MT3170B/71B, MT3270B/71B, MT3370B/71B

Data Sheet

5

Zarlink Semiconductor Inc.

0= LOGIC LOW, 1= LOGIC HIGH

Table 1 - Serial Decode Bit Table

Note:

b0=LSB of decoded DTMF digit and shifted out first.

Powerdown Mode (MT317xB/337xB)

The MT317xB/337xB devices offer a powerdown function to preserve power consumption when the device is not in

use. A logic high can be applied at the PWDN pin to place the device in powerdown mode. The ACK pin should be

kept at logic low to avoid undefined ESt/DStD and SD outputs (see Table 2).

Table 2 - Powerdown Mode

Table 3 - Call Progress Tones

852

1336

8

1

0

0

0

852

1477

9

1

0

0

1

941

1336

0

1

0

1

0

941

1209

*

1

0

1

1

941

1477

#

1

1

0

0

697

1633

A

1

1

0

1

770

1633

B

1

1

1

0

852

1633

C

1

1

1

1

941

1633

D

0

0

0

0

ACK (input)

PWDN (input)

ESt/DStD (output)

SD (output)

MT317xB/337xB

status

low

low

Refer to Fig. 4 for

timing waveforms

Refer to Fig. 4 for

timing waveforms

normal operation

low

low

low

powerdown mode

high

low

low

undefined

undefined

high

high

undefined

undefined

undefined

Frequency 1 (Hz)

Frequency 2 (Hz)

On/Off

Description

350

440

continuous

North American Dial Tones

425

---

continuous

European Dial Tones

400

---

continuous

Far East Dial Tones

480

620

0.5s/0.5s

North American Line Busy

440

---

0.5s/0.5s

Japanese Line Busy

480

620

0.25s/0.25s

North American Reorder Tones

440

480

2.0s/4.0s

North American Audible Ringing

480

620

0.25s/0.25s

North American Reorder Tones

DIGIT