Digital Line to POTS Interface

CMX615

© 1999 Consumer Microcircuits Limited

22

D/615/4

1.7.1.3 Operating Characteristics

For the following conditions unless otherwise specified:

Xtal Frequency = 3.579545MHz

± 0.1%

0dBm corresponds to 775mVrms.

DC Parameters

Notes

Min.

Typ.

Max.

Unit

I

DD

Zero-Power Mode

1, 2

-

<1.0

-

µA

OpAmp only Enabled, V

1

-

1.5

-

mA

OpAmp only Enabled, V

1

-

0.75

-

mA

All Enabled, V

1

-

5.0

7.5

mA

All Enabled, V

1

-

3.0

4.5

mA

Logic ‘1’ Input Level

3

70%

-

-

V

DD

Logic ‘0’ Input Level

3

-

-

30%

V

DD

Logic Input Leakage Current (Vin = 0 to V

3

-1.0

-

+1.0

µA

(excluding XTAL/CLOCK input)

Output Logic ‘1’ Level (I

V

-

-

V

Output Logic ‘0’ Level (I

-

-

0.4

V

IRQN O/P ‘Off State Current (V

-

-

1.0

µA

FSK Encoder and Tx UART

Notes

Min.

Typ.

Max.

Unit

Level at TONEFSK pin

4

-1.0

0.0

1.0

dBm

Twist (Mark level WRT Space level)

-2.0

0

+2.0

dB

Tx 1200bits/sec (V23 mode)

Baud Rate (set by UART and Xtal frequency)

1194

1200

1206

Baud

Mark (Logical 1) Frequency

1297

1300

1303

Hz

Space (Logical 0) Frequency

2097

2100

2103

Hz

Tx 1200bits/sec (Bell 202 mode)

Baud Rate (set by UART and Xtal frequency)

1194

1200

1206

Baud

Mark (Logical 1) Frequency

1197

1200

1203

Hz

Space (Logical 0) Frequency

2197

2200

2203

Hz

TONEFSK Signal Level

Notes

Min.

Typ.

Max.

Unit

Level at TONEFSK pin for:

Single tone

4

-1.0

0

1.0

dBm

Dual tone (per tone)

4

-4.0

-3.0

-2.0

dBm

DTMF High Frequency Group

4

-4.0

-3.0

-2.0

dBm

DTMF Low Frequency Group

4

-6.0

-5.0

-4.0

dBm

Output Impedance

-

10.0

-

k

Ω

Tone frequency resolution

-2.0

-

2.0

Hz

Tone output distortion

5

-

0.8

-

%

Notes:

1.

At 25

°C, not including any current drawn from the CMX615 pins by external circuitry other

than X1, C1 and C2.

2.

3.

Excluding XTAL/CLOCK pin.

4.

5.

Frequency above 300Hz.

6.

SPM has a soft rise and fall time of about 4.5ms. The level changes between V

in 2dB steps, 16 steps per rise and fall. When SPM is disabled, an extra 4.5ms falling tail end

of signal should be taken into consideration.