Ultra-Low-Noise Amplifier Features Selectable Gain and Broad Bandwidth

A dual, ultra-low-noise amplifier from Analog Devices features selectable gain and active impedance matching. The AD8432 provides excellent noise performance, low per-channel cost, and very broad bandwidth. The combination of selectable gain and low noise enables the amplifier to detect and resolve low-level input signals. Active impedance matching reduces signal reflection by matching signal-source and amplifier-input impedances without compromising input-noise performance. By using the pin-strapping options, designers can select from four gains—4, 8, 12, and 16. At a gain of four, the company claims the amplifier’s 200-MHz bandwidth is nearly three times that of competing devices. The AD8432, a single-ended-input amplifier that operates on a single 5-V supply, is designed for communications-infrastructure and medical-ultrasound applications. Its common die and symmetrical design ensure precise phase matching between channels. The AD8432 packaging features an exposed paddle that provides a low thermal-resistance path to the circuit board, enabling more efficient heat transfer and increasing reliability. Samples of the product in a 4-mm x 4-mm 24-lead LFCSP are available now. Pricing is set at $1.99 each in 1000-unit lots. ANALOG DEVICES INC., Norwood, MA. (781) 329-4700.