Voltages...................................... –0.3V to 28V
PLLIN/MODE, FREQ Voltages .............. –0.3V to INTV
CC
I
LIM
, PHASMD Voltages ....................... –0.3V to INTV
CC
EXTV
CC
...................................................... –0.3V to 14V
ITH1, ITH2, V
FB1
, V
FB2
Voltages ................... –0.3V to 6V
PGOOD1, PGOOD2 Voltages ....................... –0.3V to 6V
TRACK/SS1, TRACK/SS2 Voltages .............. –0.3V to 6V
Operating Junction Temperature Range
(Note 2) ................................................. –40°C to 125°C
Maximum Junction Temperature (Note 3) ............ 125°C
Storage Temperature Range................... –65°C to 150°C
I
LIM
32 31 30 29 28 27 26 25
SENSE1
–
1
FREQ 2
PHASMD 3
CLKOUT 4
PLLIN/MODE 5
SGND 6
RUN1 7
RUN2 8
UH PACKAGE
32-LEAD (5mm
×
5mm) PLASTIC QFN
T
JMAX
= 125°C,
θ
JA
= 34°C/W
EXPOSED PAD (PIN 33) IS SGND, MUST BE SOLDERED TO PCB
ORDER INFORMATION
LEAD FREE FINISH
LTC3890EUH#PBF
LTC3890IUH#PBF
TAPE AND REEL
LTC3890EUH#TRPBF
LTC3890IUH#TRPBF
PART MARKING*
3890
3890
PACKAGE DESCRIPTION
32-Lead (5mm
×
5mm) Plastic QFN
32-Lead (5mm
×
5mm) Plastic QFN
TEMPERATURE RANGE
–40°C to 125°C
–40°C to 125°C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
Consult LTC Marketing for information on non-standard lead based finish parts.
For more information on lead free part marking, go to:
http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to:
http://www.linear.com/tapeandreel/
ELECTRICAL CHARACTERISTICS
SYMBOL
V
IN
V
FB1,2
PARAMETER
Input Supply Operating Voltage Range
Regulated Feedback Voltage
The
l
denotes the specifications which apply over the full operating
junction temperature range, otherwise specifications are at T
J
= 25°C. V
IN
= 12V, V
RUN1,2
= 5V, EXTV
CC
= 0V unless otherwise noted.
CONDITIONS
(Note 4) I
TH1,2
Voltage = 1.2V
–40°C to 125°C
–40°C to 85°C
(Note 4)
(Note 4) V
IN
= 4.5V to 60V
MIN
4
l
TG1
TYP
MAX
60
UNITS
V
V
V
V
nA
%/V
0.788
0.792
0.800
0.800
±5
0.002
0.812
0.808
±50
0.02
I
FB1,2
V
REFLNREG
Feedback Current
Reference Voltage Line Regulation
3890f
2
LTC3890
ELECTRICAL CHARACTERISTICS
SYMBOL
V
LOADREG
PARAMETER
Output Voltage Load Regulation
The
l
denotes the specifications which apply over the full operating
junction temperature range, otherwise specifications are at T
J
= 25°C. V
IN
= 12V, V
RUN1,2
= 5V, EXTV
CC
= 0V unless otherwise noted.
CONDITIONS
(Note4)
Measured in Servo Loop,
Δ
ITH
Voltage = 1.2V to 0.7V
(Note4)
Measured in Servo Loop,
Δ
ITH
Voltage = 1.2V to 2V
l
MIN
TYP
0.01
MAX
0.1
UNITS
%
l
–0.01
2
1.3
–0.1
%
mmho
mA
g
m1,2
I
Q
Transconductance Amplifier g
m
Input DC Supply Current
Pulse Skip or Forced Continuous Mode
(One Channel On)
Pulse Skip or Forced Continuous Mode
(Both Channels On)
Sleep Mode (One Channel On)
(Note 4) I
TH1,2
= 1.2V, Sink/Source = 5μA
(Note 5)
RUN1 = 5V and RUN2 = 0V or
RUN1 = 0V and RUN2 = 5V,
V
FB1
= 0.83V (No Load)
RUN1,2 = 5V, V
FB1,2
= 0.83V (No Load)
RUN1 = 5V and RUN2 = 0V or
RUN1 = 0V and RUN2 = 5V,
V
FB1
= 0.83V (No Load)
RUN1,2 = 5V, V
FB1,2
= 0.83V (No Load)
RUN1,2 = 0V
INTV
CC
Ramping Up
INTV
CC
Ramping Down
Measured at V
FB1,2
, Relative to Regulated V
FB1,2
Each Channel
Each Channel
V
SENSE–
< INTV
CC
– 0.5V
V
SENSE–
> INTV
CC
+ 0.5V
In Dropout
V
TRACK1,2
= 0V
V
RUN1
Rising
V
RUN2
Rising
V
FB1,2
= 0.7V, V
SENSE1
–,
2
– = 3.3V, I
LIM
= 0
V
FB1,2
= 0.7V, V
SENSE1
–,
2
– = 3.3V, I
LIM
= INTV
