Datasheet

LT3800
3
3800fc
ELECTRICAL CHARACTERISTICS
The l denotes the specifi cations which apply over the full operating
temperature range, otherwise specifi cations are at T
A
= 25°C. V
IN
= 20V, V
CC
= BOOST = BURST_EN = 10V, SHDN = 2V,
SENSE
–
= SENSE
+
= 10V, SGND = PGND = SW = 0V, CTG = CBG = 3300pF, unless otherwise noted.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
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 (Note 5)
Output Voltage
UVLO Threshold (Rising)
UVLO Hysteresis
●
●
8.0
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
●
●
–40
3
80
20
–120
3.6 mA
µA
µA
mA
V
SHDN
Enable Threshold (Rising)
Threshold Hysteresis
●
1.30 1.35
120
1.40 V
mV
V
SENSE
Common Mode Range
Current Limit Sense Voltage
Reverse Protect Sense Voltage
Reverse Current Offset
V
SENSE
+
– V
SENSE
–
V
SENSE
+
– V
SENSE
–
, V
BURST_EN
= V
CC
V
BURST_EN
= 0V or V
BURST_EN
= V
FB
●
●
0
140 150
–150
10
36
175 mV
mV
mV
I
SENSE
Input Current
(I
SENSE
+
+ I
SENSE
–
)
V
SENSE(CM)
= 0V
V
SENSE(CM)
= 2.75V
V
SENSE(CM)
> 4V
0.8
–20
–0.3
mA
µA
mA
f
O
Operating Frequency
●
190
175
200 210
220
kHz
kHz
V
FB
Error Amp Reference Voltage Measured at V
FB
Pin
●
1.224
1.215
1.231 1.238
1.245
V
V
I
FB
Feedback Input Current 25 nA
V
FB(SS)
Soft-Start Disable Voltage
Soft-Start Disable Hysteresis
V
FB
Rising 1.185
300
V
mV
I
CSS
Soft-Start Capacitor Control Current 2 µA
g
m
Error Amp Transconductance
●
275 350 400 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,BG
Gate Drive Output On Voltage (Note 7)
Gate Drive Output Off Voltage
9.8
0.1
V
V
t
TG,BG
Gate Drive Rise/Fall Time 10% to 90% or 90% to 10% 50 ns
t
TG(OFF)
Minimum Off Time 450 ns
t
TG(ON)
Minimum On Time
●
300 500 ns
t
NOL
Gate Drive Nonoverlap Time TG Fall to BG Rise
BG Fall to TG Rise
200
150
ns
ns