LT3507 Datasheet, PDF (3/28 Pages) Linear Technology – Triple Monolithic Step-Down Regulator with LDO

LT3507
ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T_A = 25°C. V_IN1, V_IN2, V_IN3 = 12V, V_BOOST1, V_BOOST2, V_BOOST3 = 17V, unless
otherwise noted. (Note 2)
PARAMETER
CONDITIONS
MIN TYP MAX UNITS
V_C Source Current
V_C Sink Current
V_C Clamp Voltage
Switching Frequency
Switching Phase
Foldback Frequency
Frequency Shift Threshold on FB
V_C = 0.6V
V_C = 0.6V
R_T = 40.2k
SW1 to SW2,3, R_T = 40.2k
V_FB = 0V, R_T = 40.2k
100
μA
100
μA
1.7
V
l 0.9
1.1
MHz
180
Deg
120
kHz
0.4
V
RUN Threshold
1
1.5
V
PGOOD Output Voltage Low
PGOOD Pin Leakage
PGOOD Threshold Offset
Feedback Pin Voltage
I_PGOOD = 200μA
V_PGOOD = 2V
V_FB Rising
0.2
0.4
V
10
400
nA
58
80
105
mV
l 788
800
812
mV
Feedback Pin Bias Current
l
–50 –500
nA
Error Amplifier Transconductance
330
μS
Error Amplifier Voltage Gain
500
V/V
V_C Switching Threshold
Switch Leakage Current
0.9
V
0.01
10
μA
Minimum Boost Voltage Above Switch (Note 4)
1.8
2.5
V
Converter 1
V_C1 to Switch Current Gain
Switch 1 Current Limit (Note 3)
Duty Cycle = 15%
5
A/V
l
3
4.3
6
A
Switch 1 V_CESAT
BOOST1 Operating Current
Converter 2
I_SW1 = 2A
I_SW1 = 2A
400
600
mV
40
60
mA
V_C2 to Switch Current Gain
Switch 2 Current Limit (Note 3)
Duty Cycle = 15%
3.6
A/V
l
2
2.9
4
A
Switch 2 V_CESAT
BOOST2 Operating Current
Converter 3
I_SW2 = 1.5A
I_SW2 = 1.5A
350
500
mV
40
60
mA
V_C3 to Switch Current Gain
Switch 3 Current Limit (Note 3)
Duty Cycle = 15%
3.6
A/V
l
2
2.9
4
A
Switch 3 V_CESAT
BOOST3 Operating Current
LDO Regulator
I_SW3 = 1.5A
I_SW3 = 1.5A
350
500
mV
40
60
mA
Feedback Pin Voltage
l 788
800
812
mV
Feedback Pin Bias Current
–150 –500
nA
Error Amplifier Voltage Gain
1100
V/V
Line Regulation
V_IN from 5V to 36V
0.05
%/V
3507f
3