LTC3873-5 TYPICAL PERFORMANCE CHARACTERISTICSMaximum Sense ThresholdFrequency vs Temperaturevs Temperature 250 300 VIN = 5V IPRG = VIN 250 230 200 IPRG = FLOAT 210 150 IPRG = GND 190 FREQUECY (kHz) 100 170 50 MAXIMUM SENSE THRESHOLD (mV) 150 0 –60 –40 –20 0 20 40 60 80 100 120 –60 –40 –20 0 20 40 60 80 100 120 TEMPERATURE (°C) TEMPERATURE (°C) 38735 G10 3873-5 G09 PIN FUNCTIONS (TS8/DD8)IPRG (Pin 1/Pin 4): Current Sense Limit Select Pin. RUN/SS (Pin 7/Pin 6): Shutdown and External Soft-Start Pin. In shutdown, all functions are disabled and the NGATE ITH (Pin 2/Pin 3): This pin serves as the error amplifi er pin is held low. compensation point. Nominal voltage range for this pin is 0.7V to 1.9V. SW (Pin 8/Pin 5): Switch node connection to inductor and current sense input pin through external slope compensa- VFB (Pin 3/Pin 2): This pin receives the feedback voltage tion resistor. Normally, the external N-channel MOSFET’s from an external resistor divider across the output. drain is connected to this pin. GND (Pin 4/Pin 1): Ground Pin. Exposed Pad (NA/Pin 9): Ground. Must be soldered to PCB NGATE (Pin 5/Pin 8): Gate Drive for the External N-Channel for electrical contact and rated thermal performance. MOSFET. This pin swings from 0V to VIN. VCC (Pin 6/Pin 7): Supply Pin. This pin must be closely decoupled to GND (Pin 4). 38735fb 5
