...................................................... 10V to –0.3V
I
TH1,
I
TH2
, V
FB1
, V
FB2
Voltages .................. 2.7V to –0.3V
PGOOD1, PGOOD2 Voltages ..................... 8.5V to –0.3V
Peak Output Current <10μs (TG1, TG2, BG1, BG2) .....3A
INTV
CC
Peak Output Current ................................. 50mA
Operating Temperature Range (Note 2).... –40°C to 85°C
Junction Temperature (Note 3) ............................. 125°C
Storage Temperature Range .................. –65°C to 125°C
32 31 30 29 28 27 26 25
SENSE1
–
1
PLLLPF 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
LTC3827EUH#PBF
LTC3827IUH#PBF
LEAD BASED FINISH
LTC3827EUH
LTC3827IUH
TAPE AND REEL
LTC3827EUH#TRPBF
LTC3827IUH#TRPBF
TAPE AND REEL
LTC3827EUH#TR
LTC3827IUH#TR
PART MARKING*
3827
3827
PART MARKING*
3827
3827
PACKAGE DESCRIPTION
32-Lead (5mm
×
5mm) Plastic QFN
32-Lead (5mm
×
5mm) Plastic QFN
PACKAGE DESCRIPTION
32-Lead (5mm
×
5mm) Plastic QFN
32-Lead (5mm
×
5mm) Plastic QFN
TEMPERATURE RANGE
–40°C to 85°C
–40°C to 85°C
TEMPERATURE RANGE
–40°C to 85°C
–40°C to 85°C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
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/
3827ff
2
LTC3827
ELECTRICAL CHARACTERISTICS
SYMBOL
V
FB1, 2
I
VFB1, 2
V
REFLNREG
V
LOADREG
PARAMETER
Regulated Feedback Voltage
Feedback Current
Reference Voltage Line Regulation
Output Voltage Load Regulation
Main Control Loops
(Note 4) I
TH1, 2
Voltage = 1.2V
(Note 4)
V
IN
= 4V to 30V (Note 4)
(Note 4)
Measured in Servo Loop;
ΔI
TH
Voltage = 1.2V to 0.7V
Measured in Servo Loop;
ΔI
TH
Voltage = 1.2V to 2V
I
TH1, 2
= 1.2V; Sink/Source 5μA (Note 4)
(Note 5)
RUN1 = 5V, RUN2 = 0V, V
FB1
= 0.83V (No Load)
RUN1 = 0V, RUN2 = 5V, V
FB2
= 0.83V (No Load)
V
RUN1, 2
= 0V
RUN1,2 = 5V, V
FB1
= V
FB2
= 0.83V
V
IN
Ramping Down
Measured at V
FB1, 2
, Relative to Regulated V
FB1, 2
(Each Channel) V
SENSE1
–
, 2
– = V
SENSE1
+
, 2
+ = 0V
In Dropout
V
TRACK1, 2
= 0V
V
RUN1,
V
RUN2
Rising
V
FB1, 2
= 0.7V,V
SENSE1–, 2–
= 3.3V
V
FB1, 2
= 0.7V,V
SENSE1–, 2–
= 3.3V
(Note 6)
C
LOAD
= 3300pF
C
LOAD
= 3300pF
(Note 6)
C
LOAD
= 3300pF
C
LOAD
= 3300pF
●
●
●
●
●
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 12V, V
RUN/SS1, 2
= 5V unless otherwise noted.
