Datasheet

LTC3865/LTC3865-1
4
3865fb
ELECTRICAL CHARACTERISTICS
The l denotes the specifi cations which apply over the full operating
junction temperature range, otherwise specifi cations are at T
A
= 25°C (Note 2). V
IN
= 15V, V
RUN1,2
= 5V unless otherwise noted.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Main Control Loops
V
IN
Input Voltage 4.5 38 V
V
OSENSE1,2
Output Voltage Sensing (E-Grade) (Note 4) I
TH1,2
Voltage = 1.2V
VID11 = VID21 = GND, VID12 = VID22 = GND
VID11 = VID21 = GND, VID12 = VID22 = Float
VID11 = VID21 = GND, VID12 = VID22 = INTV
CC
VID11 = VID21 = Float, VID12 = VID22 = GND
VID11 = VID21 = Float, VID12 = VID22 = Float
VID11 = VID21 = Float, VID12 = VID22 = INTV
CC
VID11 = VID21 = INTV
CC
, VID12 = VID22 = GND
VID11 = VID21 = INTV
CC
, VID12 = VID22 = Float
VID11 = VID21 = INTV
CC
, VID12 = VID22 = INTV
CC
l
l
l
l
l
l
l
l
l
1.089
0.990
1.188
1.485
0.596
1.782
2.463
3.251
4.925
1.100
1.000
1.200
1.500
0.602
1.800
2.500
3.300
5.000
1.111
1.010
1.212
1.515
0.608
1.818
2.538
3.350
5.075
V
V
V
V
V
V
V
V
V
Output Voltage Sensing (I-Grade) (Note 4) I
TH1,2
Voltage = 1.2V
VID11 = VID21 = GND, VID12 = VID22 = GND
VID11 = VID21 = GND, VID12 = VID22 = Float
VID11 = VID21 = GND, VID12 = VID22 = INTV
CC
VID11 = VID21 = Float, VID12 = VID22 = GND
VID11 = VID21 = Float, VID12 = VID22 = Float
VID11 = VID21 = Float, VID12 = VID22 = INTV
CC
VID11 = VID21 = INTV
CC
, VID12 = VID22 = GND
VID11 = VID21 = INTV
CC
, VID12 = VID22 = Float
VID11 = VID21 = INTV
CC
, VID12 = VID22 = INTV
CC
l
l
l
l
l
l
l
l
l
1.084
0.985
1.182
1.478
0.593
1.773
2.450
3.234
4.900
1.100
1.000
1.200
1.500
0.602
1.800
2.500
3.300
5.000
1.117
1.015
1.218
1.523
0.611
1.827
2.550
3.366
5.100
V
V
V
V
V
V
V
V
V
I
OSENSE1,2
Feedback Current (Note 4) VID11 = VID21 = VID12 = VID22 = Float –10 –50 nA
V
REFLNREG
Reference Voltage Line Regulation V
IN
= 4.5V to 38V (Note 4) 0.002 0.02 %/V
V
LOADREG
Output Voltage Load Regulation (Note 4)
Measured in Servo Loop; ΔI
TH
Voltage = 1.2V to 0.7V
Measured in Servo Loop; ΔI
TH
Voltage = 1.2V to 1.6V
l
l
0.01
–0.01
0.1
–0.1
%
%
g
m1,2
Transconductance Amplifi er g
m
I
TH1,2
= 1.2V; Sink/Source 5µA; (Note 4) 2.2 mmho
I
Q
Input DC Supply Current
Normal Mode
Shutdown
(Note 5)
V
IN
= 15V
V
RUN1,2
= 0V
3
30 50
mA
µA
UVLO Undervoltage Lockout on INTV
CC
V
INTVCC
Ramping Down 3.3 V
UVLO
HYS
UVLO Hysteresis 0.55 V
V
OVL
Feedback Overvoltage Lockout Measured at V
OSENSE1,2
with VID Pins Floating
l
0.64 0.66 0.68 V
I
SENSE
Sense Pins Total Current (Each Channel); V
SENSE1,2
= 3.3V ±1 ±2 µA
DF
MAX
Maximum Duty Cycle In Dropout 94 95 %
I
TK/SS1,2
Soft-Start Charge Current V
TK/SS1,2
= 0V 0.9 1.3 1.7 µA
V
RUN1,2
RUN Pin On Threshold V
RUN1
, V
RUN2
Rising
l
1.1 1.22 1.35 V
V
RUN1,2HYS
RUN Pin On Hysteresis 80 mV
I
RUN1,2HYS
RUN Pin Current Hysteresis 4.5 µA
V
SENSE(MAX)
Maximum Current Sense Threshold
(E-Grade)
V
ITH1,2
= 3.3V, I
LIM
= 0V
V
ITH1,2
= 3.3V, I
LIM
= Float (Note 8)
V
ITH1,2
= 3.3V, I
LIM
= INTV
CC
In Overvoltage Condition
l
l
l
l
24
44
68
–63
30
50
75
–53
36
56
82
–43
mV
mV
mV
mV
Maximum Current Sense Threshold
(I-Grade)
V
ITH1,2
= 3.3V, I
LIM
= 0V
V
ITH1,2
= 3.3V, I
LIM
= Float (Note 8)
V
ITH1,2
= 3.3V, I
LIM
= INTV
CC
In Overvoltage Condition
l
l
l
l
22
42
66
–65
30
50
75
–53
38
58
84
–41
mV
mV
mV
mV
TG R
UP
TG Driver Pull-Up On-Resistance TG High 2.6 
TG R
DOWN
TG Driver Pull-Down On-Resistance TG Low 1.5 
BG R
UP
BG Driver Pull-Up On-Resistance BG High 3 