Datasheet

LTC3783
3
3783fb
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Main Control Loop/Whole System
V
IN
Input Voltage Range 3 36 V
I
Q
Input Voltage Supply Current
Continuous Mode
Shutdown Mode
(Note 4)
V
OV/FB
= 1.5V, V
ITH
= 0.75V
V
RUN
= 0V
1.5
20
mA
µA
V
RUN
+
Rising RUN Input Threshold Voltage 1.348 V
V
RUN
–
Falling RUN Input Threshold Voltage 1.223 1.248 1.273 V
V
RUN(HYST)
RUN Pin Input Threshold Hysteresis 100 mV
I
RUN
RUN Pin Input Current 5 nA
V
SENSE(MAX)
Maximum Current Sense Threshold 125 150 180 mV
I
SENSE(ON)
SENSE Pin Current (GATE High) V
SENSE
= 0V 70 µA
I
SENSE(OFF)
SENSE Pin Current (GATE Low) V
SENSE
= 36V 0.2 µA
I
SS
Soft-Start Pin Output Current V
SS
= 0V -50 µA
Voltage/Temperature Reference
V
REF
Reference Voltage
l
1.218
1.212
1.230 1.242
1.248
V
V
I
REF
Max Reference Pin Output Current 0.5 mA
∆V
REF
/∆V
IN
Reference Voltage Line Regulation 3V ≤ V
IN
≤ 36V 0.002 0.02 %/V
∆V
REF
/∆I
REF
Reference Voltage Load Regulation 0mA ≤ I
REF
≤ 0.5mA 0.2 1.0 %/mA
T
MAX
Overtemperature SD Threshold Rising 165 °C
T
HYST
Overtemperature Hysteresis 25 °C
Error Amplifier
I
OV/FB
OV/FB Pin Input Current 18 60 nA
∆V
OV/FB(OV)
OV/FB Overvoltage Lockout Threshold V
OV/FB(OV)
– V
OV/FB(NOM)
in %, V
FBP
≤ V
REF
7 %
V
OV/FB(FB)
OV/FB Pin Regulation Voltage 2.5V < V
FBP
< 36V 1.212 1.230 1.248 V
I
FBP
, I
FBN
Error Amplifier Input Current 0V ≤ V
FBP
≤ V
REF
2.5V < V
FBP
< 36V
–0.4
50
µA
µA
V
FBP
– V
FBN
Error Amplifier Offset Voltage
(Note 5)
0V ≤ V
FBP
≤ V
REF
2.5V < V
FBP
≤ 36V (V
ILIM
= V
REF
)
2.5V < V
FBP
≤ 36V (V
ILIM
= 0.123V)
–3
100
10
3 mV
mV
mV
g
m
Error Amplifier Transconductance V
FBP
≤ V
REF
2.5V < V
FBP
< 36V
1.7
14
mmho
mmho
A
VOL
Error Amplifier Open-Loop Gain 500 V/V
Oscillator
f
OSC
Oscillator Frequency
Oscillator Frequency Range
R
FREQ
= 20kΩ 250
20
300 350
1000
kHz
kHz
D
MAX
Maximum Duty Cycle 85 90 97 %
f
SYNC
/f
OSC
Recommended Max SYNC Freq Ratio f
OSC
= 300kHz (Note 6) 1.25 1.3
t
SYNC(MIN)
SYNC Minimum Input Pulse Width V
SYNC
= 0V to 5V 25 ns
t
SYNC(MAX)
SYNC Maximum Input Pulse Width V
SYNC
= 0V to 5V 0.8/f
OSC
ns
V
IH(SYNC)
SYNC Input Voltage High Level 1.2 V
V
HYST(SYNC)
SYNC Input Voltage Hysteresis 0.5 V
The l denotes the specifications which apply over the full operating temperature
range, otherwise specifications are T
A
= 25°C. V
IN
= 12V, V
RUN
= 1.5V, V
SYNC
= 0V, V
FBP
= V
REF
, R
T
= 20k, unless otherwise specified.
ELECTRICAL CHARACTERISTICS