LTC3676/LTC3676-1
Power Management Solution
for Application Processors
FEATURES
DESCRIPTION
Quad I2C Adjustable High Efficiency Step Down
DC/DC Converters: 2.5A, 2.5A, 1.5A, 1.5A
n Three 300mA LDO Regulators (Two Adjustable)
n DDR Power Solution with V
TT and VTTR Reference
n Pushbutton ON/OFF Control with System Reset
n Independent Enable Pin-Strap or I2C Sequencing
n Programmable Autonomous Power-Down Control
n Dynamic Voltage Scaling
n Power Good and Reset Functions
n Selectable 2.25MHz or 1.12MHz Switching Frequency
n Always Alive 25mA LDO Regulator
n 12µA Standby Current
n Low Profile 40-Lead 6mm 6mm QFN and 48-Lead
Exposed Pad LQFP
n AEC-Q100 Qualified for Automotive Application
The LTC®3676 is a complete power management solution
for advanced portable application processor-based systems. 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 I2C serial port is used
to control regulator enables, power-down sequencing,
output voltage levels, dynamic voltage scaling, operating
modes and status reporting.
n
APPLICATIONS
Supports Freescale i.MX6, ARM Cortex, and Other
Application Processors
n Handheld Instruments and Scanners
n Portable Industrial and Medical Devices
n Automotive Infotainment
n High End Consumer Devices
n Multi-Rail Systems
n
Regulator start-up is sequenced by connecting outputs to
enable pins in the desired order or via the I2C port. System
power-on, power-off and reset functions are controlled by
pushbutton interface, pin inputs, or I2C.
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.
All registered trademarks and trademarks are the property of their respective owners.
TYPICAL APPLICATION
VIN
2.7V TO 5.5V
VRTC
3V
25mA
VDD(HIGH)
2.97V
300mA
VLDO3
1.8V
300mA
3V
300mA
LDO1
1µF
VIN
SW3
LTC3676-1
LDO2
SW2
Start-Up Sequence
1.5µH
1.5µH
1µF
LDO3
SW4
SW1
ENABLES VTTR
PWR_ON WAKE
ON
PGOOD
I 2C
GND
VSOC
1.38V
47µF 1.5A
VLDO3
1.5µH
VTT
1/2 VDDQ
1.5A
47µF
VARM AND VSOC
VDDR
1V/DIV
VTTR (1/2 VDDQ)
WAKE
2
VDD(HIGH)
1V/DIV
VDDR (VDDQ)
1.5V
47µF 2.5A
1µF
6
WAKE
5V/DIV
1.5µH
1µF
LDO4
VARM
1.38V
47µF 2.5A
VTT AND VTTR
1ms/DIV
3676 TA01b
TO µPROCESSOR
3676 TA01a
Rev. G
Document Feedback
For more information www.analog.com
1
LTC3676/LTC3676-1
ABSOLUTE MAXIMUM RATINGS
(Note 1)
VIN, DVDD, SW1, SW2, SW3, SW4................ –0.3V to 6V
SW1, SW2, SW3, SW4
(Transient t < 1µs, Duty Cycle < 5%)................ –2V to 7V
PVIN1, PVIN2, PVIN3, PVIN4, VIN_L2,
VIN_L3, VIN_L4................................... –0.3V to VIN + 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 DVDD + 0.3V
Operating Junction Temperature Range
(Notes 2, 3)............................................. –40°C to 150°C
Storage Temperature Range.......................–65 to 150°C
PIN CONFIGURATION
VIN_L2 2
SW2
IRQ
WAKE
EN_B2
PVIN2
PVIN1
EN_B1
RSTO
30 EN_L2
FB_L2 1
30 EN_L2
29 ON
VIN_L2 2
29 ON
