Datasheet

LT3507A
3
3507af
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. (Notes 2, 7)
PARAMETER CONDITIONS MIN TYP MAX UNITS
Minimum Operating Voltage Internal UVLO on V
IN1
l
3.8 4 V
Input Quiescent Current Not Switching, V
BIAS
= 3.3V 2 3.5 mA
Bias Quiescent Current Not Switching, V
BIAS
= 3.3V 5 7.5 mA
Shutdown Current V
RUN1,2,3
= 0V 1 µA
Reference Voltage Line Regulation 5V < V
IN1
< 36V 0.01 %/V
V
C
Source Current V
C
= 0.6V 20 µA
V
C
Sink Current V
C
= 0.6V 30 µA
V
C
Clamp Voltage 1.8 V
Switching Frequency R
T
= 40.2k
l
0.9 1.1 MHz
Switching Phase SW1 to SW2,3, R
T
= 40.2k 180 Deg
Foldback Frequency V
FB
= 0V, R
T
= 40.2k 120 kHz
Frequency Shift Threshold on FB 0.4 V
RUN Threshold 1 1.5 V
PGOOD Output Voltage Low I
PGOOD
= 200µA 0.2 0.4 V
PGOOD Pin Leakage V
PGOOD
= 2V 10 400 nA
PGOOD Threshold Offset V
FB
Rising 58 80 105 mV
Feedback Pin Voltage
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 0.9 V
Switch Leakage Current
0.01 10 µA
Minimum Boost Voltage Above Switch (Note 4) 1.8 2.5 V
I
TRK/SS
V
TRK/SS
= 0V 1.25 µA
V
IN1
-V
INSW
I
VINSW
= 1mA 0.35 V
Converter 1
V
C1
to Switch Current Gain 6 A/V
Switch 1 Current Limit (Note 3) Duty Cycle = 15%
l
4.3 5.1 6 A
Switch 1 V
CESAT
I
SW1
= 2A (Note 6) 400 600 mV
BOOST1 Operating Current I
SW1
= 2A 40 60 mA
Converter 2
V
C2
to Switch Current Gain 4.3 A/V
Switch 2 Current Limit (Note 3) Duty Cycle = 15%
l
2.7 3.3 4 A
Switch 2 V
CESAT
I
SW2
= 1.5A (Note 6) 350 500 mV
BOOST2 Operating Current I
SW2
= 1.5A 40 60 mA