Linear Analog Devices DC2985A User manual
1
DEMO MANUAL DC2985A
Rev. 0
1
Rev. 0
DESCRIPTION
LT3380
Multi-Output Power Management Solution with 4 Buck
Switching and 3 LDO Linear Regulators with I2C
DC2985A is a multi-output power management solution
demonstration circuit, featuring the LT
®
3380. It contains
two 2.5A, two 1.5A synchronous step-down DC/DC regu-
lators and three 300mA LDO regulators.
All regulators can be enabled with external enable pins.
After the first regulator is enabled, the remaining enable
pins use a precision threshold to allow hardwire-pro-
grammed Power-Up Sequence.
All registered trademarks and trademarks are the property of their respective owners.
PERFORMANCE SUMMARY
BOARD PHOTO
A micro-USB communication interface is integrated on
board to allow software GUI to write or read the registers
in LT3380 via its I
2
C serial port. This GUI can control
regulator enables, power-down sequencing, output volt-
age levels, dynamic voltage scaling, operation modes,
status reporting and other special functions.
Refer to LT3380 data sheet for more details on the electri-
cal specifications and the setting of its command registers.
Design files for this circuit board are available.
Specifications are at TA= 25°C
Figure1. DC2985A Board Photo
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
VIN Input Voltage Range 2.7 5.5 V
VBUCK1 BUCK1 Output Voltage BUCK1 Enabled, I(BUCK1) = 0A ~ 2.5A 1.20 V
VBUCK2 BUCK2 Output Voltage BUCK2 Enabled, I(BUCK2) = 0A ~ 2.5A 1.50 V
VBUCK3 BUCK3 Output Voltage BUCK3 Enabled, I(BUCK3) = 0A ~ 1.5A 2.48 V
VBUCK4 BUCK4 Output Voltage BUCK4 Enabled, I(BUCK4) = 0A ~ 1.5A 1.81 V
VLDO1 LDO1 Output Voltage LDO1 Enabled, I(LDO1) = 0A ~ 300mA 1.20 V
VLDO2 LDO2 Output Voltage LDO2 Enabled, I(LDO2) = 0A ~ 300mA 0.80 V
VLDO3 LDO3 Output Voltage LDO3 Enabled, I(LDO3) = 0A ~ 300mA 1.80 V
2
DEMO MANUAL DC2985A
Rev. 0
EFFICIENCY CURVES
Specifications are at TA= 25°C, fSW = 2.25MHz, VIN = 5V, without D1
BURST
PULSE
SKIPPING
FORCE
CONTINUOUS
LOAD CURRENT (mA)
1
10
100
1000
0
10
20
30
40
50
60
70
80
90
100
EFFICIENCY (%)
dc2985a G01
BURST
PULSE
SKIPPING
FORCE
CONTINUOUS
LOAD CURRENT (mA)
1
10
100
1000
0
10
20
30
40
50
60
70
80
90
100
EFFICIENCY (%)
dc2985a G02
BURST
PULSE
SKIPPING
FORCE
CONTINUOUS
LOAD CURRENT (mA)
1
10
100
1000
0
10
20
30
40
50
60
70
80
90
100
EFFICIENCY (%)
dc2985a G03
BURST
PULSE
SKIPPING
FORCE
CONTINUOUS
LOAD CURRENT (mA)
1
10
100
1000
0
10
20
30
40
50
60
70
80
90
100
EFFICIENCY (%)
dc2985a G04
BUCK1 1.2VOUT Efficiency BUCK2 1.5VOUT Efficiency
BUCK3 2.48VOUT Efficiency BUCK4 1.81VOUT Efficiency
3
DEMO MANUAL DC2985A
Rev. 0
TRANSIENT RESPONSE
Specifications are at TA= 25°C, fSW = 2.25 MHz, VIN = 5V
1.5A
100mA
BURST
PULSE SKIPPING
FORCE CONTINUOUS
50µs/DIV
I
OUT
2A/DIV
V
OUT
200mV/DIV
V
OUT
200mV/DIV
V
OUT
200mV/DIV
dc2985a G07
1.5A
100mA
BURST
PULSE SKIPPING
FORCE CONTINUOUS
50µs/DIV
I
OUT
2A/DIV
V
OUT
200mV/DIV
V
OUT
200mV/DIV
V
OUT
200mV/DIV
dc2985a G08
300mA
5mA
LDO1
LDO2
LDO3
50µs/DIV
V
OUT
2A/DIV
V
OUT
200mV/DIV
V
OUT
200mV/DIV
V
OUT
200mV/DIV
dc2985a G09
BUCK3 2.48VOUT Transient Response BUCK3 1.81VOUT Transient Response
LD01-LD03 Transient Response
2.5A
100mA
BURST
PULSE SKIPPING
FORCE CONTINUOUS
50µs/DIV
I
OUT
2A/DIV
V
OUT
200mV/DIV
V
OUT
200mV/DIV
V
OUT
200mV/DIV
dc2985a G05
2.5A
100mA
BURST
PULSE SKIPPING
FORCE CONTINUOUS
50µs/DIV
I
OUT
2A/DIV
V
OUT
200mV/DIV
V
OUT
200mV/DIV
V
OUT
200mV/DIV
dc2985a G06
BUCK1 1.2VOUT Transient Response BUCK2 1.5VOUT Transient Response
4
DEMO MANUAL DC2985A
Rev. 0
POWER UP SEQUENCE
Specifications are at TA= 25°C, fSW = 2.25MHz, VIN = 5V, IOUT = 100mA for all regulators
500µs/DIV
V
LDO3
V
LDO1
V
BUCK4
V
BUCK1
V
BUCK3
V
BUCK2
V
LDO2
V
PWR_ON
dc2985a G10
Regulators Power-Up Sequencing
QUICK START PROCEDURE
Follow the procedure below to familiarize yourself with
the DC2985A.
