. So I do some research work and make desicion to use the circuit as below. The simulation result as below. The real components in the design list as below. P-Channel MOSFET:  TPH1R712MD (RDSon:1.35mOhms)