DC1583A - Demo Manual

DEMO MANUAL DC1583A
LTC3625/LTC3625-1:
1A High Efficiency 2-Cell Supercapacitor
Charger with Automatic Cell Balancing
DESCRIPTION
Demonstration circuit 1583A is a 1A high efficiency 2- Cell
supercapacitor charger with automatic cell balancing featuring the LTC3625/LTC3625-1. The LTC3625/LTC3625-1
are programmable supercapacitor chargers designed to
charge two supercapacitors in series to a fixed voltage of
5.3V/4.8V (LTC3625) or 4.5V/4.0V (LTC3625-1) from a 2.7V
to 5.5V input supply. Automatic cell balancing is achieved
during the charging phase, preventing overvoltage damage
to either supercapacitor while maximizing charge rate.
High efficiency, high charging current, low quiescent
current and low minimum external parts count make the
LTC3625/LTC3625-1 ideally suited for small form factor
backup or high peak power systems.
Charging current/maximum input current level is programmed with an external resistor. When the input supply is
removed and/or the EN pin is low, the LTC3625/LTC3625-1
automatically enters a low current state, drawing less than
1μA from the supercapacitors.
The LTC3625/LTC3625-1 are offered in a 12-lead (3mm ×
4mm × 0.75mm) DFN package.
Design files for this circuit board are available at
http://www.linear.com/demo
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
PERFORMANCE SUMMARY
Typical Specifications (25°C) LTC3625
Input Voltage Range: VCC
2.7V to 5.5V
Charge Current
1.0A
VOUT
4.8V or 5.3V Dependant on JP1 Setting
Typical Specifications (25°C) LTC3625-1
Input Voltage Range: VCC
2.7V to 5.5V
Charge Current
1.0A
VOUT
4.0V or 4.5V Dependant on JP1 Setting
OPERATING PRINCIPLES
The LTC3625/LTC3625-1 are dual cell supercapacitor chargers. Their unique topology charges two series connected
capacitors to a fixed voltage with programmable charging
current preventing overvoltage damage to either of the
cells, even if they are severely mismatched. No balancing
resistors are required. The LTC3625/LTC3625-1 include an
internal buck converter between VIN and VMID to regulate
the voltage on CBOT (the bottom capacitor) as well as an
internal boost converter between VMID and VOUT to regulate the voltage on CTOP (the top capacitor). The output
current of the buck converter is user-programmed via the
PROG pin while the input current of the boost converter
is set to 2A (typical).
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DEMO MANUAL DC1583A
OPERATING PRINCIPLES
The LTC3625/LTC3625-1 contains various functions that
are digitally controlled. The CTL pin is a control function
that sets the device into a two inductor mode (low) or a
single inductor mode (high). The CTL pin must be hard
tied to either VIN or GND. A logic high on the VSEL pin sets
VOUT to 5.3V/4.5V while a logic low sets VOUT to 4.8V/4.0V.
The EN pin will enable the device with a logic high while
a logic low disables the device and VOUT becomes high
impedance.
Charging Two 2:1 Mismatched
Supercapacitors
Buck Output Current vs RPROG
2500
IPROG
CLAMPED
6
VIN = 3.6V
VMID = 2V
CTL = 0V
IBUCK (mA)
1500
100
CTOP = 50F
CBOT = 100F
RPROG = 61.9k
CTL = 0
VSEL = 0
5
VOLTAGE (V)
2000
Buck Efficiency vs IBUCK
4
95
90
VOUT
3
VMID
1000
2
500
1
EFFICIENCY (%)
3000
An internal undervoltage lockout (UVLO) circuit monitors
VIN and keeps the LTC3625/LTC3625-1 disabled until VIN
rises above 2.90V/2.63V if VSEL is high or 2.63V/2.63V if
VSEL is low. Hysteresis on the UVLO turns off the LTC3625/
LTC3625-1 if VIN drops approximately 100mV below the
UVLO rising threshold. When in UVLO, only current needed
to detect a valid input will be drawn from VIN or VOUT.
85
80
75
70
65
60
55
0
0
0
50 100 150 200 250 300 350 400 450 500
RPROG (kΩ)
0
20 40 60 80 100 120 140 160 180 200
TIME (SECONDS)
VIN = 3.6V
VMID = 2V
CTL = 0V
50
200
700
1700
1200
IBUCK (mA)
2200
QUICK START PROCEDURE
Using short twisted pair leads for any power connections
and with all loads and power supplies off, refer to Figure 1
for the proper measurement and equipment setup.
Jumper and Load Settings to start:
Connect Jumper from VOUT to VPULLUP
JP1 (VSEL) = 5.3V/4.5V
JP2 (ENABLE) = OFF
LOAD1 = OFF
1. Set VIN to 3.3V and verify that the input current is less
than 10mA. Verify that VOUT is less than 2.0V indicating
that the supercapacitor is in a low charge state.
