LTC3828 Datasheet, PDF (4/32 Pages) Linear Technology – Dual 2-Phase Step-Down Controller with Tracking

LTC3828
ELECTRICAL CHARACTERISTICS
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: T_J is calculated from the ambient temperature T_A and power
dissipation P_D according to the following formulas:
LTC3828UH: T_J = T_A + (P_D • 34°C/W)
LTC3828G: T_J = T_A + (P_D • 95°C/W)
Note 3: The IC is tested in a feedback loop that servos V_{ITH1, 2} to a
specified voltage and measures the resultant V_{OSENSE1, 2.}
Note 4: Dynamic supply current is higher due to the gate charge being
delivered at the switching frequency. See Applications Information.
Note 5: Rise and fall times are measured using 10% and 90% levels. Delay
times are measured using 50% levels.
Note 6: The minimum on-time condition is specified for an inductor
peak-to-peak ripple current ≥ 40% of I_MAX (see minimum on-time
considerations in the Applications Information section).
Note 7: The LTC3828E is guaranteed to meet performance specifications
over the –40°C to 85°C operating temperature range as assured by design,
characterization and correlation with statistical process controls.
TYPICAL PERFOR A CE CHARACTERISTICS T_A = 25°C unless otherwise noted.
Efficiency vs Output Current
and Mode (Figure 14)
100
Burst Mode
90 OPERATION
80
70
CONSTANT
FREQUENCY
60
(BURST DISABLE)
50
40
30
20
10
0
0.001
FORCED
CONTINUOUS
MODE
V_IN =15V
V_OUT = 5V
F = 260kHz
0.01
0.1
1
10
OUTPUT CURRENT (A)
3828 G01
Supply Current vs Input Voltage
(Figure 14)
1200
1000
BOTH CONTROLLERS ON
800
600
400
200
0
0
SHUTDOWN
5 10 15 20 25 30
INPUT VOLTAGE (V)
3828 G04
Efficiency vs Output Current
(Figure 14)
100
V_IN = 7V
90
V_IN = 15V
80
70
60
50
0.001
V_IN = 20V
V_OUT = 5V
F = 260kHz
0.01
0.1
1
OUTPUT CURRENT (A)
10
3828 G02
Internal 5V LDO Line Regulation
5.2
I_LOAD = 1mA
5.0
4.8
4.6
4.4
4.2
4.0
0
5 10 15 20 25 30
INPUT VOLTAGE (V)
3828 G05
Efficiency vs Input Voltage
(Figure 14)
100
90
80
70
60
V_OUT = 5V
I_OUT = 3A
F = 260kHz
50
5
10
15
20
25
30
INPUT VOLTAGE (V
3828 G03
Undervoltage Lockout vs
Temperature
3.8
3.6
3.4
3.2
3.0
–50 –25
0 25 50 75
TEMPERATURE (°C)
100 125
3828 G06
3828f
4