1. Refer to Figure2, configure the jumpers on the demo
board as follows:
JP1 = VIN
JP2 = VIN
JP3 = VIN
JP4-JP10 = DFT
JP11 = ON
JP13 = ON
2. Set PS1 to 5V, with 5A current limit. Turn on PS1. All
the regulators should come up in a default sequence:
B2 & B3 -> L2 -> B1 & B4 -> L1 & L3
3. The PGOOD LED D2 should stay off, indicating all out-
puts are in regulation. Check the output voltage of all
the regulators, they should read close to the following
values:
VVM1 = 1.2V
VVM2 = 1.5V
VVM3 = 2.48V
VVM4 = 1.81V
VVM5 = 1.2V
VVM6 = 0.8V
VVM7 = 1.8V
4. Set each electronic load to its corresponding current
level indicated in Figure2. Turn on each load. The
PGOOD LED D2 should stay off, indicating all the out-
puts are still in regulation under loads. Note that if there
are not enough electronic loads for all the regulators,
this test can be done sequentially.
5. Optional:The default input of the three LDOs are from
VIN. To increase the efficiency, the LDOs can be pow-
ered from BUCK3 by configuring JP1 to JP3 to V(B3).
They can also be powered from external source by
configuring these jumpers to EXT.
6. Optional:The power up sequence can also be pro-
grammed by configuring JP4 to JP10 to PGM/OFF.
Connect the SEQ_START to the EN_SEQ of the first
regulators to power up. Then connect the subsequent
regulators EN_SEQ to the corresponding VX_SEQ
according to the desired startup sequence. If EN_SEQ
of a regulator is not connected and the jumper is on
PGM/OFF position, this regulator is turned off.
5
DEMO MANUAL DC2985A
Rev. 0
JUMPER DESCRIPTION
JUMPER NAME FUNCTION POSITION DESCRIPTION
JP1-JP3 LDOXVIN Input for the LDOs V(B3) Input from BUCK3
EXT Input from External Source Connected to VIN_LDOXTurret
VIN Input from VIN Turret
JP4-JP10 BX_SEQ or
LX_SEQ
Power Up Sequence for the Regulators DFT Default Power Up Sequence
PGM/OFF Programmed Sequence/Regulator Off
JP12 PGOOD_LED Power On Master Enable and Disable
Status Selection
ON PWR_ON Allows Enable Pin Operation
OFF PWR_ON Inhibits Enable Pin Operation
JP13 PWR_ON_CTRL Enable/Disable Power Good LED
Indicator (Indicating Output not in
Regulation)
ON Power Good LED Indicator Enabled
EXT PWR_ON Status Controlled by External Source Connected to
PWR_ON Turret
OFF Power Good LED Indicator Disabled
7
DEMO MANUAL DC2985A
Rev. 0
DEMO CIRCUIT OPERATION
Introduction to the DC2984A
The DC2985A a multi-output power management solu-
tion with I2C interface featuring the LT3380. It contains
four synchronous buck regulators and three LDO regula-
tors. Among the four buck regulators, BUCK1 and BUCK2
deliver up to 2.5A output current, while BUCK3 and BUCK4
deliver up to 1.5A output current. All three LDOs deliver
up to 300mA output current. BUCK1-BUCK4 have default
output voltages of 1.2V, 1.5V, 2.48V and 1.81V, respec-
tively. LDO1 and LDO2 have default output voltages of
1.2V and 0.8V respectively. These voltages are configured
by voltage dividers on the corresponding FB pins and can
be changed by the user. LDO3 has a fixed voltage of 1.8V.
The DC2985A also contains an isolated USB transceiver
and a micro-controller, allowing computer-based software
GUI to read/write the registers defined in the LT3380 via
its I2C serial port. User can control regulator enables,
power-down sequencing, output voltage levels, dynamic
voltage scaling, operating modes and status reporting.
Power Up Sequencing
The LT3380 regulators can be powered up in any desired
order by pin-strapping output rails to enable pins. The
enable pins have a 0.75V (typical) input voltage threshold.
If any enable is driven high, the remaining enable input
thresholds switch to an 400mV threshold. There is a built-
in 450µs delay from the enable pin threshold crossing to
the internal enable of the regulator.
The DC2985A has a default power up sequence. User
can also program the power up sequence by selecting
JP4-JP10 to PGM/OFF position and connecting the out-
put rails to the enable pins at the Power Up Sequence
Programming Section shown in Figure2. The start of the
sequence is the rising edge of the PWR_ON pin. PWR_ON
pin can be pulled up to VIN, pulled down to ground, or
connected to an external command source by selection
JP13, PWR_ON_CTRL jumper.