2. Set JP2 to the ON position. Verify that VOUT is less
than 3.5V and that PGOOD is low.
3. Monitor PGOOD and VOUT. When PGOOD goes high,
verify VOUT is ~5.0V/4.1V.
4. Verify VOUT when the input current drops to less than
10mA indicating a fully charged capacitor. Monitor
PFO, verify PFO is high. Verify VOUT is ~5.3V/4.5V.
5. Turn on Load1 and set to 950mA. Monitor PGOOD
and VOUT. When PGOOD goes low, verify VOUT is
~5.0V/4.1V.
6. Set JP2 to OFF, monitor PFO and PGOOD, verify both
are low. Allow the supercapacitor to discharge to 1.5V,
then turn off Load1.
Note: Once JP2 is placed in the OFF position, VOUT will
drop quickly.
7. Set JP1 to 4.8V/4.0V. Set JP2 to the ON position. Verify
that VOUT is less than 3.0V and that PGOOD is low.
dc1583Af
2
DEMO MANUAL DC1583A
QUICK START PROCEDURE
8. Monitor PGOOD and VOUT. When PGOOD goes high,
verify VOUT is ~4.5V/3.7V.
9. Verify VOUT when the input current drops to less than
10mA indicating a fully charged capacitor. Verify VOUT
is ~4.8V/4.0V.
10. Turn on Load1 and set to 950mA. Monitor PGOOD
and VOUT. When PGOOD goes low, verify VOUT is
~4.3V/3.5V.
11. Set JP2 to OFF and allow the supercapacitor to discharge to 1.0V, then turn off Load1.
Figure 1. Proper Measurement Equipment Setup
GND
VIN
Figure 2. Measuring Input or Output Ripple
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DEMO MANUAL DC1583A
PARTS LIST
ITEM
QTY
REFERENCE
PART DESCRIPTION
MANUFACTURERS/PART NUMBER
Required Circuit Components
1
2
C1, C2
CAP, CHIP, X5R, 10μF, 20%, 6.3V, 0805
Murata, GRM21BR60J106E39L
2
2
C5, C6
CAP, CHIP, X5R, 22μF, 20%, 6.3V, 0805
Murata, GRM21BR60J226ME39L
3
2
C3, C4
CAP, CHIP, X7R, 0.1μF, 10%, 16V, 0402
Murata, GRM155R71C104KA88D
4
1
C9
Supercapacitor, 1.2F, 5.5V, 39mm × 17mm
CAP-XX, HS230F
5
2
L1, L2
Inductor, 3.3μH, 3.0A, 20mΩ, 7mm × 7mm
Coiltronics, DR73-3R3-R
6
1
R1
Res., CHIP, 1Ω, 1/16W, 1%, 0402
Vishay, CRCW04021R00FKED
7
1
R2
Res., CHIP, 100k, 1/16W, 1%, 0402
Vishay, CRCW0402100KFKED
8
1
R4
Res., CHIP, 71.5k, 1/16W, 1%, 0402
Vishay, CRCW040271K5FKED
9
2
R5, R6
Res., CHIP, 1M, 1/16W, 1%, 0402
Vishay, CRCW04021M00FKED
10
1
U1
1A High Efficiency 2-Cell
Supercapacitor Charger with
Automatic Cell Balancing
LTC3625EDE
Optional Demo Board Circuit Components
1
0
C7-1 - C8-1 (OPT)
Supercapacitor, 10.0F, 2.7V, 10mm × 30mm
Illinois CAP, 106DCN2R7Q
2
0
C7-2 - C8-2 (OPT)
Supercapacitor, 25.0F, 2.7V, 16mm × 25mm
Illinois CAP, 256DCN2R7Q
3
0
R3 (OPT)
RES., CHIP, 1/16W, 1%, 0402
User Selectable
4
0
U1
1A High Efficiency 2-Cell
Supercapacitor Charger with
Automatic Cell Balancing
LTC3625EDE-1
Hardware For Demo Board Only
1
5
E1 - E5
Turret, 0.09 DIA
MILL-MAX, 2501-2
2
4
E6 - E9
Turret, 0.061 DIA
MILL-MAX, 2308-2
3
2
JP1, JP2
Header, 3 PINS, 2mm
Samtec, TMM-103-02-L-S
4
2
JP1, JP2
Shunt, 2mm
Samtec, 2SN-BK-G
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4
A
GND
E2
E1
VIN
2.7V - 5.5V
R1
1
C2
10uF
6.3V
0805
4.8V / 4.0V
5.3V / 4.5V
1
3
VSEL
2
JP1
OFF
ON
ENABLE
1
3
2
JP2
*
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation
that the interconnection of its circuits as described herein will not infringe on existing patent rights.
