LTC3828 Datasheet, PDF (6/32 Pages) Linear Technology – Dual 2-Phase Step-Down Controller with Tracking

LTC3828
TYPICAL PERFOR A CE CHARACTERISTICS T_A = 25°C unless otherwise noted.
Current Sense Threshold vs
I_TH Voltage
80
70
60
50
40
30
20
10
0
–10
–20
0
0.5 1.0 1.5 2.0
V_ITH (V)
2.5
3828 G16
Soft Start-Up:
(Figure 14, with Coincident
Tracking)
V_OUT1
1V/DIV
V_OUT2
1V/DIV
Dropout Voltage vs Output Current
(Figure 14)
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
OUTPUT CURRENT (A)
3828 G17
Soft Start-Up:
(Figure 14, with Ratiometric
Tracking)
SENSE Pins Total Source Current
100
50
0
–50
–100
0
1
2
3
4
5
6
V_SENSE COMMON MODE VOLTAGE (V)
3828 G18
Soft Start-Up:
(Figure 14, with Internal Soft
Start-Up)
V_OUT1
1V/DIV
V_OUT2
1V/DIV
V_OUT1
1V/DIV
V_OUT2
1V/DIV
V_IN = 12V
V_OUT1 = 5V
V_OUT2 = 3.3V
5ms/DIV
3828 G19
Load Step: Burst Mode Operation
(Figure 14)
V_IN = 12V
V_OUT1 = 5V
V_OUT2 = 3.3V
2ms/DIV
3828 G20
Load Step: Continuous Mode
(Figure 14)
V_IN = 12V
V_OUT1 = 5V
V_OUT2 = 3.3V
100µs/DIV
Input Source/Capacitor
Instantaneous Current
(Figure 14)
V_OUT1
100mV/DIV
V_OUT2
100mV/DIV
I_L1
2A/DIV
V_IN = 12V
50µs/DIV
V_OUT1 = 5V
V_OUT2 = 3.3V
LOAD STEP = 0A TO 3A
WITH RATIOMETRIC TRACKING
V_OUT1
100mV/DIV
V_OUT2
100mV/DIV
I_L1
2A/DIV
3828 G22
V_IN = 12V
50µs/DIV
V_OUT1 = 5V
V_OUT2 = 3.3V
LOAD STEP = 0A TO 3A
WITH RATIOMETRIC TRACKING
SW1
20V/DIV
SW2
20V/DIV
I_IN
25A/DIV
3828 G23
V_IN
RIPPLE
50mV/DIV
V_IN = 12V
500ns/DIV
V_OUT1 = 5V
V_OUT2 = 3.3V
I_OUT5 = I_OUT3.3 = 2A
6
3828 G21
3828 G24
3828f