MC145572APB Freescale Semiconductor, MC145572APB Datasheet - Page 12

• Manufacturer Part Number: MC145572APB
• Description: IC ISDN INTERFACE TXCVER 44-LQFP
• Manufacturer: Freescale Semiconductor
• Type: Transceiverr

Specifications of MC145572APB

• Protocol: RS232
• Voltage - Supply: 5V
• Mounting Type: Surface Mount
• Package / Case: 44-LQFP
• Number Of Line Interfaces: 1
• Control Interface: HDLC
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Number Of Drivers/receivers: -
• Lead Free Status / Rohs Status: Not Compliant

application speciÞc parameters (i.e., primary protection) may cause some variation in transformer
2.1
The U-Interface is implemented with MotorolaÕs single chip MC145572 U-Interface Transceiver (U10 on
the NT1 and U1 on the LT side), providing ISDN Basic Rate Access capability for twisted-pair loops with
conformance to ANSI T1.601-1992. For additional speciÞcations on designing with and the operation of
the MC145572, refer to the MC145572 U-Interface Transceiver data sheet in addition to this document.
2.1.1
While the published speciÞcations for the U-Interface Transformer are intended as such, it is realized that
speciÞcations or published line interface values. Figure 2-1 (representing the NT) and Figure 2-2
(representing the LT) show the suggested architecture of the line interface. The schematic gives the
corresponding values used to interface the MC145572 to the line using Pulse Engineering PE68628
transformer. Currently all resistor values are accurate to 1%.
Secondary protection on the MC145572EVK for the NT1 side and the LT side are implemented using a
simple diode bridge consisting of four MMBD7000LT1s (D5, D6 on LT side and D18, D19 on NT1 side) to
clamp voltage surges to the power supply rail and to ground. Two populated two surge suppressors (D14,
D15, D22 on the NT1 side and D1, D2, D7 on the LT side) are on the line side of the transformer. The
circuit board has been laid out to allow resistors to be included in the line side circuitry to provide voltage
spike and power cross protection. These resistors, R17, R21 on the NT side and R1, R6 on the LT side,
are populated and jumpers are installed at JP8, JP11 on the NT1 side and JP3, JP20 on the LT side. The
jumpers can be inserted if it is desired to bypass the line side protection circuitry. The MC145572EVK
does not directly address the issue of primary protection.
Refer to the MC145572EVK Printed Circuit Board and to the MC145572 U-Interface
Transceiver data sheet to supplement this section. Please contact the factory before
committing design to PCB to be guaranteed notiÞcation of any improvements to the following
circuitry. The schematic of the MC145572EVK is in Appendix A of this manual.
U-INTERFACE
Line Interface Circuitry
Freescale Semiconductor, Inc.
For More Information On This Product,
HARDWARE REFERENCE
Go to: www.freescale.com
NOTE
MC145572EVK
2
13