Abstract: A perfect voltage reference produces a stable voltage independent of any external factors. Real-world voltagereferences, of course, are subject to errors caused by many external factors. One causeof these major errors istemperature. Without care, it is easy to operate a voltage reference outside its operating temperature range. Thisapplication note describes how references respond to temperature changes, and how self-heating can cause a voltagereference to operate outside its recommended temperature range. Once understood, this knowledge can then be used toavoid making this design error.
上傳時間： 2013-11-08
上傳用戶：xianglee
特點(FEATURES) 精確度0.1%滿刻度 (Accuracy 0.1%F.S.) 可作各式數學演算式功能如:A+B/A-B/AxB/A/B/A&B(Hi or Lo)/|A| (Math functioA+B/A-B/AxB/A/B/A&B(Hi&Lo)/|A|/etc.....) 16 BIT 類比輸出功能(16 bit DAC isolating analog output function) 輸入/輸出1/輸出2絕緣耐壓2仟伏特/1分鐘(Dielectric strength 2KVac/1min. (input/output1/output2/power)) 寬范圍交直流兩用電源設計(Wide input range for auxiliary power) 尺寸小,穩定性高(Dimension small and High stability)
上傳時間： 2013-11-24
上傳用戶：541657925
Easy-to-use and compact point-of-load power suppliesare necessary in systems with widely distributed, highcurrent, low voltage loads. The LTC®3415 provides acompact, simple and versatile solution. It includes a pairof integrated complementary power MOSFETs (32mΩtop and 25mΩ bottom) and requires no external senseresistor. A complete design requires an inductor andinput/output capacitors, and that’s it. The result is a fast,constant frequency, 7A current mode DC/DC switchingregulator.
上傳時間： 2013-10-18
上傳用戶：avensy
Automotive power systems are unforgiving electronicenvironments. Transients to 90V can occur when thenominal voltage range is 10V to 15V (ISO7637), along withbattery reversal in some cases. It’s fairly straightforwardto build automotive electronics around this system, butincreasingly end users want to operate portable electronics,such as GPS systems or music/video players,and to charge their Li-Ion batteries from the automotivebattery. To do so requires a compact, robust, effi cientand easy-to-design charging system
上傳時間： 2013-11-04
上傳用戶：wfl_yy
The LTM8020, LTM8021, LTM8022 and LTM8023 μModule®regulators are complete easy-to-use encapsulated stepdownDC/DC regulators intended to take the pain and aggravationout of implementing a switching power supplyonto a system board. With a μModule regulator, you onlyneed an input cap, output cap and one or two resistorsto complete the design. As one might imagine, this highlevel of integration greatly simplifi es the task of printedcircuit board design, reducing the effort to four categories:component footprint generation, component placement,routing the nets, and thermal vias.
上傳時間： 2014-01-18
上傳用戶：laomv123
/*--------- 8051內核特殊功能寄存器 -------------*/ sfr ACC = 0xE0; //累加器 sfr B = 0xF0; //B 寄存器 sfr PSW = 0xD0; //程序狀態字寄存器 sbit CY = PSW^7; //進位標志位 sbit AC = PSW^6; //輔助進位標志位 sbit F0 = PSW^5; //用戶標志位0 sbit RS1 = PSW^4; //工作寄存器組選擇控制位 sbit RS0 = PSW^3; //工作寄存器組選擇控制位 sbit OV = PSW^2; //溢出標志位 sbit F1 = PSW^1; //用戶標志位1 sbit P = PSW^0; //奇偶標志位 sfr SP = 0x81; //堆棧指針寄存器 sfr DPL = 0x82; //數據指針0低字節 sfr DPH = 0x83; //數據指針0高字節 /*------------ 系統管理特殊功能寄存器 -------------*/ sfr PCON = 0x87; //電源控制寄存器 sfr AUXR = 0x8E; //輔助寄存器 sfr AUXR1 = 0xA2; //輔助寄存器1 sfr WAKE_CLKO = 0x8F; //時鐘輸出和喚醒控制寄存器 sfr CLK_DIV = 0x97; //時鐘分頻控制寄存器 sfr BUS_SPEED = 0xA1; //總線速度控制寄存器 /*----------- 中斷控制特殊功能寄存器 --------------*/ sfr IE = 0xA8; //中斷允許寄存器 sbit EA = IE^7; //總中斷允許位 sbit ELVD = IE^6; //低電壓檢測中斷控制位 8051
上傳時間： 2013-10-30
上傳用戶：yxgi5
