_______________General Description
The MAX713SWEVKIT-SO is a fully assembled and tested
surface-mount board. The MAX713 high-current, switch-
mode battery charger controls a P-channel power MOS-
FET, allowing charge currents up to 1A. Switch-mode
operation typically provides 75%-efficient conversion,
reducing heat compared to linear-regulator solutions.
The MAX713SWEVKIT can also be used to evaluate the
MAX712 just by replacing the MAX713CSE with a
MAX712CSE.
____________________________Features
o
Up to 1A Charge Current
o
45V Peak Input Voltage Range
o
Switch-Mode Operation Reduces Heat Dissipation
o
Surface-Mount Components
o
Charges 1 to 16 Series Cells
Evaluates: MAX712/MAX713
MAX713 Switch-Mode Evaluation Kit
________________________________________________________________
Maxim Integrated Products
1
Call toll free 1-800-998-8800 for free samples or literature.
PART
TEMP. RANGE
BOARD TYPE
MAX713SWEVKIT-SO
0C to +70C
Surface Mount
QTY
DESCRIPTION
C1
1
C3, C5, C6
3
C4
1
0.1F, 50V capacitor
D1, D2
2
D3
1
Red LED
D4
1
J1, J2
2
L1
1
M1
1
0.3
, 50V P-channel MOSFET
International Rectifier IRFR9024
Q1, Q3, Q4
3
50V NPN transistors
Central Semiconductor CMPTA06 or
Motorola MMBTA06LT1
Q2
1
50V PNP transistor
Central Semiconductor CMPT2907A or
Motorola MMBT2907ALT1
R1, R6
0
Reserved for optional resistors
R2
1
5.1k
, 5% resistor
3A, 40V Schottky diodes
Motorola MBRS340T3
10F, 50V capacitors
Sprague 595D106X0050R
1F, 25V capacitor
Sprague 595D105X0025A
SUPPLIER
PHONE
FAX
______________Component Suppliers
DESIGNATION
8.2mA, 50V current-limiting diode
Central Semiconductor CCLHM080
2-pin power connectors
220H, 1.5A inductor
CoilCraft DO3340-224
____________________Component List
______________Ordering Information
C2
1
220pF, 50V capacitor
R3
1
0.25
, 1/2W resistor
Dale WSL-2512-R250-J or
IRC LR2010-01-R250-K
R4
1
1.5k
, 5% resistor
R5
1
470
, 5% resistor
U1
1
Maxim MAX713CSE IC
None
1
MAX712/MAX713 data sheet
None
1
3.0" x 3.0" printed circuit board
AVX
Sprague
(207) 282-5111
(603) 224-1961
(207) 283-1941
(603) 224-1430
Dale-Vishay
IRC
(402) 564-3131
(512) 992-7900
(402) 563-1841
(512) 992-3377
CoilCraft
(708) 241-7876
(708) 639-1469
Central
Semiconductor
International
Rectifier
Motorola
Nihon: USA
Nihon: Japan
(516) 435-1110
(310) 322-3331
(602) 244-3576
(805) 867-2555
81-3-3494-7411
(516) 435-1824
(310) 322-3332
(602) 244-4015
(805) 867-2556
81-3-3494-7414
Tantalum Capacitors
Low-Value Resistors
High-Current Inductor
Semiconductors
Please indicate that you are using these parts with the MAX713
when contacting the above vendors.
______________________________EV Kit
R7
1
68k
, 5% resistor
R8
1
22k
, 5% resistor
Evaluates: MAX712/7MAX13
MAX713 Switch-Mode Evaluation Kit
2
_______________________________________________________________________________________
_________________________Quick Start
The MAX713 Switch-Mode EV kit is a fully assembled
and tested surface-mount board. Follow these steps to
verify board operation.
Do not turn on the power until
all connections are completed.
1) Set the charging parameters to match the charge
current and number of cells of the battery being
charged. Refer to the section
Setting the Charging
Parameters and to the MAX712/MAX713 data sheet
for instructions. The board is shipped configured for
six cells and 1A of charge current.
2) Connect the input power source (14V to 16V, 1.3A
as configured) to the 2-pin power connector.
