LTC3858-1 Linear Technology Corporation, LTC3858-1 Datasheet - Page 4

• Manufacturer Part Number: LTC3858-1
• Description: Dual 2-Phase Synchronous Step-Down Controller
• Manufacturer: Linear Technology Corporation

www.DataSheet4U.com
ELECTRICAL CHARACTERISTICS
LTC3858-1
SYMBOL
TG1,2 t
TG1,2 t
BG1,2 t
BG1,2 t
TG/BG t
BG/TG t
t
INTV
V
V
V
V
V
V
Oscillator and Phase-Locked Loop
f
f
f
f
f
f
PGOOD1 Output
V
I
V
t
temperature range, otherwise specifi cations are at 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 LTC3858E-1 is guaranteed to meet performance specifi cations
from 0°C to 85°C. Specifi cations over the –40°C to 85°C operating
temperature range are assured by design, characterization and correlation
with statistical process controls. The LTC3858I-1 is guaranteed over the
full –40°C to 125°C operating temperature range
Note 3: T
dissipation P
4
ON(MIN)
25kΩ
65kΩ
105kΩ
LOW
HIGH
SYNC
PGOOD
PG
INTVCCVIN
LDOVIN
INTVCCEXT
LDOEXT
EXTVCC
LDOHYS
PGL
PG
CC
r
f
r
f
Linear Regulator
1D
1D
J
T
is calculated from the ambient temperature T
J
D
= T
according to the following formula:
PARAMETER
TG Transistion Time:
BG Transistion 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
Internal V
INTV
Internal V
INTV
EXTV
EXTV
Programmable Frequency
Programmable Frequency
Programmable Frequency
Low Fixed Frequency
High Fixed Frequency
Synchronizable Frequency
PGOOD1 Voltage Low
PGOOD1 Leakage Current
PGOOD1 Trip Level
Delay for Reporting a Fault (PGOOD Low)
Rise Time
Fall Time
Rise Time
Fall Time
A
+ (P
CC
CC
CC
CC
D
Load Regulation
Load Regulation
Switchover Voltage
Hysteresis Voltage
• 34°C/W)
CC
CC
Voltage
Voltage
A
and power
CONDITIONS
(Note 6)
C
C
(Note 6)
C
C
C
C
(Note 7)
6V < V
I
6V < V
I
EXTV
R
R
R
V
V
PLLIN/MODE = External Clock
I
V
V
V
V
Hysteresis
V
Hysteresis
A
CC
CC
PGOOD
LOAD
LOAD
LOAD
LOAD
LOAD
LOAD
FREQ
FREQ
PGOOD
FB
FB
FREQ
FREQ
FREQ
FB
FB
= 25°C. V
= 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
= 0V, PLLIN/MODE = DC Voltage
= INTV
= 3300pF
= 3300pF
= 3300pF
= 3300pF
= 3300pF Each Driver
= 3300pF Each Driver
IN
EXTVCC
= 25k, PLLIN/MODE = DC Voltage
= 65k, PLLIN/MODE = DC Voltage
= 105k, PLLIN/MODE = DC Voltage
= 2mA
Ramping Positive
= 5V
The
< 38V, V
l
CC
IN
< 13V
, PLLIN/MODE = DC Voltage
denotes the specifi cations which apply over the full operating
= 12V, V
EXTVCC
Note 4: The LTC3858-1 is tested in a feedback loop that servos V
a specifi ed voltage and measures the resultant V
the specifi cation at 85°C is not tested in production. This specifi cation 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 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 specifi ed for an inductor peak-
to-peak ripple current ≥ of I
the Applications Information section).
EXTVCC
EXTVCC
= 0V
RUN1,2
= 0V
= 8.5V
= 5V, EXTV
CC
MAX
= 0V unless otherwise noted.
l
(See Minimum On-Time Considerations in
MIN
4.85
4.85
375
320
485
–13
4.5
75
7
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
25
16
28
13
30
30
95
10
25
. For the LTC3858I-1,
MAX
5.35
5.35
505
380
585
850
1.1
1.1
4.9
0.4
±1
–7
13
ITH1,2
UNITS
38581f
to
kHz
kHz
kHz
kHz
kHz
kHz
mV
μA
ns
ns
ns
ns
ns
ns
ns
μs
%
%
%
%
%
%
V
V
V
V