MH88422-3 参数 Datasheet PDF下载

Preliminary Information

MH88422

14

TIP

13

TIP

11

C2

D1

10

TF

RLS

MH88422

VX

6

R3

R4

Audio Output

7

VR

100k

Audio Input

R5

4

RVLC

Ring Voltage & Loop

Current Detect Output

TXIN

3

RING

9

RING

VDD

1

AGND

2

LC

Loop Control Input

RECEIVE GAIN:

Audio input to Tip-Ring

=20log(47k/(R5+47K))+3.5dB

+

C1

= -6.5dB

TRANSMIT GAIN:

Tip-Ring to Audio Output

=20log(R4(R3+R4))-0.4dB

+5V

1) C1: 10µF, 6V Tantalum

2) C2: 0.1µF, 250V (Typical Value)

3) D1: 180VDC Foldback Diode, e.g. TISP4180, TISP5180

4) VX and VR are biased at 2.5V, therefore, coupling capacitors

may be required depending on application.

5) (R3+R4) should be > 2kΩ to prevent overload.

= -6.4dB

Note:

The VX output gain has been reduced by 6dB

(to -6.4dB) and the VR input gain has been

reduced by 9.9dB (to -6.4dB) in this example.

Figure 5 - Typical Application Circuit for Gain Adjustment

14

TIP

13

TIP

RLS

MH88422

VX

6

10µF

Audio Output

Audio Input

11

C2

D1

10

TF

TXIN

VR

7

10µF

4

RVLC

Current Detect Output

Ring Voltage & Loop

RING

Meter

Pulse

Filter

9

3

RING

1

LC

VDD

AGND

Loop Control Input

2

Meter

Pulse

Detector

+

C1

+5V

1) C1: 10µF, 6V Tantalum

2) C2: 0.1µF, 250V (Typical Value)

3) D1:180VDC Foldback Diode,

e.g. TISP4180, TISP5180.

Note:

Meter pulses at high frequency (16kHz or 12kHz) and high level (10V RMS) are used in some countries.

The VX amplifier has a low pass filter which attenuates by typically 15dB at 16kHz (For the -1 variant).

If this proves insufficient for specific applications, an LC reject filter is recommended.

Figure 6 - Typical Application Circuit with Meter Pulse Filter and Coupling Capacitor

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