for advanced portable application processor-based sys-
tems. The device contains four synchronous step-down
DC/DC converters for core, memory, I/O, and system
on-chip (SoC) rails and three 300mA LDO regulators for
low noise analog supplies. The LTC3676-1 has a ±1.5A
buck regulator configured to support DDR termination
plus a VTTR reference output. An I
2
C serial port is used
to control regulator enables, power-down sequencing,
output voltage levels, dynamic voltage scaling, operating
modes and status reporting.
Regulator start-up is sequenced by connecting outputs to
enable pins in the desired order or via the I
2
C port. System
power-on, power-off and reset functions are controlled by
pushbutton interface, pin inputs, or I
2
C.
The LTC3676 supports i.MX, PXA and OMAP processors
with eight independent rails at appropriate power levels.
Other features include interface signals such as the VSTB
pin that toggles between programmed run and standby
output voltages on up to four rails simultaneously. The
device is available in a 40-lead 6mm
6mm QFN and
48-lead exposed pad LQFP packages.
L,
LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks
of Analog Devices, Inc. All other trademarks are the property of their respective owners.
Quad I
2
C Adjustable High Efficiency Step Down
DC/DC Converters: 2.5A, 2.5A, 1.5A, 1.5A
Three 300mA LDO Regulators (Two Adjustable)
DDR Power Solution with V
TT
and VTTR Reference
Pushbutton ON/OFF Control with System Reset
Independent Enable Pin-Strap or I
2
C Sequencing
Programmable Autonomous Power-Down Control
Dynamic Voltage Scaling
Power Good and Reset Functions
Selectable 2.25MHz or 1.12MHz Switching Frequency
Always Alive 25mA LDO Regulator
12µA Standby Current
Low Profile 40-Lead 6mm
6mm QFN and 48-Lead
Exposed Pad LQFP
applicaTions
n
n
n
n
n
n
Supports Freescale i.MX6, ARM Cortex, and Other
Application Processors
Handheld Instruments and Scanners
Portable Industrial and Medical Devices
Automotive Infotainment
High End Consumer Devices
Multi-Rail Systems
Typical applicaTion
V
IN
2.7V TO 5.5V
Start-Up Sequence
1.5µH
V
ARM
1.38V
47µF 2.5A
V
SOC
1.38V
47µF 1.5A
V
DDR
(V
DDQ
)
1.5V
47µF 2.5A
V
TT
1/2 V
DDQ
47µF 1.5A
VTTR (1/2 V
DDQ
)
WAKE
2
3676 TA01a
V
RTC
3V
25mA
V
DD(HIGH)
2.97V
300mA
V
LDO3
1.8V
300mA
3V
300mA
LDO1
1µF
V
IN
SW3
WAKE
5V/DIV
V
DD(HIGH)
V
LDO3
1V/DIV
V
ARM
AND V
SOC
V
DDR
1V/DIV
V
TT
AND V
TTR
LTC3676-1
LDO2
SW2
1.5µH
1µF
LDO3
1µF
LDO4
1µF
6
ENABLES VTTR
PWR_ON WAKE
ON
PGOOD
I
2
C
GND
SW1
1.5µH
SW4
1.5µH
