Datasheet

= V

' = I

- -

DAC161P997

(Slave)

DIN

DBACK

ACKB

COMD

Master

pri_tx_b

pri_rx_b

DAC161P997

SNAS515E –JULY 2011–REVISED OCTOBER 2013

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The SWIF link realization using opto-couplers (opto-isolators) is shown in Figure 30. Points of note here are: the

opto-couplers invert the SWIF symbol waveform, and there is increased power consumption due to the relatively

large currents required to turn on the internal diodes and standing current in the pull-up resistors.

Figure 30. SWIF Link Realized with Octo-couplers

Transformer Selection and SWIF Data Link Circuit Design

In general, the transformers developed for T1/E1 telecom applications are well suited as the interface element for

the DAC161P997 in the galvanically isolated industrial transmitter. The application circuit schematic utilizing

T1/E1 transformer as the isolation element is shown in Application Circuit Examples. A number of suggested off

the shelf transformers are listed in Table 2.

Table 2. Examples of Transformers Suitable in the DAC161P997 Applications

Manufacturer P/N L

(mH) L

(µH) R

(O) C

(pF) Isolation Voltage (Vrms)

Pulse TX1491 1.2 1.2 2.7 35 1500

Coilcraft S5394–CLB 0.4 Not Specified 0.95 0.92 1500

Halo TG02-1205 1.2 Not Specified 0.7 30 1500

XFMRS XF7856-GD11 0.785 0.5 0.52 Not Specified 1500

Model suitable for simulating the behavior of the pulse transformer is shown in Figure 31. The model parameters

are readily available in the datasheets provided by the transformer manufacturers, see Table 2 for examples.

Figure 31. Pulse Transformer Model - Winding Ratio 1:1

Product Folder Links: DAC161P997