电压基准电路LM399设计说明

电压基准LM199-299-399-3999英文手册解析

TL H 5717LM199 LM299 LM399 LM3999Precision ReferenceDecember 1994LM199 LM299 LM399 LM3999Precision ReferenceGeneral DescriptionThe LM199series are precision temperature-stabilized monolithic zeners offering temperature coefficients a factor of ten better than high quality reference zeners Construct-ed on a single monolithic chip is a temperature stabilizer circuit and an active reference zener The active circuitry reduces the dynamic impedance of the zener to about 0 5X and allows the zener to operate over 0 5mA to 10mA cur-rent range with essentially no change in voltage or tempera-ture coefficient Further a new subsurface zener structure gives low noise and excellent long term stability compared to ordinary monolithic zeners The package is supplied with a thermal shield to minimize heater power and improve tem-perature regulationThe LM199series references are exceptionally easy to use and free of the problems that are often experienced with ordinary zeners There is virtually no hysteresis in reference voltage with temperature cycling Also the LM199is free of voltage shifts due to stress on the leads Finally since the unit is temperature stabilized warm up time is fastThe LM199can be used in almost any application in place of ordinary zeners with improved performance Some ideal applications are analog to digital converters calibration standards precision voltage or current sources or precision power supplies Further in many cases the LM199can re-place references in existing equipment with a minimum of wiring changesThe LM199series devices are packaged in a standard her-metic TO-46package inside a thermal shield The LM199is rated for operation from b 55 C to a 125 C while the LM299is rated for operation from b 25 C to a 85 C and the LM399is rated from 0 C to a 70 CThe LM3999is packaged in a standard TO-92package and is rated from 0 C to a 70 CFeaturesY Guaranteed 0 0001% C temperature coefficient Y Low dynamic impedance 0 5XY Initial tolerance on breakdown voltage 2%Y Sharp breakdown at 400m AY Wide operating current 500m A to 10mA Y Wide supply range for temperature stabilizer Y Guaranteed low noiseY Low power for stabilization 300mW at 25 C Y Long term stability 20ppmYProven reliability low-stress packaging in TO-46inte-grated-circuit hermetic package for low hysteresis after thermal cycling 33million hours MTBF at T A e a 25 C (TJ e a 86 CY Certified long term stability available YMIL-STD-883compliantConnection DiagramsMetal Can Package (TO-46TL H 5717–14Top ViewLM199 LM299 LM399(SeeTable on fourth pageNS Package Number H04DPlastic Package TO-92TL H 5717–10Bottom ViewLM3999(SeeTable on fourth pageNS Package Number Z03AFunctional Block DiagramsLM199 LM299 LM399TL H 5717–15LM3999TL H 5717–11C 1995National Semiconductor CorporationRRD-B30M115 Printedin U S AAbsolute Maximum RatingsSpecifications for Military Aerospaceproducts are not contained in this datasheet Refer to the following Reli-ability Electrical Test Specifications documents RETS199X for LM199 RETS199AX for LM199A Temperature Stabilizer Voltage LM199 LM299 LM39940V LM399936V Reverse Breakdown Current 20mA Forward CurrentLM199 LM299 LM3991mALM3999b 0 1mAReference to Substrate Voltage V (RS(Note1 40Vb 0 1VOperating Temperature Range LM199b 55 C to a 125 C LM299b 25 C to a 85 C LM399 LM3999b 0 C to a 70 C Storage Temperature Range b 55 C to a 150 CSoldering InformationTO-92package (10sec a 260 C TO-46package (10seca 300 CElectrical Characteristics (Notes2 5ParameterConditionsLM199H LM299HLM399H Units Min Typ Max Min Typ Max Reverse Breakdown Voltage 0 5mA s I R s 10mA 6 86 957 16 66 957 3V Reverse Breakdown Voltage 0 5mA s I R s 10mA 69612mV Change with Current Reverse Dynamic Impedance I R e 1mA0 510 51 5X Reverse Breakdown b 55 C s T A s a 85 C LM1990 000030 0001% C Temperature Coefficienta 85 C s T A s a 125 C (0 00050 0015% C b 25 C s T A s 85 C LM2990 000030 0001% C 0 C s T A s a 70 CLM3990 000030 0002% C RMS Noise 10Hz s f s 10kHz720750m V Long Term Stability Stabilized 