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LTC3634EFE#TRPBF

P1-P3P4-P6P7-P9P10-P12P13-P15P16-P18P19-P21P22-P24P25-P27P28-P28
LTC3634
1
3634fc
For more information www.linear.com/LTC3034
TYPICAL APPLICATION
FEATURES DESCRIPTION
15V Dual 3A Monolithic
Step-Down Regulator
for DDR Power
The LT C
®
3634 is a high efficiency, dual-channel monolithic
synchronous step-down regulator which provides power
supply and bus termination rails for DDR1, DDR2, and
DDR3 SDRAM controllers. The operating input voltage
range is 3.6V to 15V, making it suitable for point-of-load
power supply applications from a 5V or 12V input, as well
as various battery powered systems.
The V
TT
regulated output voltage is equal to VDDQIN•0.5.
An on-chip buffer capable of driving a 10mA load pro-
vides a low noise reference output (VTTR) also equal to
VDDQIN• 0.5.
The operating frequency is programmable and synchro-
nizable from 500kHz to 4MHz with an external resistor.
The two channels can operate 180° out-of-phase, which
relaxes the requirements for input and output capacitance.
The unique controlled on-time architecture is ideal for
powering DDR applications from a 12V supply at high
switching frequencies, allowing the use of smaller external
components.
The LTC3634 is offered in both 28-pin 4mm × 5mm QFN
and 28-pin exposed pad TSSOP packages.
Efficiency and Power Loss
vs Load Current
APPLICATIONS
n
3.6V to 15V Input Voltage Range
n
±3A Output Current per Channel
n
Up to 95% Efficiency
n
Selectable 90°/180° Phase Shift Between Channels
n
Adjustable Switching Frequency: 500kHz to 4MHz
n
VTTR = V
DDQ
/2 = V
TT
Reference
n
±1.6% Accurate VTTR at 0.75V
n
Optimal V
OUT
Range: 0.6V to 3V
n
±10mA Buffered Output Supplies V
REF
Reference Voltage
n
Current Mode Operation for Excellent Line and Load
Transient Response
n
External Clock Synchronization
n
Short-Circuit Protected
n
Input Overvoltage and Overtemperature Protection
n
Power Good Status Outputs
n
Available in (4mm × 5mm) QFN-28 and Thermally
Enhanced 28-Lead TSSOP Packages
n
DDR Memory Power Supplies
RUN1
RUN2
INTV
CC
PHMODE
MODE/SYNC
RT
ITH1
ITH2
LTC3634
3634 TA01a
1.5µH
24.3k
12.1k
0.1µF
0.01µF
V
REF
0.9V
0.1µF
PGNDSGND
BOOST1
SW1
V
ON1
VDDQIN
V
FB1
BOOST2
SW2
V
FB2
V
ON2
VTTR
V
IN1
V
IN
3.6V TO 15V
V
IN2
0.82µH
18k
100µF
×2
V
DDQ
1.8V/3A
100µF
×4
V
TT
0.9V/±3A
910pF
26.4k
324k
560pF
2.2µF
47µF
×2
L, LT, LTC, LTM, Linear Technology, the Linear logo, Burst Mode and PolyPhase are registered
trademarks and Hot Swap is a trademark of Linear Technology Corporation. All other trademarks
are the property of their respective owners. Protected by U.S. Patents including 5481178,
5847554, 6580258, 6476589, 6774611.
LOAD CURRENT (A)
0
70
80
100
1.5 2.5
3634 TA01b
30
20
0.5 1
2 3
10
60
50
40
0
90
1.4
1.6
2.0
0.6
0.4
0.2
1.2
1.0
0.8
0
1.8
EFFICIENCY (%)
POWER LOSS (W)
V
IN
= 12V
V
DDQ
V
TT
(SINKING CURRENT)
V
TT
(SOURCING CURRENT)
LTC3634
2
3634fc
For more information www.linear.com/LTC3034
ABSOLUTE MAXIMUM RATINGS
V
IN1
, V
IN2
................................................... –0.3V to 16V
V
IN1
, V
IN2
Transient (Note 2) .......................... ............18V
PGOOD1, PGOOD2, V
ON1
, V
ON2
................. –0.3V to 16V
VTTR, INTV
CC
, TRACKSS, VDDQIN .......... –0.3V to 3.6V
ITH1, ITH2, RT, MODE/SYNC
.....–0.3V to INTV
CC
+ 0.3V
V
FB1
, V
FB2
, PHMODE .................. –0.3V to INTV
CC
+ 0.3V
BOOST1-SW1, BOOST2-SW2
.................... –0.3V to 3.6V
BOOST1, BOOST2
....................................–0.3V to 19.6V
RUN1, RUN2
.................................... –0.3V to V
IN
+ 0.3V
9 10
TOP VIEW
29
PGND
UFD PACKAGE
28-LEAD (4mm × 5mm) PLASTIC QFN
11 12 13
28 27 26 25 24
14
23
6
5
4
3
2
1
PGOOD1
PHMODE
RUN1
MODE/SYNC
RT
RUN2
SGND
PGOOD2
V
IN1
V
IN1
BOOST1
INTV
CC
VTTR
BOOST2
V
IN2
V
IN2
V
FB1
TRACKSS
ITH1
V
ON1
SW1
SW1
V
FB2
VDDQIN
ITH2
V
ON2
SW2
SW2
7
17
18
19
20
