MAX8814ETA+T Maxim Integrated Products, MAX8814ETA+T Datasheet - Page 6

• 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

28V Linear Li+ Battery Charger with
Smart Autoboot Assistant
The MAX8814 charger uses voltage, current, and ther-
mal-control loops to charge a single Li+ cell and pro-
tect the battery (Figure 1). When a Li+ battery with a
cell voltage below 2.5V is inserted, the MAX8814
charger enters the prequalification stage where it
precharges that cell with 10% of the user-programmed
fast-charge current (Figure 2). When the battery voltage
exceeds 2.5V, the charger soft-starts as it enters the
fast-charge stage. In the MAX8814, the fast-charge
current level is programmed through a resistor from
ISET to GND. As the battery voltage approaches 4.2V,
Figure 1. Functional Diagram
6
6
4.25V TO 28V
2.8kΩ
_______________________________________________________________________________________
_______________________________________________________________________________________
1μF
C1
R2
ISET
IN
OVLO
V
IN
IN
BATT
Detailed Description
MAX8814
V
L
UVLO
VL
V
REF
REGULATOR
VL
GND
REFOK
REF
CURRENT SENSE,
OUTPUT DRIVER,
V
REF
AND LOGIC
EP
the charging current is reduced. Once the battery volt-
age reaches 4.2V, the IC then enters a constant voltage
regulation mode to maintain the battery at full charge.
The thermal-regulation loop limits the MAX8814 die
temperature to +115°C by reducing the charge current
as necessary. This feature not only protects the IC from
overheating, but also allows a higher charge current
without risking damage to the IC.
LOGIC
V
REF
POK
+115°C
TEMPERATURE
SENSOR
200kΩ
200kΩ
Thermal Regulation
BATT
POK
ABO
ABI
EN
BATT
V
I/O
C3
2.2μF
R3
1MΩ
Li+