LTC3857IUH#TRPBF Linear Technology, LTC3857IUH#TRPBF Datasheet - Page 4

• Manufacturer Part Number: LTC3857IUH#TRPBF
• Description: IC CTRLR STP-DN SYNC DUAL 32QFN
• Manufacturer: Linear Technology
• Series: PolyPhase®r
• Type: Step-Down (Buck)r

Specifications of LTC3857IUH#TRPBF

• Internal Switch(s): No
• Synchronous Rectifier: Yes
• Number Of Outputs: 2
• Voltage - Output: 0.8 ~ 24 V
• Frequency - Switching: 50kHz ~ 900kHz
• Voltage - Input: 4 ~ 38 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 32-QFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current - Output: -
• Power - Output: -

ELECTRICAL CHARACTERISTICS
LTC3857
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 LTC3857 is tested under pulsed 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 LTC3857I 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.
temperature range, otherwise specifications are at T
4
25kΩ
65kΩ
105kΩ
LOW
HIGH
SYNC
PGOOD
PG
J
INTVCCVIN
LDOVIN
INTVCCEXT
LDOEXT
EXTVCC
LDOHYS
PGL
PG
≈
CC
T
A
Linear Regulator
. The LTC3857E is guaranteed to meet performance specifications
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
CC
CC
CC
CC
Load Regulation
Load Regulation
Switchover Voltage
Hysteresis
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
FREQ
FREQ
PGOOD
FB
FB
FREQ
FREQ
FREQ
V
Hysteresis
V
Hysteresis
FB
FB
A
= 0mA to 50mA, V
= 0mA to 50mA, V
with Respect to Set Regulated Voltage
with Respect to Set Regulated Voltage
CC
= 25°C (Note 2). V
Ramping Negative
Ramping Positive
= 0V, PLLIN/MODE = DC Voltage
= INTV
IN
EXTVCC
= 25k, PLLIN/MODE = DC Voltage
= 65k, PLLIN/MODE = DC Voltage
= 105k, PLLIN/MODE = DC Voltage
= 2mA
Ramping Positive
= 5V
< 38V, V
The
CC
< 13V
l
, PLLIN/MODE = DC Voltage
denotes the specifications which apply over the full operating junction
EXTVCC
EXTVCC
EXTVCC
Note 3: T
dissipation P
Note 4: The LTC3857 is tested in a feedback loop that servos V
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 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).
= 0V
IN
T
J
= 12V, V
= 0V
= 8.5V
= T
J
A
is calculated from the ambient temperature T
+ (P
D
according to the following formula:
RUN1,2
D
• 34°C/W)
= 5V, EXTV
l
CC
4.85
4.85
MIN
375
320
485
–13
4.5
75
MAX
7
= 0V unless otherwise noted.
(See Minimum On-Time
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
to a
3857fc
kHz
kHz
kHz
kHz
kHz
kHz
mV
μA
μs
%
%
%
%
%
%
V
V
V
V