21
22
16
8
15
T
JMAX
= 150°C, θ
JA
= 43°C/W
EXPOSED PAD (PIN 29) IS PGND, MUST BE SOLDERED TO PCB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
TOP VIEW
FE PACKAGE
28-LEAD PLASTIC TSSOP
28
27
26
25
24
23
22
21
20
19
18
17
16
15
ITH1
TRACKSS
V
FB1
PGOOD1
PHMODE
RUN1
MODE/SYNC
RT
RUN2
SGND
PGOOD2
V
FB2
VDDQIN
ITH2
V
ON1
SW1
SW1
V
IN1
V
IN1
BOOST1
INTV
CC
VTTR
BOOST2
V
IN2
V
IN2
SW2
SW2
V
ON2
29
PGND
T
JMAX
= 150°C, θ
JA
= 25°C/W
EXPOSED PAD (PIN 29) IS PGND, MUST BE SOLDERED TO PCB
PIN CONFIGURATION
SW Source and Sink Current (DC) (Note 3) ................3A
Operating Junction Temperature Range (Notes 4, 5, 8)
LTC3634E, LTC3634I
......................... –40°C to 125°C
LTC3634H
.......................................... –40°C to 150°C
LTC3634MP
....................................... –55°C to 150°C
Storage Temperature Range
..................–65°C to 150°C
Lead Temperature
(Soldering, 10 sec, TSSOP Package)
.....................260°C
(Note 1)
LTC3634
3
3634fc
For more information www.linear.com/LTC3034
ELECTRICAL CHARACTERISTICS
The l denotes the specifications which apply over the specified junction
temperature range, otherwise specifications are at T
A
= 25°C (Note 4). V
IN
= 12V, INTV
CC
= 3.3V, unless otherwise noted.
ORDER INFORMATION
LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LTC3634EUFD#PBF LTC3634EUFD#TRPBF 3634 28-Lead (5mm × 4mm) Plastic QFN –40°C to 125°C
LTC3634IUFD#PBF LTC3634IUFD#TRPBF 3634 28-Lead (5mm × 4mm) Plastic QFN –40°C to 125°C
LTC3634HUFD#PBF LTC3634HUFD#TRPBF 3634 28-Lead (5mm × 4mm) Plastic QFN –40°C to 150°C
LTC3634MPUFD#PBF LTC3634MPUFD#TRPBF 3634 28-Lead (5mm × 4mm) Plastic QFN –55°C to 150°C
LTC3634EFE#PBF LTC3634EFE#TRPBF LTC3634FE 28-Lead Plastic TSSOP –40°C to 125°C
LTC3634IFE#PBF LTC3634IFE#TRPBF LTC3634FE 28-Lead Plastic TSSOP –40°C to 125°
C
LTC3634HFE#PBF LTC3634HFE#TRPBF LTC3634FE 28-Lead Plastic TSSOP –40°C to 150°C
LTC3634MPFE#PBF LTC3634MPFE#TRPBF LTC3634FE 28-Lead Plastic TSSOP –55°C to 150°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/. Some packages are available in 500 unit reels through
designated sales channels with #TRMPBF suffix.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V
IN
V
IN1
, Operating Supply Range
V
IN2
, Operating Supply Range
V
IN1
> 3.6V
l
l
3.6
1.4
15
15
V
V
Output Voltage Range V
ON
= V
OUT
(Note 6) 0.6 3 V
I
Q
Input DC Supply Current (V
IN1
+ V
IN2
)
Active (Note 7)
Shutdown
RUN1 = RUN2 = V
IN
RUN1 = RUN2 = 0V
1.3
15
mA
µA
V
FBREG1
Feedback Reference Voltage 3.6V < V
IN
< 15V, 0.5V < ITH < 1.8V
0°C < T
A
< 85°C
–55°C < T
A
< 150°C
l
l
0.594
0.592
0.6
0.6
0.606
0.606
V
V
V
FBREG2
Feedback Reference Voltage 3.6V < V
IN
< 15V, 0.5V < ITH < 1.8V
l
VTTR – 6 VTTR VTTR + 6 mV
VTTR VTTR Voltage Reference 1.5V < VDDQIN < 2.6V
I
LOAD
= ±10mA, C
LOAD
< 10nF
l
0.492 •
VDDQIN
0.50 •
VDDQIN
0.508 •
VDDQIN
V
I
FB
Feedback Pin Input Current ±30 nA
g
m(EA)
Error Amplifier Transconductance ITH = 1.2V 1.0 mS
t
ON(MIN)
Minimum On-Time V
ON
= 0.5V, V
IN
= 4V 20 ns
t
OFF(MIN)
Minimum Off-Time V
IN
= 6V 40 60 ns
f
OSC
Oscillator Frequency V
RT
= INTV
CC
R
T
= 162k
R
T
= 80.6k
1.4
1.7
3.4
2
2
4
2.6
2.3
4.6
MHz
MHz
MHz
I
LIM1
Channel 1 Valley Switch Current Limit
Positive Limit
Negative Limit
3.3
4.4
8
5.5
A
A
I
LIM2
Channel 2 Valley Switch Current Limit
Positive Limit
Negative Limit
3.3
4.4
8
5.5
A
A
R
DS(ON)
Channel 1
Top Switch On-Resistance
Bottom Switch On-Resistance
Channel 2
Top Switch On-Resistance
Bottom Switch On-Resistance
130
65
130
65
mΩ
mΩ
mΩ
mΩ
P1-P3P4-P6P7-P9P10-P12P13-P15P16-P18P19-P21P22-P24P25-P27P28-P28

LTC3634EFE#TRPBF

Mfr. #:
Buy LTC3634EFE#TRPBF
Manufacturer:
Analog Devices / Linear Technology
Description:
Switching Voltage Regulators 15V Dual 3A Monolithic Step Down Regulator for DDR Power
Lifecycle:
New from this manufacturer.
Delivery:
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