APM8601

DUAL CHANNEL SINGLE CELL LINEAR LITHIUM BATTERY

CHARGER WITH 28V OVP and PROGRAMMABLE CHARGE

TIMER

APM8601

Document number: DS35138 Rev. 1 - 2

8 of 14

www.diodes.com

December 2010

© Diodes Incorporated

Functional Description (continued)

INPUTS

DC

Pins 12 and 13 are the DC input. This input will allow charging from input voltages between 4.15V and 7V, and can

withstand up to 28V without device damage although charging is disabled above 7.5V (typ.).

USB

Pin 9 is the USB power input. This input will charge with input voltages from 4.15V to 7V. The charging current

drawn from USB is selected using the USEL pin, either at 95mA (1 USB power allocation unit) or 475mA (5 USB power

affect the Prequal current when charging from USB. This pin will also withstand up to 28V, but charging is disabled above

7.5V (typ.).

USB and USEL will be ignored.

GND

System ground connection.

EN

Pin 8 is the enable pin of the device. When pulled low the device will operate normally. When high, the device will

remain in the disabled state. For auto-starting, connect pin 8 directly to GND.

SETI

Pin 2 allows the charge currents to be programmed.

ICHARGE

1500

RSETI

=

respectively):

RSETI

150

IPREQUAL

=

RSETI

112.5

ITOPOFF

=

This pin can also be used to monitor the battery charging current:

RSETI

1000

VSETI

ICHARGE

×

=

THM

The thermistor connection is on pin 3. This allows the battery temperature to be monitored using a 10k NTC

thermistor, which should be placed as close as possible to the battery cell. If no thermistor is used then this input should be

connected directly to ground. The charger will operate when there is less than 315

Ω on this input (i.e., no thermistor

connected); will be disabled when there is between 315

Ω and 3.94kΩ; enabled when between 3.94kΩ and 28.3kΩ; and

disabled above 28.3k

Ω.

0°C

25°C

50°C

Hot trip Cold Trip

3000

25.1

10

4.6

55.1

‐3.2

3250

27.1

10

4.3

52.6

‐1.3

3500

29.3

10

4

50.5

0.5

3750

31.7

10

3.8

48.6

2.0

Resistance in kΩ at

Typical in °C

Thermistor

Beta

Enabled

0

315

Ω

3.94k

28.3k