Figure3 illustrates BUCKX voltage when BUCK1-BUCK4
is programmed to start in an ascending order. The demo
board connection is shown as follows:
SEQ_START -> EN_B1_SEQ
VB1_SEQ -> EN_B2_SEQ
VB2_SEQ -> EN_B3_SEQ
VB3_SEQ -> EN_B4_SEQ
1ms/DIV
dc2985a F03
V
PWR_ON
5V/DIV
V
BUCK1
2V/DIV
V
BUCK2
2V/DIV
V
BUCK3
2V/DIV
V
BUCK4
2V/DIV
Figure3. Program BUCK1-BUCK4 Power Up
Sequence in Ascending Order
Regulator Enables
When JP4-JP10 is at PGM/OFF position, and no connec-
tion is made at the Power Up Sequence Programming
Section, all the regulators are disabled. Each regulator
can be individually enabled by its corresponding enable
turret at the edge of the demo board.
LDO Input Selection
The default input of each LDO is the general input of the
demo circuit, VIN. To reduce power loss of the LDOs, the
input source of each LDO can be changed to the output
of BUCK3 by connection corresponding LDOXVIN jumper
to V(B3). Each LDO can also be powered externally by
selecting the corresponding LDOXVIN jumper to EXT and
connecting a separate source to VIN_LDOX turret. Note
that the voltage of this external LDO source must not
exceed voltage.
Power Good Indicator
Power Good LED D2 is turned on when PGOOD pin on
LT3383 is pulled low. It indicates the one or more output
voltages of the enabled regulators are low. It will also be
on when no regulator is enabled.
8
DEMO MANUAL DC2985A
Rev. 0
Install the LT3380 GUI
The LT3380 GUI can be downloaded from Analog.com or
using QuickEval software. Double click the LT3380 GUI
installer ins3380.exe. A window as shown in Figure 4
will pop up. Select I accept the agreement and then click
Next to start the installation. The GUI application will be
installed at the following location:
C:\Program Files (x86)\LT C \LT3380 GUI
Start the LT3380 GUI
The LT3380 GUI applicaiotn should show up in the Recen-
tely added section when clicking the Windows button.
Before starting the GUI, please make sure that DC2985A is
connected to the PC with micro-USB cable. Click LT3380
GUI to start the GUI application. If LT3380 GUI cannot be
found in the Recentely added section, go to the LTC3380
GUI folder and double click em.3380.exe to start the GUI.
If DC2985A is powered up and successfully connected to
the PC with a micro-USB cable, the Dashboard of the GUI
will pop up, as shown in Figure6
USING LT3380 GUI
Figure4. License Agreement Window in GUI
Installation Process
Figure5. Completing Installation Window
Figure6. LT3380 GUI Dashboard Tab
Figure7. LT3380 GUI Engineering Tab
When the software is succefully installed, a window as
shown in Figure 5 will pop up. Click Finish to complete
the installation.
In this Dashboard tab, user can control the basic setups
of the regulators.
To get access to all the registers and change some
advanced setups of the regulators, click the Engineer-
ing tab next to the Dashboard tab. Figure7 shows the
LTC3380 Engineering tab.
9
DEMO MANUAL DC2985A
Rev. 0
To change the register setup, right click on the register,
and click Write Preset, then select the desired register
status. Figure8 shows an example of setting the register
to mask overtemperature warning.
The default setting of the Engineering tab is reading the
registers continuously. User can change this setting by
right click in the main window. User can also hide the
registers that are not used by clicking the checkbox in