22 C s T A s 28 C 2020ppm1000Hours I R e 1mA g 0 1%Temperature Stabilizer T A e 25 C Still Air V S e 30V 8 5148 515mA Supply Current T A eb 55 C2228Temperature Stabilizer 940940V Supply VoltageWarm-Up Time to 0 05%V S e 30V T A e 25 C33secInitial Turn-on Current9s V S s 40 T A e a 25 C (Note3140200140200mAElectrical Characteristics (Note2ParameterConditionsLM3999ZUnits Min Typ Max Reverse Breakdown Voltage 0 6mA s I R s 10mA 6 66 957 3V Reverse Breakdown Voltage 0 6mA s I R s 10mA 620mV Change with Current Reverse Dynamic Impedance I R e 1mA 0 62 2X Reverse Breakdown 0 C s T A s 70 C 0 00020 0005% C Temperature Coefficient RMS Noise 10Hz s f s 10kHz7m V Long Term Stability Stabilized 22 C s T A s 28 C 20ppm 1000Hours I R e1mA g 0 1%Temperature Stabilizer T A e 25 C Still Air V S e 30V1218mA Temperature Stabilizer 36V Supply VoltageWarm-Up Time to 0 05%V S e 30V T A e 25 C 5sec Initial Turn-On Current9s V S s 40 T A e 25 C140200mA2Electrical Characteristics (Notes2 5ParameterConditionsLM199AH LM299AH LM399AH Units Min Typ Max Min Typ Max Reverse Breakdown Voltage 0 5mA s I R s 10mA 6 86 957 16 66 957 3V Reverse Breakdown Voltage 0 5mA s I R s 10mA 69612mV Change with Current Reverse Dynamic Impedance I R e 1mA0 510 51 5X Reverse Breakdown b 55 C s T A s a 85 C LM199A 0 000020 00005% C Temperature Coefficienta 85 C s T A s a 125 C (0 00050 0010% C b 25 C s T A s 85 C LM299A 0 000020 00005% C 0 C s T A s a 70 CLM399A0 000030 0001% C RMS Noise 10Hz s f s 10kHz720750m V Long Term Stability Stabilized 22 C s T A s 28 C 2020ppm1000Hours I R e 1mA g 0 1%Temperature Stabilizer T A e 25 C Still Air V S e 30V 8 5148 515mA Supply Current T A eb 55 C2228Temperature Stabilizer 940940V Supply VoltageWarm-Up Time to 0 05%V S e 30V T A e 25 C 33secInitial Turn-on Current9s V S s 40 T A e a 25 C (Note3140200140200mAElectrical Characteristics (Notes2 5 ParameterConditionsLM199AH-20 LM299AH-20LM399AH-50UnitsMin Typ Max Min Typ Max Reverse Breakdown Voltage 0 5mA s I R s 10mA 6 8 6 957 16 66 957 3V Reverse Breakdown Voltage 0 5mA s I R s 10mA69612mV Change With CurrentReverse Dynamic Impedance I R e 1mA 0 510 51 5X Reverse Breakdown b 55 C s T A s 85LM199A0 000020 00005% C Temperature Coefficient85 C s T A s 125 C(0 00050 0010% C b 25 C s T A s 85 C LM299A 0 000020 00005% C0 C s T A s 70 C LM399A 0 000030 0001% CRMS Noise 10Hz s f s 10kHz720750m V Long Term Stability Stabilized 22 C s T A s 28 C 820950ppm 1000Hours I R e 1mA g 0 1%Temperature Stabilizer T A e 25 C Still Air V S e 30V 8 5148 515mA Supply Current T A e 55 C2228Temperature Stabilizer 940940V Supply VoltageWarm-Up Time to 0 05%V S e 30V T A e 25 C33s Initial Turn-on Current9s V S s 40 T A e 25 C (Note3140200140200mANote 1 The substrate is electrically connected to the negative terminal of the temperature stabilizer The voltage that can be applied to either terminal of the reference is 40V more positive or 0 1Vmore negative than the substrateNote 2 These specifications apply for 30V applied to the temperature stabilizer and b 55 C s T A s a 125 C for the LM199 b 25 C s T A s a 85 C for the LM299and 0 C s T A s a 70 C for the LM399and LM3999Note 3 This initial current can be reduced by adding an appropriate resistor and capacitor to the heater circuit See the performance characteristic graphs to determine valuesNote 4 Do not wash the LM199with its polysulfone thermal shield in TCENote 5 A military RETS electrical test specification is available for the LM199H 883 LM199AH 883 and LM199AH-20 883on request3Ordering InformationInitial 0 C to a 70 Cb 25 C to a 85 Cb 55 C to a 125 CNS TolerancePackage 2%LM299AH LM199AH LM199AH 883H04D 5%LM399H LM299HLM199H LM199H 883H04D LM399AH 5%LM3999Z Z03A Guaranteed Long LM399AH-50LM299AH-20LM199AH-20 LM199AH-20 883H04DTerm StabilityCertified Long Term DriftThe National Semiconductor LM199AH-20 LM299AH-20 and LM399AH-50are ultra-stable Zener references special-ly selected from the production runs of LM199AH LM299AH LM399AH and tested to confirm a long-term sta-bility of 20 20 or 50ppm per 1000hours