19-2800; Rev 0; 4/03
Highly Integrated, Linear Battery Charger with
Thermal Regulation for Portable Applications
The MAX1501 intelligent, constant-current, constant-
voltage (CCCV), temperature-regulated battery charger
charges a single lithium-ion (Li+) cell or three-cell
NiMH/NiCd batteries. The device integrates the current-
sense resistor, PMOS pass element, and thermal-
regulation circuitry, while eliminating the reverse-
blocking Schottky diode to create the simplest charging
solution for hand-held equipment.
The MAX1501 functions as a stand-alone charger to
control the charging sequence from the prequalification
state through fast charge, top-off, and charge termination
for single-cell Li+ or three-cell NiMH/NiCd batteries.
Alternatively, the MAX1501 collaborates with a host
microprocessor to determine the best charging algorithm.
Proprietary thermal-regulation circuitry limits the die
temperature when fast charging or while exposed to high
ambient temperatures, allowing maximum charging
current without damaging the charger. The MAX1501
continually supplies a regulated output voltage under
no-battery conditions, allowing battery changing.
The device achieves high flexibility by providing an
adjustable fast-charge current, top-off current, safety
timer, and thermal-regulation setpoint. Other features
include input power detection (ACOK) and input under-/
overvoltage protection. The MAX1501 provides active-
low control inputs.
The MAX1501 accepts a 4.5V to 13V supply, but
disables charging when the input voltage exceeds
6.5V, preventing excessive power dissipation. The
MAX1501 operates over the extended temperature
range (-40°C to +85°C) and is available in a compact
16-pin thermally enhanced 5mm x 5mm thin QFN
package with 0.8mm profile.
Cellular and Cordless Phones
Digital Cameras and MP3 Players
Charging Cradles and Docks
Pin Configuration appears at end of data sheet.
Bluetooth is a trademark of Ericsson.
o Stand-Alone or Microprocessor-Controlled (µP)
Linear 1-Cell Li+ or 3-Cell NiMH/NiCd Battery
o No FET, Reverse-Blocking Diode, or Current-
Sense Resistor Required
o 1.4A (max) Programmable Fast-Charge Current
o +95°C, +115°C, and +135°C Proprietary
Programmable Die Temperature Regulation
o 4.5V to 13V Input Voltage Range with Input
Overvoltage (OVLO) Protection Above 6.5V
o Programmable Top-Off Current Threshold: 10%,
20%, or 30% of the Fast-Charge Current
o Charge-Current Monitor for Fuel Gauging
o Programmable Safety Timer (3, 4.5, or 6 hours)
o Input Power Detection Output (ACOK) and Charge
Enable Input (CHGEN)
o Automatic Recharge
o Digital Soft-Start Limits Inrush Current
o Charge Status Outputs for LEDs or µP Interface
-40°C to +85°C
16 Thin QFN
4.5V TO 13V
Typical Operating Circuit
4.2V 1-CELL Li+
________________________________________________________________ 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.