LDO2 3
28 LDO1
LDO2 3
LDO3 4
27 VIN
LDO3 4
28 LDO1
27 VIN
26 FB_L1
VIN_L3 5
25 FB_B2
LDO4 6
VIN_L4 7
24 FB_B1
VIN_L4 7
24 FB_B1
FB_L4 8
23 FB_B4
VDDQIN 8
23 FB_B4
EN_L4 9
22 FB_B3
VTTR 9
EN_L3 10
21 PWR_ON
VIN_L3 5
41
GND
26 FB_L1
41
GND
25 FB_B2
22 FB_B3
EN_L3 10
SW3
VSTB
EN_B3
EN_B4
PVIN3
PVIN4
SCL
SDA
DVDD
SW3
VSTB
EN_B3
EN_B4
PVIN3
PVIN4
SCL
SDA
11 12 13 14 15 16 17 18 19 20
DVDD
11 12 13 14 15 16 17 18 19 20
SW4
21 PWR_ON
SW4
LDO4 6
UJ PACKAGE
40-LEAD (6mm × 6mm) PLASTIC QFN
UJ PACKAGE
40-LEAD (6mm × 6mm) PLASTIC QFN
TJMAX = 150°C, θJA = 33°C/W, θJC = 2°C/W
EXPOSED PAD (PIN 41) IS GND, MUST BE SOLDERED TO PCB
TJMAX = 150°C, θJA = 33°C/W, θJC = 2°C/W
EXPOSED PAD (PIN 41) IS GND, MUST BE SOLDERED TO PCB
LTC3676
LTC3676-1
TOP VIEW
NC
SW1
PGOOD
RST0
EN_B1
PVIN1
PVIN2
EN_B2
WAKE
IRQ
SW2
NC
NC
EN_L2
ON
LDO1
VIN
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
49
GND
36
35
34
33
32
31
30
29
28
27
26
25
NC
EN_L2
ON
LDO1
VIN
FB_L1
FB_B2
FB_B1
FB_B4
FB_B3
PWR_ON
NC
NC 13
SW4 14
DVDD 15
SDA 16
SCL 17
PVIN4 18
PVIN3 19
EN_B4 20
EN_B3 21
VSTB 22
SW3 23
NC 24
49
GND
36
35
34
33
32
31
30
29
28
27
26
25
NC 13
SW4 14
DVDD 15
SDA 16
SCL 17
PVIN4 18
PVIN3 19
EN_B4 20
EN_B3 21
VSTB 22
SW3 23
NC 24
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
48
47
46
45
44
43
42
41
40
39
38
37
48
47
46
45
44
43
42
41
40
39
38
37
NC
SW1
PGOOD
RST0
EN_B1
PVIN1
PVIN2
EN_B2
WAKE
IRQ
SW2
NC
TOP VIEW
2
TOP VIEW
40 39 38 37 36 35 34 33 32 31
40 39 38 37 36 35 34 33 32 31
FB_L2 1
PGOOD
SW1
SW2
IRQ
WAKE
EN_B2
PVIN2
PVIN1
EN_B1
TOP VIEW
RSTO
PGOOD
LTC3676-1
SW1
LTC3676
LXE PACKAGE
48-LEAD (7mm × 7mm) PLASTIC LQFP
LXE PACKAGE
48-LEAD (7mm × 7mm) PLASTIC LQFP
TJMAX = 150°C, θJA = 19°C/W, θJC = 3°C/W
EXPOSED PAD (PIN 49) IS GND, MUST BE SOLDERED TO PCB
TJMAX = 150°C, θJA = 19°C/W, θJC = 3°C/W
EXPOSED PAD (PIN 49) IS GND, MUST BE SOLDERED TO PCB
Rev. G
For more information www.analog.com
LTC3676/LTC3676-1
ORDER INFORMATION
LEAD FREE FINISH
TAPE AND REEL
PART MARKING
PACKAGE DESCRIPTION
TEMPERATURE RANGE
LTC3676EUJ#PBF
LTC3676EUJ#TRPBF
LTC3676UJ
40-Lead (6mm 6mm) Plastic QFN
–40°C to 125°C
LTC3676IUJ#PBF
LTC3676IUJ#TRPBF
LTC3676UJ
40-Lead (6mm 6mm) Plastic QFN
–40°C to 125°C
LTC3676HUJ#PBF
LTC3676HUJ#TRPBF
LTC3676UJ
40-Lead (6mm 6mm) Plastic QFN
–40°C to 150°C
LTC3676EUJ-1#PBF
LTC3676EUJ-1#TRPBF
LTC3676UJ-1
40-Lead (6mm 6mm) Plastic QFN
–40°C to 125°C
LTC3676IUJ-1#PBF
LTC3676IUJ-1#TRPBF
LTC3676UJ-1
40-Lead (6mm 6mm) Plastic QFN
–40°C to 125°C
LTC3676HUJ-1#PBF
LTC3676HUJ-1#TRPBF
LTC3676UJ-1
40-Lead (6mm 6mm) Plastic QFN
–40°C to 150°C
LEAD FREE FINISH
TRAY
PART MARKING
PACKAGE DESCRIPTION
TEMPERATURE RANGE
LTC3676ELXE#PBF
LTC3676ELXE#PBF
LTC3676LXE
48-Lead (7mm 7mm) Plastic eLQFP
–40°C to 125°C
LTC3676ILXE#PBF
LTC3676ILXE#PBF
LTC3676LXE
48-Lead (7mm 7mm) Plastic eLQFP
–40°C to 125°C
LTC3676HLXE#PBF