respectively The devices are measured every 168hours and the voltage of each device is logged and compared in such a way as to show the deviation from its initial value Each measurement is taken with a probable-worst-case deviation of g 2ppm compared to the Reference Voltage which is derived from several groups of NBS-traceable references such as LM199AH-20’s 1N827’s and saturated standard cells sothat the deviation of any one group will not cause false indi-cations Indeed this comparison process has recently been automated using a specially prepared computer program which is custom-designed to reject noisy data (andrequire a repeat reading and to record the average of the best 5of 7readings just as a sagacious standards engineer will reject unbelievable readingsThe typical characteristic for the LM199AH-20is shown be-low This computerized print-out form of each reference’sstability is shipped with the unitTypical CharacteristicsNational Semiconductor Certified Long Term DriftLM199AH-20Hrs DriftPart 6849168b 20Limits336b 24LM199AH-20140m V 504b 36LM299AH-20140m V 672b 34LM399AH-20350m V840b 401008b 36Testing Conditions Heater Voltage 30V Zener Current 1mA Ambient Temp 25 CTL H 5717–124Typical Performance CharacteristicsReverse CharacteristicsReverse Voltage ChangeDynamic ImpedanceZener Noise Voltage Stabilization Time Heater CurrentInitial Heater CurrentHeater Current (ToLimit This Surge See Next GraphHeater Surge Limit Resistor vs Minimum Supply Voltage atVarious Minimum TemperaturesHeater must be bypassed with a 2m F or larger tantalum capacitor if re-sistors are usedLow Frequency Noise Voltage Response TimeTL H 5717–3TL H 5717–2TL H 5717–75Typical ApplicationsSingle Supply Operation Split Supply Operation Negative Heater Supply with Positive Reference Buffered Reference With Single SupplyPositive Current SourceStandard Cell ReplacementTL H 5717–46Typical Applications (ContinuedNegative Current SourceSquare Wave Voltage Reference Portable CalibratorWarm-up time 10seconds intermittent operation does not degrade long term stability 14V Reference Precision ClampClamp will sink 5mA when input goes more positive than referenceTL H 5717–57Typical Applications (Continued0V to 20V Power Reference Bipolar Output ReferenceTL H 5717–6Voltage ReferenceTL H 5717–98Schematic DiagramsTemperature StabilizerTL H 5717–01 ReferenceTL H 5717–13 910Physical Dimensions inches (millimeters Order Number LM199H LM199H 883 LM299H LM399H LM199AH LM199AH 883 LM199AH-20 LM199AH-20 883LM299AH LM299AH-20 LM399AH or LM399AH-50 NS Package H04D 11LM199 LM299 LM399 LM3999 Precision Reference Physical Dimensions inches (millimeters (Continued Plastic Package Order Number LM3999Z NS Package Z03A LIFE SUPPORT POLICY NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF NATIONAL SEMICONDUCTOR CORPORATION As used herein 1 Life support devices or systems are devices or systems which (a are intended for surgical implant into the body or (b support or sustain life and whose failure to perform when properly used in accordance with instructions for use provided in the labeling can be reasonably expected to result in a significant injury to the user National Semiconductor Corporation 1111West Bardin Road Arlington TX 76017 Tel 1(800 272-9959 Fax 1(800 737-7018 2 A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system or to affect its safety or effectiveness National Semiconductor Europe Fax (a49 0-180-530 85 86 Email cnjwge tevm2 nsc com Deutsch Tel (a49 0-180-530 85 85 English Tel (a49 0-180-532 78 32 Fran ais Tel (a49 0-180-532 93 58 Italiano Tel (a49 0-180-534 16 80 National Semiconductor Hong Kong Ltd 13th Floor Straight Block Ocean Centre 5 Canton Rd Tsimshatsui Kowloon Hong Kong Tel (852 2737-1600 Fax (852 2736-9960 National Semiconductor Japan Ltd Tel 81-043-299-2309 Fax 81-043-299-2408 National does not assume any responsibility for use of any circuitry described no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specificationsThis datasheet has been download from: Datasheets for electronics components.。

