CX28331 datasheet(11/68 Pages) CONEXANT

11 / 68 page

100985A

Conexant

1-1

1.0 Pin Description

1.1 Pin Assignments

Figures 1-1 (CX28331-1x), 1-2 (CX28332-1x), and 1-3 (CX28333-1x) illustrate

pin assignments for the 80-pin Exposed Thin Quad Flat Package (ETQFP). See

Table 1-1 for the CX2833i-1x pin descriptions.

Figures 1-4 (CX28331-3x), 1-5 (CX28332-3x), and 1-6 (CX28333-3x)

illustrate pin assignments for the 100-pin ETQFP. The 100-pin package adds

more functionality, supporting new features such as Transmit Monitoring and

Transmit Monitoring Status testing. See Table 1-2 for the CX2833i-3x pin

descriptions.

The input/output (I/O) column is coded as follows:

I = Input

O = Output

I/O = Bidirectional

P = Power

NOTE:

All digital inputs and outputs contain 75 k

Ω pull-down resistors.

When a channel is disabled (i.e., the PDx pin is tied low or not connected), all

receive and transmit analog circuitry powers down. Analog inputs (RLINE) are

ignored and analog outputs (TLINE) are high impedance. Digital inputs of a

powered-down channel are still active, but ignored. Overall noise on the device

can be lowered by not driving the digital inputs of a powered-down channel.

NOTE:

When power is disconnected from the device, TLINE pins are low

impedance to ground if driven by more than one forward-bias diode

voltage (0.7 V) below ground. Additionally, driving TLINE, a

forward-bias diode voltage above the VGG pin, creates a low impedance

path from the TLINE pin to the VGG pin. Otherwise, the TLINE pins are

high impedance.

CX28331 Datasheet(PDF) 11 Page - Synaptics Incorporated.