1ms/DIV
3676 TA01b
TO µPROCESSOR
3676ff
For more information
www.linear.com/LTC3676
1
LTC3676/LTC3676-1
absoluTe MaxiMuM raTings
(Note 1)
V
IN
, DV
DD
, SW1, SW2, SW3, SW4 ............... –0.3V to 6V
SW1, SW2, SW3, SW4
(Transient t < 1µs, Duty Cycle < 5%)............... –2V to 7V
PV
IN1
, PV
IN2
, PV
IN3
, PV
IN4
, V
IN_L2
,
V
IN_L3
, V
IN_L4
.................................. –0.3V to V
IN
+ 0.3V
LDO1, FB_L1, LDO2, FB_L2, LDO3, LDO4, FB_L4,
FB_B1, FB_B2, FB_B3, FB_B4, PGOOD, VSTB, EN_B1,
EN_B2, EN_B3, EN_B4, EN_L2, EN_L3, EN_L4,
ON,
WAKE,
RSTO,
PWR_ON,
IRQ,
VTTR,
VDDQIN ....................................................... –0.3V to 6V
SDA, SCL ......................................–0.3V to DV
DD
+ 0.3V
Operating Junction Temperature Range
(Notes 2, 3) ............................................ –40°C to 150°C
Storage Temperature Range ......................–65 to 150°C
pin conFiguraTion
LTC3676
PGOOD
TOP VIEW
EN_B1
EN_B2
WAKE
PV
IN1
PV
IN2
RSTO
SW2
SW1
IRQ
SW1
LTC3676-1
PGOOD
TOP VIEW
EN_B1
EN_B2
WAKE
PV
IN1
PV
IN2
RSTO
SW2
30 EN_L2
29
ON
28 LDO1
27 V
IN
41
GND
26 FB_L1
25 FB_B2
24 FB_B1
23 FB_B4
22 FB_B3
21 PWR_ON
11 12 13 14 15 16 17 18 19 20
SW4
DV
DD
SDA
SCL
PV
IN4
PV
IN3
EN_B4
EN_B3
VSTB
SW3
IRQ
40 39 38 37 36 35 34 33 32 31
FB_L2 1
V
IN_L2
2
LDO2 3
LDO3 4
V
IN_L3
5
LDO4 6
V
IN_L4
7
FB_L4 8
EN_L4 9
EN_L3 10
11 12 13 14 15 16 17 18 19 20
SW4
DV
DD
SDA
SCL
PV
IN4
PV
IN3
EN_B4
EN_B3
VSTB
SW3
41
GND
30 EN_L2
29
ON
28 LDO1
27 V
IN
26 FB_L1
25 FB_B2
24 FB_B1
23 FB_B4
22 FB_B3
21 PWR_ON
FB_L2 1
V
IN_L2
2
LDO2 3
LDO3 4
V
IN_L3
5
LDO4 6
V
IN_L4
7
VDDQIN 8
VTTR 9
EN_L3 10
40 39 38 37 36 35 34 33 32 31
UJ PACKAGE
40-LEAD (6mm
×
6mm) PLASTIC QFN
UJ PACKAGE
40-LEAD (6mm
×
6mm) PLASTIC QFN
T
JMAX
= 150°C,
JA
= 33°C/W,
JC
= 2°C/W
EXPOSED PAD (PIN 41) IS GND, MUST BE SOLDERED TO PCB
LTC3676
NC
SW1
PGOOD
RST0
EN_B1
PV
IN1
PV
IN2
EN_B2
WAKE
IRQ
SW2
NC
TOP VIEW
T
JMAX
= 150°C,
JA
= 33°C/W,
JC
= 2°C/W
EXPOSED PAD (PIN 41) IS GND, MUST BE SOLDERED TO PCB
LTC3676-1
NC
SW1
PGOOD
RST0
EN_B1
PV
IN1
PV
IN2
EN_B2
WAKE
IRQ
SW2
NC
TOP VIEW
48
47
46
45
44
43
42
41
40
39
38
37
NC 1
FB_L2 2
VIN_L2 3
LDO2 4
LDO3 5
VIN_L3 6
LD04 7
VIN_L4 8
FB_L4 9
EN_L4 10
EN_L3 11
NC 12
49
GND
36
35
34
33
32
31
30
29
28
27
26
25
NC
EN_L2
ON
LDO1
V
IN
FB_L1
FB_B2
FB_B1
FB_B4
FB_B3
PWR_ON
NC
NC 1
FB_L2 2
VIN_L2 3
LDO2 4
LDO3 5
VIN_L3 6
LD04 7
VIN_L4 8
VDDQIN 9
VTTR 10
EN_L3 11
NC 12
48
47
46
45
44
43
42
41
40
39
38
37
49
GND
36
35
34
33
32
31
30
29
28
27
26
25
NC
EN_L2
ON
LDO1
V
IN
FB_L1
FB_B2