the Categories section. Detailed description for all the
features in the GUI is in Window ->Show Help Guide on
the top left corner of the GUI.
Figure8. Changing Register Setup in Engineering Tab
USING LT3380 GUI
10
DEMO MANUAL DC2985A
Rev. 0
PARTS LIST
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
Required Circuit Components
1 5 C1, C8-C11 CAP., 10μF, X5R, 10V, 20%,0603, AEC-Q200 TAIYO YUDEN, LMK107BBJ106MAHT
2 6 C2-C7 CAP., 1μF, X5R, 25V, 10%, 0402, AEC-Q200 MURATA, GRT155R61E105KE01D
3 4 C12, C15, C17, C19 CAP., 47μF, X5R, 6.3V, 20%, 0805, AEC-Q200 MURATA, GRT21BR60J476ME13L
4 4 C14, C16, C18, C20 CAP., 10pF, C0G, 50V, 5%, 0402, AEC-Q200 MURATA, GCM1555C1H100JA16D
5 1 C21 CAP., 0.1μF, X7R, 16V, 10%, 0402, AEC-Q200 MURATA, GCM155R71C104KA55D
6 2 L1, L2 IND., 0.82μH, PWR, 20%, AEC-Q200 COILCRAFT, XGL4020-821MEC
7 2 L3, L4 IND., 1.5μH, PWR, 20%, AEC-Q200 COILCRAFT, XGL4020-152MEC
8 2 Q1, Q2 XSTR., NPN, 40V, 200MA, SOT23-3 ON SEMICONDUCTOR, MMBT3904LT1G
9 1 R1 RES., 102k, 1%,1/16W, 0402, AEC-Q200 STACKPOLE ELECTRONICS, INC., RMCF0402FT102K
10 6 R2, R4, R6, R9, R13, R16
11 2 R3, R15 RES., 649k, 1%,1/16W, 0402 NIC, NRC04F6493TRF
12 4 R5, R8, R11, R14 RES., 20Ω, 1%,1/16W, 0402, AEC-Q200 NIC, NRC04F20R0TRF
13 1 R7 RES., 665k, 1%, 1/16W, 0402, AEC-Q200 NIC, NRC04F6653TRF
14 1 R10 RES., 412k, 1%, 1/16W, 0402 NIC, NRC04F4123TRF
15 1 R12 RES., 1.07M, 1%, 1/16W, 0402, AEC-Q200 VISHAY, CRCW04021M07FKED
16 10 R17, R18, R20-R26, R76 RES., 10k, 5%, 1/16W, 0402, AEC-Q200 NIC, NRC04J103TRF
17 2 R27, R28 RES., 4.7k, 5%, 1/16W, 0402, AEC-Q200 NIC, NRC04J472TRF
18 2 R30, R31 RES., 1k, 5%, 1/16W, 0402, AEC-Q200 NIC, NRC04J102TRF
19 8 R33-R39, R61 RES., 10k, 1%, 1/16W, 0402, AEC-Q200 VISHAY, CRCW040210K0FKED
20 7 R40-R46 RES., 10k, 1%,1/10W, 0603, AEC-Q200 PANASONIC, ERJ3EKF1002V
21 7 R54-R60 RES., 5.11M, 1%, 1/10W, 0603, AEC-Q200 VISHAY, CRCW06035M11FKED
22 2 R62,R75 RES., 100k, 5%, 1/16W, 0402, AEC-Q200 NIC, NRC04J104TRF
23 1 U1 IC, MULTI-OUTPUT POWER, 40-PIN ANALOG DEVICES, LT3380EUJM
Additional Demo Board Circuit Components
1 2 C22, C23 CAP., 22pF, NP0, 50V, 5%, 0402 WURTH ELEKTRONIK, 885012005057
2 2 C24, C31 CAP., 1μF, JB, 10V, 20%, 0402 TDK, CGB2A1JB1A105M033BC
3 1 C25 CAP., 2.2μF, X5R, 10V, 20%, 0402 WURTH ELEKTRONIK, 885012105013
4 1 C26 CAP., 10μF, X5R, 6.3V, 20%, 0603 MURATA, GRM188R60J106ME47D
5 4 C27-C30 CAP., 0.1μF, X5R, 10V, 20%, 0402 WURTH ELEKTRONIK, 885012105010
6 1 C32 CAP., 0.01μF, X7R, 25V, 10%, 0402 WURTH ELEKTRONIK, 885012205050
7 2 D1, D2 LED, RED, WATER CLEAR, 0603 WURTH ELEKTRONIK, 150060RS75000
8 1 D3 LED, BRIGHT GREEN, WATERCLEAR, 0603 WURTH ELEKTRONIK, 150060VS75000
9 1 D4 LED, YELLOW, WATERCLEAR, 0603 WURTH ELEKTRONIK, 150060YS75000
10 1 L5 IND., CHIP BEAD, 6A,0.01Ω, L-MPZ2012 TDK, MPZ2012S300AT000
11 3 M1-M3 XSTR., MOSFET, DUAL N-CH, 0.28A, SOT-563 DIODES INC., 2N7002VAC-7
11
DEMO MANUAL DC2985A
Rev. 0
PARTS LIST
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
12 3 R71, R72, R74 RES., 4.7k, 5%,1/16W, 0402, AEC-Q200 NIC, NRC04J472TRF
13 1 R63 RES., 115k, 1%, 1/10W, 0603 NIC, NRC06F1153TRF
14 1 R64 RES., 1Ω, 5%,1/16W, 0402, AEC-Q200 KOA SPEER, RK73B1ETTP1R0J
15 3 R65-R67 RES., 301Ω, 1%, 1/10W, 0603, AEC-Q200 PANASONIC, ERJ3EKF3010V
16 2 R68, R69 RES., 2.2k, 5%,1/16W, 0402, AEC-Q200 VISHAY, CRCW04022K20JNED
17 1 R70 RES., 1M, 5%, 1/16W, 0402, AEC-Q200 VISHAY, CRCW04021M00JNED
