Datasheet
LT3724
3
3724fd
ELECTRICAL CHARACTERISTICS
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 20V, V
CC
= BOOST = BURST_EN = 10V, SHDN = 2V,
SENSE
–
= SENSE
+
= 10V, SGND = PGND = SW = 0V, unless otherwise noted.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V
BOOST
Operating Voltage Range
Operating Voltage Range (Note 5)
UVLO Threshold (Rising)
UVLO Threshold Hysteresis
V
BOOST
- V
SW
V
BOOST
- V
SW
V
BOOST
- V
SW
l
l
5
400
75
20
V
V
V
mV
I
BOOST
BOOST Supply Current (Note 6)
BOOST Burst Mode Current
BOOST Shutdown Current
V
BURST_EN
= 0V
V
SHDN
= 0V
1.4
0.1
0.1
mA
µA
µA
V
CC
Operating Voltage Range (Note 5)
Output Voltage
UVLO Threshold (Rising)
UVLO Threshold Hysteresis
Over Full Line and Load Range
l
l
8
6.25
500
20
8.3
V
V
V
mV
I
VCC
V
CC
Supply Current (Note 6)
V
CC
Burst Mode Current
V
CC
Shutdown Current
Short-Circuit Current
V
BURST_EN
= 0V
V
SHDN
= 0V
l
l
–30
1.7
80
20
–55
2.1 mA
µA
µA
mA
V
FB
Error Amp Reference Voltage Measured at V
FB
Pin
l
1.224
1.215
1.231 1.238
1.245
V
V
I
FB
Feedback Input Current 25 nA
V
SHDN
Enable Threshold (Rising)
Threshold Hysteresis
l
1.3 1.35
120
1.4 V
mV
V
SENSE
Common Mode Range
Current Limit Sense Voltage
V
SENSE
+
– V
SENSE
–
l
l
0
140
150
36
175
V
mV
I
SENSE
Input Current
(I
SENSE
+
+ I
SENSE
–
)
V
SENSE(CM)
= 0V
V
SENSE(CM)
= 2.5V
V
SENSE(CM)
> 4V
400
2
–150
µA
µA
µA
f
SW
Operating Frequency
MP Grade
l
l
190
175
165
200
200
210
220
225
kHz
kHz
kHz
V
FB(SS)
Soft-Start Disable Voltage
Soft-Start Disable Hysteresis
V
FB
Rising 1.185
300
V
mV
I
SS
Soft-Start Capacitor Control Current 2 µA
g
m
Error Amp Transconductance
l
275 340 400 µmhos
A
V
Error Amp DC Voltage Gain 62 dB
V
C
Error Amp Output Range Zero Current to Current Limit 1.2 V
I
VC
Error Amp Sink/Source Current ±30 µA
V
TG
Gate Drive Output On Voltage (Note 7)
Gate Drive Output Off Voltage
C
LOAD
= 3300pF
C
LOAD
= 3300pF
9.8
0.1
V
V
t
TG
Gate Drive Rise/Fall Time 10% to 90% or 90% to 10%, C
LOAD
= 3300pF 60 ns
t
TG(OFF)
Minimum Switch Off Time 350 ns
t
TG(ON)
Minimum Switch On Time
l
300 500 ns
I
SW
SW Pin Sink Current V
SW
= 2V 300 mA