73M1916-IVT/F Maxim Integrated Products, 73M1916-IVT/F Datasheet - Page 60

• Manufacturer Part Number: 73M1916-IVT/F
• Description: Interface - Specialized DAA-FXO VolP SYSTEM LN SIDE
• Manufacturer: Maxim Integrated Products
• Type: MicroDAA with PCM Highwayr

Specifications of 73M1916-IVT/F

• Operating Supply Voltage: 3.3 V
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• Package / Case: QFN-32
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

73M1866B/73M1966B Data Sheet
9 Barrier Information
9.1
The 73M1x66B uses the Teridian MicroDAA proprietary isolation method based upon low-cost pulse
transformer coupling. This technique provides several advantages over other methods, including:
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The MicroDAA has additional and enhanced functionality such as the support of powering the Line-Side
DAA circuit from the Host-Side Device. This allows operation on leased lines circuits and on low current
conditions commonly encountered in long loops. The MicroDAA can also operate entirely from line power
when sufficient loop current is available.
Since the transformer is the only component crossing the isolation barrier, it solely determines the
isolation between the PSTN and the FXO’s digital interface. Several vendors can supply compatible
transformers with ratings up to 6000 V.
Communication of PCM data, control data and status data is performed in the digital domain and is
bidirectional at a rate of 1.536 Mbps.
9.2
The 73M1x66B has the ability to be used either in a Line Powered Mode or one where the Line-Side
Device can be powered across the barrier from the Host-Side Device. The power-on default for the
73M1x66B is Barrier Powered Mode.
9.2.1 Barrier Powered Operation
In this default mode of operation, the 73M1x66B Host-Side Device drives the pulse transformer in such a
way that power pulses are time division multiplexed into the transmit bit stream (half the time) that is
rectified by circuitry in the Line-Side Device and uses this energy to power itself.
9.2.2 Line Powered Operation
If there is sufficient current available from the PSTN line, the 73M1x66B can be programmed to use line
power instead of power from across the barrier.
9.3
Since the communication across the barrier is digital, synchronization of data across the barrier is of
absolute importance. To that end, the devices implement special procedures to ensure reliability across
the barrier.
When loss of synchronization is detected, the SLHS bit is set to 1 and likewise SYNL is also set to 1 and
initiates an interrupt to the host. Once the SYNL bit is asserted a new barrier synchronization sequence
will automatically begin.
Once read, the SLHS bit is reset, but will be set again if the synchronization loss continues.
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Lower BOM cost.
Reduced component count.
Lower radiated noise (EMI).
Improved operation in noisy environments.
Isolation Barrier
Barrier Powered Options
Synchronization of the Barrier
DS_1x66B_001
Rev. 1.6