Low Power-Loss Voltage Regulators
Fig. 5 Output Voltage Adjustment
Characteristics (Typical value)
30
R1 390Ω
25
20
15
10
5
0
101
102
103
104
105
R2 (Ω)
Fig. 7 Dropout Voltage vs. Junction
Temperature
0.7
R1=390Ω,R2=2.7kΩ
0.6
VIN ; 0.95VO
0.5
0.4
IO=3A
0.3
2A
0.2
1A
0.1
0.5A
0
–25 0 25 50 75 100 125
Junction temperature Tj (˚C)
Fig. 9 Ripple Rejection vs. Output Current
90
Cref=3.3µF
80
70
No Cref
60
50 Tj=25˚C
R1=390Ω,R2=2.7kΩ
40 VIN=12V,ei(rms)=0.5V,f=120Hz
0
1
2
3
Output current IO (A)
PQ30RV31
Fig. 6 Output Voltage vs. Input Voltage
15 R1=390Ω,R2=2.7kΩ,Tj=25˚C
10
RL=∞
5
RL=3.3Ω
0
0
5
10
15
20
Input voltage VIN (V)
Fig. 8 Ripple Rejection vs. Input Ripple
Frequency
90
Cref=3.3µF
80
70
No Cref
60
50
40
30
20
Tj=25˚C,VIN=12V
10 R1=390Ω,R2=2.7kΩ
0 IO=0.5A,ei(rms)=0.5V
0.1
1
10
100
Input ripple frequency f (kHz)
1000
Fig.10 Output Peak Current vs. Dropout
Voltage (Typical value)
7
6.5
6
5.5
5
4.5
R1=390Ω,R2=2.7kΩ,Ta=25˚C
4
0 1 234 5 6 7 8
Dropout voltage Vi–O (V)
9 10