DEMO MANUAL DC2044A
LTC4020EUHF
High Voltage Buck-Boost
Multi-Chemistry Battery Charger
Description
Demonstration circuit 2044A is a 55V buck-boost multi-
chemistry battery charger featuring the
LTC4020.
The board
will accept an input voltage between 15V and 55V. The
float voltage of the battery output (BAT) is 25.2V, with 3.3A
maximum charge current. The converter output (VOUT)
has a voltage range of 21V to 28V, with 3A maximum load
current. The LTC4020 contains a high efficiency synchro-
nous buck-boost DC/DC controller and uses a proprietary
average current mode architecture.
The LTC4020 battery charger can provide a constant-
current/constant-voltage charge algorithm (CC/CV, with
MODE pin grounded), constant-current charging (CC, with
MODE pin floated), or charging with an optimized 4-step,
3-stage lead-acid battery charge profile (connect MODE pin
to INTV
CC
, with a 0Ω jumper at the optional R29 position).
The LTC4020 data sheet gives a complete description of the
IC operation and application information. The data sheet
must be read in conjunction with this quick start guide.
Design files for this circuit board are available at
http://www.linear.com/demo/DC2044A
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
SYMBOL
Input Voltage Range
Battery Float Voltage (BAT) (Nominal)
Converter Output Voltage (VOUT)
Maximum Battery Charge Current, I
BAT
Maximum Converter Output Current, I
OUT
Typical Efficiency
Typical Converter Output Ripple
Specifications are at T
A
= 25°C
VALUE
15V to 55V
25.2V
21V to 28V
3.3A
3A
97%
56mV
P-P
CONDITIONS
I
BAT
= 0A to 3.3A
I
OUT
= 0A to 3A
I
OUT
= 0A
I
BAT
= 0A
V
IN
= 24V, V
OUT
= 25.2V, I
OUT
= 3A
V
IN
= 55V, V
OUT
= 25.2V, I
OUT
= 3A (20MHz BW)
dc2044af
1
DEMO MANUAL DC2044A
Quick start proceDure
Demonstration circuit 2044A is easy to set up to evaluate
the performance of the LTC4020. Refer to Figure 1 for
the proper measurement equipment setup and follow the
procedure below:
1. With power off, connect the input power supply (set
for 0V) to V
IN
and GND (input return).
2. Connect the converter output load between V
OUT
and
GND (Initial load: no load).
3. Connect the DVMs to the input and outputs.
4. Turn on the input power supply and slowly increase
to 24V. Check for the proper output voltages, V
OUT
of
25.2V and BAT of 25.2V.
5. Once the proper output voltages are established, adjust
the converter output load within the operating range (3A
maximum) and/or adjust input voltage (15V to 55V) and
observe the output voltage regulation, ripple voltage,
efficiency and other parameters.
Note: When measuring the output or input voltage ripple,
do not use the long ground lead on the oscilloscope probe.
See Figure 2 for the proper scope probe technique. Short,
stiff leads need to be soldered to the (+) and (–) terminals
of an output capacitor. The probe’s ground ring needs to
touch the (–) lead and the probe tip needs to touch the
(+) lead.
Additional Notes:
1. CAUTION: Be careful when testing with high voltage.
High voltage can result in an electric shock if care
is not taken.
2. CAUTION: Batteries are potentially dangerous high
energy sources. Improper connection, overcharge, or
rapid discharge could result in explosion and/or file.
Please read the specification/manual of the battery
before test.
3. The combined converter output load current and bat-
tery charging current should not exceed 3.3A.
4. Without a proper battery, BAT output can be open or
connected with other suitable loads for test purposes.
It may be a good practice to add low ESR electrolytic
capacitors to the BAT output (≥1000µF at ≥35V, for
25.2V float voltage).
Note: These capacitors help simulate the low impedance
of a battery and maintain stability of the charge current
loop. It’s only needed for test purposes with electronic
or resistive loads, and not needed in the actual battery
application/test (where the BAT load is a battery).
