LTC3899_15 Datasheet, PDF (9/38 Pages) Linear Technology – 60V Low IQ, Triple Output, Buck/Buck/Boost Synchronous Controller

Typical Performance Characteristics
LTC3899
DRV_CC Line Regulation
11
DRVSET = INTV_CC
10
9
8
7
DRVSET = GND
6
5
0 5 10 15 20 25 30 35 40 45 50 55 60 65
INPUT VOLTAGE (V)
3899 G19
SENSE Pins Total Input Current
vs V_SENSE Voltage
800
700
SENSE1, 2 PINS (BUCK)
600
500
400
300
SENSE3 PINS (BOOST)
200
100
0
0 5 10 15 20 25 30 35 40 45 50 55 60 65
V_SENSE COMMON MODE VOLTAGE (V)
3899 G22
Maximum Current Sense
Threshold vs Duty Cycle
100
90
80
BOOST
70
BUCK
60
50
40
30
20
10
0
0 10 20 30 40 50 60 70 80 90 100
DUTY CYCLE (%)
3899 G25
DRV_CC and EXTV_CC
vs Load Current
6.4
6.2
EXTV_CC = 0V
6
5.8
EXTV_CC = 8.5V
5.6
5.4
5.2
5
4.8
EXTV_CC = 5V
4.6
4.4
4.2
V_BIAS = 12V
DRVSET = GND
4
0 25 50
75 100
LOAD CURRENT (mA)
125 150
3899 G20
Buck SENSE^– Pin Input Bias
Current vs Temperature
900
800
V_OUT > INTV_CC + 0.5V
700
600
500
400
300
200
100
V_OUT < INTV_CC – 0.5V
0
-75 -50 -25 0 25 50 75 100 125 150
TEMPERATURE (°C)
3899 G23
Maximum Current Sense
Threshold vs I_TH Voltage
100
5% DUTY CYCLE
80
PULSE-SKIPPING
60
Burst Mode
40
OPERATION
20
0
–20
FORCED CONTINUOUS MODE
–40
0 0.2 0.4 0.6 0.8 1 1.2 1.4
V_ITH (V)
3899 G26
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EXTV_CC Switchover and DRV_CC
Voltages vs Temperature
11
DRV_CC
10
9 DRVSET = INTV_CC
8
EXTV_CC RISING
7
EXTV_CC FALLING
DRV_CC
6
DRVSET = GND
5
EXTV_CC RISING
4
EXTV_CC FALLING
-75 -50 -25 0 25 50 75 100 125 150
TEMPERATURE (°C)
3899 G21
Boost SENSE Pin Total Input
Current vs Temperature
200
V_IN = 12V
180
160
SENSE3+ PIN
140
120
100
80
60
40
20
0
-75 -50 -25
SENSE3– PIN
0 25 50 75 100 125 150
TEMPERATURE (°C)
3899 G24
TRACK/SS Pull-Up Current
vs Temperature
12
11.5
11
10.5
10
9.5
9
8.5
8
-75 -50 -25 0 25 50 75 100 125 150
TEMPERATURE (°C)
3899 G27
3899f
9