Datasheet
28 Maxim Integrated
Dual-Input Linear Chargers, Smart Power Selector
with Advanced Battery Temperature Monitoring
MAX8934A–MAX8934E
Always-On LDO
The ultra-low quiescent current LDO is always on and is
preset to an output voltage of 3.3V. The LDO provides
up to 30mA output current. When DC and USB are inval-
id and the battery is discharging, the LDO output volt-
age tracks V
SYS
as it drops below 3.3V. A 1FF ceramic
capacitor connected from LDO to GND is recommended
for most applications.
PCB Layout and Routing
Good design minimizes ground bounce and voltage
gradients in the ground plane. GND should connect to
the power-ground plane at only one point to minimize the
effects of power-ground currents. Battery ground should
connect directly to the power-ground plane. Connect
GND to the exposed pad directly under the IC. Use mul-
tiple tightly spaced vias to the ground plane under the
exposed pad to help cool the IC. Position input capaci-
tors from DC, SYS, BATT, and USB to the power-ground
plane as close as possible to the IC. Keep high current
traces such as those to DC, SYS, and BATT as short and
wide as possible. Refer to the MAX8934 Evaluation Kit
for a suitable PCB layout example.
Chip Information
PROCESS: BiCMOS
Table 3. Package Thermal Characteristics
Pin Configuration
Selector Guide
**For safety region 2, contact factory.
†For thermistor Beta = 3477, contact factory.
+Denotes a lead(Pb)-free/RoHS-compliant package.
*EP = Exposed pad.
Ordering Information
28-PIN 4mm x 4mm THIN QFN
SINGLE-LAYER PCB MULTILAYER PCB
Continuous
Power
Dissipation
1666.7mW
(derate 20.8mW/NC
above +70NC)
2286mW
(derate 28.6mW/NC
above +70NC)
B
JA
48NC/W 35NC/W
B
JC
3NC/W 3NC/W
MAX8934A–
MAX8934E
THIN QFN
TOP VIEW
26
27
25
24
10
9
11
DC
CEN
PEN1
PEN2
PSET
12
DONE
BATT
USB
LDO
BATT
THMSW
THMEN
1
*EP
*EXPOSED PAD
2
OT
4567
2021 19 17 16 15
DOK
UOK
USUS
ISET
CT
GND
DC
USB
3
18
28
8
FLT
V
L
SYS
23
13
GND
SYS
22
14
THM
CHG
PART TEMP RANGE PIN-PACKAGE
MAX8934BETI+ -40NC to +85NC 28 Thin QFN-EP*
MAX8934CETI+ -40NC to +85NC 28 Thin QFN-EP*
MAX8934DETI+ -40NC to +85NC 28 Thin QFN-EP*
MAX8934EETI+ -40NC to +85NC 28 Thin QFN-EP*
PART
SAFETY
REGION**
SYS VOLTAGE (V)
THERMISTOR
BETA†
TOP-OFF TIMER
USB INPUT CURRENT
LIMIT (max)
MAX8934AETI+ 1 5.3 3964 15s
500mA
MAX8934BETI+ 1 4.35 3477 60min
500mA
MAX8934CETI+ 1 4.35 3964 15s
500mA
MAX8934DETI+ 1 4.35 3477 60min
1.5A
MAX8934EETI+ 1 4.35 3477 15s
500mA