5. BAT float voltage can be easily adjusted with the resis-
tor divider R8/R10. Converter output voltage V
OUT
can
be adjusted with the resistor divider R9/R11. Adjust/
optimize the loop compensations if necessary.
dc2044af
2
DEMO MANUAL DC2044A
parts List
ITEM
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
QTY
1
4
1
1
1
1
1
2
1
1
1
6
1
2
1
1
1
1
1
2
1
5
2
1
1
1
1
1
1
1
8
1
2
1
2
REFERENCE
C1
C2, C3, C15, C17
C4
C5
C6
C8
C9
C19, C20
C10
C11
C12
C14, C16, C18, C23, C27, C28
C21
D1, D2
D3
D4
D6
L1
M1
M2, M3
R2
R1, R4, R5, R12, R13
R6, R7
R8
R9
R10
R11
R14
R15
R16
R21 TO 25, R34, R35, R37
R36
R18, R20
R19
R26, R27
PART DESCRIPTION
CAP, CHIP, X7S, 0.1µF, 10%, 100V, 0603
CAP, CHIP, C0G, 100pF, 10%, 16V, 0402
CAP, CHIP, C0G, 0.1µF, 10%, 16V, 1206
CAP, CHIP, X7R 10nF, 10%, 50V, 0603
CAP, CHIP, C0G, 680pF, 10%, 50V, 0603
CAP, CHIP, C0G, 68pF, 5%, 16V, 0402
CAP, CHIP, X5R, 0.22µF, 10%, 25V, 0603
CAP, CHIP, X7R, 0.001µF, 10%, 25V, 0603
CAP, CHIP, X5R, 2.2µF, 10%, 16V, 0603
CAP, CHIP, X7R, 0.033µF, 10%, 25V, 0402
CAP, CHIP, X7S, 4.7µF,20%, 100V, 1210
CAP, CHIP, X5R, 10µF, 20%, 6.3V, 0805
DIODE, SMT, SUPERBARRIER, 60V, 0.5A,
SOD123
DIODE, LED, RED, SMT, 0603
DIODE, LED, GREEN, 0603
DIODE, SMT SCHOTTKY BARRIER RECTIFIER,
SMA
IND, SMT, 15µH, 10A, 20%, 10mm × 11.3mm
P-CHANNEL MOSFET, –60V, –14.4A,
PowerPAKSO8
DUAL N-CHANNEL MOSFET, 60V, 9.7A,
PowerPAKSO8
RES, CHIP, 510kΩ, 5%, 0402
RES, CHIP, 100kΩ, 5%, 0402
RES, CHIP, 20Ω, 5%, 0402
RES, CHIP, 226kΩ, 0.1%, 0603
RES, CHIP, 226kΩ, 1%, 0402
RES, CHIP, 24.9kΩ, 0.1%, 0402
RES, CHIP, 24.9kΩ, 1%, 0402
RES, CHIP, 10kΩ, 1%, 0402
RES, CHIP, 56kΩ, 1%, 0402
RES, CHIP, 47kΩ, 1%, 0402
RES, CHIP, 0Ω JUMPER, 0402
RES, CHIP, 0Ω JUMPER, 0603
RES, CHIP, 100Ω, 5%, 0402
RES, CHIP, 4.7Ω, 5%, 0402
RES, CHIP, 3kΩ, 5%, 0402
MANUFACTURER/PART NUMBER
TDK, C1608X7S2A104K
AVX, 0402YA101KAT9A
KEMET, C1206H104J3GACTU
AVX, 06035C103KAT
AVX, 06035A681KAT2A
AVX, 0402YA680JAT4A
AVX, 06033D224KAT2A
AVZ, 06033C102KAT2A
TDK, C1608X5R1C225K
TDK, C1005X7R1E333K
TDK, C3225X7S2A475M
AVX, 08056D106KAT2A
DIODES INC, SBR0560S1
PANASONIC, LNJ208R8ARA
LITE-ON, LTST-C190KGKT
VISHAY, B360A-E3
COILCRAFT, XAL1010-153MEB
VISHAY, Si7461DP-T1-E3
VISHAY, Si7960DP-T1-E3
VISHAY, CRCW0402510KFKED
VISHAY, CRCW0402100KJNED
VISHAY, CRCW040220R0JNED
VISHAY, TNPW06030F226BEEA
VISHAY, CRCW0402226KFKED
VISHAY, TNPW04020F24K9BEED
VISHAY, CRCW040224K9FKED
VISHAY, CRCW040210K0FKED
VISHAY, CRCW040256K0FKED
VISHAY, CRCW040247K0FKED
VISHAY, CRCW04020000Z0ED
VISHAY, CRCW06030000Z0EA
VISHAY, CRCW0402100RJNED
VISHAY, CRCW04024R70JNED
VISHAY, CRCW04023K00JNED
Required Circuit Components
CAP, ELEC, 56µF, 20%, 63V, 10.3mm × 10.3mm SUNCON, 63HVH56M
dc2044af
5
京公网安备 11010802033920号
EEWORLD