LTC3676HLXE#PBF
LTC3676LXE
48-Lead (7mm 7mm) Plastic eLQFP
–40°C to 150°C
LTC3676ELXE-1#PBF
LTC3676ELXE-1#PBF
LTC3676LXE-1
48-Lead (7mm 7mm) Plastic eLQFP
–40°C to 125°C
LTC3676ILXE-1#PBF
LTC3676ILXE-1#PBF
LTC3676LXE-1
48-Lead (7mm 7mm) Plastic eLQFP
–40°C to 125°C
LTC3676HLXE-1#PBF
LTC3676HLXE-1#PBF
LTC3676LXE-1
48-Lead (7mm 7mm) Plastic eLQFP
–40°C to 150°C
LTC3676ELXE#WPBF
LTC3676ELXE#WPBF
LTC3676LXE
48-Lead (7mm 7mm) Plastic eLQFP
–40°C to 125°C
LTC3676ILXE#WPBF
LTC3676ILXE#WPBF
LTC3676LXE
48-Lead (7mm 7mm) Plastic eLQFP
–40°C to 125°C
LTC3676HLXE#WPBF
LTC3676HLXE#WPBF
LTC3676LXE
48-Lead (7mm 7mm) Plastic eLQFP
–40°C to 150°C
AUTOMOTIVE PRODUCTS*
Contact the factory for parts specified with wider operating temperature ranges.
Tape and reel specifications. Some packages are available in 500 unit reels through designated sales channels with #TRMPBF suffix.
*Versions of this part are available with controlled manufacturing to support the quality and reliability requirements of automotive applications. These
models are designated with a #W suffix. Only the automotive grade products shown are available for use in automotive applications. Contact your local
Analog Devices account representative for specific product ordering information and to obtain the specific Automotive Reliability reports for these models.
Rev. G
For more information www.analog.com
3
LTC3676/LTC3676-1
ELECTRICAL CHARACTERISTICS
The l denotes the specifications which apply over the specified operating
junction temperature range, otherwise specifications are at TA = 25°C (Note 2). VIN = PVIN1 = PVIN2 = PVIN3 = PVIN4 = VIN_L2 = VIN_L3 =
VIN_L4 = DVDD = 3.8V. All regulators disabled unless otherwise noted.
PARAMETER
CONDITIONS
Operating Input Supply Voltage, VIN
VIN Standby Current
MIN
l
PWR_ON = 0V
TYP
2.7
12
l
MAX
UNITS
5.5
V
21
µA
PVIN
V
50
200
300
µA
µA
µA
0.05
µA
Step-Down Switching Regulators 1, 2, 3 and 4
Output Voltage Range
VFB
Burst Mode VIN Quiescent Current
Pulse-Skipping Mode VIN Quiescent Current
Forced Continuous VIN Quiescent Current
VFB = 850mV (Note 5)
VFB = 850mV (Note 5)
VFB = 0V (Note 5)
Feedback Pin Input Current
VFB = 850mV
Maximum Duty Cycle
VFB = 0V
SW Pull-Down Resistance
Regulator Disabled
625
Ω
Feedback Reference Soft-Start Rate
(Note 6)
0.8
V/ms
High Feedback Regulation Voltage (VFB)
DVBxA[4:0] = DVBxB[4:0] = 11111,
VIN = 2.7V to 5.5V
l
788
800
812
mV
Default Feedback Regulation Voltage (VFB)
DVBxA[4:0] = DVBxB[4:0] = 11001,
VIN = 2.7V to 5.5V
l
714
725
736
mV
Low Feedback Regulation Voltage (VFB)
DVBxA[4:0] = DVBxB[4:0] = 00000,
VIN = 2.7V to 5.5V
l
404
412.5
421
mV
®
23
120
170
l
l
l
–0.05
100
Feedback LSB Step Size
Switching Frequency
%
12.5
BUCKx[2] = 0
BUCKx[2] = 1
l
l
1.7
0.85
l
2
2.25
1.125
mV
2.7
1.35
MHz
MHz
1.5A Step-Down Switching Regulators 1 and 2
PMOS Current Limit
A
