LTC3868 Linear Technology, LTC3868 Datasheet - Page 3

• Manufacturer Part Number: LTC3868
• Description: Low IQ Dual 2-Phase Synchronous Step-Down Controller
• Manufacturer: Linear Technology

elecTrical characTerisTics
SYMBOL
g
I
UVLO
V
I
I
DF
I
V
V
V
V
I
V
Gate Driver
TG1,2
BG1,2
TG1,2 t
TG1,2 t
BG1,2 t
BG1,2 t
TG/BG t
BG/TG t
t
temperature range, otherwise specifications are at T
Q
SENSE
SENSE
SS1,2
DSC1,2
ON(MIN)
m1,2
OVL
RUN1,2
RUN1,2
SS1,2
SS1,2
SENSE(MAX)
MAX
LA
LT
+
–
LT
r
f
r
f
On
Hyst RUN Pin Hysteresis
1D
1D
PARAMETER
Transconductance Amplifier g
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
Undervoltage Lockout
Feedback Overvoltage Protection
SENSE
SENSE
Maximum Duty Factor
Soft-Start Charge Current
RUN Pin On Threshold
SS Pin Latchoff Arming Threshold
SS Pin Latchoff Threshold
SS Discharge Current
Maximum Current Sense Threshold
Pull-Up On-Resistance
Pull-Down On-Resistance
Pull-Up On-Resistance
Pull-Down On-Resistance
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
Bottom Gate Off to Top Gate On Delay
Top Switch-On Delay Time
Minimum On-Time
+
–
Pins Current
Pins Current
m
CONDITIONS
(Note 4) I
(Note 5)
RUN1 = 5V and RUN2 = 0V or
RUN1 = 0V and RUN2 = 5V,
V
RUN1,2 = 5V, V
RUN1 = 5V and RUN2 = 0V or
RUN1 = 0V and RUN2 = 5V,
V
RUN1,2 = 5V, V
RUN1,2 = 0V
INTV
INTV
Measured at V
Each Channel
Each Channel
V
V
In Dropout, FREQ = 0V
V
V
V
V
Short-Circuit Condition V
V
V
V
V
(Note 6)
C
C
(Note 6)
C
C
C
C
(Note 7)
A
FB1
FB1
OUT1,2
OUT1,2
SS1,2
RUN1
SS1
SS1
SS1,2
FB1,2
FB1,2
FB1,2
LOAD
LOAD
LOAD
LOAD
LOAD
LOAD
= 25°C. V
= 0.83V (No Load)
= 0.83V (No Load)
, V
, V
CC
CC
= 0.7V, V
= 0.7V, V
= 0.7V, V
= 0V
, V
= 4.5V
= 3300pF
= 3300pF
= 3300pF
= 3300pF
= 3300pF Each Driver
= 3300pF Each Driver
Ramping Up
Ramping Down
< INTV
> INTV
SS2
SS2
The
RUN2
TH1,2
Rising from 1V
Falling from 2V
l
Rising
IN
= 1.2V, Sink/Source = 5µA
FB1,2
CC
CC
FB1,2
FB1,2
denotes the specifications which apply over the full operating
SENSE1
SENSE1
SENSE1
= 12V, V
– 0.5V
+ 0.5V
, Relative to Regulated V
= 0.83V (No Load)
= 0.83V (No Load)
–,
–,
–,
2
2
2
– = 3.3V, I
– = 3.3V, I
– = 3.3V, I
RUN1,2
FB1,2
= 0.5V,
= 5V, EXTV
LIM
LIM
LIM
= 0
= FLOAT
= INTV
FB1,2
CC
CC
= 0V unless otherwise noted.
l
l
l
MIN
1.21
3.6
0.7
1.9
1.3
98
22
43
64
7
7
www.DataSheet4U.com
99.4
TYP
1.26
170
300
540
1.3
3.8
1.0
1.5
2.5
1.5
2.4
1.1
10
50
10
30
50
75
25
16
28
13
30
30
95
2
2
8
4
2
LTC3868
MAX
1.31
250
450
700
4.2
1.4
2.1
1.7
25
36
57
86
13
±1
±1
13
4
UNITS
mmho
3868fb

mA
mA
mV
mV
mV
mV
µA
µA
µA
µA
µA
µA
µA
µA
ns
ns
ns
ns
ns
ns
ns
%
%
Ω
Ω
Ω
Ω
V
V
V
V
V