基于LM399的高精密度稳压电源

基于Ｌ９Ｍ３９的高精密度稳压电源
陈太洪
（江苏技术师范学院电气信息工程系，江苏常州２３１）１０５
摘要：简要介绍了一种以Ｌ９Ｍ３９为基准稳压电源构成的高精密度稳压电源的设计，电源结构简单、该
差。次表面隐埋技术则在半导体内部产生击穿，可
结温变化约为ｌ℃ ，入偏置电压约变化８Ｖ。为输此，Ａ３４要采用稳压电源供电。Ｃ１０
十１５Ｖ稳压电压通过Ｒ９加到Ｌ９Ｍ３９内稳压
使噪声电压显著降低，定性大幅提高。恒温器电稳
ＣＨＥＮｉｈｎＴａ— ｏｇ
（ｐ．ｏｅｔｉｎｎｏｍａｉｎＥｎｉｅｒｎｆＪａｇｕＴｅｃｅｓＣｌｇｆＴｅｈｏｏｙ，ＤｅｔｆＥｌｃｒｃａｄＩｆｒｔｏｇｎｅｉｇｏｉｎｓａｈｒｏｌｅｏｃｎｌｇｅ
输｛
１３电路工作原理．
图３是基于Ｌ９Ｍ３９的输出为ｌＡ１的高精／０Ｖ
密度稳压电源的原理图。图３中电路采用全波整流，经电容滤波将交流１电压变为平滑的直流再８Ｖ电压，然后通过Ｔ１和Ｔ、２Ｔ３和Ｔ４组成的调整元件供给负载稳定的直流电压。负载电流为１Ａ时，
ｉ卤
１２ＬＭ３９的结构原理．９
ｌ
需要选用直流放大倍数高达１００倍的晶体管，０因

德州TI DSP2812

DSPF2812芯片介绍TMS32OF2812是美国TI公司推出的C2000平台上的定点32位DSP芯片，主频150MHZ、处理性能可达150MIPS(每秒钟执行的百万指令数)，每条指令周期6.67ns。

TMS32OF2812采用哈佛总线结构，具有统一的存储模式，包括4M可寻址程序空间和4M可寻址数据空间。

同时片内具有128×16位的FLASH存储器和18K×16位的SRAM，以及4K×16位的引导ROM。

最大支持外扩512K×16位的SRAM和512K ×16位的FLASH。

具有两个事件管理器（EVA、EVB）以及外设中断模块（PIE），最大支持96个外部中断。

TMS32OF2812的外部存储器接口（XINTF）被映射到5个独立的存储空间。

设计时，六路250KHz独立采集AD转换器AD7656和液晶显示模块T6963C可以直接和它接口。

可将AD7656以及T6963C液晶显示模块都被映射到区域0中，外扩的256K×16位的SRAM则被映射到区域6中。

高速DSP(数字信号处理器)的出现使采用数字方法实时计算谐波和无功电流变得更为现实。

在基于DSP控制的有源电力滤波器中，将非线性负载的三相电流直接送人DSP内部的A/D，DSP进行处理后将计算出的指令电流通过D/A送给外部的电流跟踪控制电路;或者在DSP中实现数字控制算法，通过拍口或PWM口直接发出开关控制信号。

用软件的方法实现谐波和无功电流的计算，能很好的解决模拟方法由于元器件老化和温漂带来的问题，抗干扰能力也大大增强;由于DSP芯片强大的运算能力，先进的控制理论可以得以实现，由于只需更改软件，系统变得更加简单。