PMOS On-Resistance (Note 7)
160
mΩ
NMOS On-Resistance (Note 7)
80
mΩ
2.5A Step-Down Switching Regulators 3 and 4
PMOS Current Limit
l
3.0
A
PMOS On-Resistance (Note 7)
120
mΩ
NMOS On-Resistance (Note 7)
70
mΩ
Step-Down Switching Regulator 1 and VTTR (LTC3676-1)
Buck 1 Feedback Regulation Voltage
VDDQIN = 1.5V
l
VTTR – 10
VTTR
VTTR + 10
mV
VTTR Output Voltage
VDDQIN = 1.5V
l
0.49•VDDQIN
0.5•VDDQIN
0.51•VDDQIN
mV
l
–10
10
mA
VTTR Maximum Output Current
IVIN VTTR Enabled
1
mA
10
V/ms
625
Ω
LDO Regulators 2, 3 and 4
Feedback Reference Soft-Start Rate
Output Pull-Down Resistance
Regulator Disabled
LDO Regulator 1
Output Voltage Range
VFB_L1
Feedback Regulation Voltage (VFB_L1)
l
689
VIN
725
761
mV
Line Regulation
ILDO1 = 1mA, VLDO1 = 1.2V,
VIN = 2.7V to 5.5V
0.15
%/V
Load Regulation
ILDO1 = 0.1mA to 25mA,
VLDO1 = 3.3V
0.1
%
4
Rev. G
For more information www.analog.com
LTC3676/LTC3676-1
ELECTRICAL CHARACTERISTICS
The l denotes the specifications which apply over the specified operating
junction temperature range, otherwise specifications are at TA = 25°C (Note 2). VIN = PVIN1 = PVIN2 = PVIN3 = PVIN4 = VIN_L2 = VIN_L3 =
VIN_L4 = DVDD = 3.8V. All regulators disabled unless otherwise noted.
PARAMETER
CONDITIONS
Available Output Current
MIN
l
Short-Circuit Output Current Limit
Dropout Voltage (Note 4)
ILDO1 = 25mA, VLDO1 = 3.3V
Feedback Pin Input Current
VFB_L1 = 850mV
TYP
MAX
25
UNITS
mA
65
100
mA
200
280
mV
–0.05
0.05
µA
1.7
VIN
V
VFB_L2
VIN_L2
V
LDO Regulator 2
VIN_L2 Input Voltage
LDO2 Output Voltage Range
l
ILDO2 = 1mA
Available Output Current
l
300
mA
VIN_L2 Quiescent Current
VIN_L2 Shutdown Current
Regulator Enabled, ILDO2 = 0A
Regulator Disabled
l
l
12
0
25
1
µA
µA
VIN Quiescent Current
Regulator Enabled
l
50
85
µA
0.725
0.743
V
Feedback Regulation Voltage (VFB_L2)
l
0.707
Line Regulation
ILDO2 =1mA, VIN = 2.7V to 5.5V
0.01
%/V
Load Regulation
ILDO2 = 1mA to 300mA
0.01
%
Dropout Voltage (Note 4)
ILDO2 = 300mA, VLDO2 = 2.5V
ILDO2 = 300mA, VLDO2 = 1.2V
210
450
Feedback Pin Input Current
VFB_L2 = 725mV
Short-Circuit Current Limit
–0.05
770
mA
260
615
mV
mV
0.05
µA
VIN
V
1.854
V
LDO Regulator 3
VIN_L3 Input Voltage
Output Voltage
VIN_L3 = VIN, ILDO3 = 1mA
Available Output Current
l
2.35
l
1.746
l
300
1.8
mA
VIN_L3 Quiescent Current
VIN_L3 Shutdown Current
Regulator Enabled, ILDO3 = 0A
Regulator Disabled
l
l
14
0
25
1
50
85
VIN Quiescent Current
Regulator Enabled
l
Line Regulation
ILDO3 =1mA, VIN = 2.7V to 5.5V
0.01
%/V
Load Regulation
ILDO3 = 1mA to 300mA
0.05
%
ILDO3 = 300mA, VLDO3 = 1.8V
280
Short-Circuit Current Limit
Dropout Voltage (Note 4)
µA
µA
µA
770
mA
350
mV
1.7
VIN
V
VFB_L4
VIN_L4
V
LDO Regulator 4
VIN_L4 Input Voltage
LDO4 Output Voltage Range (LTC3676)
l
ILDO4 = 1mA
Feedback Regulation Voltage (LTC3676) (VFB_L4)
Output Voltage (LTC3676-1)
ILDO4 = 1mA, LDOB[4:3] = 00
