LTC3868 Linear Technology, LTC3868 Datasheet - Page 4

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

elecTrical characTerisTics
LTC3868
SYMBOL
INTV
V
V
V
V
V
V
Oscillator and Phase-Locked Loop
f
f
f
f
f
f
PGOOD1 and PGOOD2 Outputs
V
I
V
t
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Ratings for extended periods may affect device reliability and
lifetime.
Note 2: The LTC3868E is guaranteed to meet performance specifications
from 0°C to 85°C. Specifications over the –40°C to 85°C operating
temperature range are assured by design, characterization and correlation
with statistical process controls. The LTC3868I is guaranteed over the full
–40°C to 85°C operating temperature range.
Note 3: T
dissipation P
temperature range, otherwise specifications are at T

105kΩ
LOW
HIGH
SYNC
PGOOD
PG
25kΩ
65kΩ
INTVCCVIN
LDOVIN
INTVCCEXT
LDOEXT
EXTVCC
LDOHYS
PGL
PG
T
J
CC
= T
Linear Regulator
J
A
is calculated from the ambient temperature T
+ (P
D
according to the following formula:
PARAMETER
Internal V
INTV
Internal V
INTV
EXTV
EXTV
Programmable Frequency
Programmable Frequency
Programmable Frequency
Low Fixed Frequency
High Fixed Frequency
Synchronizable Frequency
PGOOD Voltage Low
PGOOD Leakage Current
PGOOD Trip Level
Delay for Reporting a Fault (PGOOD Low)
D
• 34°C/W)
CC
CC
CC
CC
Load Regulation
Load Regulation
Switchover Voltage
Hysteresis
CC
CC
Voltage
Voltage
A
and power
CONDITIONS
6V < V
I
6V < V
I
EXTV
R
R
R
V
V
PLLIN/MODE = External Clock
I
V
V
V
Hysteresis
V
V
Hysteresis
CC
CC
PGOOD
A
FREQ
FREQ
PGOOD
FB
FB
FREQ
FREQ
FREQ
= 25°C. V
= 0mA to 50mA, V
= 0mA to 50mA, V
FB
FB
with Respect to Set Regulated Voltage
with Respect to Set Regulated Voltage
Ramping Negative
Ramping Positive
CC
= 0V, PLLIN/MODE = DC Voltage
= INTV
= 25k, PLLIN/MODE = DC Voltage
= 65k, PLLIN/MODE = DC Voltage
= 105k, PLLIN/MODE = DC Voltage
IN
EXTVCC
= 2mA
= 5V
Ramping Positive
The
< 24V, V
l
< 13V
CC
IN
denotes the specifications which apply over the full operating
, PLLIN/MODE = DC Voltage
= 12V, V
EXTVCC
Note 4: The LTC3868 is tested in a feedback loop that servos V
specified voltage and measures the resultant V
Note 5: Dynamic supply current is higher due to the gate charge being
delivered at the switching frequency. See Applications information.
Note 6: Rise and fall times are measured using 10% and 90% levels. Delay
times are measured using 50% levels.
Note 7: The minimum on-time condition is specified for an inductor
peak-to-peak ripple current ≥ 40% of I
Considerations in the Applications Information section).
EXTVCC
EXTVCC
= 0V
RUN1,2
= 0V
= 8.5V
= 5V, EXTV
CC
= 0V unless otherwise noted.
l
4.85
4.85
MIN
375
320
485
–13
MAX
4.5
75
7
(See Minimum On-Time
www.DataSheet4U.com
FB1,2
TYP
250
440
835
350
535
105
–10
0.7
0.6
4.7
0.2
2.5
2.5
5.1
5.1
10
25
.
MAX
5.35
5.35
505
380
585
850
4.9
0.4
1.1
1.1
±1
–7
13
ITH1,2
UNITS
to a
3868fb
kHz
kHz
kHz
kHz
kHz
kHz
mV
µA
µs
%
%
%
%
%
%
V
V
V
V