New Content (1)
Rarely Asked QuestionsCurrent Noise in FET Input Amps
Features and Benefits
- 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°C
- Low offset voltage: ±80 µV maximum at TA = 25°C
- Offset voltage drift: ±1.2 µV/°C maximum at TA = −40°C to 85°C
- 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
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°C to +125°C and operates from +5 V to +36 V (±2.5 V to ±18 V) with specifications at +5 V and ±18 V. The devices are available in an 8-lead SOIC package with an exposed pad (EPAD).
- PLL filter amplifiers
- Transimpedance amplifiers
- Photodiode sensor interfaces
- Low noise charge amplifiers
Product Lifecycle Recommended for New Designs
This product has been released to the market. The data sheet contains all final specifications and operating conditions. For new designs, ADI recommends utilization of these products.
Evaluation Kits (1)
The evaluation board for the ADA4625-2 is a 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.
Features & Benefits
- 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
Tools & Simulations
LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.
Models for the following parts are available in LTspice:
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.
Sample & Buy
The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.