LTC3861 Typical perFormance characTerisTicsRUN Threshold vs TemperatureRUN Pull-Up Current vs Temperature 2.25 2.2 2.20 RISING 2.0 2.15 1.8 TAGE (V) 2.10 1.6 2.05 1.4 RUN PIN VOL 2.00 RUN PIN CURRENT (µA) FALLING 1.95 1.2 1.90 1.0 –50 –25 0 25 50 75 100 125 150 –50 0 50 100 150 TEMPERATURE (°C) TEMPERATURE (°C) 3861 G28 3861 G29 TRACK/SS CurrentTRACK/SS Pull-Up Currentvs TRACK/SS Voltagevs Temperature 0.5 3.0 0 2.9 2.8 –0.5 2.7 –1.0 2.6 –1.5 2.5 –2.0 2.4 TRACK/SS PIN CURRENT (µA) TRACK/SS PIN CURRENT (µA) –2.5 2.3 –3.0 2.2 0 1 2 3 4 5 –50 0 50 100 150 TRACK/SS PIN VOLTAGE (V) TEMPERATURE (°C) 3861 G30 3861 G31 pin FuncTionsFB1 (Pin 1), FB2 (Pin 10): Error Amplifier Inverting Input. that amplifier. Multiphase operation can then be achieved Connect to VSNSOUT1, VNSOUT2 with a compensation by connecting all of the COMP pins together and using network for remote VOUT sensing. Connecting the FB to VCC one channel as the master and all others as slaves. When disables the differential and error amplifiers of the respec- the RUN pin is low, the respective COMP pin is actively tive channel, and will three-state the amplifier outputs. pulled down to ground. COMP1 (Pin 2), COMP2 (Pin 9): Error Amplifier Outputs. VSNSP1 (Pin 3), VSNSP2 (Pin 8): Differential Sense PWM duty cycle increases with this control voltage. The Amplifier Noninverting Input. Connect this pin to the mid- error amplifiers in the LTC3861 are true operational ampli- point of the feedback resistive divider between the positive fiers with low output impedance. As a result, the outputs and negative output capacitor terminals. of two active error amplifiers cannot be directly connected VSNSN1 (Pin 4), VSNSN2 (Pin 7): Differential Sense Am- together! For multiphase operation, connecting the FB pin plifier Inverting Input. Connect this pin to sense ground on an error amplifier to VCC will three-state the output of at the output load. 3861fb 8 For more information www.linear.com/LTC3861 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Functional Diagram Operation Applications Information Typical Applications Package Description Related Parts