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5
SLTS165E - FEBRUARY 2002 - REVISED MARCH 2003
PT4822
—
48V
35-W Triple Output Isolated DC/DC
Converter for Logic Applications
PT4822 Electrical Specifications
(Unless otherwise stated, the operating conditions are: T
a
=25°C, V
in
=48V, and I
o
=0.5I
o
max)
PT4822
Typ
Characteristics
Symbols
Conditions
Min
Max
Units
Output Current
I
o
Each output
Io
1
(3.3V)
Io
2
(1.8V)
Io
3
(1.5V)
0.25
(1)
0.1
0.1
—
36
—
3.24
1.76
1.47
—
—
—
—
—
—
—
—
—
—
—
—
—
—
350
—
—
—
—
—
—
—
—
—
3.3
1.8
1.5
±0.5
±0.5
±0.1
±0.1
—
—
86
40
25
25
200
3
±10
14
400
35.5
34
140
(4)
8
6
6
12
75
80
3.36
1.84
1.53
—
—
±0.5
±0.5
±3
(3)
±3
(3)
—
—
—
—
—
—
—
—
450
—
—
—
(2)
(2)
(2)
(1)
(1)
A
Total (Io
1
+ Io
2
+ Io
3
)
Continuous
Surge (1 minute)
(2)
A
Input Voltage Range
V
in
V
Set-Point Voltage
V
o
Vo
1
Vo
2
Vo
3
Vo
1
V
Temperature Variation
Reg
temp
–40°C
≤
T
a
≤
+85°C, I
o
=I
o
min
%V
o
Vo
2
/Vo
3
Line Regulation
Load Regulation
Total Output Voltage Variation
Reg
line
Reg
load
V
o
tol
All outputs, Over V
in
range
All outputs, 0
≤
I
o
≤
I
o
max
Includes set-point, line, load,
–40°C
≤
T
a
≤
+85°C
Io
1
=6A, Io
2
=2A, Io
3
=2A
%V
o
%V
o
Vo
1
%V
o
Vo
2
/Vo
3
Efficiency
V
Ripple/Noise
(0 to 20MHz bandwidth)
η
V
n
%
Vo
1
Vo
2
Vo
3
mV
pp
Transient Response
t
tr
V
os
V
o
adj
I
TRIP
s
V
on
V
off
t
on
0.1A/μs load step, 50% to 75% I
o
max
V
o
over/undershoot
μSec
%V
o
%V
o
A
kHz
V
Output Adjust Range
Over-Current Threshold
Switching Frequency
Under Voltage Lockout
Vo
1
/Vo
2
/Vo
3
Total, all outputs. Reset with auto-recovery
Over V
in
and I
o
ranges
V
in
increasing
V
in
decreasing
V
in
=48V step
Referenced to –V
in
(pin 4)
Turn-On Time
Enable Control (pins 1 & 2)
High-Level Input Voltage
Low-Level Input Voltage
Low-Level Input Current
Standby Input Current
Internal Input Capacitance
External Output Capacitance
ms
V
IH
V
IL
I
IL
I
in
standby
C
int
Co
1
Co
2
Co
3
V
iso
C
iso
R
iso
4
–0.2
—
—
—
0
0
0
1500
—
10
—
—
1
1
1.14
220
220
220
—
2,200
—
15
(5)
0.8
2
5
—
1,000
(6)
1,000
(6)
1,000
(6)
—
—
—
V
mA
mA
μF
pins 1 & 2 open circuit
μF
Primary/Secondary Isolation
V
pF
M
Notes:
(1) The converter will operate down to no load with reduced specifications.
(2) The sum-total current from outputs Vo
1
, Vo
2
, and Vo
3
cannot exceed 12ADC.
(3) Limits are specified by design.
(4) Measured from the application of the input voltage to the instance that all outputs are in regulation.
(5) The Enable inputs (pins 1 & 2) have internal pull-ups. Leaving pin 1 open-circuit and connecting pin 2 to –V
in
allows the the converter to operate when
input power is applied. The maximum open-circuit voltage is 4V.
(6) Ultra-low ESR capacitors, such as organic or polymer aluminum electrolytic types, may cause instability. Consult the factory before using.