Low Power-Loss Voltage Regulators
Fig.11 Dropout Voltage vs. Junction
Temperature (PQ20WZ11)
0.18
0.17
PQ20WZ51/PQ20WZ11
Fig.12 Quiescent Current vs. Junction
Temperature
5
4
3
2
1
0
–25
0
25
50
75 100
Junction temperature T
j
(˚C)
125
V
IN
=5V
I
O
=0A
V
C
=2.7V
R
1
=2kΩ
R
2
=500Ω
Dropout voltage V
i
–O
(V)
0.16
0.15
0.14
0.13
0.12
0.11
0.1
V
IN
=3.135V, Vc=2.7V, R
1
=2kΩ, R
2
=500Ω, I
O
=0.5A
–25
0
25
50
75
100
Junction temperature T
j
(˚C)
125
Fig.13 Ripple Rejection vs. Input Ripple
Frequency
80
75
Ripple rejection RR (dB)
Fig.14 Ripple Rejection vs. Output Current
(PQ20WZ51)
80
75
70
65
60
55
50
45
40
T
j
=25˚C
V
IN
=5V
R
1
=2kΩ
R
2
=0.5kΩ
e
i(rms)
=0.5V
f=120Hz (sine wave)
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Output current I
O
(A)
Ripple rejection RR (dB)
70
65
60
55
50
PQ20WZ51
PQ20WZ11
T
j
=25˚C I
O
=0.3A
V
IN
=5V e
i(rms)
=0.5V (sine wave)
45
R
1
=2kΩ RR=20 log(e
i(rms)
/e
o(rms)
)
R
2
=0.5kΩ
40
0.1
1
10
100
Input ripple frequency f (kHz)
Fig.15 Ripple Rejection vs. Output Current
(PQ20WZ11)
80
75
70
65
60
55
50
45
40
T
j
=25˚C
V
IN
=5V
R
1
=2kΩ
R
2
=0.5kΩ
e
i(rms)
=0.5V
f=120Hz (sine wave)
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Output current I
O
(A)
Ripple rejection RR (dB)
Fig.16 Circuit Operating Current vs. Input
Voltage (PQ20WZ51)
20
Quiescent current I
q
(mA)
Circuit operating current I
BIAS
(mA)
Vc=2.7V,
R
1
=2kΩ, R
2
=500Ω
(Vo=3.3V)
15
R
L
=6.6Ω
10
R
L
=11Ω
5
R
L
=∞Ω
0
0
1
2
3
4
5
Input voltage V
IN
(V)
6
SHARP [ SHARP ELECTRIONIC COMPONENTS ]