18 1 R73 RES., 10k, 5%, 1/16W, 0402 SAMSUNG, RC1005J103CS
19 1 U2 IC, USB 2.0 μModule TRANSCEIVER, BGA-44 ANALOG DEVICES, LTM2884CY
20 1 U3 IC, MEMORY, MCU, 32BIT, 256KB FLASH, TQFP48 MICROCHIP, ATSAMD21G18A-AUT
21 1 U4 IC,REG LDO ADJ, 100mA, TSOT23-5 ANALOG DEVICES, LT1761ES5-BYP
22 1 Y1 CRYSTAL, 32.768kHz, 12.5pF, 3.2x1.5mm SMD ABRACON, ABS07-32.768KHZ-4-T
Hardware: For Demo Board Only
1 17 E1, E2, E4, E5, E7, E8,
E10-E12, E23-E30
TEST POINT, TURRET, 0.094" MTG. HOLE, PCB
0.062" THICK
MILL-MAX, 2501-2-00-80-00-00-07-0
2 13 E3, E6, E9, E13-E22 TEST POINT, TURRET, 0.064" MTG. HOLE, PCB
0.062" THICK
MILL-MAX, 2308-2-00-80-00-00-07-0
3 1 J1 CONN., uUSB 2.0, RCPT., 5-PIN, 1PORT,REVERSE
MOUNT, R/A HORZ., TYPE B, FLANGELESS
TE CONNECTIVITY, 1932788-1
4 1 J2 CONN., HDR, MALE, 2x5, 1.27mm, VERT, ST, THT WURTH ELEKTRONIK, 62201021121
5 1 J3 CONN., HDR, MALE, 1x5, 2.54mm, VERT, ST, THT SAMTEC, TSW-105-07-L-S
6 4 JP1-JP3, JP11 CONN., HDR., MALE, 1x4, 2mm, THT, STR SULLINS CONNECTOR SOLUTIONS,
7 8 JP4-JP10, JP12 CONN., HDR, MALE, 1x3, 2mm, VERT, STR, THT WURTH ELEKTRONIK, 62000311121
8 4 MP1-MP4 STANDOFF, NYLON, SNAP-ON, 0.25" (6.4mm) KEYSTONE, 8831
9 12 XJP1-XJP12 CONN., SHUNT, FEMALE, 2 POS, 2mm WURTH ELEKTRONIK, 60800213421
12
DEMO MANUAL DC2985A
Rev. 0
SCHEMATIC DIAGRAM
5
5
4
4
3
3
2
2
1
1
D D
C C
B B
A A
300mA
IRQ
ON
5A
NOTES: UNLESS OTHERWISE SPECIFIED -
ALL RESISTORS ARE ±1%, 0402
ALL CAPACITORS ARE ±10%, 50V, 0402
ALL INDUCTORS ARE ±20%
0.80V
2.35V - VIN
1.7V - VIN
300mA
LDO3VIN
EXT
OFF
1.20V
300mA
VIN
EXT
1.80V
LDO2VIN
2.7V - 5.5V
VIN
I2C/OFF
ON
EXT
VIN
LDO1VIN
1.7V - VIN
EXT
PWR_ON_CTRL
V(B3)
V(B3)
V(B3)
PRODUCTION
0303 WL
DESCRIPTION DATEREV
REVISION HISTORY
ECO APPROVED
12-19-19
PGOOD
INJ1
INJ2
INJ3
INJ4
VIN
GND
VIN_LDO2
V (LDO2)
GND
VIN_LDO3
V (LDO3)
GND
VIN_LDO1
GND
V (LDO1)
GND
EN_L1
IRQ
PGOOD
PWR_ON
EN_B4
EN_B3
EN_B2
EN_B1
EN_L2
EN_L3
1.03V-1.81V-2.00V
V (B4)
1.5A
GND
V (B3)
1.5A
1.41V-2.48V-2.74V
GND
0.85V-1.50V-1.66V
V (B2)
2.5A
GND
2.5A
GND
0.68V-1.20V-1.32V
V (B1)
PGOOD LED
SWITCHING AND 3 LDO LINEAR REGULATORS WITH I2C
MULTIOUTPUT POWER MANAGEMENT SOLUTION WITH 4 BUCK
VLDO1
SCL
SDA
VIN
VLDO2
VLDO3
DVDD
VIN
EN_L1
VBUCK4
VBUCK3
VBUCK2
VBUCK1
EN_B4
EN_B3
EN_B2
EN_B1
EN_L2
EN_L3
VIN
VIN VBUCK3
VIN VBUCK3
VIN VBUCK3
PWR_ON
PWR_ON
IRQ
DATE:
SHEET OF
TITLE: SCHEMATIC
APPROVALS
PCB DES.
APP ENG.
SIZE:
SCHEMATIC NO. AND REVISION:
CUSTOMER NOTICE
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A
CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS;
HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
www.analog.com
SKU NO.
IC NO.
12
NJC
WL
LT3380
DC2985A
710-DC2985A_REV03
N/A 12-19-19DATE:
SHEET OF
TITLE: SCHEMATIC
APPROVALS
PCB DES.
APP ENG.
SIZE:
SCHEMATIC NO. AND REVISION:
CUSTOMER NOTICE
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A
CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS;
HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
www.analog.com
SKU NO.
IC NO.
12
NJC
WL
LT3380
DC2985A
710-DC2985A_REV03
N/A 12-19-19DATE:
SHEET OF
TITLE: SCHEMATIC
APPROVALS
PCB DES.
APP ENG.
SIZE:
SCHEMATIC NO. AND REVISION:
CUSTOMER NOTICE
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A
CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS;
HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
www.analog.com
SKU NO.
IC NO.