CC
V
FB1,2
= 0.7V, V
SENSE1
–,
2
– = 3.3V, I
LIM
= FLOAT
l
l
l
l
l
l
l
2
50
75
mA
μA
Sleep Mode (Both Channels On)
Shutdown
UVLO
V
OVL
I
SENSE+
I
SENSE–
Undervoltage Lockout
Feedback Overvoltage Protection
SENSE
+
Pin Current
SENSE
–
Pins Current
60
14
3.6
7
4.0
3.8
10
100
25
4.2
4.0
13
±1
±1
μA
μA
V
V
%
μA
μA
μA
%
μA
V
V
mV
mV
mV
mV
Ω
Ω
Ω
Ω
ns
ns
ns
ns
ns
ns
ns
3890f
700
98
0.7
1.15
1.20
22
43
64
99
1.0
1.21
1.25
50
30
50
75
2.5
1.5
2.4
1.1
36
57
85
1.4
1.27
1.30
DF
MAX
I
TRACK/SS1,2
V
RUN1
On
V
RUN2
On
V
SENSE(MAX)
Maximum Duty Factor
Soft-Start Charge Current
RUN1 Pin On Threshold
RUN2 Pin On Threshold
Maximum Current Sense Threshold
V
RUN1,2
Hyst RUN Pin Hysteresis
Gate Driver
TG1,2
BG1,2
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
(Note 6)
C
LOAD
= 3300pF
C
LOAD
= 3300pF
(Note 6)
C
LOAD
= 3300pF
C
LOAD
= 3300pF
C
LOAD
= 3300pF Each Driver
C
LOAD
= 3300pF Each Driver
(Note 7)
TG1,2 t
r
TG1,2 t
f
BG1,2 t
r
BG1,2 t
f
TG/BG t
1D
BG/TG t
1D
t
ON(MIN)
25
16
28
13
30
30
95
3
LTC3890
ELECTRICAL CHARACTERISTICS
SYMBOL
V
INTVCCVIN
V
LDOVIN
V
INTVCCEXT
V
LDOEXT
V
EXTVCC
V
LDOHYS
f
25kΩ
f
65kΩ
f
105kΩ
f
LOW
f
HIGH
f
SYNC
V
PGL
I
PGOOD
V
PG
PARAMETER
Internal V
CC
Voltage
INTV
CC
Load Regulation
Internal V
CC
Voltage
INTV
CC
Load Regulation
EXTV
CC
Switchover Voltage
EXTV
CC
Hysteresis
Programmable Frequency
Programmable Frequency
Programmable Frequency
Low Fixed Frequency
High Fixed Frequency
Synchronizable Frequency
PGOOD Voltage Low
PGOOD Leakage Current
PGOOD Trip Level
R
FREQ
= 25k, PLLIN/MODE = DC Voltage
R
FREQ
= 65k, PLLIN/MODE = DC Voltage
R
FREQ
= 105k, PLLIN/MODE = DC Voltage
V
FREQ
= 0V, PLLIN/MODE = DC Voltage
V
FREQ
= INTV
CC
, PLLIN/MODE = DC Voltage
PLLIN/MODE = External Clock
I
PGOOD
= 2mA
V
PGOOD
= 5V
V
FB
with Respect to Set Regulated Voltage
V
FB
Ramping Negative
Hysteresis
V
FB
with Respect to Set Regulated Voltage
V
FB
Ramping Positive
Hysteresis
t
PG
Delay for Reporting a Fault
–13
–10
2.5
10
2.5
25
l
The
l
denotes the specifications which apply over the full operating
junction temperature range, otherwise specifications are at T
J
= 25°C. V
IN
= 12V, V
RUN1,2
= 5V, EXTV
CC
= 0V unless otherwise noted.
CONDITIONS
6V < V
IN
< 60V, V
EXTVCC
= 0V
I
CC
= 0mA to 50mA, V
EXTVCC
= 0V
6V < V
EXTVCC
< 13V
I
CC
= 0mA to 50mA, V
EXTVCC
= 8.5V
EXTV
CC
Ramping Positive
4.5
4.85
MIN
4.85
TYP
5.1
0.7
5.1
0.6
4.7
250
105
375
320
485
75
0.2
440
835
350
535
380
585
850
0.4
±1
–7
505
MAX
5.35
1.1
5.35
1.1
4.9
UNITS
V
%
V
%
V
mV
kHz
kHz
kHz
kHz
kHz
kHz
V
μA
%
%
%
%
μs
INTV
CC
Linear Regulator
Oscillator and Phase-Locked Loop
PGOOD1 and PGOOD2 Outputs
7
13
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 LTC3890E is guaranteed to meet performance specifications
from 0°C to 125°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 LTC3890I is guaranteed
over the full –40°C to 125°C operating junction temperature range.
Note 3:
T
J
is calculated from the ambient temperature T
A
and power
dissipation P
D
according to the following formula:
T
J
= T
A
+ (P
D
• 34°C/W)
Note 4:
The LTC3890 is tested in a feedback loop that servos V
ITH1,2
to a
specified voltage and measures the resultant V
FB1,2
. The specification at
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
MAX
(See Minimum On-Time
Considerations in the Applications Information section).
PCB设计
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