ULTRA-LOW VOLTAGE OPERATION CHARGE PUMP IC FOR STEP-UP DC-DC CONVERTER STARTUP

S-882Z Series

Seiko Instruments Inc.

11

If the Schottky diode (SD1) has a large reverse current or if a pull-down resistor is added to the OUT pin of the

DC-DC converter.

Moreover, if a Schottky diode is added between the OUT pin of the S-882Z Series and the power supply pin (VDD

obtained with the above described conditional expression.

Cautions 1.

The S-882Z Series can start up the step-up DC-DC converter more reliably as the discharge

note that the time from when the input power is input until the step-up DC-DC converter

starts becomes longer in this case.

≥ 2.2 V, the minimum value of the operation input voltage (the minimum input voltage value

required for power to be output from the OUT pin of the S-882Z Series) rises from 0.3 V to

0.35 V (refer to Table 6).

Table 6

Discharge Start Voltage

Value

Minimum Operation Input

Voltage Value

Temperature Range

1.8, 2.0 V

0.3 V

−30 to +60°C

1.8 to 2.4 V

0.35 V

−40 to +85°C

Caution The above connection diagram and constant will not guarantee

successful operation. Perform thorough evaluation using the actual

application to set the constant.

Standard Circuit

S-882Z Series

CPOUT

VSS

VIN

OUT

VM

Figure 15

Caution

The above connection diagram and constant will not guarantee successful operation. Perform

thorough evaluation using the actual application to set the constant.