MAX8934G Datasheet, PDF (1/29 Pages) Maxim Integrated Products – Dual-Input Linear Charger, Smart Power Selector with Advanced Battery Temperature Monitoring

19-5296; Rev 0; 6/10
Dual-Input Linear Charger, Smart Power Selector
with Advanced Battery Temperature Monitoring
General Description
The MAX8934G dual-input Li+/Li-Poly linear battery char-
ger with Smart Power SelectorK safely charges a single
Li+/Li-Poly cell in accordance with JEITA* recommenda-
tions. The MAX8934G monitors the battery temperature
(TBATT) while charging, and automatically adjusts the
fast-charge current and charge termination voltage as the
battery temperature varies. The MAX8934G also monitors
the battery temperature while the battery is discharging,
and provides a warning flag (OT) to the system in the
event that the battery is over temperature. Safety region
2 is supported (see Figure 6 for details). An ultra-low IQ,
always-on LDO provides an additional 3.3V supply for
system power.
The MAX8934G operates 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 MAX8934G features a Smart Power Selector to make
the best use of limited USB or adapter power. Input cur-
rent limit and battery charge current limit are indepen-
dently set. Input power not used by the system charges
the battery. Charge current limit and DC current limit can
be set up to 1.5A and 2A, respectively, while USB input
current can be set to 100mA or 500mA. Automatic input
selection switches the system load from battery to external
power.
The MAX8934G provides a SYS output voltage of 4.35V.
Other features include overvoltage protection (OVP),
open-drain charge status and fault outputs, power-OK
monitors, charge timers, and a battery thermistor moni-
tor. Additionally, on-chip thermal limiting reduces the
battery charge-rate to prevent charger overheating.
The MAX8934G is available in a 28-pin, 4mm x 4mm,
TQFN package.
Applications
PDAs, Palmtop, and Wireless Handhelds
Portable Media, MP3 Players, and PNDs
Digital Still Cameras and Digital Video Cameras
Handheld Game Systems
*JEITA (Japan Electronics and Information Technology
Industries Association) Standard, A Guide to the Safe Use of
Secondary Lithium Ion Batteries on Notebook–Type Personal
Computers, April 20, 2007.
Smart Power Selector is a trademark of Maxim Integrated
Products, Inc.
Features
S Li+ Charger with Smart Power Selector, No
External MOSFETs Needed
S ^{Monitors Battery Temperature and Adjusts Charge}
Current and Termination Voltage Automatically
per JEITA Recommendations
S ^{OT Flags System of a Hot Battery During}
Discharge
S ^{Ultra-Low I}Q^{, Always-On 3.3V LDO}
S Common or Separate USB and Adapter Inputs
S Automatic Adapter/USB/Battery Switchover
S Load Peaks in Excess of Adapter Rating are
Supported by Battery
S ^{Input OVP to 16V (DC) and 9V (USB)}
S 40mI SYS-to-BATT Switch
S Thermal Regulation Prevents Overheating
S 4.35V SYS Regulation Voltage
Ordering Information
PART
TEMP RANGE PIN-PACKAGE
MAX8934GETI+
-40NC to +85NC 28 Thin QFN-EP**
+Denotes a lead(Pb)-free/RoHS-compliant package.
**EP = Exposed pad.
Typical Operating Circuit
AC
ADAPTER
USB
DC Q1
USB Q2
LDO
3.3V ALWAYS-ON
LINEAR
REGULATOR
SYS
CHARGE
CURRENT
LOAD
CURRENT
Q3
CHARGE
AND
SYS LOAD
BATT
SWITCH
GND
MAX8934G
SYSTEM
LOAD
BATTERY
________________________________________________________________ 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.