DESCRIPTION
The LP508 is an 8 pin Class A amplifier utilizing Gennums proprietary low voltage bipolar JFET technology. It consists of 2 single ended, low noise inverting gain blocks. The first block has a typical open loop gain of 50 dB, with the closed loop gain set by the ratio of the feedback resistor to the the source impedance. The second block has the output transistor bias set by RE and VRE at pin 7 which is 27 mV.
Typically, the gain of the first block is set to 29 dB, with the second block at 32 dB, giving a total gain of 61 dB.

FEATURES
• 1 µV input referred noise
• 1.0 to 5 VDC operating range
• 61 dB typical gain (adjustable)
• 0.28 to 2.0 mA range of transducer current
• 1 % electrical distortion
• the first and second blocks can be DC coupled
• 4.0 kΩ microphone decoupling resistor, on-chip
• 100 Hz to 50 kHz frequency response
• volume control range >40 dB