LDOB[4:3] = 01
LDOB[4:3] = 10
LDOB[4:3] = 11
Available Output Current
l
0.707
0.725
0.743
V
l
l
l
l
1.164
2.425
2.716
2.91
1.2
2.5
2.8
3.0
1.236
2.575
2.884
3.09
V
V
V
V
l
300
mA
VIN_L4 Quiescent Current
VIN_L4 Shutdown Current
Regulator Enabled, ILDO4 = 0A
Regulator Disabled
l
l
12
0
25
1
µA
µA
VIN Quiescent Current
Regulator Enabled
l
50
85
µA
Line Regulation
ILDO4 =1mA, VIN = 2.7V to 5.5V
0.01
%/V
Rev. G
For more information www.analog.com
5
LTC3676/LTC3676-1
ELECTRICAL CHARACTERISTICS
The l denotes the specifications which apply over the specified operating
junction temperature range, otherwise specifications are at TA = 25°C (Note 2). VIN = PVIN1 = PVIN2 = PVIN3 = PVIN4 = VIN_L2 = VIN_L3 =
VIN_L4 = DVDD = 3.8V. All regulators disabled unless otherwise noted.
PARAMETER
CONDITIONS
Load Regulation (LTC3676)
Load Regulation (LTC3676-1)
ILDO4 = 1mA to 300mA
MIN
0.01
0.05
TYP
Dropout Voltage (Note 4)
ILDO4 = 300mA, VLDO4 = 2.5V
ILDO4 = 300mA, VLDO4 = 1.2V
210
450
Feedback Pin Input Current (LTC3676)
VFB_L4 = 725mV
Short-Circuit Current Limit
–0.05
MAX
UNITS
%
%
770
mA
260
615
mV
mV
0.05
µA
1.2
V
Enable Inputs
Threshold Rising
All Enables Low
l
0.75
Threshold Falling
One Enable High
l
0.4
0.7
Precision Threshold
One or More Enables
l
0.370
0.400
Input Pull-Down Resistance
0.430
4.5
V
MΩ
VSTB, PWR_ON Inputs
Threshold
l
0.370
Pull-Down Resistance
0.400
0.430
4.5
V
MΩ
Pushbutton Interface
ON Threshold Rising
ON Threshold Falling
ON Input Current
l
l
ON = VIN
ON = 0V
0.4
–1
0.75
0.7
–40
1.2
V
V
1
µA
µA
ON Low Time to IRQ Low
50
ms
ON High Time to IRQ High
0.2
µs
ON Low Time to WAKE High
400
ms
10
sec
IRQ Minimum Pulse Width
50
ms
IRQ Blanking from WAKE Low
1
sec
Minimum WAKE Low Time
1
sec
WAKE High Time with PWR_ON = 0V
5
sec
PWR_ON High to WAKE High
3
ms
PWR_ON Low to WAKE Low
3
ms
ON Low Time to Hard Reset
CNTRL[6] = 0
Status Output Pins (WAKE, PGOOD, RSTO, IRQ)
WAKE Output Low Voltage
IWAKE = 3mA
WAKE Output High Leakage Current
VWAKE = 3.8V
PGOOD Output Low Voltage
IPGOOD = 3mA
PGOOD Output High Leakage Current
VPGOOD = 3.8V
0.1
–0.1
0.1
–0.1
PGOOD Threshold Rising
PGOOD Threshold Falling
V
0.1
µA
0.4
V
0.1
µA
–6
–8
RSTO Output Low Voltage
IRSTO = 3mA
RSTO Output High Leakage Current
VRSTO = 3.8V
0.1
–0.1
LDO1 Power Good Threshold Rising
LDO1 Power Good Threshold Falling
%
%
0.4
V
0.1
µA
–7.5
–10
IRQ Output Low Voltage
IIRQ = 3mA
IRQ Output High Leakage Current
VIRQ = 3.8V
6
0.4
0.1
–0.1
%
%
0.4
V
0.1
µA
Rev. G
For more information www.analog.com
LTC3676/LTC3676-1
ELECTRICAL CHARACTERISTICS
The l denotes the specifications which apply over the specified operating
junction temperature range, otherwise specifications are at TA = 25°C (Note 2). VIN = PVIN1 = PVIN2 = PVIN3 = PVIN4 = VIN_L2 = VIN_L3 =
VIN_L4 = DVDD = 3.8V. All regulators disabled unless otherwise noted.
