LTC3425_15 Datasheet, PDF (4/24 Pages) Linear Technology – 5A, 8MHz, 4-Phase Synchronous Step-Up DC/DC Converter

LTC3425
TYPICAL PERFOR A CE CHARACTERISTICS
SWA, SWB, SWC, SWD
at 1MHz/Phase
SW Pin and Oscillator SYNCOUT
SW Pin and Inductor Current in
Discontinous Mode. Antiring
Circuit Eliminates High Frequency
Ringing
SWA TO SWD
5V/DIV
SWA
2V/DIV
SYNCOUT
2V/DIV
I_L
0.2A/DIV
SW
2V/DIV
250ns/DIV
3425 G01
Transient Response 0.5A to 1.5A
Fixed Frequency Mode Operation
250ns/DIV
3425 G02
Output Voltage Ripple at 2.5A
Load with Only Four 4.7µF
Ceramic Capacitors
V_IN = 2.4V
V_OUT = 3.3V
C_OUT = 220µF
250ns/DIV
3425 G03
Output Voltage Ripple at 2.5A
Load with a 47µF Ceramic Bulk
Capacitor
V_OUT AC
100mV/DIV
LOAD
CURRENT
0.5A/DIV
V_OUT AC
50mV/DIV
V_OUT AC
10mV/DIV
V_IN = 2.4V
V_OUT = 3.3V
C_OUT = 220µF
100µs/DIV
3425 G04
Soft-Start and Inrush Current
Limiting
V_IN = 2.4V
500ns/DIV
V_OUT = 3.3V
FREQUENCY = 1MHz/PHASE
Burst Mode Operation
I_IN
0.5A/DIV
SS Pin
1V/DIV
V_OUT
2V/DIV
SWA
2V/DIV
V_OUT AC
50mV/DIV
V_IN = 2.4V
500µs/DIV
V_OUT = 3.3V
C_SOFTSTART = 0.015µF
3425 G07
V_IN = 2.4V
V_OUT = 3.3V
C_OUT = 220µF
25µs/DIV
3425 G05
V_IN = 2.4V
500ns/DIV
V_OUT = 3.3V
FREQUENCY = 1MHz/PHASE
3425 G06
Transient Response 10mA to 1A
Automatic Burst Mode Operation
I_OUT
1A/DIV
BURST PIN
1V/DIV
V_OUT AC
200mV/DIV
3425 G08
V_IN = 2.4V
V_OUT = 3.3V
C_OUT = 220µF
1ms/DIV
3425 G10
3425f
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