U1
LTC3625EDE
LTC3625EDE-1
-B
6
SW1
VOUT
13
GND
PFO
PGOOD
VMID
4.5V - 4.0V
5.3V - 4.8V
PROG
R4
71.5k
EN
VSEL
CTL
PFI
8
9
10
1
R6 1M
R5 1M
1
Unless noted:
Resistors: Ohms, 0402, 1%, 1/16W
Capacitors: uF, 0402, 6.3V
3.3uH
L2
3.3uH
L1
12
11
VOUT
SW2
2
VIN
-A
5
4
3
7
* U1
ASSY TYPE
R3
OPT
R2
100K
3
BAL
V+
CUSTOMER NOTICE
C6
22uF
6.3V
20%
0805
C5
22uF
6.3V
20%
0805
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
J. DREW
SCALE = NONE
NC
PCB DES.
APP ENG.
APPROVALS
C9
HS230F
1.2F
39mm x 17mm
5.5V
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.
C4
0.1uF
16V
C3
0.1uF
16V
2
1
C1
10uF
6.3V
0805
1
C8-1
10F
OPT
C7-1
10F
OPT
C8-2
25F
OPT
C7-2
25F
OPT
PFO
PGOOD
V PULL-UP
GND
GND
VMID
* VOUT
DATE
06-15-10
1630 McCarthy Blvd.
Milpitas, CA 95035
Phone: (408)432-1900 www.linear.com
Fax: (408)434-0507
LTC Confidential-For Customer Use Only
E9
E8
E7
E6
E5
E4
E3
J. DREW
APPROVED
DATE:
SIZE
Monday, August 23, 2010
SHEET 1
OF
1
1A HIGH EFFICIENCY 2-CELL SUPERCAPACITOR CHARGER WITH
AUTOMATIC CELL BALANCING
IC NO. LTC3625EDE / LTC3625EDE-1
REV.
N/A
2
DEMO CIRCUIT 1583A-A/B
TECHNOLOGY
+
+
DESCRIPTION
2
REVISION HISTORY
PRODUCTION FAB
REV
TITLE: SCHEMATIC
+
+
ECO
A
DEMO MANUAL DC1583A
SCHEMATIC DIAGRAM
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DEMO MANUAL DC1583A
DEMONSTRATION BOARD IMPORTANT NOTICE
Linear Technology Corporation (LTC) provides the enclosed product(s) under the following AS IS conditions:
This demonstration board (DEMO BOARD) kit being sold or provided by Linear Technology is intended for use for ENGINEERING DEVELOPMENT
OR EVALUATION PURPOSES ONLY and is not provided by LTC for commercial use. As such, the DEMO BOARD herein may not be complete
in terms of required design-, marketing-, and/or manufacturing-related protective considerations, including but not limited to product safety
measures typically found in finished commercial goods. As a prototype, this product does not fall within the scope of the European Union directive on electromagnetic compatibility and therefore may or may not meet the technical requirements of the directive, or other regulations.
If this evaluation kit does not meet the specifications recited in the DEMO BOARD manual the kit may be returned within 30 days from the date
of delivery for a full refund. THE FOREGOING WARRANTY IS THE EXCLUSIVE WARRANTY MADE BY THE SELLER TO BUYER AND IS IN LIEU
OF ALL OTHER WARRANTIES, EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING ANY WARRANTY OF MERCHANTABILITY OR FITNESS
FOR ANY PARTICULAR PURPOSE. EXCEPT TO THE EXTENT OF THIS INDEMNITY, NEITHER PARTY SHALL BE LIABLE TO THE OTHER FOR
ANY INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES.
The user assumes all responsibility and liability for proper and safe handling of the goods. Further, the user releases LTC from all claims
arising from the handling or use of the goods. Due to the open construction of the product, it is the user’s responsibility to take any and all
appropriate precautions with regard to electrostatic discharge. Also be aware that the products herein may not be regulatory compliant or
agency certified (FCC, UL, CE, etc.).
No License is granted under any patent right or other intellectual property whatsoever. LTC assumes no liability for applications assistance,
customer product design, software performance, or infringement of patents or any other intellectual property rights of any kind.
LTC currently services a variety of customers for products around the world, and therefore this transaction is not exclusive.
Please read the DEMO BOARD manual prior to handling the product. Persons handling this product must have electronics training and
observe good laboratory practice standards. Common sense is encouraged.
This notice contains important safety information about temperatures and voltages. For further safety concerns, please contact a LTC application engineer.
Mailing Address:
Linear Technology
1630 McCarthy Blvd.
Milpitas, CA 95035
Copyright © 2004, Linear Technology Corporation
dc1583Af
6
Linear Technology Corporation
LT 1110 • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507
●
www.linear.com
© LINEAR TECHNOLOGY CORPORATION 2010
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