TCM320AC46

GENERALPURPOSE AUDIO INTERFACE FOR DSP

SLWS001 − D4091, JUNE 1993

POST OFFICE BOX 655303

POST OFFICE BOX 1443

4

general information

system reliability features

The device should be powered up and initialized as follows:

1.

GND is applied.

2.

3.

All clocks are connected.

4.

TTL high is applied to PDN.

5.

FSX and/or FSR synchronization pulses are applied.

Even though the device is heavily protected against latch-up, it is still possible to cause it to latch-up under

certain improper power conditions where excess current is forced into or out of one or more terminals. To assure

supply) and GND.

On the transmit channel, digital outputs DOUT and TSX are held in the high-impedance state for approximately

four frames (500

functional and occur in the proper time slot. The analog circuits on the transmit side require approximately 60

ms to reach their equilibrium value due to the autozero circuit settling time. To further enhance system integrity,

DOUT and TSX are placed in the high-impedance state after an interruption of CLK.

power-down and standby operations

To minimize power consumption, a power-down mode and three standby modes are provided.

For power down, an external low signal is applied to PDN. In the absence of a signal, PDN is internally pulled

up to a high logic level and the device remains active. In the power-down mode, the average power consumption

is reduced to 3 mW.

The standby modes give the user the options of putting the entire device on standby, putting only the transmit

channel on standby, or putting only the receive channel on standby. To place the entire device on standby, both

FSX and FSR are held low. For transmit-only operation, FSX is pulsed and FSR is held low. For receive-only

operation, FSR is pulsed and FSX is held low. In the standby mode with both transmit and receive on standby,

power consumption is reduced to 8 mW. See Table 1 for power-down and standby procedures.