Datasheet
© 2009 Microchip Technology Inc. DS22190B-page 19
MCP73213
5.9 Thermal Regulation
The MCP73213 shall limit the charge current based on
the die temperature. The thermal regulation optimizes
the charge cycle time while maintaining device
reliability. Figure 5-1 depicts the thermal regulation for
the MCP73213 device. Refer to Section 1.0
“Electrical Characteristics” for thermal package
resistances and Section 6.1.1.2 “Thermal
Considerations” for calculating power dissipation.
.
FIGURE 5-1: Thermal Regulation.
5.10 Thermal Shutdown
The MCP73213 suspends charge if the die
temperature exceeds +150°C. Charging will resume
when the die temperature has cooled by approximately
10°C. The thermal shutdown is a secondary safety
feature in the event that there is a failure within the
thermal regulation circuitry.
5.11 Status Indicator
The charge status outputs are open-drain outputs with
two different states: Low (L), and High Impedance
(Hi-Z). The charge status outputs can be used to
illuminate LEDs. Optionally, the charge status outputs
can be used as an interface to a host microcontroller.
Table 5-2 summarize the state of the status outputs
during a charge cycle.
5.12 Battery Short Protection
Once a single-cell Li-Ion battery is detected, an internal
battery short protection (BSP) circuit starts monitoring
the battery voltage. When V
BAT
falls below a typical
1.7V battery short protection threshold voltage, the
charging behavior is postponed. 25 mA (typical)
detection current is supplied for recovering from battery
short condition.
Preconditioning mode resumes when V
BAT
raises
above battery short protection threshold. The battery
voltage must rise approximately 150 mV above the
battery short protection voltage before the MCP73213
device become operational.
0
30
60
90
120
150
25 40 55 70 85 100 115 130 145 160
Junction Temperature (°C)
Fast Charge Current (mA)
V
DD
= 9.1V
R
PROG
= 10 kΩ
TABLE 5-2: STATUS OUTPUTS
CHARGE CYCLE
STATE
STAT
Shutdown Hi-Z
Standby Hi-Z
Preconditioning L
Constant Current Fast
Charge
L
Constant Voltage L
Charge Complete - Standby Hi-Z
Temperature Fault 1.6 second 50% D.C.
Flashing (Type 2)
Hi-Z (Type 1)
Timer Fault 1.6 second 50% D.C.
Flashing (Type 2)
Hi-Z (Type 1)
Preconditioning Timer Fault 1.6 second 50% D.C.
Flashing (Type 2)
Hi-Z (Type 1)