ELECTRICAL CHARACTERISTICS (continued)

Symbol

Parameter

Test Condition

Min.

Typ.

Max.

Unit

Fig.

DTMF Level on the line

High Frequency Group

Low Frequency Group

Ω,

–8

–10

–6

–8

–4

–6

dBm

dBm

7

Pre-emphasis

1.0

2

3.0

dB

7

DIS

DTMF Output Distortion

5

8

%

7

DTMF Att. pin Impedance

32

K

Ω

Receive Gain

Ω

Ω

29.5

24

31.0

26

32.5

28

dB

dB

8

Receive Gain Variation

Ω

Ω

Ω

–20

–20

+10

+10

dB

dB

dB

8

Reveive Output Distortion

Ω

2

2

2

%

%

%

8

Receive Noise

Ω;

200

8

Receive Output Impedance

35

Ω

8

Pacifier Tone Level on

Earphone

∞

60

600

mVrms

mVrms

8

KEYBOARD INTERFACE

TKD

FKS

KRU

KRD

Keypad Debounce Time

Keypad Scan Frequency

Keypad Pullup Resistance

Keypad Pulldown Resistance

32

250

100

500

ms

Hz

K

Ω

Ω

PULSE MODE

TPT

FPT

PR

TB

TM

IDP

PDP

Pacifier Tone Duration

Pacifier Tone Frequency

Pulse Rate

Break Time

Make Time

Inter Digit Pause

Predigit Pause

75

500

10

60

40

820

50

ms

Hz

PPS

ms

ms

ms

ms

TONE MODE

TRIS

TR

TPSD

TISD

TDUR

Tone Output Rise Time

Tone Signalling Rate

Pre Signal Delay

Inter Signal Delay

Tone Output Duration

40

5

100

100

5ms

1/s

ms

ms

ms

THD

Hold Mode Delay

400

ms

tHFP

Hook Flash Timing

L3914A

L3924A

L3934A

585

300

100

ms

ms

ms

Notes:

1. All inputs unloaded. Quiescent mode (oscillator off).

4. Memory retention voltage is the point where memory is guaranteed but circuit operation is not. Proper memory retention is guaranteed if

either the minimum IMR is provided or the minimum VMR. The design does not have to provide both the minimum current and voltage

simultaneously.

µV

L3914A - L3924A - L3934A

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