Many system designers need an easy way to producea negative 3.3V power supply. In systems that alreadyhave a transformer, one option is to swap out the existingtransformer with one that has an additional secondarywinding. The problem with this solution is that manysystems now use transformers that are standard, offthe-shelf components, and most designers want toavoid replacing a standard, qualifi ed transformer with acustom version. An easier alternative is to produce thelow negative voltage rail by stepping down an existingnegative rail. For example, if the system already employsan off-the-shelf transformer with two secondary windingsto produce ±12V, and a –3.3V rail is needed, a negativebuck converter can produce the –3.3V output from the–12V rail.
上傳時間： 2013-10-09
上傳用戶：Jerry_Chow
The LTC3546 is a dual output current mode buck regulatorwith fl exible output current partitioning. Beyondthe advantages normally associated with dual outputregulators (reduced size, cost, EMI and part count, withimproved effi ciency), the LTC3546’s outputs can bepartitioned for either 3A and 1A outputs, or two 2A outputs.This increases its application range and simplifi esmultiple supply rail designs. A confi gurable Burst Mode®clamp for each output sets the current transition levelbetween Burst Mode operation and forced continuousconduction mode to optimize effi ciency over the entireoutput range. An adjustable switching frequency up to4MHz and internal power MOSFET switches allow forsmall and compact footprints.
上傳時間： 2013-11-04
上傳用戶：yxgi5
In general, a Hot Swap controller provides two importantfunctions to boards that can be plugged and unpluggedfrom a live backplane:
上傳時間： 2013-10-23
上傳用戶：行者Xin
The LTM4600 DC/DC μModule regulator is a complete highpower density stepdown regulator for 10A continuous (14Apeak) loads. The device has two voltage options: 20VINmaximum for the LTM4600EV and 28VIN maximum for theLTM4600HVEV each housed in a small 15mm ¥ 15mm ¥2.8mm LGA surface mount package.
上傳時間： 2013-10-10
上傳用戶：adada
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
For a variety of reasons, it is desirable to charge batteriesas rapidly as possible. At the same time, overchargingmust be limited to prolong battery life. Such limitation ofovercharging depends on factors such as the choice ofcharge termination technique and the use of multi-rate/multi-stage charging schemes. The majority of batterycharger ICs available today lock the user into one fixedcharging regimen, with at best a limited number ofcustomization options to suit a variety of application needsor battery types. The LTC®1325 addresses these shortcomingsby providing the user with all the functionalblocks needed to implement a simple but highly flexiblebattery charger (see Figure 1) which not only addressesthe issue of charging batteries but also those of batteryconditioning and capacity monitoring.
上傳時間： 2013-10-19
上傳用戶：royzhangsz
Demonstration circuit 1562A is an engineering toolto design and evaluate the LTC699X-X family ofTimerBlox circuits. The center section of the boardcontains a pre-configured TimerBlox function.DC1562A comes in twelve timing function variationsas outlined in Table 1.Surrounding the center board is a ”playground”prototyping area. The prototyping area has padsfor Dip-8, S8, MS8, or S6 packages with breadboarding connections to each pin and two convenientpower buses and ground bus surrounding theentire area. This area is for conditioning signals tocontrol the timer function and for adding loads controlled in time.
上傳時間： 2013-10-18
上傳用戶：如果你也聽說
The P89LPC912/913/914 are single-chip microcontrollers in low-cost 14-pin packages, based on a high performance processor architecture that executes instructions in two to four clocks, six times the rate of standard 80C51 devices. Many system level functions have been incorporated into the P89LPC912/913/914 in order to reduce component count, board space, and system cost.
上傳時間： 2013-10-12
上傳用戶：司令部正軍級
HIGH SPEED 8051 μC CORE - Pipe-lined Instruction Architecture; Executes 70% of Instructions in 1 or 2 System Clocks - Up to 25MIPS Throughput with 25MHz System Clock - 22 Vectored Interrupt Sources MEMORY - 4352 Bytes Internal Data RAM (256 + 4k) - 64k Bytes In-System Programmable FLASH Program Memory - External Parallel Data Memory Interface – up to 5Mbytes/sec DIGITAL PERIPHERALS - 64 Port I/O; All are 5V tolerant - Hardware SMBusTM (I2CTM Compatible), SPITM, and Two UART Serial Ports Available Concurrently - Programmable 16-bit Counter/Timer Array with 5 Capture/Compare Modules - 5 General Purpose 16-bit Counter/Timers - Dedicated Watch-Dog Timer; Bi-directional Reset CLOCK SOURCES - Internal Programmable Oscillator: 2-to-16MHz - External Oscillator: Crystal, RC, C, or Clock - Real-Time Clock Mode using Timer 3 or PCA SUPPLY VOLTAGE ........................ 2.7V to 3.6V - Typical Operating Current: 10mA @ 25MHz - Multiple Power Saving Sleep and Shutdown Modes 100-Pin TQFP (64-Pin Version Available) Temperature Range: –40°C to +85°C
標簽： C8051F020
上傳時間： 2013-10-12
上傳用戶：lalalal
為了使音頻信號分析儀小巧可靠，成本低廉，設計了以2片MSP430F1611單片機為核心的系統。該系統將音頻信號送入八階巴特沃茲低通濾波器，對信號進行限幅放大、衰減、電平位移、緩沖，并利用一單片機負責對前級處理后的模擬信號進行采樣，將采集得到的音頻信號進行4 096點基2的FFT計算，并對信號加窗函數提高分辨率，另一單片機負責對信號的分析及控制顯示設備。此設計精確的測量了音頻信號的功率譜、周期性、失真度指標，達到較高的頻率分辨率，并能將測量結果通過紅外遙控器顯示在液晶屏上。 Abstract: o make the audio signal analyzer cheaper， smaller and more reliable， this system sends the audio signal to the eight-order butterworth filter， and then amplifies， attenuates， buffers it in a limiting range， transfers the voltage level of the signal before utilizing two MSP430F1611 MCU to realize the audio analysis. One is charged for sampling and dealing with the processed audio signal collected by the 4096 point radix-2 FFT calculation and imposes the window function to improve the frequency resolution. The other one controls the display and realizes the spectrum， periodicity， power distortion analysis in high resolution which is displayed in the LCD screen through the infrared remote control.
上傳時間： 2013-12-11
上傳用戶：jasonheung
