sames

SA545

4/18

Keypad

R1

R2

R3

R4

C1

C2

C3

Nominal frequency (Hz)

697

770

852

941

1209

1336

1477

Deviation from nominal (%)

-,07

-,10

+,19

-,15

-,17

-,20

-,22

There will be an additional error due to any deviation in the oscillator frequency from 560

kHz.

FUNCTIONAL OVERVIEW

The SAMES SA545 is a family of keypad switchable Loop Disconnect (LD)/Dual Tone

multi-Frequency (DTMF) dialler devices for use in low-cost, dual dialling mode telephone

instruments.

The devices feature automatic storage of a single telephone number of up to 24 digits

for Last Number Redial (LNR) purposes as well as10 repertory dialling memories capable

of each storing 24 digits. The low current consumption of the SA545 ensures memory

retention while powered from the line.

Two modes of operation are available. The first is a LD/DTMF mode which operates

normally in LD mode, but can be switched temporarily via the keypad to DTMF mode

during a call. This mode has been optimised for applications such as home banking,

credit-card verification and other applications requiring low speed data communications.

The second mode allows DTMF dialling only.

The Lock function will be described in the Functional Description.

The SA545 family is pin compatible with SAMES SA541 family.

Ordering Information

S A 5 4 X 5 X / X

Lock Option

L : with (22 pin package)

Blank : without (20 pin package)

On-Hook Current Option

3

:

5µA @ 2.5V

6

:

1µA @ 2.5V

9

:

1µA @ 3V

Blank

:

MF Digits dialled after */# not stored

/1 :

All MF digits stored