Low Power-Loss Voltage Regulators
Fig.11 Dropout Voltage vs. Junction
Temperature (PQ20WZ11)
0.18
0.17
0.16
0.15
0.14
0.13
0.12
0.11
VIN=3.135V, Vc=2.7V, R1=2kΩ, R2=500Ω, IO=0.5A
0.1
–25 0 25 50 75 100 125
Junction temperature Tj (˚C)
Fig.13 Ripple Rejection vs. Input Ripple
Frequency
80
75
70
PQ20WZ11
65
PQ20WZ51
60
55
50 Tj=25˚C IO=0.3A
45
VIN=5V ei(rms)=0.5V (sine wave)
R1=2kΩ RR=20 log(ei(rms)/eo(rms))
40 R2=0.5kΩ
0.1
1
10
100
Input ripple frequency f (kHz)
Fig.15 Ripple Rejection vs. Output Current
(PQ20WZ11)
80
75
70
65
60
55
Tj=25˚C
50
VIN=5V
R1=2kΩ
45
R2=0.5kΩ
ei(rms)=0.5V
f=120Hz (sine wave)
40
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Output current IO (A)
PQ20WZ51/PQ20WZ11
Fig.12 Quiescent Current vs. Junction
Temperature
5
VIN=5V
IO=0A
4
VC=2.7V
R1=2kΩ
R2=500Ω
3
2
1
0
–25 0 25 50 75 100 125
Junction temperature Tj (˚C)
Fig.14 Ripple Rejection vs. Output Current
(PQ20WZ51)
80
75
70
65
60
55
Tj=25˚C
50
VIN=5V
R1=2kΩ
45
R2=0.5kΩ
ei(rms)=0.5V
f=120Hz (sine wave)
40
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Output current IO (A)
Fig.16 Circuit Operating Current vs. Input
Voltage (PQ20WZ51)
20 Vc=2.7V,
R1=2kΩ, R2=500Ω
(Vo=3.3V)
15
RL =6.6Ω
10
RL =11Ω
5
RL =∞Ω
0
01 2 345 6
Input voltage VIN (V)