MH88632BT データシートの表示（PDF） - Mitel Networks

部品番号

コンポーネント説明

メーカー

MH88632BT

Central Office Interface Circuit

Mitel Networks 

MH88632B

Preliminary Information

Both Gains are programmable in the range -12dB to

+6dB. This wide range is capable of accommodating

most system loss plans. See Tables 3 and 4.

Caller Line Identification

Caller Line Identification (CLI) provides the called

party with the calling party telephone number. The

Central Office will utilise the voice path of a regular

loop-start telephone line when the MH88632B is in

the on-hook state. The CLI information is typically a

Frequency Shift Keyed (FSK) data signal which is

output at TX.

Supervisory Features

Line Status Detection Outputs

The MH88632B 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; grounded tip lead; and grounded ring lead.

If these Supervisory Features and the Control

Features are used as indicated in Figure 3 they can

implement common Network Protocols such as

Loop-Start Signalling and Ground-Start Signalling.

1. 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 output switches to a

logic 0 after 50ms of applied ringing voltage and

remains at a logic 0 for 50ms after ringing voltage is

removed.

2. Forward Loop and Reverse Loop Detect

Outputs (FL & RL)

The FL output provides a logic 0 when either forward

loop battery or forward loop current is detected, that

is the Ring pin voltage is negative with respect to Tip

pin voltage.

The RL output provides a logic 0 when either reverse

loop battery or reverse loop current is detected, that

is the Tip pin voltage is negative with respect to Ring

pin voltage.

3. Tip Ground and Ring Ground Detect Outputs

(TG & RG)

The TG output provides a logic 0 when the Tip pin is

at ground (AGND) potential.

The RG output provides a logic 0 when the Ring pin

is at ground (AGND) potential.

Control Inputs

The MH88632B accepts control signals from the

system controller at the inputs Loop Relay Control

(LRC), Bias Relay Control (BRC) and Ground Ring

Relay Control (GRC). These energize the relay drive

outputs Loop Relay Drive (LRD), Bias Relay Drive

(BRD) and Ground Ring Relay Drive (GRD)

respectively. Each output is active low and has an

internal clamp diode to VRLY.

The intended use of each of these relay drivers is

shown in Figure 3. LRC is being used to add and

remove the Line Termination from across Tip and

Ring. BRC is used to connect Tip and Ring to -48V

via external bias resistors. GRC is controlling the

connection of Ring to AGND via an external bias

resistor.

If these Control Features and the Supervisory

Features are used as intended they can be used to

implement common Network Protocols such as

Loop-Start Signalling and Ground-Start Signalling.

Mechanical Information

See Figure 9 for mechanical specifications for the

MH88632B and Figure 10 for mechanical

specifications for the MH88632BT.

2-244

Share Link: