AN2390 datasheet(31/42 Pages) STMICROELECTRONICS

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AN2390

How to use the evaluation board

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The total time was around 99 minutes in which the constant current phase remained for

around 30 minutes. Figure 20 shows the graph of the output current versus time.

Figure 20.

Output Current vs. Time

The variation in the output current was around +/- 10mA and the variation in output voltage

was +/- 20 mV.

3.3.3

NiMH battery charger

The following parameter values are used for the NiMH charger.

The following values are programmed for the different phases:

1) Pre-charging Phase:

Here Vbat <= 1.0 V and charging current: 0.1 C = 200 mA

Charging time taken by the battery: 10 minutes (approximately)

2) Constant Current Phase:

Charging Current = 1 A and Programmed charging time = 2 Hr

Output Current (mA) Vs Time (Minutes)

200

400

600

800

1000

1200

Tim e (Minutes)

Table 8.

Table 8: NiMH battery charger parameters

SL No

Parameter name

Value

Input Parameter

Input Supply Voltage

5 V

Max Input Supply Current

2 A

Output Parameter

Max Battery Output Voltage

1.7 V / cell

Output Current

1000 mA

AN2390 Datasheet(PDF) 31 Page - STMicroelectronics