LT8613 PIN FUNCTIONS ISP (Pin 25): Current Sense (+) Pin. This is the noninvert- ICTRL (Pin 28): Current Adjustment Pin. ICTRL adjusts ing input to the current sense amplifier. the maximum ISP-ISN drop before the LT8613 reduces ISN (Pin 26): Current Sense (–) Pin. This is the inverting output current. Connect directly to INTVCC or float for full- input to the current sense amplifier. scale ISP-ISN threshold of 50mV or apply values between GND and 1V to modulate current limit. There is an internal IMON (Pin 27): Proportional-to-Current Monitor Output. 1.4µA pull-up current on this pin. Float or tie to INTVCC This pin sources a voltage 20 times the voltage between when unused. the ISP and ISN pins such that: GND (Exposed Pad Pin 29): Ground. The exposed pad VIMON = 20 • (VISP-VISN). must be connected to the negative terminal of the input IMON can source 200µA and sink 10µA. Float IMON capacitor and soldered to the PCB in order to lower the if unused. thermal resistance. BLOCK DIAGRAM VIN VIN CIN – INTERNAL 0.97V REF + 3.4V BIAS R3 1V + REG OPT EN/UV – SHDN SLOPE COMP INTV R4 CC OPT C OSCILLATOR VCC ERROR PG 200kHz TO 2.2MHz BST ±9% AMP + V C + C BURST SWITCH M1 BST V – DETECT LOGIC SW L OUT AND ANTI- SHOOT SHDN C1 R1 TSD THROUGH M2 INTVCC UVLO R2 VIN UVLO FB PGND C SHDN SS TSD (OPT) 2.1µA VIN UVLO TR/SS R + ISP C R F R T RT – – SEN R ISN + VOUT SYNC + 1.0V 20R COUT 1× 1.4µA GND ICTRL IMON 8613 BD Rev. A 10 For more information www.analog.com Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Electrical Characteristics Pin Configuration Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Package Description Revision History Typical Application Related Parts