Datasheet

3
LT3437
3437fc
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
I
VIN
Supply Quiescent Current BIAS = 0V, FB = 1.15V, V
C
= 0.8V, SYNC = 2V 1.35 2 mA
BIAS = 5V, FB = 1.15V, V
C
= 0.8V, SYNC = 2V 0.475 1 mA
Minimum BIAS Voltage (Note 5) 2.7 3.15 V
I
BIASS
BIAS Sleep Current (Note 4) ● 110 180 µA
I
BIAS
BIAS Quiescent Current SYNC = 2V 0.75 1 mA
Minimum Boost Voltage (Note 6) I
SW
= 500mA 1.8 2.5 V
Input Boost Current (Note 7) I
SW
= 0.5A 11 16 mA
I
SW
= 0.25A 8 13 mA
V
REF
Reference Voltage (V
REF
) 3.3V < V
VIN
< 80V ● 1.225 1.25 1.275 V
I
FB
FB Input Bias Current 50 200 nA
EA Voltage Gain (Note 8) 900 V/V
EA Voltage g
m
dI(V
C
)= ±10µA 650 µMho
EA Source Current FB = 1.15V 15 35 55 µA
EA Sink Current FB = 1.35V 15 30 55 µA
V
C
to SW g
m
1A/V
V
C
Switching Threshold V
SYNC
= 2V 500 mV
V
C
High Clamp 1.5 1.75 2.1 V
I
PK
SW Current Limit ● 500 650 900 mA
SW V
CESAT
Switch Saturation Voltage I
SW
= 250mA ● 200 400 mV
(Note 9) I
SW
= 500mA ● 400 800 mV
Switching Frequency ● 165 200 240 kHz
Maximum Duty Cycle 95 %
Minimum SYNC Amplitude 1.5 2 V
SYNC Frequency Range 240 700 kHz
SYNC Input Impedance 50 kΩ
I
CSS
C
SS
Current Threshold (Note 10) FB = 0V 4 10 16 µA
The ● denotes the specifications which apply over the –40°C to 125°C
temperature range, otherwise specifications are at T
J
= 25°C. V
IN
= 12V, SHDN = 12V, BIAS = 5V, FB = 1.25V, C
SS
/SYNC = 0V unless
otherwise noted.
ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the –40°C to 140°C
temperature range, otherwise specifications are at T
J
= 25°C. V
IN
= 12V, SHDN = 12V, BIAS = 5V, FB = 1.25V, C
SS
/SYNC = 0V unless
otherwise noted.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V
SHDN
SHDN Threshold ● 1.1 1.3 1.5 V
I
SHDN
SHDN Input Current SHDN = 12V ● 530 µA
Minimum Input Voltage (Note 3) ● 2.5 3.5 V
I
VINS
Supply Shutdown Current SHDN = 0V, BOOST = 0V, FB/PGFB = 0V, BIAS = 0V 0.1 2 µA
Supply Sleep Current (Note 4) BIAS = 0V, FB = 1.35V ● 150 300 µA
FB = 1.35V
● 45 75 µA
ELECTRICAL CHARACTERISTICS