Datasheet
LTC3867
3
3867f
ELECTRICAL CHARACTERISTICS
The l denotes the specifications which apply over the specified operating
junction temperature range, otherwise specifications are at T
A
= 25°C (Note 2). V
IN
= 15V, V
RUN
= 5V unless otherwise specified.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Main Control Loop/Whole System
V
IN
Input Voltage Range 4 38 V
V
OUT
Output Voltage Range 0.6 14 V
V
FB
Regulated Feedback Voltage I
TH
=1.2V, 0°C to 85°C
I
TH
=1.2V, –40°C to 125°C (Note 3)
l
595.5
594
600
600
604.5
606
mV
mV
I
FB
Feedback Current –15 –50 nA
V
REFLNREG
Reference Voltage Line Regulation V
IN
= 4.5V to 38V 0.002 0.02 %/V
V
LOADREG
Output Voltage Load Regulation ΔI
TH
=1.2V to 0.7V
ΔI
TH
=1.2V to 1.6V
l
l
0.01
–0.01
0.1
–0.1
%
%
g
m
Transconductance Amplifier g
m
I
TH
=1.2V, Sink/Source 5µA 2 mmho
V
OVL
Feedback Overvoltage Lockout Measured at V
FB
l
5 7.5 10 %
I
Q
Input DC Supply Current
Normal Mode
Shutdown
V
RUN
= 0V (Note 4)
3.5
30
50
mA
µA
DF
MAX
Maximum Duty Factor In Dropout, f
SW
= 600kHz 96 98 %
UVLO Undervoltage Lockout
V
INTVCC
Falling 3.0 3.2 3.4 V
UVLO
HYS
UVLO Hysteresis 600 mV
I
SENSE
Sense Pin Bias Currents V
SENSE
= 3.3V
l
±1 ±2 µA
I
TEMP
DCR Tempco Compensation Current V
ITEMP
= 500mV
l
27 30 33 µA
I
FAST
Fast Transient Programming Current V
IFAST
= 500mV
l
9 10 11 µA
I
TK/SS
Soft-Start Charge Current V
TK/SS
= 0V 1 1.25 1.4 µA
V
RUN
RUN Pin On Threshold V
RUN
Rising
l
1.1 1.22 1.34 V
V
RUN(HYS)
RUN Pin On Hysteresis 80 mV
I
RUN
RUN Pin Pull-Up Current
RUN < On Threshold
RUN > On Threshold
RUN < 1.1V
RUN > 1.34V
1
5
µA
µA
V
SENSE(MAX)
Maximum Current Sense Threshold I
TH
=1.85V, V
SENSE
=3.3V
I
LIM
= 0V
I
LIM
= 1.5V
I
LIM
= Float
I
LIM
= 3.7V
I
LIM
= INTV
CC
l
l
l
l
l
25
35
45
55
69
30
40
50
60
75
35
45
55
65
79
mV
mV
mV
mV
mV
t
ON(MIN)
Minimum On-Time (Note 6) 65 ns
Power Good
V
PGOOD(ON)
PGOOD Pull-Down Resistance 90 200 Ω
I
PGOOD(OFF)
PGOOD Leakage Current V
PGOOD
= 5V –2 2 µA
t
PGOOD
PGOOD Delay V
PGOOD
High to Low 45 µs
V
PG1
PGOOD Trip Level—with Delay V
FB
with Respect to Set Output Voltage
V
FB
Ramping Up
V
FB
Ramping Down
5
–5
7.5
–7.5
10
–10
%
%