For technical support and more information, see inside back cover or visit www.ti.com
PT5520 Series
1.5-A 5-V/3.3-V Input Adjustable
Integrated Switching Regulator
Specifications
Characteristics
(Unless otherwise stated, T
a
=25°C, V
in
=5V, C
out
=100µF, and I
o
=I
o
max)
Symbols
I
o
V
in
V
o
tol
∆Reg
temp
∆Reg
line
∆Reg
load
∆Reg
tot
η
Conditions
Over V
in
range
Over I
o
range
V
o
=3.3V
V
o
≤2.5V
Min
0.1
(1)
4.5
3.1
—
—
—
—
—
PT5521
PT5522
PT5523
PT5524
PT5525
PT5526
PT5527
—
—
—
—
—
—
—
—
—
—
—
—
V
in
–0.5
–0.2
—
100
(4)
–40
(5)
-40
—
—
—
PT5520 SERIES
Typ
Max
—
—
—
±0.5
—
—
—
89
86
84
83
81
79
76
15
50
50
4
600
(2)
—
—
–0.5
—
—
—
500
15
(7)
6.5
1.5
5.5
5.5
±2
—
±6
±10
±3
—
—
—
—
—
—
—
30
—
100
—
—
Open
(3)
0.5
—
—
+85
(6)
+125
—
—
—
Units
A
V
%V
o
%V
o
mV
mV
%V
o
Output Current
Input Voltage Range
Set-Point Voltage Tolerance
Temperature Variation
Line Regulation
Load Regulation
Total Output Variation
Efficiency
–40°C <T
a
<+85°C
Over V
in
range
Over I
o
range
Includes set-point, line, load,
–40°C
≤
T
a
≤
+85°C
%
V
o
Ripple (pk-pk)
Transient Response
Current Limit
Switching Frequency
Inhibit Control (pin1)
Input High Voltage
Input Low Voltage
Input Low Current
External Capacitance
Absolute Maximum
Operating T
emperature Range
Storage T
emperature
Mechanical Shock
Mechanical Vibration
Weight
Flammability
V
r
t
tr
∆V
tr
I
lim
ƒ
o
V
IH
V
IL
I
IL
C
out
T
a
T
s
20MHz bandwidth
1A/µs load step from 50% to 100% I
o
max
V
o
over/undershoot
Over V
in
and I
o
ranges
Referenced to GND (pin3)
Pin 1 to GND
Over V
in
range
—
Per Mil-STD-883D, Method 2002.3 , 1 msec,
Half Sine, mounted to a fixture
Per Mil-STD-883D, Method 2007.2,
20-2000 Hz, Soldered in a PC board
—
Materials meet UL 94V-0
mV
µSec
mV
A
kHz
V
mA
µF
°C
°C
G’s
G’s
grams
—
—
Notes:
(1) The ISR will operate down to no load with reduced specifications.
(2) This is a typical value only. The switching frequency will vary with input voltage.
(3) The Inhibit control (pin 1) has an internal pull-up, and if left open-circuit the module will operate when input power is applied. A small low-leakage
(<100nA) MOSFET is recommended to control this input. Ensure an On/Off transition time of
≤
10µs. See application notes for more information.
(4) The PT5520 Series requires a 100µF electrolytic or tantalum output capacitor for proper operation in all applications.
(5) For operation below 0°C, the output capacitor C
2
must have stable characteristics. Use either a low ESR tantalum or Oscon® capacitor.
(6) See SOA curves or consult factory for the appropriate derating.
(7) The case pins on the through-hole package types (suffixes N & A) must be soldered. For more information see the applicable package outline drawing.
