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Features
18V to 36V Input Range
-40° to +100°C Operating Temp
1500 VDC Isolation
88.5% Efficiency
Programmable Output Voltage
6.5V to 17.5V
Remote On/Off
Differential Remote Sense
N+1 Current Sharing
Over-Current Protection
Over-Temperature Protection
Over-Voltage Protection
Solderable Copper Case
Description
The PT4475 Excalibur module
combines state-of-the-art power
conversion technology with un-
paralleled flexibility. Operating off a
standard 24V telecom input, the PT4475
provides a full 100W output at load
currents up to 8.5A, and over the
programmable output voltage range of
6.5V to 17.5V.
The PT4475 features high efficiency,
ultra-fast transient response, and the
capability for true N+1 current sharing.
This product also includes output short
circuit and over-temperature protection.
L
O
A
D
PT4475
+V
sns
+V
out
-V
out
-V
sns
7
8-13
14-19
20
21
25
22
24
23
VID0 - VID4
+V
in
–V
in
1
2
3
Inhibit
C
1
+
PROGRAMMING PINS
+V
OUT
+V
IN
–V
IN
–V
OUT
C
2
Standard Application
C1 = Optional 33F, 100V electrolytic capacitor
C2 = Optional 1F, 100V ceramic capacitor
Programming pins, VID0–VID4, are shown
configured for Vo =12.0V
For normal operation, pin 3 (Inhibit) must be
connected to –Vin.
For operation in N+1 configuration, consult the
related application note.
Pins 6 & 26 are used for N+1 configurations only.
100-W 8.5-A Programmable
Isolated DC/DC Converter
PT4475—24V
SLTS128A
(Revised 9/4/2001)
Specifications
Characteristics
Conditions
PT4475
(T
a=25
°C unless noted)
Symbols
(V
in= 24V, Vo=12.0V unless noted)
Min
Typ
Max
Units
Output Current
Io
Over Vin range (100W max)
0.1
—
8.5 (1)
A
Current Limit
Icl
Vin = 18V
—
10
—
A
Current Sharing
Single line referenced to –Vsense
——±10
%
Input Voltage Range
Vin
Io = 0 to Iomax
18
24
36
V
Output Voltage Tolerance
Vo
Over Vin range, Io =Iomax
Ta =-40 to +100°C case
—
±1.0
±2.0
%Vo
Line Regulation
Regline
Over Vin range @ max Io
—
±0.1
±1.0
%Vo
Load Regulation
Regload
0 to 100% of Io max
—
±0.5
±1.0
%Vo
Vo Ripple/Noise
Vn
Io =Iomax
—
120
150
mVpp
Transient Response
ttr
50% to 75% Iomax @ 0.1A/s
—
N/A
—
Sec
Vo over/undershoot (no ext caps)
—
1.0
—
%Vo
50% to 100% Iomax @1.0A/s
—
200
—
Sec
Vo over/undershoot (no ext. caps)
—
5
—
%Vo
Vo Rise Time
Votr
At turn-on
—
10
mSec
Efficiency
η
Io =5A
—
89
—
%
Switching Frequency
o
—
300
—
kHz
Remote On/Off
Off
referenced to -Vin
+2.5
—
+75.0
VDC
On
-0.5
—
+0.8
Over-Voltage Protection
OVP
Shutdown and latch off
—
125
—
%Vo
Isolation
—
1500
—
VDC
Operating Temperature Range
Tc
Measured at center of case
–40
—
+100
°C
Over-Temperature Shutdown
OTP
Case temperature - Auto reset
—
+110
—
°C
Storage Temperature
Ts
—
-40
—
+125
°C
Reliability
MTBF
Per Bellcore TR-332
1.7
—
10
6
Hrs
50% stress, t =40°C, ground benign
Mechanical Shock
—
Per Mil-STD-883D, Method 2002.3,
—
500
—
G’s
1mS, Half-sine, mounted to a fixture
Mechanical Vibration
—
Vertical (Suffix N)
—
10 (2)
—G’s
(Mil-STD-883D, 20-2000Hz)
Horizontal (Suffixes A, C)
20 (2)
Weight
—
90
—
grams
Notes:
(1) The maximum output current is limited to 8.5A or 100/VOUT, Whichever is less.
(2) Only the case pins on the through-hole package types (suffixes N & A) must be soldered. For more information see the applicable package outline drawing.