MAX8677A Datasheet, PDF (1/21 Pages) Maxim Integrated Products – 1.5A Dual-Input USB/AC Adapter Charger and Smart Power Selector

19-0722; Rev 1; 1/07
1.5A Dual-Input USB/AC Adapter Charger
and Smart Power Selector
General Description
The MAX8677A is an integrated 1-cell Li+ charger and
Smart Power Selector™ with dual (DC and USB) power
inputs. It can operate with either separate inputs for
USB and AC adapter power*, or from a single input that
accepts both. All power switches for charging and
switching the load between battery and external power
are included on-chip. No external MOSFETs are
required.
The MAX8677A features a Smart Power Selector to
make the best use of limited USB or adapter power.
The battery charge current and input current limit are
independently set up to 1.5A and 2A, respectively.
Input power not used by the system charges the bat-
tery. USB input current can be set to 100mA or 500mA.
Automatic input selection switches the system load
from battery to external power.
Other features include overvoltage protection (OVP),
charge status and fault outputs, power-OK monitors,
charge timer, and battery thermistor monitor.
Additionally, on-chip thermal limiting reduces the battery
charge rate to prevent overheating. The MAX8677A is
available in a 4mm x 4mm, 24-pin TQFN-EP package.
.
Applications
PDAs, Palmtops, and Wireless Handhelds
Smart Cell Phones
Portable Media/MP3 Players
GPS Navigation
Digital Cameras
Typical Operating Circuit
AC
ADAPTER _DC
Q1
CHARGE
CURRENT
SYS
LOAD
CURRENT
USB
USB
Q2
Q3
CHARGE AND
SYS LOAD
SWITCH
MAX8677A
BAT
GND
SYSTEM
LOAD
BATTERY
Features
o Complete Charger and Smart Power Selector
o No External MOSFETs Required
o Common or Separate USB and Adapter Inputs
o System Operates with Discharged or No Battery
o Automatic Adapter/USB/Battery Switchover
o Load Peaks Over Adapter Rating Are Supported
by Battery
o Input Overvoltage Protection to 16V
o 40mΩ System-to-Battery Switch
o Thermal Regulation Prevents Overheating
o CHG, DOK, UOK, and FLT Indicators
o 5.3V (typ) SYS Regulation Voltage
Ordering Information
PART
TEMP RANGE ^PIN-
PACKAGE
MAX8677AETG+ -40°C to +85°C ^{24 TQFN-EP}
(4mm x 4mm)
+Denotes a lead-free package.
PKG
CODE
T2444-4
Pin Configuration
18 17 16 15 14 13
CHG 19
12 THM
SYS 20
11 ISET
SYS 21
DOK 22
MAX8677A
10 CT
9 GND
UOK 23
8 VL
FLT 24
7 PSET
123456
TQFN
(4mm x 4mm x 0.8mm)
*Protected by US Patent #6,507,172.
Smart Power Selector is a trademark of Maxim Integrated
Products, Inc.
________________________________________________________________ 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.