CS5201−1

http://onsemi.com

4

10

Temperature (°C)

Frequency (Hz)

Figure 7. Adjust Pin Current vs.

Temperature

Figure 8. Ripple Rejection vs. Frequency

Time (mS)

Figure 9. Transient Response

Figure 10. Short Circuit Current vs.

85

3.5

300

0

70

65

60

55

50

45

40

0

20 30 40 50 60 70 80 90 100 110 120 130

75

65

55

45

35

25

15

3.3

3.1

2.9

2.7

2.5

2.3

2.1

1.9

1.7

1.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

200

100

0

−100

−200

1000

500

0

12

345

67

89

10

APPLICATIONS INFORMATION

The CS5201−1 linear regulator provides adjustable voltages

at currents up to 1.0 A. The regulator is protected against

overcurrent conditions and includes thermal shutdown.

The CS5201−1 has a composite PNP−NPN output

transistor and requires an output capacitor for stability. A

detailed procedure for selecting this capacitor is included in

the Stability Considerations section.

Adjustable Operation

The CS5201−1 has an output voltage range of 1.25 V to

5.5 V. An external resistor divider sets the output voltage as

shown in Figure 11. The regulator maintains a fixed 1.25 V

(typical) reference between the output pin and the adjust pin.

A resistor divider network R1 and R2 causes a fixed current

to flow to ground. This current creates a voltage across R2

that adds to the 1.25 V across R1 and sets the overall output

voltage. The adjust pin current (typically 50

mA) also flows

through R2 and adds a small error that should be taken into

The output voltage is set according to the formula:

VOUT + VREF

R1 ) R2

R1

) IAdj

R2

pin current.