MAXIM MAX1507/MAX1508EVKIT

19-2895; Rev 0; 6/03
MAX1507/MAX1508 Evaluation Kit
Component List
DESIGNATION
C1
QTY
1
Features
♦ Simple, Stand-Alone Li+ Charger
♦ Safely Precharges Deeply Discharged Li+ Cells
♦ 4.25V to 13V Input Voltage Range
♦ 7V Overvoltage Protection Threshold
♦ Resistor-Programmable Charge Current Up
to 0.8A
♦ Charge Current Monitored by a Resistor
♦ Programmable Die-Temperature Regulation Set
Points (MAX1507 Only)
♦ ACOK Output (MAX1508 Only)
♦ Fully Assembled and Tested
DESCRIPTION
1µF ±20%, 6.3V X5R ceramic
capacitor (0603)
TDK C1608X5R0J105MT or
Taiyo Yuden JMK107BJ105MG
Ordering Information
PART
MAX1507/
MAX1508EVKIT
TEMP RANGE
0°C to +70°C
IC PACKAGE
8 TDFN
Note: The MAX1508ETA device must be ordered separately.
1
0.47µF ±20%, 6.3V or 10V X5R
ceramic capacitor (0603)
TDK C1608X5R0J474MT or
Taiyo Yuden JMK107BJ474MG
C3
1
1µF ±20%, 16V X5R ceramic
capacitor (0805)
TDK C2012X5R1C105MT or
Taiyo Yuden EMK212BJ105MG
The MAX1507/MAX1508 EV kit is a fully assembled and
tested surface-mount board. Follow the steps below to
verify board operation. Do not turn on the power supply until indicated:
JU1
1
2-pin header
JU2
1
3-pin header
R1
1
2.80kΩ ±1% resistor (0603)
U1
1
MAX1507ETA
(8-pin Thin DFN 3mm ✕ 3mm)
1) MAX1507: Verify that a shunt is installed on JU2
(TEMP) to set the charger to a +95°C regulated maximum die temperature. MAX1508: Remove the shunt
from JU2 and connect a 100kΩ resistor from the
TEMP pad of the EV kit to the logic I/O voltage. The
ACOK logic signal is present at the TEMP test point.
CHARGING
1
Red LED, T-1 3/4 (5mm)
None
2
Shunts
JU1 and JU2
None
1
MAX1507EVKIT PC board
C2
Quick Start
2) Verify the shunt is removed from JU1 (EN) to set the
EV kit for charge default-enable mode.
3) Observe correct Li+ cell polarity. Connect a singlecell Li+ battery across the BATT+ and BATT- pads of
the EV kit.
Component Suppliers
PHONE
FAX
Panasonic
SUPPLIER
714-373-7366
714-737-7323
www.panasonic.com
WEBSITE
Taiyo Yuden
800-348-2496
847-925-0899
www.t-yuden.com
TDK
847-803-6100
847-390-4498
www.component.tdk.com
Note: Please indicate you are using the MAX1507/MAX1508 when contacting these component suppliers.
________________________________________________________________ Maxim Integrated Products
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
1
Evaluates: MAX1507/MAX1508
General Description
The MAX1507/MAX1508 evaluation kit (EV kit) is a complete, fully assembled, and tested circuit board that
demonstrates the MAX1507 linear battery charger for a
single-cell lithium-ion (Li+) battery. To evaluate the
MAX1508, U1 must be removed and replaced with a
MAX1508 device. The EV kit safely charges a single Li+
battery to 4.2V. The EV kit accepts a power-supply
input of 4.25V to 13V, but disables charging when the
input voltage exceeds 7V. Jumpers on the EV kit allow
adjustments to the die-temperature regulation levels
(MAX1507 only) and the ability to disable the charger.
An LED on the board indicates the status of the charging cycle.
Evaluates: MAX1507/MAX1508
MAX1507/MAX1508 Evaluation Kit
4) Connect a 4.25V to 7V power supply across the VIN
and GND pads of the EV kit. The positive terminal
connects to the VIN pad.
5) Turn on the power supply to begin charging.
6) Verify the red LED turns on.
7) The red LED turns on during prequalification and
fast-charge conditions. The red LED turns off when
the battery current drops to 10% of the fast-charging current.
Detailed Description
The MAX1507/MAX1508 EV kit demonstrates the highly
integrated, stand-alone MAX1507/MAX1508 linear battery
chargers for single-cell Li+ batteries. The EV kit safely
charges a single Li+ battery to 4.2V. The EV kit accepts a
power-supply input of 4.25V to 13V, but disables charging when the input voltage exceeds 7V, protecting
against unqualified or faulty AC adapters. Jumpers on the
EV kit allow access to the input pins of the charger to
configure the die-temperature regulation levels
(MAX1507) and to disable the charger. The red LED on
the board indicates the status of the charging cycle.