从PWM方法进行区分，对APF的数字控制方法主要有滞环控制、三角波控制与空间矢量控制。

2)D/A电路D/A采用MAXIM公司的MAX526芯片，T形电阻网络结构，十二位，并行输人，四通道，误差最大为ILSB，建立时间为3us。

高稳定激光原子磁力仪恒流源电路设计

高稳定激光原子磁力仪恒流源电路设计陈立杰;黄光明;杨国卿【摘要】针对用于原子磁力仪的895 nm VCSEL激光器,提出了一种电路结构简单,高稳定性的压控恒流源电路.此电路使用了一种巧妙的精密恒流源电路与一种常见的压控微电流源电路相并联,在保证高稳定性和一定精度的基础上,实现了低成本、小体积和低功耗.通过实验检测表明,恒流源的稳定性优于10-6A(最大波动0.35μA),电流步进连续可调,电路面积为4.5 cm ×4.5 cm,最大功耗为468 mW,能够很好地满足小型激光泵浦的原子磁力仪对激光器的控制要求.【期刊名称】《激光与红外》【年(卷),期】2019(049)008【总页数】7页(P1007-1013)【关键词】高稳定性;VCSEL激光器;恒流源;磁力仪【作者】陈立杰;黄光明;杨国卿【作者单位】华中师范大学物理科学与技术学院,湖北武汉430079;华中师范大学物理科学与技术学院,湖北武汉430079;杭州电子科技大学电子信息学院,浙江杭州310018【正文语种】中文【中图分类】TN7071 引言高精度的激光泵浦原子磁力仪是分析和测量磁场的有效工具,学科交叉研究的开展使相关的弱磁测量技术发展迅速,高精度磁测技术在地球物理勘探、地质灾害预报、海陆矿藏勘测、环境监测和生物医药等领域展现出巨大的潜力。

同时不同的应用领域对原子光泵磁力仪控制系统的功耗和体积提出了不同的要求[1-2]。

原子磁力仪系统的光源部分主要由半导体激光器及相关控制器、光路元件组成。

激光器在磁力仪中非常重要,是光源部分的核心组件[3]。

在激光器的应用过程中,需要激光器有较高的功率稳定性以及激光的波长稳定性,驱动电流的稳定和温度都会引起激光器的功率和波长变化。

因此设计能够稳定激光器工作温度与输出功率的驱动电路非常必要[4-6]。

虽然很多的高精度商用电流源(比如Anglent的B2902A)都可以满足对激光器电流的控制精度和稳定性要求,但是商用电流源通常价格昂贵,体积和功耗都比较大,不适合集成到自主研发的磁力仪当中。

常用芯片资料

LM8365 "双定时LED电子钟电路 " LM8365 双定时LED电子钟电路，中文杂志扫描的PDF文件。
MAX038 0.1Hz-20MHz单片函数发生器
MAX232 "5V电源多通道RS232驱动器/接收器 " +5V-Powered,Multichannel RS232 Drivers/Receivers
Microchip "PIC系列单片机RS232通讯应用 " Microchip PIC系列单片机与数字温度计的RS232通讯应用，内有典型应用电路图、源程序等，可供你作为单片机与RS232通讯方面的应用参考。
MM5369 3.579545MHz-60Hz 17级分频振荡器常用于LM8361、LM8362、LM8365等电子钟电路将3.579545MHz晶体振荡分频到60Hz
LM431 "可调电压基准电路 "
LM567/LM567C "锁相环音频译码器 "
LM741 "运算放大器 " LM741A/LM741E/LM741/LM741C 运算放大器
LM831 "双低噪声音频功率放大器 "
LM833 "双低噪声音频放大器 "
MC145407 "RS232驱动器/接收器 " EIA-232/V.28 CMOS Driver/Receiver,5V Only, 3 x 3
MC145583 "RS232驱动器/接收器 " 3.3V - 5.0V EIA-232/V.28 CMOS Driver/Receiver, 3 x 5
MC2833 "低功率调频发射系统 " Low Power FM Tranmistter System

