Revision 11/2/2010

Preliminary and all contents are subject to change without prior notice

© Seaward Electronics Inc., 2007. • www.seawardinc.com.cn • Page 5

Typical Operating Characteristics

Icharge Versus Vin

0

50

100

150

200

250

300

350

4

4.5

5

5.5

6

6.5

7

Vin/(V)

Vout Versus Vin

4.245

4.250

4.255

4.260

4.265

4.270

44.5

55.5

66.5

7

Vin/V

Pin Functions

Pin

Pin Function Description

Pin

Pin Function Description

Vin

P Positive Input Supply Voltage. Provides

power to the charger. Vin can range

from 4.75V to 6V and should be

bypassed with at least a 1

μF capacitor.

BAT-

Charge Current Output. Provides charge current to the battery and

regulates the final float voltage to 4.22V. SE9021 will automatically

identify the polarity so this pin can be connected to BAT+ also.

GND

LED4

LED4 is part of the Running Horse display during charging. When the

charging is near completion, about 90%, the flashing frequency would

be increased by about 2X . When the charging is completed, LED4 is

ON.

BAT+

Charge Current Output. Provides

charge current to the battery and

regulates the final float voltage to

4.22V. SE9021 will automatically

identify the polarity so this pin can be

connected to BAT- also.

LED1

LED1 has Dual Functions. It is used also as Battery connection

indicator, when the Battery is properly connected but the power is not

yet connected. When the Power is properly inserted, LED1 joins

LED2/3 as part of the Running Horse display. When the charging is

near completion, about 90%, the flashing frequency would be

increased by about 2X. When the charging is completed, LED1 is ON.

LED2

LED2 is part of the Running Horse

display during charging. When the

charging is near completion, about

90%, the flashing frequency would be

increased by about 2X. When the

charging is completed, LED2 is ON.

LED3

LED3 is part of the Running Horse display during charging. When the

charging is near completion, about 90%, the flashing frequency would

be increased by about 2X . When the charging is completed, LED3 is

ON.