DEVICE DESCRIPTION The ZLDO Series low dropout linear regulators operate with an exceptionally low dropout voltage, typically only 30mV with a load current of 100mA. The regulator series features output voltages in the range 2.7 to 18 volts, this device provides an output voltage of 4.85 volts. The ZLDO485 consumes a typical quiescent current of only 1mA and is rated to supply load currents up to 300mA. A battery low flag is available to indicate potential power fail situations. If the input voltage falls to within 200mV of the regulated output voltage then the error output pulls low. The device also features an active high disable control. Once disabled the ZLDO quiescent current falls to typically 11mA. The ZLDO devices are packaged in Zetex SM8 8 pin small outline surface mount package, ideal for applications where space saving is important. The device low dropout voltage, low quiescent current and small size make it ideal for low power and battery powered applications. Battery powered circuits can make particular use of the low battery flag and shutdown features. FEATURES · Very low dropout voltage · 6mV dropout at 10mA output · 30mV dropout at 100mA output · 100mV dropout at 300mA output · 4.85 volt fixed output · Other voltages available · Low quiescent current · 1mA quiescent (typ) at 300mA output · Low battery flag · Shutdown control · Surface mount package APPLICATIONS · Battery powered devices · Portable instruments · Portable communications · Laptop/Palmtop computers · Electronic organisers 4.85 VOLT ULTRA LOW DROPOUT REGULATOR ISSUE 2 - MAY 1997 LOW BATTERY COMPARATOR Low Battery Flag Vin OUTPUT DRIVE BIAS CIRCUIT SHUTDOWN THERMAL SHUTDOWN Shutdown Control BANDGAP REFERENCE Vo Shaping Gnd Cs ZLDO485 4-