For technical support and more information, see inside back cover or visit www.ti.com
PT5520 Series
1.5-A 5-V/3.3-V Input Adjustable
Integrated Switching Regulator
Typical Characteristics
Performance Data; V
in
=5.0V
(See Note A)
Efficiency vs Output Current
100
Performance Data; V
in
=3.3V
(See Note A)
Efficiency vs Output Current
100
90
90
Efficiency - %
Efficiency - %
80
70
60
PT5521
PT5522
PT5523
PT5524
PT5525
PT5526
PT5527
80
70
60
PT5522
PT5523
PT5524
PT5525
PT5526
PT5527
50
50
40
0
0.3
0.6
0.9
1.2
1.5
40
0
0.3
0.6
0.9
1.2
1.5
Iout (A)
Iout (A)
Ripple vs Output Current
20
20
Ripple vs Output Current
15
15
10
5
PT5522
PT5523
PT5524
PT5521
PT5525
PT5526
PT5527
10
PT5522
PT5523
PT5524
PT5525
PT5526
PT5527
Ripple - mV
Ripple - mV
5
0
0
0.3
0.6
0.9
1.2
1.5
0
0
0.3
0.6
0.9
1.2
1.5
Iout (A)
Iout (A)
Power Dissipation vs Output Current
1
0.75
Power Dissipation vs Output Current
0.8
0.6
0.6
0.4
PT5521
PT5522
PT5523
PT5524
PT5525
PT5526
PT5527
0.45
0.3
PT5522
PT5523
PT5524
PT5525
PT5526
PT5527
Pd - Watts
0.2
Pd - Watts
0.15
0
0
0.3
0.6
0.9
1.2
1.5
0
0
0.3
0.6
0.9
1.2
1.5
Iout (A)
Iout (A)
Safe Operating Area; V
in
=5.0V
(See Note B)
90.0
80.0
Safe Operating Area; V
in
=3.3V
(See Note B)
90.0
80.0
Ambient Temperature (°C)
70.0
60.0
50.0
40.0
30.0
20.0
0.0
0.3
0.6
0.9
1.2
1.5
Ambient Temperature (°C)
Airflow
200LFM
120LFM
60LFM
Nat conv
70.0
60.0
50.0
40.0
30.0
20.0
0.0
0.3
0.6
0.9
1.2
1.5
200LFM
120LFM
60LFM
Nat conv
Iout (A)
Iout (A)
Note A:
Characteristic data has been developed from actual products tested at 25°C. This data is considered typical data for the ISR.
Note B:
SOA curves represent operating conditions at which internal components are at or below manufacturer’s maximum rated operating temperatures.
For technical support and more information, see inside back cover or visit www.ti.com
Application Notes
PT5500/5520 Series
Adjusting the Output Voltage of the PT5500/20
Series of Excalibur Step-Down ISRs
The output voltage of both the PT5500 and PT5520
series ISRs may be adjusted higher or lower than the
factory trimmed pre-set voltage with the addition of a
single external resistor. Table 1 accordingly gives the
allowable adjustment range for each model for either
series as V
a
(min) and V
a
(max).
Adjust Up:
An increase in the output voltage is obtained by
adding a resistor R
2
, between pin 5 (V
o
adj) and pin 3 (GND).
Adjust Down:
pin 4 (V
out
).
Add a resistor
(R
1
),
between pin 5 (V
o
adj) and
Notes:
1. Use only a single 1% resistor in either the
(R
1
)
or R
2
location. Place the resistor as close to the ISR as possible.
2. Never connect capacitors from V
o
adj to either GND or
V
out
. Any capacitance added to the V
o
adjust pin will
affect the stability of the ISR.
3. For each model, adjustments to the output voltage may
place additional limits on the minimum input voltage.
The revised minimum input voltage must comply with the
following requirement.
V
in
(min) = (V
a
+ 0.5)V or as specified in the data sheet,
whichever is greater.
Figure 1
+ V
IN
2
V in
PT5500
GND
Vo(adj)
Vo
4
+V
O
3
5
C1
1
µF
C e r a m i c
(Optional)
(R1)
Adj Down
C2
1 0 0
µF
(Req'd)
+
R2
Adjust Up
COM
COM
The values of
(R
1
)
[adjust down], and R
2
[adjust up], can
also be calculated using the following formulas. Refer to
Figure 1 and Table 2 for both the placement and value of the
required resistor; either
(R
1
)
or R
2
as appropriate.
(R
1
)
R
2
Where:
=
=
V
o
V
a
R
o
R
s
R
o
(V
a
– 0.9)
V
o
– V
a
0.9 R
o
V
a
– V
o
– R
s
– R
s
kΩ
kΩ
= Original output voltage
= Adjusted output voltage
= The resistance value from Table 1
= The series resistance from T
able 1
Table 1
ISR ADJUSTMENT RANGE AND FORMULA PARAMETERS
3.0 Adc Rated
PT5501
PT5502
PT5503
1.5 Adc Rated
PT5521
PT5522
PT5523
Vo (nom)
Va (min)
Va (max)
Ro (kΩ)
Ω
Rs (kΩ)
3.3
2.88
3.5
10.0
49.9
2.5
1.97
2.95
10.0
20.0
2.0
1.64
2.45
10.0
20.0
PT5504
PT5524
1.8
1.5
2.25
10.0
20.0
PT5505
PT5525
1.5
1.3
1.95
10.0
20.0
PT5506
PT5526
1.2
1.08
1.65
10.0
20.0
PT5507
PT5527
1.0
0.97
1.45
10.2
20.0
For technical support and more information, see inside back cover or visit www.ti.com