CS8101

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7

APPLICATION NOTES

SWITCH

Q1

500 k

W

0.1

mF

500 k

W

100 k

W

100 k

W

RESET

I/O Port

mP

RESET

ENABLE

Figure 6. Microprocessor Control of CS8101 Using External Switching Transistor Q1

CS8101

GND

The ENABLE pin of the CS8101 can be tied to the battery

voltage provided a series resistor is used as shown in Figure 7.

The maximum allowed voltage on the ENABLE pin without

the resistor is 10 V. Direct voltages greater than 10 V applied

to the pin without the series resistor may damage the device.

The system designer should note the turn−on threshold (typ

1.4 V) is on the ENABLE pin. The threshold will be higher

60 k

ENABLE

0.64 V

ON/OFF

Control

10 k

50 k

STABILITY CONSIDERATIONS

The output or compensation capacitor helps determine

three main characteristics of a linear regulator: start−up

delay, load transient response and loop stability.

Figure 8. Test and Application Circuit Showing

Output Compensation

0.1

mF

ENABLE

10

mF

RESET

CS8101

minimum temperature expected.

The capacitor value and type should be based on cost,

availability, size and temperature constraints. A tantalum or

aluminum electrolytic capacitor is best, since a film or

ceramic capacitor with almost zero ESR can cause

instability. The aluminum electrolytic capacitor is the least

expensive solution, but, if the circuit operates at low

temperatures (−25

°C to −40°C), both the value and ESR of

the capacitor will vary considerably. The capacitor

manufacturers data sheet usually provides this information.

should work for most applications, however it is not

necessarily the optimized solution.