NJW4100

-13 -

Ver.2005-01-20

7. Reference Voltage Block (VREF pin)

This block generates 1.24V and 4.2V reference voltages. The VREF pin outputs 1.24V. In addition to the IC internal

reference voltage, this is also used as a reference voltage for charge current setting and temperature detection setting.

8. Power Block,

An integrated

incorporates a 200mV hysteresis width to prevent chattering.

As required, insert a bypass capacitor near the IC's V

9. LED Block (LED-R pin, LED-G pin)

The 2 LEDs can indicate charge status. (Figure 5)

The LED drive circuit is an open collector output configuration.

Therefore, it is easy to set a constant LED drive current with resistance values.

The expression for setting the current that flows through the LEDs is shown below.

or

Figure 5. LED Drive Circuit

LED-G

LED-R

Input