LTC1876 Datasheet, PDF (5/36 Pages) Linear Technology – High Efficiency, 2-Phase, Dual Synchronous Step-Down Switching Controller and Step-Up Regulator

TYPICAL PERFOR A CE CHARACTERISTICS
Efficiency vs Output Current and
Mode (Figure 1)
100
Burst Mode
90 _OPERATION
80
70
FORCED
60
CONTINUOUS
50
MODE
40
CONSTANT
30
FREQUENCY
(BURST DISABLE)
20
10
0
0.001
V_IN = 15V
V_OUT = 5V
0.01
0.1
1
10
OUTPUT CURRENT (A)
1876 G01
V_IN Supply Current vs Input
Voltage and Mode (Figure 1)
1000
Efficiency vs Output Current
(Figure 1)
100
V_OUT = 5V
V_IN = 7V
90
V_IN = 10V
80
V_IN = 15V
V_IN = 20V
70
60
50
0.001
0.01
0.1
1
OUTPUT CURRENT (A)
10
1876 G02
EXTV_CC Voltage Drop
250
800
200
600
150
BOTH
CONTROLLERS ON
400
100
200
0
0
STANDBY
SHUTDOWN
5 10 15 20 25
INPUT VOLTAGE (V)
30 35
1876 G04
50
0
0
10
20
30
40
50
CURRENT (mA)
1876 G05
Internal 5V LDO Line Regulation
5.1
I_LOAD = 1mA
5.0
4.9
4.8
4.7
4.6
4.5
4.4
0
5 10 15 20 25 30 35
INPUT VOLTAGE (V)
1876 G07
Maximum Current Sense
Threshold vs Duty Factor
75
50
25
0
0
20
40
60
80
100
DUTY FACTOR (%)
1876 G08
LTC1876
Efficiency vs Input Voltage
(Figure 1)
100
V_OUT = 5V
I_OUT = 3A
90
80
70
60
50
5
15
25
INPUT VOLTAGE (V)
35
1876 G03
INTV_CC and EXTV_CC Switch
Voltage vs Temperature
5.05
INTV_CC VOLTAGE
5.00
4.95
4.90
4.85
4.80
EXTV_CC SWITCHOVER THRESHOLD
4.75
4.70
– 50 – 25
0 25 50 75
TEMPERATURE (°C)
100 125
1876 G06
Maximum Current Sense
Threshold vs Percent of Nominal
Output Voltage (Foldback)
80
70
60
50
40
30
20
10
0
0
25
50
75
100
PERCENT ON NOMINAL OUTPUT VOLTAGE (%)
1876 G09
1876fa
5