原标题：ADI ADA4625－1高电单电源轨到轨输出运算放大器解决方案

　　ADI公司的ADA4625-1/ADA4625-2是业界领先的高电压单电源轨到轨输出(RRO)精密结型场效应晶体管(JFET)输入运算放大器,具有市场上前所未有的速度和低噪声水平.宽增益带宽积为18 MHz,高电压摆率为48 V/μs,低电压噪声密度为3.3 nV/√Hz(1 kHz，典型值),低峰峰值噪声为0.15 μV p-p(0.1 Hz至10 Hz),低输入偏置电流为±15 pA(典型值,TA = 25℃), 低失调电压为±80 μV(最大值,TA = 25℃),失调电压漂移为±1.2 μV/℃(最大值,TA = −40℃至85℃),快速建立时间为700 ns(典型值,0.01%),双电源供电电压为±2.5 V至±18 V,单电源供电电压为5 V至36 V,轨到轨输出,具有高容性负载驱动能力,输出短路电流为±46 mA,无相位反转和单位增益稳定.主要用在PLL滤波器放大器,跨阻放大器,光电二极管传感器接口和低噪声电荷放大器.本文介绍了ADA4625-1/ADA4625-2主要特性,简化电路图,以及多种应用电路包括20位精度±10V电压源,带DC伺服低噪音水听器放大器和加速度计放大器,吉它预放大器, 10Hz四阶车比雪夫低通滤波器(0.01dB波纹)电路等以及评估板EVAL-ADA4625-2ARDZ主要特性,电路图,材料清单和PCB设计图.

　　The ADA4625-1/ADA4625-2 build on Analog Devices, Inc., high voltage, single-supply, rail-to-rail output (RRO), precision junction field effect transistor (JFET) input op amps, taking that product type to a level of speed and low noise that has not been made available to the market previously.

　　The ADA4625-1/ADA4625-2 provide optimal performance in high voltage, high gain, and low noise applications. The input common-mode voltage range includes the negative supply, and the output swings rail to rail. This enables the user to maximize dynamic input range in low voltage, single supply applications without the need for a separate negative voltage power supply for ground sense.

　　The combination of wide bandwidth, low noise, and low input bias current makes the ADA4625-1/ADA4625-2 especially suitable for phase-locked loop (PLL), active filter amplifiers and for high tuning voltage (VTUNE), voltage controlled oscillators (VCOs) and preamplifiers where low level signals require an amplifier that provides both high amplification and wide bandwidth.

　　The ADA4625-1/ADA4625-2 are unity-gain stable, and there is no phase reversal when input range exceeds either supply rail by 200 mV. The output is capable of driving loads up to 1000 pF and/or 600 Ω loads.

　　The ADA4625-1/ADA4625-2 are specified for operation over the extended industrial temperature range of −40℃ to +125℃ and operates from +5 V to +36 V (±2.5 V to ±18 V) with specifi-cations at +5 V and ±18 V. The devices are available in an 8-lead SOIC package with an exposed pad (EPAD).

　　ADA4625-1/ADA4625-2主要特性:

　　Wide gain bandwidth product: 18 MHz typical

　　High slew rate: 48 V/μs typical

　　Low voltage noise density: 3.3 nV/√Hz typical at 1 kHz

　　Low peak-to-peak noise: 0.15 μV p-p, 0.1 Hz to 10 Hz

　　Low input bias current: ±15 pA typical at TA = 25℃

　　Low offset voltage: ±80 μV maximum at TA = 25℃

　　Offset voltage drift: ±1.2 μV/°C maximum at TA = −40℃ to 85℃

　　Fast settling: 0.01% in 700 ns typical

　　Wide range of operating voltages

　　Dual-supply operation: 2.5 V to ±18 V

　　Single-supply operation: 5 V to 36 V

　　Input voltage range includes V−

　　Rail-to-rail output

　　High capacitive load drive capability

　　Output short-circuit current: ±46 mA

　　No phase reversal

　　Unity-gain stable

　　ADA4625-1/ADA4625-2应用:

　　PLL filter amplifiers

　　Transimpedance amplifiers

　　Photodiode sensor interfaces

　　Low noise charge amplifiers

图1.ADA4625-1/ADA4625-2简化电路图

　　图2.20位精度±10V电压源简化电路(所有电源和去耦未显示)

图3.带DC伺服低噪音水听器放大器电路

图4.带DC伺服加速度计放大器电路

图5.吉它预放大器电路

图6.10Hz四阶车比雪夫低通滤波器(0.01dB波纹)电路

　　评估板EVAL-ADA4625-2ARDZ

　　Evaluation Board User Guide for the ADA4625-2 Low Noise, Fast Settling, Single Supply, RRO, JFET Op Amp

　　This user guide describes the evaluation board for the ADA4625-2 low noise, fast settling, single-supply, rail-to-rail output (RRO), junction field effect transistor (JFET) op amp in an 8-lead small outline integrated circuit (SOIC) package with an exposed pad. The design of this evaluation board emphasizes simplicity and ease of use. This evaluation board is a two layer board that accommodates edge mounted Subminiature Version A (SMA) connectors on the inputs and outputs. The SMA connectors provide efficient connection to test equipment or other circuitry.

　　The evaluation board ground plane, component placement, and power supply bypassing are optimized for maximum circuit flexibility and performance. The exposed pad of the ADA4625-2 is connected to the ground plane on the evaluation board to enhance thermal and noise performance. The evaluation board uses a combination of surface mount technology (SMT) component case size 0603, with the exception of the C2 and C6 bypass capacitors, which have a maximum standard size of 1206. The evaluation board features a variety of unpopulated resistor and capacitor pads that provide the user with multiple choices and extensive flexibility for different application circuits and configurations, such as active loop filters, transimpedance amplifiers (TIAs), and charge amplifiers.

　　Consult the ADA4625-2 data sheet for full details. The data sheet must be used in conjunction with this user guide when using the evaluation board.

　　评估板EVAL-ADA4625-2ARDZ主要特性:

　　Full featured evaluation board for the ADA4625-2

　　Enables quick prototyping

　　User defined circuit configuration

　　Edge mounted SMA connector provisions

　　Easy connection to test equipment and other circuits

　　EVALUATION KIT CONTENTS

　　EVAL-ADA4625-2ARDZ evaluation board

　　图7.评估板EVAL-ADA4625-2ARDZ外形图(正面)

　　图8.评估板EVAL-ADA4625-2ARDZ外形图(背面)

图9.评估板EVAL-ADA4625-2ARDZ电路图

　　评估板EVAL-ADA4625-2ARDZ材料厂清单: