LTC3124_15 Datasheet, PDF (7/28 Pages) Linear Technology – 15V, 5A 2-Phase Synchronous Step-Up DC/DC Converter with Output Disconnect

TYPICAL PERFORMANCE CHARACTERISTICS
Configured as front page application at T_A = 25°C, unless otherwise specified.
LTC3124
Short-Circuit Response
V_OUT
5V/DIV
INDUCTOR B
CURRENT
2A/DIV
SHORT-CIRCUIT
APPLIED
SHORT-CIRCUIT
REMOVED
INDUCTOR A
CURRENT
2A/DIV
I_LOAD = 500mA 100µs/DIV
3124 G28
SWA and SWB at 1MHz/Phase
V_SWB
5V/DIV
V_SWA
5V/DIV
I_LOAD = 1500mA 500ns/DIV
3124 G29
SW Pins while Synchronizing
to 1.2MHz
V_SWB
5V/DIV
V_SWA
5V/DIV
Output Voltage Ripple at 1.5A
Load with Two 10µF Ceramic
Capacitors
V_OUT
20mV/DIV
AC-COUPLED
INDUCTOR B
CURRENT
500mA/DIV
INDUCTOR A
CURRENT
500mA/DIV
I_LOAD = 1500mA 500ns/DIV
3124 G30
500ns/DIV
3124 G31
PIN FUNCTIONS
SWB, SWA (Pin 1, Pin 3): Phase B and Phase A Switch
Pins. Connect inductors from these pins to the input sup-
ply. Keep PCB trace lengths as short and wide as possible
to reduce EMI and voltage overshoot. When V_OUT ≥ V_IN +
2V, internal anti-ringing resistors are connected between
V_IN and both SWA and SWB after their respective induc-
tor currents have dropped to near zero, to minimize EMI.
These anti-ringing resistors are also activated in shutdown
and during the sleep periods of Burst Mode operation.
PGNDB, PGNDA, PGND (Pin 2, Pin 4, Exposed Pad
Pin 17): Power Ground. When laying out your PCB, provide
a short, direct path between PGND and the output capaci-
tors and tie directly to the ground plane. The exposed pad
is ground and must be soldered to the PCB ground plane
for rated thermal and electrical performance.
V_IN (Pin 5): Input Supply Pin. The device is powered from
V_IN if V_IN is initially greater than approximately 3.5V, with
V_IN continuing to supply the device down to approximately
3V; otherwise the greater of V_IN and V_OUT supplies the
3124f
For more information www.linear.com/LTC3124
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