AP1509

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Characteristics

Symbol

Test Conditions

Min

Typ

Max

Unit

AP1509-ADJ

Output feedback

1.193

1.23

1.28

V

Efficiency

η

76

%

AP1509-3.3V

Output voltage

3.168

3.3

3.465

V

Efficiency

η

78

%

AP1509-5V

Output voltage

4.8

5

5.25

V

Efficiency

η

83

%

AP1509-12V

Output voltage

11.4

12

12.6

V

Efficiency

η

90

%

FUNCTI ON DESCRIPTION

This is the positive input supply for the IC switching regulator. A suitable input bypass

capacitor must be presented at this pin to minimize voltage transients and to supply the

switching currents needed by the regulator.

Ground

Circuit ground.

Output

Internal switch. The voltage at this pin switches between (+VIN – VSAT) and

approximately – 0.5V, with a duty cycle of approximately VOUT / VIN. To minimize

coupling to sensitive circuitry, the PC board copper area connected to this pin should be

minimized.

Feedback

Senses the regulated output voltage to complete the feedback loop.

SD

Allows the switching regulator circuit to be shutdown using logic level signals thus

dropping the total input supply current to approximately150uA. Pulling this pin below a

threshold voltage of approximately 1.3V turns the regulator on, and pulling this pin above

1.3V (up to a maximum of18V) shuts the regulator down. If this shutdown feature is not

needed, the SD pin can be wired to the ground pin.