Observe the polarity indicated next to the connec-
tor. The input supply must be 2V greater than the
maximum battery charging voltage, and capable of
providing the charge current.
3) Connect the battery to the 2-pin battery terminal.
Observe the polarity markings.
4) Turn on the power to the board and use a DVM to
confirm the voltage across the battery and the
sense resistor.
_______________Detailed Description
Input Supply Range
The input power supply must be at least 2V greater than
the peak battery voltage. The upper limit is determined
by the breakdown voltage of the P-channel power MOS-
FET and the capacitors across the input supply. When
choosing an adapter for use with the MAX712/MAX713
switch-mode circuit, make sure that the lowest wall-cube
voltage level during fast charge and full load is a least 2V
higher than the maximum battery voltage while being fast
charged. Typically, the voltage on the battery pack is
higher during a fast-charge cycle than while in trickle
charge or while supplying a load. The voltage across
some battery packs may approach 1.9V/cell. This mini-
mum input voltage requirement is critical, because its
violation may inhibit proper termination of the fast-charge
cycle. A safe rule of thumb is to choose a source that
has a minimum input voltage = 2V + (1.9V x the maxi-
mum number of cells to be charged).
The components included in this kit are rated at 50V, so
the input source must never exceed 50V. Depending
on your application, you can substitute capacitors and
other components with different ratings.
The EV kit is shipped with all programming inputs
(PGM0-PGM3) open. This sets the MAX713 for six cells,
1A of charging current, 45 minutes maximum charge
time, and 42 seconds between battery voltage mea-
surements. The default conditions require an input
source greater than 14V and capable of greater than
1.3A. Be sure to read the section titled
Setting the
Charging Parameters before connecting any battery.
A current-limiting diode (D4) on the EV kit allows a wide
input voltage range. This diode provides a fixed 8mA of
current to the MAX713 shunt regulator. For applications
with a narrow input voltage range, you can replace the
diode with a resistor selected for the same current flow
between the input source and the V+ pin.
Setting the Charging Parameters
For each battery type connected, the EV kit must be set
for the proper number of cells, the proper maximum
charging time and sampling intervals, and the proper
charging current. Select the number of cells by connect-
ing the PGM0 and PGM1 pins per Table 1. Whenever
changing the number of cells to be charged, PGM0 and
PGM1 need to be adjusted accordingly. Attempting to
charge more or fewer cells than the number pro-
grammed may disable the voltage-slope fast-charge ter-
mination circuitry.
The EV kit is shipped with PGM0 and PGM1 open, which
sets the number of cells at six. You can alter the pro-
grammed number of cells by installing jumper wires
across the holes provided on the board. For example, to
configure the board for four cells, solder wires between
pins 1 & 4 of SW1 (PGM0) and pins 1 & 2 of SW2 (PGM1).
Table 1. Programming the Number of Cells
NUMBER
OF CELLS
PGM0
CONNECTION
SW1
JUMPER
PGM1
CONNECTION
SW2
JUMPER
1
V+
14
V+
14
V+
14
Open
--
3
V+
14
REF
13
4
V+
14
BATT-
12
5
Open
--
V+
14
6
Open
--
Open
--
7
Open
--
REF
13
8
Open
--
BATT-
12
9
REF
13
V+
14
10
REF
13
Open
--
11
REF
13
REF
13
12
REF
13
BATT-
12
13
BATT-
12
V+
14
14
BATT-
12
Open
--
15
BATT-
12
REF
13
16
BATT-
12
BATT-
12
2
Evaluates: MAX712/MAX713
MAX713 Switch-Mode Evaluation Kit
