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Pin Function

1+Vin

2–Vin

3

EN 1

4

EN 2

5

TEMP

6

Pin Not Present

7

Do Not Connect

PT4850 Series

25-A Triple Output Isolated DC/DC

Converter For Logic Applications

Pin Function

10

11

12

COM

13

COM

14

COM

15

16

17

18

COM

On/Off Enable Logic

Pin Configuration

Pin Descriptions

Pin 3

Pin 4

Output Status

1×

Off

01

On

×0

Off

Notes:

Logic 1 =Open circuit

Logic 0 = –Vin (pin 2) potential

For positive Enable function, connect pin 3

to pin 2 and use pin 4.

For negative Enable function, leave pin 4

open and use pin 3.

+Vin:

The positive input supply for the module with

respect to –Vin. When powering the module from a

–48V telecom central office supply, this input is

connected to the primary system ground.

–Vin:

The negative input supply for the module, and

the 0VDC reference for the EN 1, and EN 2 inputs.

When powering the module from a +48V supply,

this input is connected to the 48V(Return).

EN 1:

The negative logic input that activates the

module output. This pin must be connected to –Vin

to enable the module’s outputs. A high impedance

disables the module’s outputs.

EN 2:

The positive logic input that activates the

module output. If not used, this pin should be left

open circuit. Connecting this input to –Vin disables

the module’s outputs.

TEMP:

This pin produces an output signal that tracks

a temperature that is approximately the module’s

metal case. The output voltage is referenced to –Vin

and rises approximately 10mV/°C from an intital

value of 0.1VDC at –40°C. The signal is available

whenever the module is supplied with a valid input

voltage, and is independant of the enable logic status.

Ω will adversly

affect the module’s over-temperature shutdown threshold.

Use a high-impedance input when monitoring this signal.)

Vo 1:

The highest regulated output voltage, which is

referenced to the COM node.

Vo 2:

The regulated output that is designed to power

logic circuitry. It is referenced to the COM node.

Vo 3:

The low-voltage regulated output that provides

power for a µ-processor or DSP core, and is refer-

enced to the COM node.

COM:

The secondary return reference for the module’s

three regulated output voltages. It is DC isolated from

the input supply pins.

than the preset value. If not used, this pin should be

left open circuit.

proves the load regulation of the applicable output

by allowing the regulation circuit to compensate for

voltage drop between the converter and load. If

desired these inputs may be left disconnected.

Note: Shaded functions indicate those pins that are at primary-side potential.

Pin Function

19

COM

20

COM

21

22

23

24

25

26

Do Not Connect

SLTS166C - FEBRUARY 2002 - REVISED MARCH 2003

Environmental Specifications

Characteristics

Symbols

Conditions

Min

Typ

Max

Units

Operating Temperature Range

–40

—

°C

Case Temperature

—

—

105

°C

Storage Temperature

—

–40

—

+125

°C

Over Temperature Protection

OTP

Case temperature

—

110

125

°C

Mechanical Shock

Per Mil-STD-883D, Method 2002.3

—

500

—

G’s

1 msec, ½ Sine, mounted

Mechanical Vibration

Mil-STD-883D, Method 2007.2

Suffix N

—

—

G’s

20-2000 Hz

Suffix A, C

—

—

Weight

—

Vertical/Horizontal

—

90

—

grams

Flammability

—

Meets UL 94V-O

Notes:

(i) See SOA curves or consult factory for appropriate derating.

(ii) The case pins on through-hole pin configurations (N & A) must be soldered. For more information see the applicable package outline drawing.