ltc3858-2 Linear Technology Corporation, ltc3858-2 Datasheet - Page 4

• Manufacturer Part Number: ltc3858-2
• Description: Ltc3858-2 - Low Iq, Dual 2-phase Synchronous Step-down Controller
• Manufacturer: Linear Technology Corporation

ELECTRICAL CHARACTERISTICS
LTC3858-2
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 LTC3858-2 is tested under pulsed load conditions such that
T
from 0°C to 85°C. Specifications over the –40°C to 125°C operating
junction temperature range are assured by design, characterization and
correlation with statistical process controls. The LTC3858I-2 is guaranteed
over the full –40°C to 125°C operating junction temperature range.
Note that the maximum ambient temperature is determined by specific
operating conditions in conjunction with board layout, the rated package
thermal resistance and other environmental factors.
junction temperature range, otherwise specifications are at T
otherwise noted.
4
25kΩ
65kΩ
105kΩ
LOW
HIGH
SYNC
PGOOD
PG
J
INTVCCVIN
LDOVIN
INTVCCEXT
LDOEXT
EXTVCC
LDOHYS
PGL
PG
≈ T
CC
A
. The LTC3858E-2 is guaranteed to meet performance specifications
Linear Regulator
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)
CC
CC
CC
CC
Load Regulation
Load Regulation
Switchover Voltage
Hysteresis Voltage
CC
CC
Voltage
Voltage
CONDITIONS
6V < V
I
6V < V
I
EXTV
R
R
R
V
V
PLLIN/MODE = External Clock
I
V
V
V
CC
CC
PGOOD
V
Hysteresis
V
Hysteresis
FREQ
FREQ
PGOOD
FB
FB
FREQ
FREQ
FREQ
FB
FB
= 0mA to 50mA, V
= 0mA to 50mA, V
with Respect to Set Regulated Voltage
with Respect to Set Regulated Voltage
Ramping Negative
Ramping Positive
CC
= 25k, PLLIN/MODE = DC Voltage
= 65k, PLLIN/MODE = DC Voltage
= 105k, PLLIN/MODE = DC Voltage
= 0V, PLLIN/MODE = DC Voltage
= INTV
IN
EXTVCC
= 2mA
Ramping Positive
= 5V
< 38V, V
The
CC
< 13V
, PLLIN/MODE = DC Voltage
A
EXTVCC
= 25°C (Note 2). V
l
denotes the specifications which apply over the full operating
EXTVCC
EXTVCC
= 0V
Note 3: T
dissipation P
Note 4: The LTC3858-2 is tested in a feedback loop that servos V
a specified voltage and measures the resultant V
85°C is not tested in production. This specification is assured by design,
characterization and correlation to production testing at 125°C.
Note 5: Dynamic supply current is higher due to the gate charge being
delivered at the switching frequency. See the Applications information
section.
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 ≥ of 40% I
Considerations in the Applications Information section).
T
= 0V
= 8.5V
J
= T
J
A
is calculated from the ambient temperature T
+ (P
D
IN
according to the following formula:
D
= 12V, V
• 34°C/W)
RUN1,2
l
= 5V, EXTV
MAX
4.85
4.85
MIN
375
320
485
–13
4.5
75
7
(See Minimum On-Time
CC
= 0V unless
FB1,2
TYP
250
105
440
835
350
535
–10
5.1
0.7
5.1
0.6
4.7
0.2
2.5
2.5
10
25
. The specification at
A
and power
MAX
5.35
5.35
505
380
585
850
1.1
1.1
4.9
0.4
±1
–7
13
ITH1,2
UNITS
38582f
to
kHz
kHz
kHz
kHz
kHz
kHz
mV
μA
μs
%
%
%
%
%
%
V
V
V
V