M62244FP
11. Setting the voltages
The recharge-start voltage, adapter-detection voltage 1, and adapter-detection voltage 2 can be adjusted to desired
thresholds through the connection of external resistors that adjust the voltages on the Vrchg, Vadp1, and Vadp2
pins, respectively.
When a pin is open, the corresponding voltage is the IC’s internal setting as specified in the electrical
characteristics.
When the Vadp1 pin, Vadp2 pin, and Vrchg pin are open-circuit, the output voltage is the VBG voltage (constant
voltage source used inside the IC) divided by 20 kΩ and 100 kΩ, as shown in section 2, Pin-Internal Equivalent
Circuits. The settings are given below.
<Method of setting>
Let the detection voltages when the recharge-start voltage, adapter-detection voltage 1, and adapter-detection
voltage 2 pins are open-circuit be Vrchg_o (V), Vadp1_o (V), and Vadp2_o (V), respectively, and the required
detection-voltage values be Vrchg_c (V), Vadp1_c (V), and Vadp2_c (V), respectively. The voltage to be applied
to each of the adjustment pins is then obtained by the equations under (1), (2), and (3) below.
(1) Recharge-start voltage
Voltage on the Vrchg pin
Voltage setting on the Vrchg pin (V) =
(2) Adapter-detection voltage 1
(open-circuit)
Vrchg_o
×Vrchg_c
× Vadp1_c
× Vadp2_c
Voltage on the Vadp1 pin
(open-circuit)
Voltage setting on the Vadp1 pin (V) =
(3) Adapter-detection voltage 2
Vadp1_o
Voltage on the Vadp2 pin
(open-circuit)
Voltage setting on the Vadp2 pin (V) =
Vadp2_o
Desired detection values are obtained by using external resistors to apply the voltages obtained by the above
equations to the corresponding pins.
Either connect a resistor between the adjustment pin and ground, or connect one resistor between the Vcvref pin
and adjustment pin and another between the adjustment pin and ground. Note, however, when using the Vcvref pin,
that –5 mA is specified as the maximum load-current for this pin. Take care in selecting the resistor values.
Note: In the descriptions of pins Vrchg, Vadp1, and Vadp2 pins in section 1, Description of pins, decibel units are
used to describe how the voltages on these pins set the detection voltages. The values used in the above
equations are calculated after changing the values as shown below. The calculation is on the assumption
that each pin carries the rated voltage of 1.0 V when in its open-circuit state.
(4) Recharge-start voltage
Vrchg_c
Vrchg_o
=
3.95 → 11.8dB
Voltage on the Vrchg pin
Voltage on the Vrchg pin
(open-circuit)
Rev.1.0, Sep.19.2003, page 14 of 17
RENESAS [ RENESAS TECHNOLOGY CORP ]