极管及钽电容品牌的一些参数

极管及钽电容品牌的一些参数晶体二极管晶体二极管在电路中常用“D”加数字表示，如：D5表示编号为5的二极管。

1、作用：二极管的主要特性是单向导电性，也就是在正向电压的作用下，导通电阻很小；而在反向电压作用下导通电阻极大或无穷大。

正因为二极管具有上述特性，无绳电话机中常把它用在整流、隔离、稳压、极性保护、编码控制、调频调制和静噪等电路中。

电话机里使用的晶体二极管按作用可分为：整流二极管（如1N4004）、隔离二极管（如1N4148）、肖特基二极管（如BAT85）、发光二极管、稳压二极管等。

2、识别方法：二极管的识别很简单，小功率二极管的N极（负极），在二极管外表大多采用一种色圈标出来，有些二极管也用二极管专用符号来表示P极（正极）或N极（负极），也有采用符号标志为“P”、“N”来确定二极管极性的。

发光二极管的正负极可从引脚长短来识别，长脚为正，短脚为负。

3、测试注意事项：用数字式万用表去测二极管时，红表笔接二极管的正极，黑表笔接二极管的负极，此时测得的阻值才是二极管的正向导通阻值，这与指针式万用表的表笔接法刚好相反。

稳压二极管稳压二极管在电路中常用“ZD”加数字表示，如：ZD5表示编号为5的稳压管。

1、稳压二极管的稳压原理：稳压二极管的特点就是击穿后，其两端的电压基本保持不变。

这样，当把稳压管接入电路以后，若由于电源电压发生波动，或其它原因造成电路中各点电压变动时，负载两端的电压将基本保持不变。

2、故障特点：稳压二极管的故障主要表现在开路、短路和稳压值不稳定。

在这3种故障中，前一种故障表现出电源电压升高；后2种故障表现为电源电压变低到零伏或输出不稳定。

常用稳压二极管的型号及稳压值如下表：型号1N4728 1N4729 1N4730 1N4732 1N4733 1N4734 1N4735 1N4744 1N4750 1N4751 1N4761稳压值 3.3V 3.6V 3.9V 4.7V 5.1V 5.6V 6.2V 15V 27V 30V 75V电感电感在电路中常用“L”加数字表示，如：L6表示编号为6的电感。

精密基准电压源LM399系列

-31-精密基准电压源L M399系列西安石油学院孟开元李绍敏摘要:精密基准电压源L M399系列是迄今为止同类产品中温度系数最低的器件,内部有恒温电路,可保证器件的长期稳定性。

本文主要介绍了该系列基准电压源的结构原理和性能特点,并简要说明了应用方法。

关键词:精密基准电压温度系数恒温电路参数最小值典型值最大值单位反向击穿电压6.66.957.3V反向动态阻抗0.51.5Ω击穿电压温度系数0.000030.0001%　℃温度稳定器电源电压940V1、L M399系列的性能特点L M399系列器件采用标准的密封TO 246型封装,外面加有热保温罩。

L M199的工作温度范围是-55℃到+125℃,L M299的工作温度范围是-25℃到+85℃,L M399的工作温度范围是0℃到+70℃。

其中L M399的使用最广泛,价格也较便宜。

其特点如下:●电压温度系数不超过0.5PPM/℃;●动态阻抗低,典型值为0.5Ω;●击穿电压的初始容差为2%;●低噪声;●低功耗(平衡时),25℃时为300mW ;●长期稳定性好。

基准电压源最重要的技术指标是电压温度系数,它表示温度变化引起的输出电压漂移量(亦称温漂)。

可以看出,在目前生产的基准电压源中,L M199、L M299和L M399的电压温度系数最低,性能最佳。

下面就应用最多的L M399作一介绍。

L M399的电特性如下表所列。

作为高精度的基准电压源,L M399可取代普通的齐纳稳压管,用于A /D 转换器、精密稳压电源、精密恒流源、电压比较器等。

在许多情况下,只需作很小的布线变化,就可用L M399来替换仪器中的电压基准。

2、L M399的结构原理L M399的内部电路可分成两部分:基准电压源和恒温电路。

图1表示了它的管脚排列、结构框图及电路符号。

1、2脚分别是基准电压源的正负极,3、4脚之间接9～14V 的直流电压。

(b )图中的H 表示恒温器。

L M399的基准电压由隐埋齐纳管提供。