FB_B1
FB_B4
FB_B3
PWR_ON
NC
NC 13
SW4 14
DVDD 15
SDA 16
SCL 17
PV
IN4
18
PV
IN3
19
EN_B4 20
EN_B3 21
VSTB 22
SW3 23
NC 24
LXE PACKAGE
48-LEAD (7mm
×
7mm) PLASTIC LQFP
LXE PACKAGE
48-LEAD (7mm
×
7mm) PLASTIC LQFP
T
JMAX
= 150°C,
JA
= 19°C/W,
JC
= 3°C/W
EXPOSED PAD (PIN 49) IS GND, MUST BE SOLDERED TO PCB
T
JMAX
= 150°C,
JA
= 19°C/W,
JC
= 3°C/W
EXPOSED PAD (PIN 49) IS GND, MUST BE SOLDERED TO PCB
3676ff
2
For more information
www.linear.com/LTC3676
NC 13
SW4 14
DVDD 15
SDA 16
SCL 17
PV
IN4
18
PV
IN3
19
EN_B4 20
EN_B3 21
VSTB 22
SW3 23
NC 24
LTC3676/LTC3676-1
orDer inForMaTion
LEAD FREE FINISH
LTC3676EUJ#PBF
LTC3676IUJ#PBF
LTC3676HUJ#PBF
LTC3676EUJ-1#PBF
LTC3676IUJ-1#PBF
LTC3676HUJ-1#PBF
TAPE AND REEL
LTC3676EUJ#TRPBF
LTC3676IUJ#TRPBF
LTC3676HUJ#TRPBF
LTC3676EUJ-1#TRPBF
LTC3676IUJ-1#TRPBF
LTC3676HUJ-1#TRPBF
http://www.linear.com/product/LTC3676#orderinfo
PART MARKING*
LTC3676UJ
LTC3676UJ
LTC3676UJ
LTC3676UJ-1
LTC3676UJ-1
LTC3676UJ-1
PACKAGE DESCRIPTION
40-Lead (6mm
6mm) Plastic QFN
40-Lead (6mm
6mm) Plastic QFN
40-Lead (6mm
6mm) Plastic QFN
40-Lead (6mm
6mm) Plastic QFN
40-Lead (6mm
6mm) Plastic QFN
40-Lead (6mm
6mm) Plastic QFN
TEMPERATURE RANGE
–40°C to 125°C
–40°C to 125°C
–40°C to 150°C
–40°C to 125°C
–40°C to 125°C
–40°C to 150°C
LEAD FREE FINISH
LTC3676ELXE#PBF
LTC3676ILXE#PBF
LTC3676HLXE#PBF
LTC3676ELXE-1#PBF
LTC3676ILXE-1#PBF
LTC3676HLXE-1#PBF
TRAY
LTC3676ELXE#PBF
LTC3676ILXE#PBF
LTC3676HLXE#PBF
LTC3676ELXE-1#PBF
LTC3676ILXE-1#PBF
LTC3676HLXE-1#PBF
PART MARKING*
LTC3676LXE
LTC3676LXE
LTC3676LXE
LTC3676LXE-1
LTC3676LXE-1
LTC3676LXE-1
PACKAGE DESCRIPTION
48-Lead (7mm
7mm) Plastic eLQFP
48-Lead (7mm
7mm) Plastic eLQFP
48-Lead (7mm
7mm) Plastic eLQFP
48-Lead (7mm
7mm) Plastic eLQFP
48-Lead (7mm
7mm) Plastic eLQFP
48-Lead (7mm
7mm) Plastic eLQFP
TEMPERATURE RANGE
–40°C to 125°C
–40°C to 125°C
–40°C to 150°C
–40°C to 125°C
–40°C to 125°C
–40°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.
Consult LTC Marketing for information on nonstandard 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/.
Some packages are available in 500 unit reels through
designated sales channels with #TRMPBF suffix.
3676ff
For more information
www.linear.com/LTC3676
3
LTC3676/LTC3676-1
The
l
denotes the specifications which apply over the specified operating
junction temperature range, otherwise specifications are at T
A
= 25°C (Note 2). V
IN
= PV
IN1
= PV
IN2
= PV
IN3
= PV
IN4
= V
IN_L2
= V
IN_L3
=
V
IN_L4
= DV
DD
= 3.8V. All regulators disabled unless otherwise noted.