_______________________________________________________________________________________
3
Table 2. Programming the Timing Functions
TIMEOUT
(MINUTES)
SAMPLE
INTERVAL
(SECONDS)
SLOPE
LIMIT
TRICKLE
VOLTAGE
(mV)
PGM2
CONNECTION
SW3
JUMPER
PGM3
CONNECTION
SW4
JUMPER
22
21
Off
4
Open
--
V+
14
22
21
On
4
REF
13
V+
14
33
21
Off
4
V+
14
V+
14
33
21
On
4
BATT-
12
V+
14
45
42
Off
8
Open
--
Open
--
45
42
On
8
REF
13
Open
--
66
42
Off
8
V+
14
Open
--
66
42
On
8
BATT-
12
Open
--
90
84
Off
16
Open
--
REF
13
90
84
On
16
REF
13
REF
13
132
84
Off
16
V+
14
REF
13
132
84
On
16
BATT-
12
REF
13
180
168
Off
32
Open
--
BATT-
12
180
168
On
32
REF
13
BATT-
12
264
168
Off
32
V+
14
BATT-
12
264
168
On
32
BATT-
12
BATT-
12
MAX713
BATT+
V+
PGM0
PGM1
BATT
PGM2
TLO
PGM3
VLIMIT
TEMP
GND
CC
FASTCHG
THI
5
15
3
4
9
1
10
1
2
3
4
2
3
4
2
3
4
2
3
4
1
1
1
7
2
12
6
GND
13
8
REF
R8
22k
R7
68k
DRV
REF
SW1
SW2
SW3
SW4
R5 470
C1
1
F
10V
R6
OPEN
R3
0.25
C3
10
F
50V
BATT+
BATT-
C4
0.1
F
Q2
2N2907
Q3
CMPTA06
JU1
JUMPER
Q4
CMPTA06
R1
OPEN
3
2
FAST CHARGE
D4
CCLHM080
(8mA CURRENT-
LIMITING DIODE)
Q1
CMPTA06
C6
10
F
50V
1
1
1
1
2
2
3
3
2
3
2
C5
10
F
50V
D3
LED
RED
1
R2
5.1k
JU2
CUT HERE
R4
1.5k
M1
IRFR9024
L1
DO3340
220
H
D1
MBRS340T3
D2
MBRS340T3
DCIN
14
C2
220pF
11
CURRENT-
SENSE
RESISTOR
REF
16
U1
Figure 1. MAX713 Switch-Mode EV Kit Schematic
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
4
___________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 (408) 737-7600
1995 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
Evaluates: MAX712/MAX713
MAX713 Switch-Mode Evaluation Kit
This jumper configuration connects PGM0 to V+ and
PGM1 to BATT-.
Select the maximum charging time and the time interval
between cell voltage readings for delta-slope termination
by connecting the PGM2 and PGM3 pins per Table 2.
Refer to the MAX712/MAX713 data sheet for detailed
information on the operation of these pins.
The charge current is determined by the value of the
current-sense resistor (R3) and the fixed 250mV across
the resistor during fast-charge. To change the charge
current, calculate the new current-sense resistor value
and install that value in the position provided (R8), then
remove the factory-installed R3. Choose R
SENSE
using
the following formula:
R
SENSE
= 0.25V/I
FAST
See the MAX712/MAX713 data sheet for detailed informa-
tion on setting the fast-charge and trickle-charge currents.
Inductor Selection
The inductor value is not critical to circuit operation.
However, the greater its value, the lower the output ripple
current. The CoilCraft inductor used on the evaluation
board was chosen because it is the highest value (220H)
surface-mount inductor with a 1.5A rating currently avail-
able. Larger inductors, such as toroids, may be used for
lower output ripple current or higher current-charge rates.
Gate-Drive Current
The voltage swing on the gate of the power MOSFET
(M1) must be greater than 8V and less than 15V.
Transistors Q1 and Q2 provide a low-impedance drive
to the gate. If the DCIN voltage is less than 15V, the
MAX713 DRV pin can be directly connected to Q1 and
Q2. For DCIN voltages greater than 15V, a transistor
level shifter (Q3, R4) is inserted to provide the proper
voltage swing to Q1 and Q2. Q3 is mounted on the
evaluation board, but it is not used in the standard con-
figuration. If Q3 is needed, then cut the trace across
JU2 and solder a jumper across JU1.
Figure 2. MAX713 EV Kit Component Placement Guide--
Component Side
Figure 3. MAX713 EV Kit PC Board Layout--Component Side
Figure 4. MAX713 EV Kit PC Board Layout--Solder Side
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