MH88634CV-K1 参数 Datasheet PDF下载

MH88634CV-K

Data Sheet

The DC line termination circuitry provides the line with an active DC load termination which is equivalent to a DC

resistance of 280

Ω

at 20 mA.

Ringing Equivalent Number

The Ringing Equivalent Number (REN) is application specific. See the governing regulatory body specification for

details.

Input Impedance

The input impedance (Zin) is the AC impedance that the MH88634CV-K places across Tip and Ring to terminate

the Telephone line. This is fixed at 600

Ω.

Network Balance Impedance

The MH88634CV-K Network Balance Impedance is fixed at 600

Ω.

2-4 Wire Conversion

The device converts the balanced 2-Wire input, presented by the line at Tip and Ring, to a ground referenced signal

at TX. This circuit operates with or without loop current; signal reception with no loop current is required for on-hook

reception enabling the detection of Caller Line Identification (CLI) signals.

Conversely, the device converts the ground referenced signal input at RX, to a balanced 2-Wire signal across Tip

and Ring.

The 4-Wire side (TX and RX) can be interfaced to a filter/codec, such as the Zarlink MT896X, for use in digital voice

switched systems.

During full duplex transmission, the signal at Tip and Ring consists of both the signal from the device to the line and

the signal from the line to the device. The signal input at RX, being sent to the line, must not appear at the output

TX. In order to prevent this, the device has an internal cancellation circuit. The measure of attenuation is

Transhybrid Loss (THL).

Transmit and Receive Gain

The Transmit Gain of the device is the gain from the balanced signal across Tip and Ring to the ground referenced

signal at TX. It is set at 0 dB.

The Receive Gain of the device is the gain from the ground referenced signal at RX to the balanced signal across

Tip and Ring. It is set at -2 dB.

Supervision Features

Line Status Detection Outputs

The MH88634CV-K supervisory circuitry provides the signalling status outputs which are monitored by the system

controller. The supervisory circuitry is capable of detecting: Ringing Voltage; Forward and Reverse loop battery;

Forward and Reverse loop current; and Switch Hook.

Ringing Voltage Detect Output (RV)

The RV output provides a logic 0 when ringing voltage is detected across Tip and Ring. This detector includes a

filter which ensures that the output toggles at the ringing cadence and not at the ringing frequency. Typically this

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