MAX8856 Datasheet, PDF (1/13 Pages) Maxim Integrated Products – Linear Battery Charger

19-4277; Rev 0; 9/08
EVAALVUAAILTAIOBNLEKIT
USB/AC Adapter, Li+ Linear Battery Charger
with Integrated 50mΩ Battery Switch in TDFN
General Description
The MAX8856 complete 1-cell Li+ battery charge-man-
agement IC operates from either a USB port or AC
adapter. It integrates a battery disconnect switch, cur-
rent-sense circuit, PMOS pass element, and thermal-
regulation circuitry, while eliminating the external
reverse-blocking Schottky diode, to create a simple
and small charging solution. The charging sequence
initiates from power-OK indication, through prequalifi-
cation, fast-charge, top-off charge, and finally charg-
ing-complete indication for single-cell Li+ batteries.
Charging is controlled using constant current, constant
voltage, or constant die-temperature (CCCVCT_J) regu-
lation for safe operation in handhelds.
Two logic inputs (EN1, EN2) select suspend mode,
100mA, 500mA, or ≤ 1A input current limits to comply
with USB requirements. Proprietary thermal-regulation
circuitry limits the die temperature to +100°C to prevent
excessive heat on the system PC board. Additional
safety features include an NTC thermistor input (THM)
to protect the battery. A 3.5V to 4.2V SYS output, in
conjunction with the low-R_DSON battery switch, powers
the system even when the battery is deeply discharged
or not installed. The IC also offers a +3.3V/500µA out-
put (V_L), a charging status flag (CHG), and an input-
supply detection flag (POK). The MAX8856 operates
from a +4.25V to +5.5V supply and includes undervolt-
age lockout below +3.4V and overvoltage protection
up to +14V.
Applications
Cellular Phones, Smartphones, PDAs
Digital Cameras, MP3 Players
USB Appliances, Charging Cradles and Docks
TOP VIEW
Pin Configuration
14 13 12 11 10 9 8
MA8856
12 34 567
Features
♦ Small, 3mm x 3mm Thermally Enhanced TDFN
Package (0.8mm max height)
♦ USB-Compliant Suspend Mode (20µA)
♦ Selectable 100mA, 500mA, and Up to 1A Input
Current Limits
♦ USB or AC Adapter Input
♦ +6V to +14V Input Overvoltage Protection
♦ Input UVLO Below +4V Rising (3.5V Falling)
♦ Automatic Current Sharing Between Battery
Charging and System
♦ Die Temperature Regulation (+100°C)
♦ Low Dropout Voltage, 250mV at 0.5A
♦ NTC Thermistor Input
♦ Charge Status and Input-Supply Detection Flags
Ordering Information
PART
TEMP RANGE PIN-PACKAGE
MAX8856ETD+
-40°C to +85°C
14 TDFN 3mm x
3mm (T1433-1)
+Denotes a lead-free/RoHS-compliant package.
TOP
MARK
AEJ
Typical Operating Circuit
USB/AC-ADAPTER
OVP UP TO 14V
INPUT
CURRENT
SELECTION
μP
IN
GND
V_L
CONTROL
EN1
EN2
GATE
SETI
MAX8856
STATUS
INDICATORS
CHG
POK
SYS ^{3.5V TO 4.2V}
0.1μF
BAT
THM
TDFN
________________________________________________________________ Maxim Integrated Products 1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.