TLC2543是TI公司的12位串行模數轉換器，使用開關電容逐次逼近技術完成A/D轉換過程。由于是串行輸入結構，能夠節省51系列單片機I/O資源；且價格適中，分辨率較高，因此在儀器儀表中有較為廣泛的應用。 TLC2543的特點 （1）12位分辯率A/D轉換器； （2）在工作溫度范圍內10μs轉換時間； （3）11個模擬輸入通道； （4）3路內置自測試方式； （5）采樣率為66kbps； （6）線性誤差±1LSBmax； （7）有轉換結束輸出EOC； （8）具有單、雙極性輸出； （9）可編程的MSB或LSB前導； （10）可編程輸出數據長度。 TLC2543的引腳排列及說明 TLC2543有兩種封裝形式：DB、DW或N封裝以及FN封裝，這兩種封裝的引腳排列如圖1，引腳說明見表1 TLC2543電路圖和程序欣賞 #include<reg52.h> #include<intrins.h> #define uchar unsigned char #define uint unsigned int sbit clock=P1^0; sbit d_in=P1^1; sbit d_out=P1^2; sbit _cs=P1^3; uchar a1,b1,c1,d1; float sum,sum1; double sum_final1; double sum_final; uchar duan[]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f}; uchar wei[]={0xf7,0xfb,0xfd,0xfe}; void delay(unsigned char b) //50us { unsigned char a; for(;b>0;b--) for(a=22;a>0;a--); } void display(uchar a,uchar b,uchar c,uchar d) { P0=duan[a]|0x80; P2=wei[0]; delay(5); P2=0xff; P0=duan[b]; P2=wei[1]; delay(5); P2=0xff; P0=duan[c]; P2=wei[2]; delay(5); P2=0xff; P0=duan[d]; P2=wei[3]; delay(5); P2=0xff; } uint read(uchar port) { uchar i,al=0,ah=0; unsigned long ad; clock=0; _cs=0; port<<=4; for(i=0;i<4;i++) { d_in=port&0x80; clock=1; clock=0; port<<=1; } d_in=0; for(i=0;i<8;i++) { clock=1; clock=0; } _cs=1; delay(5); _cs=0; for(i=0;i<4;i++) { clock=1; ah<<=1; if(d_out)ah|=0x01; clock=0; } for(i=0;i<8;i++) { clock=1; al<<=1; if(d_out) al|=0x01; clock=0; } _cs=1; ad=(uint)ah; ad<<=8; ad|=al; return(ad); } void main() { uchar j; sum=0;sum1=0; sum_final=0; sum_final1=0; while(1) { for(j=0;j<128;j++) { sum1+=read(1); display(a1,b1,c1,d1); } sum=sum1/128; sum1=0; sum_final1=(sum/4095)*5; sum_final=sum_final1*1000; a1=(int)sum_final/1000; b1=(int)sum_final%1000/100; c1=(int)sum_final%1000%100/10; d1=(int)sum_final%10; display(a1,b1,c1,d1); } }
上傳時間： 2013-11-19
上傳用戶：shen1230
#include<iom16v.h> #include<macros.h> #define uint unsigned int #define uchar unsigned char uint a,b,c,d=0; void delay(c) { for for(a=0;a<c;a++) for(b=0;b<12;b++); }; uchar tab[]={ 0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90,
上傳時間： 2013-10-21
上傳用戶：13788529953
Digitemp Junior – An RS-232 Port-Powered Digital Thermometer Digitemp Jr. is a device that is designed to measure and report ambient temperature. When connected to an RS-232 port on any PC, it will periodically measure and report in ASCII form the ambient temperature in degrees Celsius. These temperature readings can be monitored with any terminal program. If the terminal program supports capture to disk, the temperature readings can be saved to disk for further analysis with a spreadsheet program or other data analysis tool. The simple ASCII output format of Digitemp Jr. makes it rel- atively easy to write custom software for receiving, recording, and analyzing ambient temperature data. Best of all, Digitemp Jr. requires no external power sup- plies or batteries. It is powered directly by the RS-232 port.
上傳時間： 2013-10-21
上傳用戶：baitouyu
Digitemp Jr. is a device that is designed to measure and report ambient temperature. When connected to an RS-232 port on any PC, it will periodically measure and report in ASCII form the ambient temperature in degrees Celsius. These temperature readings can be monitored with any terminal program. If the terminal program supports capture to disk, the temperature readings can be saved to disk for further analysis with a spreadsheet program or other data analysis tool. The simple ASCII output format of Digitemp Jr. makes it relatively easy to write custom software for receiving, recording, and analyzing ambient temperature data. Best of all, Digitemp Jr. requires no external power supplies or batteries. It is powered directly by the RS-232 port.
上傳時間： 2013-10-20
上傳用戶：Maple
