LTC3890
elecTrical characTerisTics
SYMBOL
I
FB1,2
V
REFLNREG
V
LOADREG
PARAMETER
Feedback Current
Reference Voltage Line Regulation
Output Voltage Load Regulation
The
l
denotes the specifications which apply over the specified operating
junction temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 12V, V
RUN1,2
= 5V, EXTV
CC
= 0V unless otherwise noted.
(Note 2)
CONDITIONS
(Note 4)
(Note 4) V
IN
= 4.5V to 60V
(Note 4)
Measured in Servo Loop,
∆
ITH
Voltage = 1.2V to 0.7V
(Note 4)
Measured in Servo Loop,
∆
ITH
Voltage = 1.2V to 2V
l
MIN
TYP
±5
0.002
0.01
MAX
±50
0.02
0.1
UNITS
nA
%/V
%
l
–0.01
2
1.3
2
50
60
14
–0.1
%
mmho
mA
mA
g
m1,2
I
Q
Transconductance Amplifier g
m
Input DC Supply Current
Pulse-Skipping or Forced Continuous
Mode (One Channel On)
Pulse-Skipping or Forced Continuous
Mode (Both Channels On)
Sleep Mode (One Channel On)
Sleep Mode (Both Channels On)
Shutdown
(Note 4) I
TH1,2
= 1.2V, Sink/Source = 5µA
(Note 5)
RUN1 = 5V and RUN2 = 0V, V
FB1
= 0.83V or
RUN1 = 0V and RUN2 = 5V, V
FB2
= 0.83V
RUN1,2 = 5V, V
FB1,2
= 0.83V (No Load)
RUN1 = 5V and RUN2 = 0V, V
FB1
= 0.83V (No Load) or
RUN1 = 0V and RUN2 = 5V, V
FB2
= 0.83V (No Load)
RUN1,2 = 5V, V
FB1,2
= 0.83V (No Load)
RUN1,2 = 0V
INTV
CC
Ramping Up
INTV
CC
Ramping Down
Measured at V
FB1,2
, Relative to Regulated V
FB1,2
Each Channel
Each Channel
V
SENSE–
< INTV
CC
– 0.5V
V
SENSE–
> INTV
CC
+ 0.5V
In Dropout
V
TRACK/SS1,2
= 0V
V
RUN1
Rising
V
RUN2
Rising
V
FB1,2
= 0.7V, V
SENSE1
–,
2
– = 3.3V, I
LIM
= 0
V
FB1,2
= 0.7V, V
SENSE1
–,
2
– = 3.3V, I
LIM
= INTV
CC
V
FB1,2
= 0.7V, V
SENSE1
–,
2
– = 3.3V, I
LIM
= FLOAT
l
l
l
l
75
100
25
4.2
4.0
13
±1
±1
µA
µA
µA
V
V
%
µA
µA
µA
%
µA
V
V
mV
mV
mV
mV
Ω
Ω
Ω
Ω
ns
ns
ns
ns
ns
UVLO
Undervoltage Lockout
Feedback Overvoltage Protection
3.6
7
3.92
3.80
10
I
SENSE+
I
SENSE–
SENSE
+
Pin Current
SENSE
–
Pins Current
700
98
0.7
1.15
1.20
22
43
64
99
1.0
1.21
1.25
50
l
l
l
Maximum TG1, 2 Duty Factor
I
TRACK/SS1,2
Soft-Start Charge Current
V
RUN1
V
RUN2
RUN1 Pin On Threshold
RUN2 Pin On Threshold
RUN1,2 Pin Hysteresis
V
SENSE(MAX)
Maximum Current Sense Threshold
Gate Driver
TG1,2 Pull-Up On-Resistance
TG1,2 Pull-Down On-Resistance
BG1,2 Pull-Up On-Resistance
BG1,2 Pull-Down On-Resistance
TG1,2 t
r
TG1,2 t
f
BG1,2 t
r
BG1,2 t
f
TG/BG t
1D
TG Transition Time:
Rise Time
Fall Time
BG Transition Time:
Rise Time
Fall Time
Top Gate Off to Bottom Gate On Delay
Synchronous Switch-On Delay Time
1.4
1.27
1.30
36
57
85
30
50
75
2.5
1.5
2.4
1.1
(Note 6)
C
LOAD
= 3300pF
C
LOAD
= 3300pF
(Note 6)
C
LOAD
= 3300pF
C
LOAD
= 3300pF
C
LOAD
= 3300pF Each Driver
25
16
28
13
30
3890fb
3
LINEAR [ LINEAR INTEGRATED SYSTEMS ]
