Features
| • | 0.58nV total input noise @ 12MHz |
| • | >3.0dB Noise figure advantage over shunt termination |
| • | <.5ns group delay repeatability |
| • | High cutoff -3dB @ 33MHz |
| • | Low cutoff -3dB @ 0.5MHz |
| • | 2.0dB noise figure @ 50
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| • | -60dBc intermod for 2VPP @ 5MHz |
| • | Programmable noise figure vs. IBIAS1
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| • | Supply current: 11mA |
| • | Available in 8-pin SOIC |
Description The CLC5509 is a high performance, ultra low noise preamplifier designed for applications requiring unconditional stability for wide ranges of complex input loads. Both input impedance and gain are externally adjustable, which make it simple to interface to peizoelectric ultrasound transducers. The CLC5509 preamplifier's low 0.58nV total input noise makes it ideal for noise sensitive front ends. The high repeatability in group delay over voltage and temperature translates into precision edge measurements for Doppler applications.
The IC consists of an emitter input, common base amplifier stage followed by a low distortion, closed loop buffer. The Noise Figure can be user programmed by controlling the emitter current (IBIAS1) which sets emitter resistance re. External negative feedback creates a well controlled input impedance to allow a near noiseless active input transmission line termination. The preamp is stable against changes in source impedance of 50 to 200 over temperature and supply variations, with gains from 14dB to 26dB. The CLC5509 preamp architecture is also well suited for use with magneto-resistive tape or disk drive heads. In these applications the head bias current can be reused to bias the preamp. The part is packaged in an 8-pin plastic SOIC, and runs off ±5V supplies. External biasing is required for the input signal path.
The CLC5509 is constructed using an advanced complementary bipolar process and National Semiconductor's proven high performance architectures.
Applications
| • | Ultrasound preamp |
| • | Tape drive preamp |
| • | Disk drive preamp |
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