PARAMETER
CONDITIONS
Undervoltage Lockout Rising
Undervoltage Lockout Falling
Undervoltage Warning
SYMBOL
I2C Port
DVVDD
IDVDD
DVVDD_UVLO
ADDRESS
VIH
VIL
IIH
IIL
VOL_SDA
fSCL
tBUF
tHD_STA
tSU_STA
tSU_STO
tHD_DAT(O)
tHD_DAT(I)
tSU_DAT
tLOW
tHIGH
tf
tr
tSP
l
l
MIN
TYP
MAX
UNITS
2.35
2.55
2.45
2.65
V
V
CNTRL[4:2] = 000 (POR Default)
CNTRL[4:2] = 001
CNTRL[4:2] = 010
CNTRL[4:2] = 011
CNTRL[4:2] = 100
CNTRL[4:2] = 101
CNTRL[4:2] = 110
CNTRL[4:2] = 111
PARAMETER
DVDD Input Supply Voltage
DVDD Quiescent Current
DVDD UVLO Level
LTC3676 Device Address
LTC3676-1 Device Address
SDA/SCL Input Threshold Rising
SDA/SCL Input Threshold Falling
SDA/SCL High Input Current
SDA/SCL Low Input Current
SDA Output Low Voltage
Clock Operating Frequency
Bus Free Time Between Stop and Start
Condition
Hold Time After Repeated Start Condition
Repeated Start Condition Setup Time
Stop Condition Setup Time
Data Hold Time Output
Data Hold Time Input
Data Setup Time
SCL Clock Low Period
SCL Clock High Period
Clock/Data Fall Time
Clock/Data Rise Time
Input Spike Suppression Pulse Width
2.7
2.8
2.9
3.0
3.1
3.2
3.3
3.4
CONDITIONS
MIN
l
1.6
SCL/SDA = 0kHz
SDA = SCL = 5.5V
SDA = SCL = 0V
ISDA = 3mA
TYP
–1
–1
0.3
1
0111100[R/W]
0111101[R/W]
70
30
0
0
V
V
V
V
V
V
V
V
MAX
5.5
1
1
1
0.4
400
1.3
CB = Capacitance of BUS Line (pF)
CB = Capacitance of BUS Line (pF)
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 LTC3676 is tested under pulsed load conditions such that
TJ ≈ TA. The LTC3676E is guaranteed to meet specifications from
0°C to 85°C junction temperature. Specifications over the –40°C to
125°C operating junction temperature range are assured by design,
characterization and correlation with statistical process controls. The
LTC3676I is guaranteed over the –40°C to 125°C operating junction
temperature range and the LTC3676H is guaranteed over the full –40°C to
150°C operating junction temperature range. High junction temperatures
0.6
0.6
0.6
0
0
100
1.3
0.6
20 + 0.1CB
20 + 0.1CB
900
300
300
50
UNITS
V
µA
V
%DVDD
%DVDD
µA
µA
V
kHz
µs
µs
µs
µs
ns
ns
ns
µs
µs
ns
ns
ns
degrade operating lifetimes; operating lifetime is derated for junction
temperatures greater than 125°C. The junction temperature (TJ in °C) is
calculated from the ambient temperature (TA in °C) and power dissipation
(PD, in Watts), and package to junction ambient thermal impedance
(JA in Watts/°C ) according to the formula:
TJ = TA + (PD • JA).
Note that the maximum ambient temperature consistent with these
specifications is determined by specific operating conditions in
conjunction with board layout, the rated package thermal impedance and
other environmental factors.
