Datasheet

LTC3646/LTC3646-1
3
36461fa
For more information www.linear.com/LTC3646
elecTrical characTerisTics
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C (Note 2), PVIN = SVIN = 12V unless otherwise noted.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Input Supply (PVIN, SVIN)
V
IN
Input Voltage Operating Range
l
4.0 40 V
V
IN(OV)
Input Supply Overvoltage Lockout V
IN
Rising
Hysteresis (V
IN
Falling)
l
l
43.5
2.0
46
2.5 2.9
V
V
V
IN(UV)
Input Supply Undervoltage Lockout V
IN
Falling
Hysteresis (V
IN
Rising)
3.2 3.35
250
3.5 V
mV
I
Q
DC Supply Current (Note 3)
Forced Continuous
Sleep Mode
Shutdown Mode V
RUN
= 0V
620
140
8
875
190
µA
µA
µA
Main Control Loop
V
OUT
Output Voltage Range (Note 4) LTC3646
LTC3646-1
2.0
0.6
30
15
V
V
V
FB
Feedback Reference Voltage –40°C < T
A
< 85°C
l
0.594
0.591
0.6
0.6
0.606
0.609
V
V
Feedback
Voltage Line Regulation V
IN
= 4.0V to 40V, I
TH
= 1.5V 0.05 %/V
Feedback Voltage Load Regulation I
TH
= 1.0V to 1.8V 0.12 %
Feedback Input Current V
FB
= 0.6V
l
0 ±20 nA
g
m(EA)
Error Amplifier Transconductance External Comp 300 µS
t
ON(MIN)
Minimum On-Time V
IN
= 40V, R
RT
= 30k, V
ON
= 2V 30 ns
t
OFF(MIN)
Minimum Off-Time 80 ns
I
LIM
Valley Switch Current Limit
l
0.9 1.2 1.5 A
Internal Oscillator Frequency V
RT
= V
INTVCC
R
RT
= 450kΩ
R
RT
= 60kΩ
R
RT
= 30kΩ
1.6
0.19
1.25
2.55
2.25
0.2
1.5
3.0
2.95
0.27
1.75
3.45
MHz
MHz
MHz
MHz
External Clock Frequency Range 0.2 3.0 MHz
R
DS(ON)
Top Switch On-Resistance (Note 5)
Bottom Switch On-Resistance (Note 5)
V
IN
= 5.5V
V
IN
= 5.5V
200
120
mΩ
mΩ
Switch Leakage V
IN
= V
SW
= 40V, V
RUN
= 0
V
IN
= 40V, V
SW
= 0V, V
RUN
= 0
±1
±1
µA
µA
Internal V
CC
Regulator
V
INTVCC
INTV
CC
Voltage
l
4.8 5.0 5.2 V
INTV
CC
Load Regulation (Note 6) I
INTVCC
= 0mA to 5mA 0.5 %
INTV
CC
Undervoltage Lockout INTV
CC
Falling 3.0 V
INTV
CC
UVLO Hysteresis 0.3 V
EXTV
CC
Switchover Voltage EXTV
CC
Rising 4.25 4.5 4.65 V
EXTV
CC
Hysteresis 200 mV
Operation
V
RUN
RUN Pin Threshold RUN Rising
RUN Falling
Hysteresis
1.17
1.06
1.21
1.10
110
1.26
1.14
V
V
mV
RUN Pin Leakage Current RUN = 1.3V 0
±1 µA
V
PGOOD(UT)
PGOOD Overvoltage Threshold FB Rising
FB Falling
5.0
3.5
7.5
5
10 %V
FB
V
PGOOD(LT)
PGOOD Undervoltage Threshold FB Falling
FB Rising
–5.0
–3.5
–7.5
–5
–10 %V
FB
t
PGOOD
PGOOD Filter Time RT = INTV
CC
15 30 µs