MAX8814ETA+T Maxim Integrated Products, MAX8814ETA+T Datasheet - Page 8

• Manufacturer Part Number: MAX8814ETA+T
• Description: IC LI+ BATT CHARGER 28V 8-TDFN
• Manufacturer: Maxim Integrated Products

Specifications of MAX8814ETA+T

• Function: Charge Management
• Battery Type: Lithium-Ion (Li-Ion)
• Voltage - Supply: 0 V ~ 28 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-TDFN Exposed Pad
• Product: Charge Management
• Operating Supply Voltage: 4.25 V to 6.8 V
• Supply Current: 0.23 mA
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Charge Safety Timers: No
• Mounting Style: SMD/SMT
• Temperature Monitoring: No
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

The maximum charging current is programmed by an
external resistor connected from ISET to GND (R
Calculate R
where I
ohms. ISET can be used to monitor the fast-charge cur-
rent level. The output current from ISET is 877.2µA per
ampere of charging current. The output voltage at ISET
is proportional to the charging current:
The voltage at ISET is nominally 1.4V at the selected
fast-charge current and falls with charging current as
the cell becomes fully charged or as the thermal-regu-
lation circuitry activates.
28V Linear Li+ Battery Charger with
Smart Autoboot Assistant
Figure 3. Microprocessor-Interfaced Li+ Battery Charger
8
_______________________________________________________________________________________
FAST-CHARGE
ISET
FACTORY TEST
AC ADAPTER
R
V
Applications Information
as follows:
FIXTURE
ISET
ISET
GND
OR
=
=
Charge-Current Selection
is in amperes and R
I
I
FAST CHARGE
CHARGE
1596
10kΩ
−
R1
1140
V
0.1μF
1μF
×
C1
C2
R
ISET
IN
ABO
ABI
GND
ISET
ISET
is in
EP
MAX8814
).
ISET
Connect a ceramic capacitor from BATT to GND for
proper stability. Use a 2.2µF X5R ceramic capacitor for
most applications. Connect a 1µF ceramic capacitor
from IN to GND. Use a larger input bypass capacitor
for high charging currents to reduce supply noise.
The MAX8814 is available in a thermally enhanced
TDFN package with an exposed paddle. Connect the
exposed paddle to a large copper ground plane to pro-
vide a thermal contact between the device and the cir-
cuit board for increased power dissipation. The exposed
paddle transfers heat away from the device, allowing the
IC to charge the battery with maximum current, while
minimizing the increase in die temperature.
The MAX8814 operates from a well-regulated DC
source. The full charging input voltage range is 4.25V
to 7V. The device can withstand up to 28V on the input
without damage to the IC. If V
internal overvoltage-protection circuitry disables charg-
ing until the input falls below 7V. An appropriate power
supply must provide at least 4.25V at the desired peak
charging current.
R2
2.8kΩ
BATT
POK
EN
C3
2.2μF
10kΩ
R4
VI/O
R3
1MΩ
Li+
C4
0.1μF
Thermal Considerations
ON
GPIO
GPIO
ADC
Capacitor Selection
IN
SUPPLY
POWER
SYSTEM
DC Input Sources
is greater than 7V, the