CX11250 View Datasheet(PDF) - Conexant Systems

Part Name

Description

Manufacturer

CX11250

SmartHSF™ Mobile Modem

Conexant Systems 

Label

AVDD

AGND

POR

VREF

VC

Pin

24

23

30

8

7

CLK

27

PWR+

31

DVDD

26

DGND

25

DIB_P

28

DIB_N

29

RAC1,

9,

TAC1

11

RAC2

10,

TAC2

12

EIR

15

EIC

2

DAC

6

TRDC

5

EIO

21

EIF

22

RXG

4

RXI

3

TXA

18

MOVEN (GPIO1) 32

RBIAS

13

DCF

16

SmartHSF Mobile Modem Data Sheet

Table 3-5. CX20463 LSD Pin Signal Definitions

I/O Type

Signal Name/Description

SYSTEM SIGNALS

PWR

AGND_LSD

It

REF

REF

Analog Power Supply. Connect to the LSD DVDD pin.

LSD Analog Ground. LSD Analog Ground. Connect to AGND_LSD at the

GND_LSD/AGND_LSD tie point and to the analog ground plane.

Power-On Reset. Connect to LSD DVDD pin.

Output Reference Voltage. Connect to VC through C42 and to AGND_LSD through

C45 and C76. Ensure a very close proximity between C42 and C45 and the VREF pin.

Output Middle Reference Voltage. Connect to VREF through V42 and to AGND_LSD

through C44 and C74. Ensure a very close proximity between C44 and the VC pin. Use

a short path and a wide trace to AGND_LSD pin.

DIB INTERFACE SIGNALS

I

PWR

PWR

GND_LSD

I/O

I/O

Clock. Provides input clock, AC-coupled, to the LSD. Connect to DIB transformer

secondary winding undotted terminal through R32 and C26 in series, and through R120

shared with LSD DGND pin through diode D2.

Digital Power Input. Provides unregulated input digital power to the LSD. Connect to

DIB transformer secondary winding dotted terminal through R125, and to GND_LSD

though zener diode D4 and C70 in parallel.

Digital Power. Connect to pin 24 (AVDD), to DIB transformer secondary winding dotted

terminal through R124, and to GND_LSD through C28, C30, and C72 in parallel.

LSD Digital Ground. Connect to DIB transformer secondary winding undotted terminal

through diode D2 in series with R120, and to GND_LSD at the GND_LSD/AGND_LSD

tie point.

Data and Control Positive. Connect to HSD DIB_DATAP through C22 in the DIB and

R34 on the LSD side. DIB_P and DIB_N signals are differential, and ping-pong between

DIB and HSD (half duplex).

Data and Control Negative. Connect to HSD DIB_DATAN through C24 in the DIB and

R36 on LSD side. DIB_P and DIB_N signals are differential, and ping-pong between

DIB and HSD (half duplex).

TIP AND RING INTERFACE

Ia,

Ia

Ia,

Ia

Oa

Oa

Oa

Ia

Oa

Ia

Oa

Ia

Oa

Ot12

Ia

Ia

RING1 AC Coupled and TIP1 AC Coupled. AC-coupled voltage from telephone line

used to detect ring.

Connect RAC1 to the diode bridge AC top connection (RING) through R2 and C2.

Connect TAC1 to the diode bridge AC bottom connection (TIP) through R4 and C4.

RING2 AC Coupled and TIP2 AC Coupled. Not used. Leave open.

Electronic Inductor Resistor. Electronic inductor resistor switch.

Electronic Inductor Capacitor Switch. Internally switched to no connect when pulse

dialing and to ground all other times. This is needed to eliminate pulse dial interference

from the electronic inductor AC filter capacitor.

DAC Output Voltage. Output voltage of the reference DAC.

TIP and RING DC Measurement. Input on-hook voltage (from a resistive divider). Used

internally to extract TIP and RING DC voltage and Line Polarity Reversal (LPR)

information.

Electronic Inductor Output. Calculated voltage is applied to this output to control

offhook, pulse dial, and DC IV mask operation.

Electronic Inductor Feedback. Electronic inductor feedback.

Receiver Gain. Receiver operational amplifier output.

Receive Analog Input. Receiver operational amplifier inverting input.

Transmit Analog Output. Transmit signal used for canceling echo in the receive path.

MOV Enable. Connect to pulse dial voltage protection circuit for Australia/Poland/Italy

use. Leave open if the product is not intended for Australia, Poland, or Italy.

Receiver Bias. Connect to GND through R54.

Resistive Divider Midpoint. Connect to LSD analog ground.

100553B

Conexant

3-19

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