Datasheet LTC3417A-2 (Analog Devices) - 6

LTC3417A-2
TYPICAL PERFORMANCE CHARACTERISTICS RDS(ON) vs VIN OUT2 Frequency vs VIN Frequency vs Temperature
0.20 6 15 TA = 27°C 4 0.19 10 FREQ = VIN P-CHANNEL SWITCH 2 FREQ = 143k TO GROUND 0.18 5 0 (Ω) 0.17 –2 0 DS(ON) FREQ = 143k TO GROUND R –4 0.16 FREQ = V –5 IN –6 FREQUENCY VARIATION (%) FREQUENCY VARIATION (%) 0.15 –10 N-CHANNEL SWITCH –8 0.14 –10 –15 2 2.5 3 3.5 4 4.5 5 5.5 2 2.5 3 3.5 4 4.5 5 5.5 –50 –25 0 25 50 75 100 125 VIN (V) VIN (V) TEMPERATURE (°C) 3417A-2 G16 3417A-2 G17 3417A-2 G18
PIN FUNCTIONS (DFN/TSSOP) RUN1 (Pin 1/Pin 2):
Enable for 1.5A Regulator. When
SYNC/MODE (Pin 9/Pin 12):
Combination Mode Selection at Logic 1, 1.5A regulator is running. When at 0V, 1.5A and Oscillator Synchronization Pin. This pin controls the op- regulator is off. When both RUN1 and RUN2 are at 0V, the eration of the device. When the voltage on the SYNC/MODE part is in shutdown. pin is >(VIN – 0.5V), Burst Mode operation is selected. When the voltage on the SYNC/MODE pin is < 0.5V, pulse
VIN1 (Pin 2/Pin 3):
Supply Pin for P-Channel Switch of skipping mode is selected. When the SYNC/MODE pin is 1.5A Regulator. held at VIN/2, forced continuous mode is selected. The
ITH1 (Pin 3/Pin 4):
Error Amplifi er Compensation Point oscillation frequency can be synchronized to an external for 1.5A Regulator. The current comparator threshold oscillator applied to this pin. When synchronized to an increases with this control voltage. Nominal voltage range external clock, pulse skip mode is selected. for this pin is 0V to 1.5V.
SW2 (Pin 10/Pin 13):
Switch Node Connection to the
VFB1 (Pin 4/Pin 5):
Receives the feedback voltage from Inductor for the 1A Regulator. This pin swings from VIN2 external resistive divider across the 1.5A regulator output. to PGND2. Nominal voltage for this pin is 0.8V.
PGOOD (Pin 11/Pin 14):
Power Good Pin. This common
VFB2 (Pin 5/Pin 6):
Receives the feedback voltage from drain-logic output is pulled to GND when the output volt- external resistive divider across the 1A regulator output. age of either regulator is –6% below regulation. If either Nominal voltage for this pin is 0.8V. RUN1 or RUN2 is low (the respective regulator is in sleep
I
mode and therefore the output voltage is low), then PGOOD
TH2 (Pin 6/Pin 7):
Error Amplifi er Compensation Point for 1A regulator. The current comparator threshold increases refl ects the regulation of the running regulator. with this control voltage. Nominal voltage range for this
FREQ (Pin 12/Pin 15):
Frequency Set Pin. When FREQ is pin is 0V to 1.5V. at VIN, internal oscillator runs at 1.5MHz. When a resistor
RUN2 (Pin 7/Pin 8):
Enable for 1A Regulator. When at is connected from this pin to ground, the internal oscillator Logic 1, 1A regulator is running. When at 0V, 1A regula- frequency can be varied from 0.6MHz to 4MHz. tor is off. When both RUN1 and RUN2 are at 0V, the part
GNDA (Pin 13/Pin 16):
Analog Ground Pin for Internal is in shutdown. Analog Circuitry.
VIN2 (Pin 8/Pin 9):
Supply Pin for P-Channel Switch of 1A
PHASE (Pin 14/Pin 17):
Selects 1A regulator switching Regulator and Supply for Analog Circuitry. phase with respect to 1.5A regulator switching. Set to 3417a2fa 6