MAX8900BEWV+T Maxim Integrated Products, MAX8900BEWV+T Datasheet - Page 26

• Manufacturer Part Number: MAX8900BEWV+T
• Description: IC LI-ION/POLY BATT CHRGR 30WLP
• Manufacturer: Maxim Integrated Products

Specifications of MAX8900BEWV+T

• Function: Battery Monitor
• Battery Type: Lithium-Ion (Li-Ion), Lithium-Polymer (Li-Pol)
• Voltage - Supply: 3.4 V ~ 8.7 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 30-WLP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Thermal foldback maximizes the battery charge current
while regulating the MAX8900_ junction temperature. As
shown in Figure 12, when the die temperature exceeds
T
charge-current target by A
rent reaches 25% of the fast-charge current setting. The
charger maintains 25% of the fast-charge current until
the die temperature reaches T
the MAX8900_ is rated for a maximum ambient tempera-
ture of +85NC. Furthermore, although the maximum die
temperature of the MAX8900_ is +150NC, it is common
industry practice to design systems in such a way that
the die temperature never exceeds +125NC. Limiting the
maximum die temperature to +125NC extends long-term
reliability.
As shown in Figure 12, when the MAX8900_ die tempera-
ture exceeds T
1.2A Switch-Mode Li+ Chargers with ±22V Input
Rating and JEITA Battery Temperature Monitoring
26
Figure 11. Thermistor Monitor Detail
REG
R
THRM
A. BASIC THERMISTOR CONFIGURATION
, a thermal limiting circuit reduces the battery
R
TB
T
SHDN
AVL: E5
THM: E4
, the IC goes into thermal shutdown.
AVL
TREG
ANALOG SUPPLY
AVL IS THE
INTERNAL
SHDN
, until the charge cur-
COLD: T1
COOL: T2
WARM: T3
HOT: T4
Thermal Shutdown
Thermal Foldback
. Please note that
THERMOMETER
DECODE LOGIC
MAX8900_
CONTROLLER
TO DC-DC
CHARGE
BAT_T
R
B. ADVANCED THERMISTOR CONFIGURATION
TP
During shutdown, the step-down charger is off and all
internal blocks except the bias circuitry is turned off. Once
the junction has cooled by 15NC, the IC resumes operation.
Figure 12. Charge Current vs. Junction Temperature
T
R
R
TB
TS
R
THRM
AVL: E5
THM: E4
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
50
I
I
FC
FC
vs. JUNCTION TEMPERATURE
= 0.756A
= 1.19A
75
AVL
CHARGE CURRENT
ANALOG SUPPLY
100
AVL IS THE
INTERNAL
T
J
(°C)
COLD: T1
COOL: T2
WARM: T3
HOT: T4
125
T2 < V
THERMOMETER
DECODE LOGIC
150
THM
MAX8900_
< T3
175
CONTROLLER
TO DC-DC
CHARGE
BAT_T