12
NJC
WL
LT3380
DC2985A
710-DC2985A_REV03
N/A 12-19-19
C17
47uF
0805
20%
D2
RED
R27
4.7k
5%
E24
E10
R26 10k 5%
R24 10k 5%
C13
OPT
0805
E15
R7
665k
E28
R17 10k 5%
E8
C1
10uF
0603
E21
U1
LT3380-UJM
VIN
27
GND
41
FB_L1
8
SW1 11
GND
26
PVIN1 15
SCL
14
DVDD
12
SDA
13
PVIN2 16
FB_B1 23
SW2 20
FB_B2 22
PVIN3 35
SW3 31
FB_B3 25
PVIN4 36
SW4 40
FB_B4 24
EN_B1
17 EN_B2
18 EN_B3
34 EN_B4
37
GND
28
EN_L1
9
VIN_L2
2
EN_L2
30
LDO2
3
FB_L2
1
EN_L3
10
VIN_L3
5
LDO3
4
LDO1
6
GND
38
nIRQ
32
VIN_L1
7
GND
33
PGOOD
39
GND
19
PWR_ON
21
GND
29
R22 10k 5%
L3
1.5uH
XGL4020-152MEC
JP3
C10
10uF
0603
R18 10k 5%
TP1
L1
0.82uH
XGL4020-821MEC
E3
R20 10k 5%
C6
1uF
JP11
C14
10pF
5%
E19
C7
1uF
E18
E11
C18
10pF
5%
R13
1M
E7
E30
E25
TP4
E29
D1
RED
E9
R9
1M
E5
C15
47uF
0805
20%
E23
JP2
E14
R14
20
C8
10uF
0603
C2
1uF
R76 10k 5%
R11
20
C5
1uF
R25 10k 5%
JP12
R6
1M
R31
1k
5%
C11
10uF
0603
E20
C19
47uF
0805
20%
C4
1uF
R23 10k 5%
R8
20
R15
649k
E6
TP3
R3
649k
L4
1.5uH
XGL4020-152MEC R5
20
L2
0.82uH
XGL4020-821MEC
E22
E27
R10
412k
R29
5.1k
5%
R30
1k
5%
R21 10k 5%
C16
10pF
5%
E4
R12
1.07M
C9
10uF
0603
R4
1M
C3
1uF
C12
47uF
0805
20%
R75
100k
5%
E13
C20
10pF
5%
JP1
R16
1M
R62
100k
5%
R2
1M
C21
0.1uF
E12
E16
R1
102k
E2
E26
TP2
E17
R28
4.7k
5%
E1
13
DEMO MANUAL DC2985A
Rev. 0
Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog
Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications
subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
SCHEMATIC DIAGRAM
5
5
4
4
3
3
2
2
1
1
D D
C C
B B
A A
SDA
SCL
GND
DVDD
IRQ
COMM
STATUS
3.3V
5V
UNLESS OTHERWISE SPECIFIED
1. RESISTORS: OHMS, 0402, 1%, 1/16W
2. CAPACITORS: 0402, 10%, 10V
Close
to
J1.1
5V
PWR_ON - > B2 &B3 - > L2 - > B1 & B4 - > L1 & L3DEFAULT POWER UP SEQUENCE
DFT
PGM/OFF
DFT DFT DFT DFT DFT DFT
EN_B2
Move JP4-JP10 into the PGM/OFF position
and connect TP14-TP21 with TP5-TP11
to program the startup sequence.
EN_B3 EN_L2 EN_B4 EN_B1 EN_L3 EN_L1 VL1_SEQ VL2_SEQ VL3_SEQ VB1_SEQ VB2_SEQ VB3_SEQ VB4_SEQ SEQ_START
PGM/OFF PGM/OFF PGM/OFF PGM/OFF PGM/OFF PGM/OFF
I2C CONTROL
B3_SEQ B4_SEQ
B2_SEQ B1_SEQL2_SEQ L3_SEQ L1_SEQ
PCA ADDITIONAL PARTS
SWITCHING AND 3 LDO LINEAR REGULATORS WITH I2C
MULTIOUTPUT POWER MANAGEMENT SOLUTION WITH 4 BUCK
Vcc_MCU
Vcc_MCU
Vcc Vcc_MCU Vcc_MCU
Vcc_MCU
Vcc_MCU
VCCin
Vcc_MCU
Vcc
Vcc_MCU
SCL
SDA
DVDD
SDA
SCL
IRQ
IRQ
DVDD
VIN
PWR_ON VBUCK2 VLDO2 VBUCK1
EN_B2 EN_B3 EN_L2 EN_B4 EN_B1 EN_L3 EN_L1
VLDO1 VLDO2 VLDO3 VBUCK1 VBUCK2 VBUCK3 VBUCK4 VINPWR_ON
DATE:
SHEET OF
TITLE: SCHEMATIC
APPROVALS
PCB DES.
APP ENG.
SIZE:
SCHEMATIC NO. AND REVISION:
CUSTOMER NOTICE
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A
CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS;
HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
www.analog.com
SKU NO.
IC NO.
22
NJC
WL
LT3380
DC2985A
710-DC2985A_REV03
N/A 12-19-19DATE:
SHEET OF
TITLE: SCHEMATIC
APPROVALS
PCB DES.
APP ENG.
SIZE:
SCHEMATIC NO. AND REVISION:
CUSTOMER NOTICE
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A
CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS;
HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
www.analog.com
SKU NO.
IC NO.
22
NJC
WL
LT3380
DC2985A
710-DC2985A_REV03
N/A 12-19-19DATE:
SHEET OF
TITLE: SCHEMATIC
APPROVALS
PCB DES.
APP ENG.
SIZE:
SCHEMATIC NO. AND REVISION:
CUSTOMER NOTICE
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A
CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS;
HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
www.analog.com
SKU NO.
IC NO.
