Datasheet

LTC3891
3
3891fa
The l denotes the specifications which apply over the full operating junction
temperature range, otherwise specifications are at T
A
= 25°C (Note 2), V
IN
= 12V, V
RUN
= 5V, EXTV
CC
= 0V unless otherwise noted.
ELECTRICAL CHARACTERISTICS
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V
IN
Input Supply Operating Voltage Range 4 60 V
V
FB
Regulated Feedback Voltage (Note 4); I
TH
Voltage = 1.2V
–40°C to 85°C
LTC3891E, LTC3891I
LTC3891H, LTC3891MP
l
l
0.792
0.788
0.786
0.800
0.800
0.800
0.808
0.812
0.812
V
V
V
I
FB
Feedback Current (Note 4) ±5 ±50 nA
V
REFLNREG
Reference Voltage Line Regulation (Note 4); V
IN
= 4.5V to 60V 0.002 0.02 %/V
V
LOADREG
Output Voltage Load Regulation (Note 4)
Measured in Servo Loop;
∆I
TH
Voltage = 1.2V to 0.7V
l
0.01 0.1 %
(Note 4)
Measured in Servo Loop;
∆I
TH
Voltage = 1.2V to 2V
l
–0.01 –0.1 %
g
m
Transconductance Amplifier g
m
(Note 4); I
TH
= 1.2V; Sink/Source 5µA 2 mmho
I
Q
Input DC Supply Current (Note 5)
Pulse Skip or Forced Continuous Mode V
FB
= 0.83V (No Load) 2 mA
Sleep Mode V
FB
= 0.83V (No Load) 50 75 µA
Shutdown RUN = 0V 14 25 µA
UVLO Undervoltage Lockout INTV
CC
Ramping Up
INTV
CC
Ramping Down
l
l
3.6
3.92
3.80
4.2
4.0
V
V
V
OVL
Feedback Overvoltage Protection Measured at V
FB
Relative to Regulated V
FB
7 10 13 %
I
SENSE
+
SENSE
+
Pin Current ±1 µA
I
SENSE
–
SENSE
–
Pins Current V
SENSE
–
< INTV
CC
– 0.5V
V
SENSE
–
> INTV
CC
+ 0.5V 700
±2 µA
µA
DF
MAX
Maximum Duty Factor In Dropout 98 99 %
I
TRACK/SS
Soft-Start Charge Current V
TRACK
= 0V 7 10 14 µA
V
RUN
On RUN Pin On Threshold V
RUN
Rising
l
1.15 1.21 1.27 V
V
RUN
Hyst RUN Pin Hysteresis 50 mV
V
SENSE(MAX)
Maximum Current Sense Threshold V
FB
= 0.7V, V
SENSE
–
= 3.3V, I
LIM
= 0
V
FB
= 0.7V, V
SENSE
–
= 3.3V, I
LIM
= INTV
CC
V
FB
= 0.7V, V
SENSE
–
= 3.3V, I
LIM
= FLOAT
l
l
l
22
43
64
30
50
75
36
57
85
mV
mV
mV
ORDER INFORMATION
LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LTC3891EFE#PBF LTC3891EFE#TRPBF LTC3891FE 20-Lead Plastic TSSOP –40°C to 125°C
LTC3891IFE#PBF LTC3891IFE#TRPBF LTC3891FE 20-Lead Plastic TSSOP –40°C to 125°C
LTC3891HFE#PBF LTC3891HFE#TRPBF LTC3891FE 20-Lead Plastic TSSOP –40°C to 150°C
LTC3891MPFE#PBF LTC3891MPFE#TRPBF LTC3891FE 20-Lead Plastic TSSOP –55°C to 150°C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
Consult LTC Marketing for information on non-standard lead based finish parts.
For more information on lead free part marking, go to: http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/