SOT23 Selling Leads, SOT23 Datasheet PDF

Pinout/Connection Diagram

The circuit reduces noise and ripple voltage by 40 dB over the 100-Hz to 20-kHz audio range. It provides a clean source of 5-V power for driving audio circuits in portable applications such as cellular phones and multimedia notebook computers. Most linear regulators reject noise only up to 1000 Hz or so, and the bulk of a low-frequency passive filter is unwelcome in portable applications. The circuit shown accepts noisy V_cc in the 4.5- to 6-V range and produces quiet V_cc at a dc level 7 percent lower. For example, it produces 4.65 V at 1 A from a nominal 5-V source, with only 200 μA of quiescent current. The largest capacitor is 10 μF and the resistors can be 0.1 W or surface-mount 0805 size. When operating, the circuit acts as a wide-bandwidth buffered voltage follower (not a regulator) whose dc output level is 7 percent below V_in。 R1 and R3 form a voltage divider that provides the 7 percent attenuation, and C4 helps to form a 93-percent filter replica of V_in at the op amp's inverting input. The op amp's small input bias current (25 nA typical) allows large resistor values for R1 and R3, yet limits the maximum dc error to only 20 mV. The result is a low-pass filter with a 2-Hz corner frequency that provides 20 dB of attenuation at 20 Hz.

Features

· Ultra-Low 500nA Supply Current
  (MAX6375/MAX6376/MAX6377)
· Thresholds Available from 2.20V to 4.63V in
  Approximately 100mV Increments
· ±2.5% Threshold Accuracy Over Temperature
· Low Cost
· Available in Three Versions: Push-Pull OUT,
  Push-Pull OUT, and Open-Drain OUT
· Power-Supply Transient Immunity
· No External Components
· Available in Either a 3-Pin SC70
  or 3-Pin SOT23 Package