Input Source
The MAX1507/MAX1508 EV kit requires a power supply
with an output voltage between 4.25V and 6.5V for proper operation. The MAX1507/MAX1508 chargers are
designed to handle a maximum input voltage of 13V, but
disable charging when the input voltage exceeds the
overvoltage protection threshold of 7V or when the input
voltage minus the battery voltage is less than 30mV.
Temperature Regulation Setting
JU2 allows the user to set the maximum operating die
temperature of the MAX1507. During charging, if the die
approaches the programmed temperature setting, the
charger reduces the charging current to keep the die
temperature from exceeding the programmed die temperature. The MAX1508 has a fixed die-temperature
regulation point of +100°C. Connect JU2 to +95°C
(+90°C typ), or connect JU2 to +135°C (+130°C typ), or
leave unconnected for a +100°C die-temperature regulation point.
Charge Profile
The MAX1507/MAX1508 chargers use voltage, current,
and thermal control loops to facilitate charging of a single Li+ cell and to protect the battery. When a Li+ battery with a cell voltage below 2.5V is inserted, the
charger enters the prequalification stage where it precharges that cell with 10% of the user-programmed
fast-charge current. Once the cell has passed 2.5V, the
charger soft-starts before it enters the fast-charge
stage. The fast-charge current level is programmed
with a resistor from ISET to ground. A red LED indicates
the charge status. As the battery voltage approaches
4.2V, the charging current is reduced. If the battery current drops 10% of the fast-charging current, the red
LED turns off, signaling the battery is fully charged. If at
any point while charging the battery the die temperature approaches the temperature-regulation set point,
the MAX1507/MAX1508 reduces the charging current
so the die temperature does not exceed the temperature-regulation set point.
VL
Disable the Charger
The MAX1507/MAX1508 linear chargers contain an
internal linear regulator available on the VL output pin.
This pin requires a 0.47µF ceramic bypass capacitor.
The VL output pin is regulated to 3.3V whenever the
input voltage is above 3.8V.
EN = high disables the charger and terminates the
charging cycle. Connect a shunt on JU1 to disable the
charger. However, the VL node is still valid at 3.3V. The
red LED is off when EN = high.
Fast-Charge Current
The red LED is a visual indicator of the charging status
of a connected battery. Table 1 describes the state of
the red LED during normal operation.
The maximum battery charge current is programmed
by R1 connected between the ISET pin and ground.
The EV kit’s fast-charging current is set to 520mA with
the 2.80kΩ resistor installed at R1. To reconfigure the
charging current, use the following equation to select a
new value for R1:
R1 = 1044 x 1.4V / ICHARGE
2
CHG
_______________________________________________________________________________________
MAX1507/MAX1508 Evaluation Kit
Evaluates: MAX1507/MAX1508
Table 1. Charge States
EN
VIN
VBATT
IBATT
LED
STATE
X
VBATT
VIN
0
Off
Shutdown
Low
4.25V ≤ VIN ≤ 7V
<2.5V
10% of IFAST
On
Prequalification
Low
4.25V ≤ VIN ≤ 7V
≥2.5V
IFAST*
On
Fast-charge
Low
4.25V ≤ VIN ≤ 7V
4.2V
10% of IFAST
Off
Full charge
Low
>7V
X
0
Off
Overvoltage
High
X
X
0
Off
Disabled
X = Don’t care.
*IFAST is reduced as necessary to maintain the die-temperature-regulation set point.
IN
2
C3
1µF
IN
BATT
CHG
GND
BATT+
7
C1
1µF
GND
CHARGING
CHG
8
BATT-
3
U1
VL
TEMP
(ACOK)
MAX1507
+135°C
6 TEMP
+95°C
JU2
ISET
4
(ACOK)
VL
ISET
EN
VL
1
C2
0.47µF
5
JU1
OFF
EN
R1
2.80kΩ
Figure 1. MAX1507/MAX1508 EV Kit Schematic
_______________________________________________________________________________________
3
Evaluates: MAX1507/MAX1508
MAX1507/MAX1508 Evaluation Kit
Figure 2. MAX1507/MAX1508 EV Kit Component Placement
Guide—Component Side
Figure 3. MAX1507/MAX1508 EV Kit PC Board Layout—
Component Side
Figure 4. MAX1507/MAX1508 EV Kit PC Board Layout—Solder
Side
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
© 2003 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.