Tyco MX4428 technical manual MXP Power Supply, MXP Block Diagram

MX4428 MXP Engineering /Technical Manual

Document: LT0273

MXP Technical Description

Switching PSU

+40V ISO

POWER SUPPLY

U11

+5V ISO

U10

24V IN

+V

Q22

+VS

Q17

0V ISO

RL3

D36

C65.C66

D44

0V

opto

24V OUT

R90

Connect / Disconnect

coupler Feedback

0V IN

0V

OC6

D37

0V OUT

0V

U7C, U7D

RESPONDER

D35

MIN V

LOOP

RESPONDER LOOP INTERFACE

OC5

Isolation Barrier

OC1

RL3

opto

U7A

opto

coupler

Watchdog /

CHNL1

coupler

OC3

Reset

opto

Q18, Q20

U8

Generator

Line Drivers /

coupler

Latching

U6

Receivers

Disconn In -

opto OC2

Relay

CHNL2

U7B

coupler

Drive

Data / Address

Q19, Q20

opto

coupler

OC4

Diagnostic

RAM

FLASH

64kb / 256kb

256kb / 512kB

Port

68302 CPU /

U3, U4

U2

Pseudo RS232

Interface

Comms Processor

U1

MICROPROCESSOR and MEMORY

Nosex RX

40VReset

Overload -

AD1..5

Relay

RL1

5 bit D/A

Drive

RL2

Q5, Q6

Convertor

R76-R82

RL1

40V ISO

Overcurrent

Left

Detector /

Modulator

Shutdown

0V ISO

Analog

Q14, Q15

Q12, Q2, Q1,

(NOSEx)

Q4, Q13

RL2

Loop

ANALOG LOOP INTERFACE

Right

Receive

0V ISO

Discriminator

Q3, U13A

Sense

OC7

Return Fault

Figure 7.1 MXP Block Diagram

7.2.3MXP POWER SUPPLY

The raw power to the board is supplied from the 24VIN terminal (via D36) or the 24VOUT terminal (via D34), or both, depending on the Loop conditions.

This voltage "+V" is smoothed and maintained by reservoir capacitors C65, C66, and C71, which store sufficient charge to maintain the circuitry under transient loop fault conditions.

From "+V" the following supplies are derived:

Page 7-4 24 March 2006 Issue 1.5