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MA2001A

Major Power Technology Co., Ltd.

Rev.1.1

Nov 23, 2013

Under Voltage Lockout (UVLO)

To avoid mis-operation of the device at low input voltages an under voltage lockout

is included that disables the device, if the input voltage falls below (2.25V-100mV).

Over Voltage Protection

OVP measure the output voltage for open circuit protection. Connect OVP pin

Input Capacitor Selection

The input capacitor reduces the surge current drawn from the input and

switching noise from the device. The input capacitor impedance at the switching

frequency shall be less than input source impedance to prevent high frequency

switching current passing to the input. A low ESR input capacitor sized for maximum

RMS current must be used. Ceramic capacitors with X5R or X7R dielectrics are highly

recommended because of their low ESR and small temperature coefficients. A 2.2uF

ceramic capacitor for most applications is sufficient. For a lower output power

requirement application, this value can be decreased.

Output Capacitor Selection

The output capacitor is required to keep the output voltage ripple small and to

ensure regulation loop stability. The output capacitor must have low impedance at the

switching frequency. Ceramic capacitors with X5R or X7R dielectrics are

recommended due to their low ESR and high ripple current. A 1uF ceramic capacitors

works for most of the applications. Higher capacitor values can be used to improve the

load transient response.