MAX4805
Octal High-Voltage-Protected, Low-Power, Low-Noise Operational Amplifiers
Industry's First High-Voltage-Protected, Low-Noise Op Amp for In-Probe Use in Ultrasound Imaging Applications
Top
Overview
Features and Benefits
- High Density/8 Channels Per Package
- I/O Protection for TX Burst Up to ±100V
- Very Fast Recovery Time After TX Burst 1.5µs (typ)
- OVP for Signals Greater Than ±2.7V
- Extremely Low Power Dissipation 8mW/ch (typ)
- 65Ω (typ) Low-Signal Output Impedance
- 44MHz -3dB Bandwidth (typ)
- Voltage Gain 6dB (MAX4805) (typ), 9dB (MAX4805A) (typ)
- Low Voltage Noise 2.2nV/
(typ) (MAX4805)
- Low Voltage Noise 2.2nV/ (typ) (MAX4805A)
- Low Current Noise 2.0pA/ (typ) (MAX4805)
- Low Current Noise 1.7pA/ (typ) (MAX4805A)
- Ultra-Small (5mm x 5mm), 32-Pin TQFN Package
Product Details
The MAX4805/MAX4805A are octal high-voltage-protected operational amplifiers. These devices are a fully integrated, very compact solution for in-probe amplification of echo signals coming from transducers in an ultrasound system. The use of in-probe buffering improves system signal-to-noise ratio (SNR) for transducers featuring high-output impedance. This results in greater penetration depth and sensitivity. The MAX4805/MAX4805A can be adopted in ultrasound probes without any change in the system (scanner machine). Typical applications include high-impedance piezoelectric transducers (PZT) and capacitive micromachined ultrasonic transducers (CMUT) in-probe buffering and amplification. The MAX4805 is optimized for PZT applications, and the MAX4805A is optimized for CMUT applications.
The MAX4805/MAX4805A feature eight operational amplifiers configured in a noninverting configuration. The small-signal output impedance of these operational amplifiers is 65Ω (typ) for matching the typical cable impedance. The low-noise amplifier features 44MHz (typ) -3dB bandwidth and very low voltage and current noise, ensuring excellent noise figure. The output signals of these operational amplifiers are limited with diodes in an antiparallel configuration to GND.
The MAX4805/MAX4805A provide HV protection for inputs and outputs of the operational amplifiers. The operational amplifiers inputs are protected by an external HV capacitor. An integrated automatic high-voltage switch protects the output of the amplifier from HV bursts. Transmitted bursts reach the transducer through a pair of integrated, antiparallel diodes. Each channel is able to sustain transmission burst up to ≤ 100V. The high-voltage (HV) protection is automatically activated as soon as the TX voltage is greater than ±2.7V (typ); no dedicated TX/RX signal is required.
The MAX4805 and the MAX4805A differ in terms of input-current noise, input impedance, and voltage gain. Depending on the equivalent transducer source impedance, either the MAX4805 or the MAX4805A can be used to optimize a better noise figure.
The MAX4805/MAX4805A are available in the 32-pin TQFN package. All devices are specified for the commercial 0°C to +70°C temperature range.
Applications
- Ultrasound Imaging, PZT NDT Probes
- Ultrasound Medical Imaging, CMUT Probes
- Ultrasound Medical Imaging, PZT HF Probes
Product Categories
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.
Documentation & Resources
Design Resources
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.
Support & Discussions
Sample & Buy
Ordering FAQs
See our Ordering FAQs for answers to questions about online orders, payment options and more.
Buy Now Pricing
(**) Displayed Buy Now Price and Price Range is based on small quantity orders.
List Pricing
(*)The 1Ku 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. authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.
Lead Times
Please see the latest communication from our CCO regarding lead times.
Sampling
Selecting the Sample button above will redirect to the third-party ADI Sample Site. The part selected will carry over to your cart on this site once logged in. Please create a new account there if you have never used the site before. Contact SampleSupport@analog.com with any questions regarding this Sample Site.