22
NJC
WL
LT3380
DC2985A
710-DC2985A_REV03
N/A 12-19-19
R57
5.11M
0603
R59
5.11M
0603
PCB1 PCB, DC2985A REV03
TP9 TP21TP15
JP7
13
2
TP20
JP9
13
2
C24
1uF
MP3 STANDOFF,NYLON,SNAP-ON,0.25" (6.4mm)
R56
5.11M
0603
U3
ATSAMD21G18A-AUT
PA0/XIN32/EIC/SCOM1PAD0/TC2
1
PA1/XOUT32/EIC/SCOM1PAD1/TC2
2
PA2/EIC/AIN0 3
PA3/EIC/REF/AIN1 4
GNDANA
5
VDDANA
6
PB8/EIC/AIN2/SCOM4PAD0/TC4 7
PB9/EIC/AIN3/SCOM4PAD1//TC4 8
PA4/EIC/REF/AIN4/SCOM0PAD0/TC0 9
PA5/EIC/AIN5/SCOM0PAD1/TC0 10
PA6/EIC/AIN6/SCOM0PAD2/TC1 11
PA7/EIC/AIN7/SCOM0PAD3/TC1 12
PA8/I2C/AIN16/SCOM2PAD0+/TC0 13
PA9/I2C/EIC/AIN17/SCOM2PAD1+/TC0 14
PA10/EIC/AIN18/SCOM2PAD2+/TC1 15
PA11/EIC/AIN19/SCOM2PAD3+/TC1 16
VDDIO1
17
GND1
18
PB10/EIC/SCOM4PAD2/TC5 19
PB11/EIC/SCOM4PAD3/TC5 20
PA12/I2C/EIC/SCOM2PAD0+/TC2 21
PA13/I2C/EIC/SCOM2PAD1+/TC2 22
PA14/XIN/EIC/SCOM2PAD2+/TC3 23
PA15/XOUT/EIC/SCOM2PAD3+/TC3 24
PA16/I2C/EIC/SCOM1PAD0+/TC2 25
PA17/I2C/EIC/SCOM1PAD1+/TC2 26
PA18/EIC/SCOM1PAD2+/TC3 27
PA19/EIC/SCOM1PAD3+/TC3 28
PA20/EIC/SCOM5PAD2+ 29
PA21/EIC/SCOM5PAD3+ 30
PA22/I2C/EIC/SCOM5PAD0+/TC4 31
PA23/I2C/EIC/SCOM5PAD1+/TC4 32
PA24/EIC/SCOM3PAD2+/TC5
33 PA25/EIC/SCOM3PAD3+/TC5
34
GND2
35
VDDIO2
36
PB22/EIC/SCOM5PAD2 37
PB23/EIC/SCOM5PAD3 38
PA27/EIC
39
40
RESETN
PA28/EIC 41
GND3
42
VDDCORE1
43
VDDIN
44
PA30/EIC/SCOM1PAD2/TC1 45
PA31/EIC/SCOM1PAD3/TC1 46
PB2/EIC/AIN10/SCOM5PAD0 47
PB3/EIC/AIN11/SCOM5PAD1
48
C23
22pF
50V
5%
J3
1
2
3
4
5
R44
10K
0603
C32
0.01uF
TP7
R41
10K
0603
TP18
R68
2.2k
5%
R74 4.7k
5%
R36
10k
U4
LT1761-S5-BYP
IN
1
GND
2
BYP 3
ADJ 4
OUT 5
TP14
R38
10k
R70
1M
5%
R45
10K
0603
R55
5.11M
0603
STNCL1 TOOL, STENCIL, 700-DC2985A REV03
TP5
R65
301
0603
R35
10k
LB1 BOARD S/N LABEL
TP19
R33
10k
C31
1uF
D4
YELLOW
C29
0.1uF
R64
1
5%
R71 4.7k
5%
Q1
MMBT3904LT1G
32
1
R67
301
0603
TP10
JP4
13
2
C27
0.1uF
TP13
R40
10K
0603
C26
10uF
6.3V
0603
M1B
2N7002VAC-7
JP6
13
2
C25
2.2uF
JP8
13
2
JP10
13
2
TP8
U2
LTM2884-BGA
D1+
A2
D1-
A1
SPND-PWR
A3
ON
A4
VLO
A5
GND
B1
GND
B2
GND
B3
GND
B4
GND
B5
GND
B6
GND
B7
GND
B8
GND
B9
GND
B10
GND
B11
GND2 K1
GND2 K2
GND2 K3
GND2 K4
GND2 K5
GND2 K6
GND2 K7
GND2 K8
GND2 K9
GND2 K10
GND2 K11
GND2 L3
GND2 L4
GND2 L6
GND2 L7
GND
A6
VBUS
A7
VCC
A8 VCC
A9 VCC
A10 VCC
A11
D2- L1
D2+ L2
VLO2 L5
VCC2 L8
VCC2 L9
VCC2 L10
VCC2 L11
R46
10K
0603
MP2 STANDOFF,NYLON,SNAP-ON,0.25" (6.4mm)
R63
115k
0603
MP4 STANDOFF,NYLON,SNAP-ON,0.25" (6.4mm)
M1A
2N7002VAC-7
R19
196k
0603
J2
1 2
3
5 6
4
7 8
109
R42
10K
0603
C22
22pF
50V
5%
R69
2.2k
5%
M3A
2N7002VAC-7
MP1 STANDOFF,NYLON,SNAP-ON,0.25" (6.4mm)
R37
10k
TP6 TP17
M3B
2N7002VAC-7
Y1
32.768kHz
1 2
R61
10k
R39
10k
R43
10K
0603
TP11
M2B
2N7002VAC-7
R72 4.7k
5%
C30
0.1uF
R34
10k
L5
30 OHMS@100MHz
1 2
M2A
2N7002VAC-7
R66
301
0603
R58
5.11M
0603
R60
5.11M
0603
TP12
D3
GREEN
C28
0.1uF
R51
OPT R52
OPT
Q2
MMBT3904LT1G
32
1
R47
OPT R53
OPT
J1
uUSB 2.0
1932788-1
VBUS 1
D- 2
D+ 3
ID 4
GND 5
GND
6GND
7
R48
OPT
TP16
R73 10k
5%
R49
OPT
JP5
13
2
R50
OPT
R54
5.11M
0603
RESETN
RESETN
14
DEMO MANUAL DC2985A
Rev. 0
ANALOG DEVICES, INC. 2020
05/20
www.analog.com
ESD Caution
ESD (electrostatic discharge) sensitive device. Charged devices and circuit boards can discharge without detection. Although this product features patented or proprietary protection
circuitry, damage may occur on devices subjected to high energy ESD. Therefore, proper ESD precautions should be taken to avoid performance degradation or loss of functionality.