PARAMETER
Operating Input Supply Voltage, V
IN
V
IN
Standby Current
Step-Down Switching Regulators 1, 2, 3 and 4
Output Voltage Range
Burst Mode
®
V
IN
Quiescent Current
Pulse-Skipping Mode V
IN
Quiescent Current
Forced Continuous V
IN
Quiescent Current
Feedback Pin Input Current
Maximum Duty Cycle
SW Pull-Down Resistance
Feedback Reference Soft-Start Rate
High Feedback Regulation Voltage (V
FB
)
Default Feedback Regulation Voltage (V
FB
)
Low Feedback Regulation Voltage (V
FB
)
Feedback LSB Step Size
Switching Frequency
1.5A Step-Down Switching Regulators 1 and 2
PMOS Current Limit
PMOS On-Resistance (Note 7)
NMOS On-Resistance (Note 7)
2.5A Step-Down Switching Regulators 3 and 4
PMOS Current Limit
PMOS On-Resistance (Note 7)
NMOS On-Resistance (Note 7)
Step-Down Switching Regulator 1 and VTTR (LTC3676-1)
Buck 1 Feedback Regulation Voltage
VTTR Output Voltage
VTTR Maximum Output Current
I
VIN
VTTR Enabled
LDO Regulators 2, 3 and 4
Feedback Reference Soft-Start Rate
Output Pull-Down Resistance
LDO Regulator 1
Output Voltage Range
Feedback Regulation Voltage (V
FB_L1
)
Line Regulation
Load Regulation
I
LDO1
= 1mA, V
LDO1
= 1.2V,
V
IN
= 2.7V to 5.5V
I
LDO1
= 0.1mA to 25mA,
V
LDO1
= 3.3V
l
l
l
elecTrical characTerisTics
CONDITIONS
l
MIN
2.7
l
TYP
12
MAX
5.5
21
PV
IN
UNITS
V
µA
V
µA
µA
µA
µA
%
Ω
V/ms
PWR_ON = 0V
V
FB
V
FB
= 850mV (Note 5)
V
FB
= 850mV (Note 5)
V
FB
= 0V (Note 5)
V
FB
= 850mV
V
FB
= 0V
Regulator Disabled
(Note 6)
DVBxA[4:0] = DVBxB[4:0] = 11111,
V
IN
= 2.7V to 5.5V
DVBxA[4:0] = DVBxB[4:0] = 11001,
V
IN
= 2.7V to 5.5V
DVBxA[4:0] = DVBxB[4:0] = 00000,
V
IN
= 2.7V to 5.5V
BUCKx[2] = 0
BUCKx[2] = 1
l
l
l
l
l
l
23
120
170
–0.05
100
625
0.8
788
714
404
800
725
412.5
12.5
50
200
300
0.05
812
736
421
mV
mV
mV
mV
l
l
1.7
0.85
2
2.25
1.125
2.7
1.35
MHz
MHz
A
160
80
3.0
120
70
VDDQIN = 1.5V
VDDQIN = 1.5V
l
l
l
mΩ
mΩ
A
mΩ
mΩ
VTTR + 10
0.51•VDDQIN
10
mV
mV
mA
mA
V/ms
Ω
V
IN
VTTR – 10
0.49•VDDQIN
–10
VTTR
0.5•VDDQIN
1
10
Regulator Disabled
V
FB_L1
689
625
725
0.15
0.1
761
mV
%/V
%
3676ff
4
For more information
www.linear.com/LTC3676
LTC3676/LTC3676-1
The
l
denotes the specifications which apply over the specified operating
junction temperature range, otherwise specifications are at T
A
= 25°C (Note 2). V
IN
= PV
IN1
= PV
IN2
= PV
IN3
= PV
IN4
= V
IN_L2
= V
IN_L3
=
V
IN_L4
= DV
DD
= 3.8V. All regulators disabled unless otherwise noted.
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