2-247

Preliminary Information

MH88632

Table 3: Input Impedance Settings

Note 1: NA indicates high impedance (10k

Ω) connection to this pin does not effect the resulting network balance.

Note 2: See Figure 4 & 5 for Applications Circuits

Table 4: Network Balance Settings

.

Note 1: NA indicates high impedance (10k

Ω) connection to this pin does not effect the resulting network balance.

Note 2:Low indicates Logic Low.

Note 3: See Figures 6 and 7 for Application Circuit.

Table 5: Control Decode Table

Note 1: VT - VR = Differential voltage from Tip to Ring VR - VT = Differential voltage from Ring to Tip

Note 2: Low indicates Logic Low. High indicates logic High.

Note 3: See Figures 8 & 10 for Application Circuit.

Table 6: Loop Current Setting

Note 1: VT - VR = Differential voltage from Tip to Ring VR - VT = Differential voltage from Ring to AGND

Note 2: A > -B indicates that “A” is less negative than “-B”. A<-B indicates that “A” is more negative than “-B”.

Note 3:Low indicates Logic Low. High indicates logic High.

Note 4: See Figure 8 for Application Circuit.

Z2

Z1

Z600

Z900

NA

Connect Z1 to Z600

NA

600

Ω

NA

Connect Z1

to Z9000

NA

Connect Z1

to Z900

900

Ω

Connect network from Z1 to Z2

NA

NA

0.1 x impedance between Z1 & Z2

NS (Input)

N2

N1

NATT

Low

NA

NA

NA

High

NA

Connect N1 to NATT

AT&T compromise (350

Ω + 1kΩ // 210nF)

Zin must be 600

Ω

High

Connect network from N1 to

AGND equivalent to 10 x

NETBAL. Connect network

from N1 to N2 equivalent to 10

NA

0.1 x impedance between N1 & N2

Loop Status

Loop Condition

LRC (Input)

FL (Output)

RL (Output)

Forward Battery

VT-VR > 40 V

Low

Low

High

Forward Current

VT-VR > 3.4 V

High

Low

High

Reverse Battery

VR-VT > 40V

Low

High

Low

Forward Current

VR-VT > 3.4 V

High

High

Low

No Battery

IVT-VRI > 1.0 V

Low

High

High

No Current

IVT-VRI > 10 V

High

High

High

Not Valid

No Condition

High or Low

Low

Low

Loop Status

Loop Condition

RG (Output)

TG (Output)

Ring and Tip open

VT-VG > -14 V

VR-VG < -14V

High

High

Ring Ground and Tip

Open

VR-VG > -12 V

VT-VG < -14V

Low

High

Tip Ground and Ring

Open

VT-VG > -12 V

VR-VG < -14V

High

Low

Ring and Tip Ground

VR-VG > -12 V

VT-VG < -12V

Low

Low