Legal Terms and Conditions
By using the evaluation board discussed herein (together with any tools, components documentation or support materials, the “Evaluation Board”), you are agreeing to be bound by the terms and
conditions set forth below (“Agreement”) unless you have purchased the Evaluation Board, in which case the Analog Devices Standard Terms and Conditions of Sale shall govern. Do not use the Evaluation
Board until you have read and agreed to the Agreement. Your use of the Evaluation Board shall signify your acceptance of the Agreement. This Agreement is made by and between you (“Customer”)
and Analog Devices, Inc. (“ADI”), with its principal place of business at One Technology Way, Norwood, MA 02062, USA. Subject to the terms and conditions of the Agreement, ADI hereby grants to
Customer a free, limited, personal, temporary, non-exclusive, non-sublicensable, non-transferable license to use the Evaluation Board FOR EVALUATION PURPOSES ONLY. Customer understands and
agrees that the Evaluation Board is provided for the sole and exclusive purpose referenced above, and agrees not to use the Evaluation Board for any other purpose. Furthermore, the license granted
is expressly made subject to the following additional limitations:Customer shall not (i) rent, lease, display, sell, transfer, assign, sublicense, or distribute the Evaluation Board;and (ii) permit any Third
Party to access the Evaluation Board. As used herein, the term “Third Party”includes any entity other than ADI, Customer, their employees, affiliates and in-house consultants. The Evaluation Board is
NOT sold to Customer;all rights not expressly granted herein, including ownership of the Evaluation Board, are reserved by ADI. CONFIDENTIALITY. This Agreement and the Evaluation Board shall all
be considered the confidential and proprietary information of ADI. Customer may not disclose or transfer any portion of the Evaluation Board to any other party for any reason. Upon discontinuation of
use of the Evaluation Board or termination of this Agreement, Customer agrees to promptly return the Evaluation Board to ADI. ADDITIONAL RESTRICTIONS. Customer may not disassemble, decompile
or reverse engineer chips on the Evaluation Board. Customer shall inform ADI of any occurred damages or any modifications or alterations it makes to the Evaluation Board, including but not limited
to soldering or any other activity that affects the material content of the Evaluation Board. Modifications to the Evaluation Board must comply with applicable law, including but not limited to the RoHS
Directive. TERMINATION. ADI may terminate this Agreement at any time upon giving written notice to Customer. Customer agrees to return to ADI the Evaluation Board at that time. LIMITATION OF
LIABILITY. THE EVALUATION BOARD PROVIDED HEREUNDER IS PROVIDED “AS IS”AND ADI MAKES NO WARRANTIES OR REPRESENTATIONS OF ANY KIND WITH RESPECT TO IT. ADI SPECIFICALLY
DISCLAIMS ANY REPRESENTATIONS, ENDORSEMENTS, GUARANTEES, OR WARRANTIES, EXPRESS OR IMPLIED, RELATED TO THE EVALUATION BOARD INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTY OF MERCHANTABILITY, TITLE, FITNESS FOR A PARTICULAR PURPOSE OR NONINFRINGEMENT OF INTELLECTUAL PROPERTY RIGHTS. IN NO EVENT WILL ADI AND ITS
LICENSORS BE LIABLE FOR ANY INCIDENTAL, SPECIAL, INDIRECT, OR CONSEQUENTIAL DAMAGES RESULTING FROM CUSTOMER’S POSSESSION OR USE OF THE EVALUATION BOARD, INCLUDING
BUT NOT LIMITED TO LOST PROFITS, DELAY COSTS, LABOR COSTS OR LOSS OF GOODWILL. ADI’S TOTAL LIABILITY FROM ANY AND ALL CAUSES SHALL BE LIMITED TO THE AMOUNT OF ONE
HUNDRED US DOLLARS ($100.00). EXPORT. Customer agrees that it will not directly or indirectly export the Evaluation Board to another country, and that it will comply with all applicable United States
federal laws and regulations relating to exports. GOVERNING LAW. This Agreement shall be governed by and construed in accordance with the substantive laws of the Commonwealth of Massachusetts
(excluding conflict of law rules). Any legal action regarding this Agreement will be heard in the state or federal courts having jurisdiction in Suffolk County, Massachusetts, and Customer hereby submits
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