Rev. G
For more information www.analog.com
7
LTC3676/LTC3676-1
ELECTRICAL CHARACTERISTICS
Note 3: The LTC3676 includes overtemperature protection that is intended
to protect the device during momentary overload conditions. Junction
temperature will exceed 150°C when overtemperature protection is active.
Continuous operation above the specified maximum operating junction
temperature may impair device reliability.
Note 4: Dropout voltage is defined as (VIN – VLDO1) for LDO1 or
(VIN_Lx – VLDOx) for other LDOs when VLDOx is 3% lower than VLDOx
measured with VIN = VIN_Lx = 4.3V.
Note 5: Dynamic supply current is higher due to the gate charge being
delivered at the switching frequency.
Note 6: Soft-Start measured in test mode with regulator error amplifier in
unity-gain mode.
Note 7: The switching regulator PMOS and NMOS on-resistance is
guaranteed by correlation to wafer level measurements.
TYPICAL PERFORMANCE CHARACTERISTICS
Standby IVIN vs VIN
Step-Down Switching Regulator
IVIN vs VIN
LDO2 to LDO4 IVIN vs VIN
16
900
250
ENABLE 3 LDOs
14
8
6
4
ENABLE 2 LDOs
150
ENABLE 1 LDO
100
ENABLE ONE BUCK
100
3.5
4.0
4.5
5.0
0
2.50
5.5
4.50
3.50
1200
Burst Mode OPERATION
VIN CURRENT (µA)
ENABLE TWO BUCKS
ENABLE ONE BUCK
60
40
Oscillator Frequency
vs Temperature
2.30
ALL REGULATORS ENABLED
2.25
800
600
400
Burst Mode OPERATION
3.0
3.5
4.0
4.5
VOLTAGE (V)
5.0
5.5
0
–50
2.20
2.15
2.10
2.05
200
20
2.5
5.5
PULSE-SKIPPING
ENABLE THREE BUCKS
80
5.0
3676 G03
1000
ENABLE FOUR BUCKS
120
3.5
4.0
4.5
VOLTAGE (V)
3.0
3676 G02
Input Supply Current
vs Temperature
160
100
2.5
VIN (V)
Step-Down Switching Regulator
IVIN vs VIN
140
0
5.50
FREQUENCY (MHz)
3.0
3676 G01
IVIN (µA)
400
200
VOLTAGE (V)
STANDBY
0
100
50
TEMPERATURE (°C)
150
3676 G05
3676 G04
8
ENABLE TWO BUCKS
500
300
50
0
2.5
0
ENABLE THREE BUCKS
600
2
180
ENABLE FOUR BUCKS
700
IVIN (µA)
VIN CURRENT (µA)
10
PULSE-SKIPPING MODE
800
200
12
IVIN (µA)
VIN = 3.8V, TA = 25°C unless otherwise noted
2.00
–50
0
50
100
TEMPERATURE (°C)
150
3676 G06
Rev. G
For more information www.analog.com
LTC3676/LTC3676-1
TYPICAL PERFORMANCE CHARACTERISTICS
Oscillator Frequency Change
vs VIN
100
0.4
90
90
80
80
BURST
70
EFFICIENY (%)
PERCENT CHANGE (%)
0.6
100
0.2
0
–0.2
60
PULSE
SKIPPING
50
40
FORCED
CONTINUOUS
30
–0.4
3.5
3.0
4.0
4.5
5.0
0
5.5
1
VIN (V)
1
1000
100
10
LOAD CURRENT (mA)
3676 G09
Buck RDS(ON) vs VIN
200
250
VIN = 3.3V
90 PULSE-SKIPPING MODE
180
VOUT = 1.2V
50
40
BUCK 1, 2 PMOS
150
BUCK 3, 4 PMOS
BUCK 1, 2 NMOS
100
30
BUCK 3, 4 PMOS
120
100
BUCK 1, 2 NMOS
80
BUCK 3, 4 NMOS
60
BUCK 3, 4 NMOS
50
20
140
RDS(ON) (mΩ)
VOUT = 2.5V
BUCK 1, 2 PMOS
160
200
RDS(ON) (mΩ)
EFFICIENY (%)
VIN = 5V
VOUT = 1.2V
0
Buck RDS(ON) vs Temperature
100
60
FORCED
