LTC3878_15 Datasheet, PDF (6/26 Pages) Linear Technology – Fast, Wide Operating Range No RSENSE Step-Down DC/DC Controller

LTC3878
Typical Performance Characteristics
Error Amplifier g_m vs Temperature
2.0
1.9
1.8
1.7
1.6
1.5
1.4
1.3
1.2
1.1
1.0
–50
0
50
100
TEMPERATURE (°C)
3878 G19
Shutdown Current
vs Input Voltage
35
30
25
20
15
10
5
10 15 20 25 30 35 40
INPUT VOLTAGE (V)
3878 G20
Quiescent Current vs INTV_CC
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
4.0 4.5 5.0 5.5 6.0 6.5 7.0
INTV_CC (V)
3878 G21
INTV_CC Load Regulation
0
V_IN = 12V
–0.2
–0.4
–0.6
–0.8
–1.0
–1.2
–1.4
–1.6
–1.8
–2.0
0
10
20
30
40
INTV_CC LOAD CURRENT (mA)
50
3878 G22
INTV_CC Dropout
0
–200
V_IN = 4.5V
–400
–600
–800
–1000
–1200
0
10
20
30
40
INTV_CC LOAD CURRENT (mA)
50
3878 G23
INTV_CC vs INTV_CC I_LOAD
6
V_IN = 12V
5
INTV_CC
4
I_LOAD
FALLING
INTV_CC
I_LOAD
RISING
3
DO NOT EXCEED ≥50mA
2
CONTINUOUS
I_LIMIT = 150mA,
1
INTV_CC > 0.7V
I_LIMIT = 22mA,
INTV_CC < 0.7V
0
0
50
100
150
200
I_LOAD (mA)
3878 G24
Efficiency: LTC3878 vs LTC1778
94
92
LTC3878
90
LTC1778
88
1.6%
86
Q_T = RJK0305DPB
84
Q_B = RJK0330DPB
L = PULSE PA0513.441NLT
82
f_SW = 300kHz
V_IN = 12V
V_OUT = 1.2V
80
0
5
10
15
20
25
LOAD CURRENT (A)
3878 G25
RUN/SS Pin Current vs
Temperature
1.6
V_IN = 15V
V_OUT = 1.2V
FCB = INTV_CC
1.4
1.2
1.0
0.8
–50
0
50
TEMPERATURE (°C)
100
3878 G26
3878fa