CONDITIONS
MIN
0.792
TYP
0.800
–5
0.002
0.1
– 0.1
1.55
80
80
8
115
3.5
8
98
0.75
0.5
90
80
10
–660
99.4
1.0
0.7
100
100
50
50
40
40
70
70
180
5.0
7.2
4.5
5.25
0.2
7.5
0.2
4.7
0.2
V
PLLLPF
= Floating; PLLIN/MODE = DC Voltage
V
PLLLPF
= 0V; PLLIN/MODE = DC Voltage
V
PLLLPF
= INTV
CC
; PLLIN/MODE = DC Voltage
PLLIN/MODE = External Clock; V
PLLLPF
= 0V
360
220
475
400
250
530
115
440
280
580
140
5.5
1.0
7.8
1.0
1.35
0.9
110
115
90
90
90
80
125
125
20
160
4
12
MAX
0.808
–50
0.02
0.5
–0.5
UNITS
V
nA
%/V
%
%
mmho
μA
μA
μA
μA
V
%
μA
%
μA
V
mV
mV
ns
ns
ns
ns
ns
ns
ns
V
%
V
%
V
V
kHz
kHz
kHz
kHz
g
m1, 2
I
Q
Transconductance Amplifier g
m
Input DC Supply Current
Sleep Mode (Channel 1 On)
Sleep Mode (Channel 2 On)
Shutdown
Sleep Mode (Both Channels)
Undervoltage Lockout
Feedback Overvoltage Lockout
Sense Pins Total Source Current
Maximum Duty Factor
RUN Pin ON Threshold
Maximum Current Sense Threshold
TG Transition Time:
Rise Time
Fall Time
BG Transition Time:
Rise Time
Fall Time
UVLO
V
OVL
I
SENSE
DF
MAX
V
RUN1, 2
ON
V
SENSE(MAX)
I
TRACK/SS1, 2
Soft-Start Charge Current
TG1, 2 t
r
TG1, 2 t
f
BG1, 2 t
r
BG1, 2 t
f
TG/BG t
1D
BG/TG t
2D
t
ON(MIN)
V
INTVCCVIN
V
LDOVIN
V
INTVCCEXT
V
LDOEXT
V
EXTVCC
V
LDOHYS
f
NOM
f
LOW
f
HIGH
f
SYNCMIN
Top Gate Off to Bottom Gate On Delay C
LOAD
= 3300pF Each Driver
Synchronous Switch-On Delay Time
Bottom Gate Off to Top Gate On Delay C
LOAD
= 3300pF Each Driver
Top Switch-On Delay Time
Minimum On-Time
Internal V
CC
Voltage
INTV
CC
Load Regulation
Internal V
CC
Voltage
INTV
CC
Load Regulation
EXTV
CC
Switchover Voltage
EXTV
CC
Hysteresis
Nominal Frequency
Lowest Frequency
Highest Frequency
Minimum Synchronizable Frequency
(Note 7)
8.5V < V
IN
< 30V, V
EXTVCC
= 0V
I
CC
= 0mA to 20mA, V
EXTVCC
= 0V
V
EXTVCC
= 8.5V
I
CC
= 0mA to 20mA, V
EXTVCC
= 8.5V
EXTV
CC
Ramping Positive
INTV
CC
Linear Regulator
Oscillator and Phase-Locked Loop
3827ff
3
LTC3827
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 12V, V
RUN/SS1, 2
= 5V unless otherwise noted.
SYMBOL
f
SYNCMAX
I
PLLLPF
PARAMETER
Maximum Synchronizable Frequency
Phase Detector Output Current
Sinking Capability
Sourcing Capability
PGOOD Voltage Low
PGOOD Leakage Current
PGOOD Trip Level
CONDITIONS
PLLIN/MODE = External Clock; V
PLLLPF
= 2V
f
PLLIN/MODE
< f
OSC
f
PLLIN/MODE
> f
OSC
I
PGOOD
= 2mA
V
PGOOD
= 5V
V
FB
with Respect to Set Regulated Voltage
V
FB
Ramping Negative
V
FB
Ramping Positive
–12
8
–10
10
MIN
650
TYP
800
–5
5
0.1
0.3
±1
–8
12
MAX
UNITS
kHz
μA
μA
V
μA
%
%
ELECTRICAL CHARACTERISTICS
PGOOD Output
V
PGL
I
PGOOD
V
PG
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2:
The LTC3827E 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 LTC3827I is guaranteed to meet
performance specifications over the full –40°C to 85°C operating
temperature range.
Note 3:
T
J
is calculated from the ambient temperature T
A
and power
dissipation P
D
according to the following formulas:
T
J
= T
A
+ (P
D
• 34 °C/W)
Note 4:
The LTC3827 is tested in a feedback loop that servos V
ITH1, 2
to a
specified voltage and measures the resultant V
FB1, 2.
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).
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