LTC1798 Series TYPICAL PERFORMANCE CHARACTERISTICSLTC1798-2.5LTC1798-5 Input CurrentLTC1798-2.5 Input Current0.1Hz to 10Hz Noisevs Input Voltage in Dropoutvs Input Voltage in Dropout 1400 250 VIN = 2.7V TA = –55°C 1200 TA = 25°C 200 1000 TA = 25°C T T A = 125°C A = 125°C 800 150 5µV/DIV 600 100 T INPUT CURRENT (µA) 400 INPUT CURRENT (µA) A = –55°C 50 200 0 0 1SEC/DIV 0 1 2 3 4 5 6 7 8 9 10 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 1798 G10 INPUT VOLTAGE (V) INPUT VOLTAGE (V) 1798 G11 1798 G12 PIN FUNCTIONS DNC (Pins 1, 5, 7, 8): Do Not Connect. Connected R1+ R2 internally for post package trim. These pins must be left VOUT = 2. V 385 ; R1 is connected from OUT R2 unconnected. to FB and R2 from FB to GND. Selecting R2 ≥ 10k will IN (Pin 2): Positive Supply. Bypassing with a 0.1µF capaci- make IOUT < 250µA. tor is recommended if the output loading changes. (VOUT + 0.2V) ≤ V GND (Pin 4): Negative Supply or Ground Connection. IN ≤ 12.6V. DNC (Pin 3): (LTC1798-2.5/LTC1798-3/LTC1798-4.1/ OUT (Pin 6): Reference Output. The output can source LTC1798-5) Do Not Connect. Connected internally for post up to 10mA and sink up to 2mA. It is stable with output package trim. This pin must be left unconnected. bypass capacitor ranging from 0µF to 1µF. FB (Pin 3): (LTC1798) Resistor Divider Feedback Pin. Connect a resistor divider from OUT to GND and the center tap to FB. This pin sets the output potential. 1798fc 5 Document Outline FEATURES DESCRIPTION APPLICATIONS TYPICAL APPLICATION ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION ORDER INFORMATION AVAILABLE OPTIONS ELECTRICAL CHARACTERISTICS TYPICAL PERFORMANCE CHARACTERISTICS PIN FUNCTIONS BLOCK DIAGRAM APPLICATIONS INFORMATION PACKAGE DESCRIPTION REVISION HISTORY TYPICAL APPLICATION RELATED PARTS
