CS52015−1
70
IO = 10 mA
65
60
55
50
45
40
0 10 20 30 40 50 60 70 80 90 100 110 120 130
Temperature (°C)
Figure 7. Adjust Pin Current vs.
Temperature
85
75
65
55
TCASE = 25°C
45
IOUT = 1.5 A
(VIN − VOUT) = 3.0 V
35
VRIPPLE = 1.0 VPP
CAdj = 0.1 mF
25
15
101
102
103
104
105
106
Frequency (Hz)
Figure 8. Ripple Rejection vs. Frequency
300
200
100
0
−100
−200
1500
750
0
0
VOUT = 3.3 V
COUT = CIN = 22 mF Tantalum
CAdj = 0.1 mF
12345678
Time (mS)
Figure 9. Transient Response
9 10
3.5
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 4.5 5.0 5.5 6.0 6.5 7.0
VIN − VOUT (V)
Figure 10. Short Circuit Current vs.
VIN − VOUT
APPLICATIONS INFORMATION
The CS52015−1 linear regulator provides adjustable
voltages at currents up to 1.5 A. The regulator is protected
against overcurrent conditions and includes thermal
shutdown.
The CS52015−1 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 CS52015−1 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 1.25V
(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
account if precise adjustment of VOUT is necessary.
The output voltage is set according to the formula:
ǒ Ǔ VOUT + VREF
R1 ) R2
R1
) IAdj
R2
The term IAdj × R2 represents the error added by the adjust
pin current.
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