Philips Semiconductors

Product data

SA57005

Multiple output low noise, low dropout linear regulator

2002 Jun 20

8

APPLICATION INFORMATION

For good performance, the following points must be considered:

Input capacitor

An input capacitor of

≥1 µF is required between the SA57005 input

and the ground (the amount of capacitance may be increased

without limit).

pin (not more than 1 cm) and returned to a clean analog ground.

Any good quality ceramic, tantalum or film capacitor will work.

Output capacitor

Phase compensation is made for securing stable operation even if

the load current varies. For this reason, an output capacitor with

good frequency characteristics is needed at each of the three

outputs. Set it as close to the circuit as possible and make the wiring

as short as possible.

The value of the output capacitance has to be at least 1

µF. Also it

must have the ESR (Equivalent Series Resistance) value within the

stable range shown Figure 8.

PS (Chip Enable) pins

These active-HIGH ON/OFF pins must be actively terminated. If the

function is not to be used, the corresponding PS pin should be tied

same state, either both active or both inactive depending on the

input of PS2/3.

the impedance of these lines is high, there is a chance to pick-up

noise or malfunction.

SA57005

12

34

87

65

1

µF

1

Ω

1

Ω

1

Ω

1

µF

1

µF

1

µF

GND

PS1

PS2/3

NC

SL01706

Figure 11. Typical application circuit.