10

Am79R70 Data Sheet

Notes:

two-wire AC input impedance (ZSL) is a 600

Ω resistance synthesized by the programming network shown below.

2. a. Overload level is defined when THD = 1%.

b. Overload level is defined when THD = 1.5%.

matches the programmed impedance.

4. Not tested in production. This parameter is guaranteed by characterization or correlation to other tests.

5. This parameter is tested at 1 kHz in production. Performance at other frequencies is guaranteed by characterization.

group delay to less than 2 µs and increases 2WRL. The effect of group delay on linecard performance may also be compensated

for by synthesizing complex impedance with the QSLAC or DSLAC device.

of the battery selected.

Table 1. SLIC Decoding

(DET) Output

State

C3 C2 C1

2-Wire Status

E1 = 1

E1 = 0

Battery Selection

0

0

0

0

Open Circuit

Ring trip

Ring trip

B2EN

1

0

0

1

Ringing

Ring trip

Ring trip

2

0

1

0

Active

Loop detector

Ground key

3

0

1

1

On-hook TX (OHT)

Loop detector

Ground key

4

1

0

0

Tip Open

Loop detector

Ground key

B2EN = 1**

5

1

0

1

Standby

Loop detector

Ground key

6*

1

1

0

Active Polarity Reversal

Loop detector

Ground key

B2EN

7*

1

1

1

OHT Polarity Reversal

Loop detector

Ground key

Notes:

* Only –1 performance grade devices support polarity reversal.

RT2 = 150 k

Ω

CT1 = 60 pF

RT1 = 150 k

Ω

VTX

RSN

RRX = 300 k

Ω

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