19-2890; Rev 2; 8/05
Linear Li+ Battery Charger with Integrated Pass FET,
Thermal Regulation, and ACOK in 3mm x 3mm TDFN
The MAX1508 is an intelligent, stand-alone constant-cur-
rent, constant-voltage (CCCV), thermally regulated linear
charger for a single-cell lithium-ion (Li+) battery. The
MAX1508 integrates the current-sense circuit, MOS pass
element, and thermal-regulation circuitry, and also elimi-
nates the reverse-blocking Schottky diode, to create the
simplest and smallest charging solution for hand-held
The MAX1508 functions as a stand-alone charger to con-
trol the charging sequence from the prequalification state
through fast-charge, top-off charge, and full-charge indi-
cation. The MAX1508Y and MAX1508Z eliminate the pre-
qualification state to allow startup into a load without a
Proprietary thermal-regulation circuitry limits the die
temperature to +100°C when fast charging or while
exposed to high ambient temperatures, allowing maxi-
mum charging current without damaging the IC.
The MAX1508 achieves high flexibility by providing an
adjustable fast-charge current by an external resistor.
Other features include the charging status (CHG) of the
battery, an active-low control input (EN) for the
MAX1508 and MAX1508Z (active-high control input for
the MAX1508Y), and an active-low input power-source
detection output (ACOK).
The MAX1508 accepts a +4.25V to +13V supply, but dis-
ables charging when the input voltage exceeds +7V to
protect against unqualified or faulty AC adapters. The
MAX1508 operates over the extended temperature
range (-40°C to +85°C) and is available in a compact
8-pin thermally enhanced 3mm x 3mm thin DFN pack-
age with 0.8mm height.
Cellular and Cordless Phones
Digital Cameras and MP3 Players
Charging Cradles and Docks
♦ Stand-Alone Linear 1-Cell Li+ Battery Charger
♦ No External FET, Reverse-Blocking Diode, or
Current-Sense Resistor Required
♦ Programmable Fast-Charge Current (0.8A max)
♦ Proprietary Die-Temperature Regulation Control
♦ +4.25V to +13V Input Voltage Range with Input
Overvoltage Protection (OVP) Above +7V
♦ Charge-Current Monitor for Fuel Gauging
♦ Low Dropout Voltage—130mV at 0.425A
♦ Input Power-Source Detection Output (ACOK)
♦ Soft-Start Limits Inrush Current
♦ No Prequalification State for the MAX1508Y and
♦ Charge Status Output (CHG) for LED or
♦ Small 3mm x 3mm 8-Pin Thin DFN Package,
♦ Active-Low Charge Enable (EN) (MAX1508 and
♦ Active-High Charge Enable (EN) (MAX1508Y)
TEMP RANGE PIN-PACKAGE
-40°C to +85°C 8 Thin DFN-EP*
-40°C to +85°C 8 Thin DFN-EP*
*EP = Exposed paddle.
+Denotes lead-free package.
Ordering Information continued at end of data sheet.
8 7 65
Typical Operating Circuit appears at end of data sheet.
+1 2 3 4
Bluetooth is a trademark of Ericsson.
3mm x 3mm THIN DFN
( ) ARE FOR THE MAX1508Y ONLY
________________________________________________________________ Maxim Integrated Products 1
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.