AN-9721

APPLICATION NOTE

© 2010 Fairchild Semiconductor Corporation

www.fairchildsemi.com

Rev. 1.0.0 • 12/23/10

4

Seiko

Instrument’s

S-5842ADAAQ-I6T1G

temperature

sensor provides a logic 1 on its open-drain DETL pin which,

when connected to the FAN54xx’s DISABLE pin with a

pull-up resistor to VREG, inhibits charging when outside the

allowable temperature range.

DISABLE

PMID

FAN5403

S-5842ADAAQ-I6T1G

VREG

Figure 3.

Temperature Limit IC Inhibits Charging

Below 0°C and Above 60°C

If a thermistor is provided inside the battery pack, the circuit

in Figure 4 raises the DISABLE when battery temperature is

outside the 0°C to 60°C.

DISABLE

U1A

4.7K

β = 3500

VREG

11K

6K

2K

10K

U1B

100K

Figure 4.

Disabling Charge at Temperature

Extremes Using a Thermistor

Some battery vendors allow some charging outside the

JEITA-recommended temperature range if charge current,

time, and voltage are restricted. Consult the battery vendor

for safe charging recommendations.

Related Datasheets

FAN5400 Family

FAN5420 Family.

DISCLAIMER

FAIRCHILD SEMICONDUCTOR RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO ANY PRODUCTS

HEREIN TO IMPROVE RELIABILITY, FUNCTION, OR DESIGN. FAIRCHILD DOES NOT ASSUME ANY LIABILITY ARISING OUT OF THE

APPLICATION OR USE OF ANY PRODUCT OR CIRCUIT DESCRIBED HEREIN; NEITHER DOES IT CONVEY ANY LICENSE UNDER ITS

PATENT RIGHTS, NOR THE RIGHTS OF OTHERS.

LIFE SUPPORT POLICY

FAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS

WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD SEMICONDUCTOR CORPORATION.

As used herein:

1.

Life support devices or systems are devices or systems

which, (a) are intended for surgical implant into the body, or

(b) support or sustain life, or (c) whose failure to perform

when properly used in accordance with instructions for use

provided in the labeling, can be reasonably expected to

result in significant injury to the user.

2.

A critical component is any component of a life support

device or system whose failure to perform can be

reasonably expected to cause the failure of the life support

device or system, or to affect its safety or effectiveness.