CONTINUOUS
3676 G08
Step-Down Switching Regulators 3
and 4 Efficiency vs IOUT
70
40
10
1000
100
10
LOAD CURRENT (mA)
3676 G07
80
PULSE
SKIPPING
50
20
VIN = 3.3V
VOUT = 1.2V
10
–0.8
2.5
60
30
20
–0.6
BURST
70
EFFICIENY (%)
0.8
40
20
10
0
Step-Down Switching Regulators 1
and 2 Efficiency vs IOUT
Step-Down Switching Regulators 1
and 2 Efficiency vs IOUT
100
10
LOAD CURRENT (mA)
1
0
–50
1000
0
50
100
TEMPERATURE (°C)
150
3676 G10
0
VIN (V)
3676 G12
3676 G11
Step-Down Switching Regulator
Current Limit vs Temperature
5.5
4.5
3.5
2.5
LTC3676-1 VDDQIN, VTTR and
VTT Start-Up
Step-Down Switching Regulator
Load Step
4.5
CURRENT (A)
PGOOD
5V/DIV
BUCK 3, 4
4.0
VDDQIN
1V/DIV
3.5
500mA/DIV
VTT (BUCK1)
1V/DIV
2.5
2.0
1.5
–50
ILOAD = 0.5A TO 1.5A
VTTR
1V/DIV
BUCK 1, 2
3.0
400µs/DIV
0
50
100
TEMPERATURE (°C)
VOUT = 1.2V
100mV/DIV
3676 G14
COUT = 44µF
10µs/DIV
3676 G15
150
3676 G13
Rev. G
For more information www.analog.com
9
LTC3676/LTC3676-1
TYPICAL PERFORMANCE CHARACTERISTICS
LDO1 Dropout Voltage
vs Temperature
400
LTC3676-1
ILOAD = –1.2A TO 1.2A
1A/DIV
COUT = 88µF
80
ILDO1 = 25mA
350
VTT = 0.75V
DROPOUT VOLTAGE (mV)
100mV/DIV
LDO1 Short-Circuit Current
vs Temperature
LDO1 SHORT-CIRCUIT CURRENT (mA)
LTC3676-1 VTT Load Step
40µs/DIV
VLDO1 = 1.8V
300
250
VLDO1 = 3.3V
200
150
100
3676 G16
50
0
–55
0
50
70
65
60
55
50
45
40
–55
150
100
TEMPERATURE (°C)
75
0
50
100
TEMPERATURE (°C)
3676 G17
450
ILDO = 200mA
400
DROPOUT VOLTAGE (mV)
1.2V
20mA
ILDO1
10mA/DIV
3676 G18
LDO2 to LDO4 Dropout Voltage
vs Temperature
LDO1 Load Step Response
VLDO1
50mV/DIV
1mA
40µs/DIV
150
3676 G19
VLDO = 1.2V
350
300
VLDO = 1.8V
250
200
VLDO = 3.3V
150
100
50
0
–50
0
50
100
TEMPERATURE (°C)
150
3676 G20
LDO2 to LDO4 Short-Circuit
Current vs Temperature
LDO2 to LDO4 Load Step Response
LDO SHORT-CIRCUIT CURRENT (mA)
800
750
700
50mV/DIV
VLDO = 1.8V
650
600
ILOAD = 220mA
550
100mA/DIV
500
10mA
450
400
10µs/DIV
350
300
–50
0
50
100
TEMPERATURE (°C)
3676 G22
150
3676 G21
10
Rev. G
For more information www.analog.com
LTC3676/LTC3676-1
PIN FUNCTIONS
(QFN/LQFP)
FB_L2 (Pin 1/Pin 2): Feedback Input for LDO2. Set fullscale output voltage using a resistor divider connected
from LDO2 to this pin to ground.
SW4 (Pin 11/Pin 14): Switch Pin for Step-Down Switching Regulator 4. Connect one side of step-down switching
regulator 4 inductor to this pin.
VIN_L2 (Pin 2/Pin 3): Power Input for LDO2. This pin
should be bypassed to ground with a 1μF or greater
ceramic capacitor.Voltage on VIN_L2 should not exceed
voltage on VIN pin.
DVDD (Pin 12/Pin 15): Supply Voltage for I2C Serial Port.
This pin sets the logic reference level of SCL and SDA I2C
pins. DVDD resets I2C registers to power-on state when
driven to
工商网监
湘ICP备2023018690号
