Symbol

Parameter

Test Conditions

Min.

Typ.

Max.

Unit

DTMF Attenuation Pin Impedance

25

32

39

k

Ω

Receive gain (see Figure 11)

29.5

23.0

31.0

25.0

32.5

27.0

dB

dB

Receive Gain Variation (see Figure 11)

Ω

Ω

-20

-20

+10

10

dB

dB

dB

Receive Distortion (see Figure 11)

Ω

2

2

2

%

%

%

Receive Noise (see Figure 11)

Ω

200

µV

Receive Output Impedance

(see Figure 11)

35

Ω

Pacifier Tone Level on Earphone

(see Figure 11)

∞

Ω

60

600

TKD

FKS

KRU

KRD

Keyboard Interface

Keypad Debounce Time

Keypad Scan Frequency

Keypad Pullup Resistance

Keypad Pulldown Resistance

See Figures 4 and 5

32

250

100

500

ms

Hz

k

Ω

Ω

TRIS

TR

TPSD

TISD

TDUR

Tone Mode

Tone Output Rise Time

Tone Signalling Rate

Presignal Delay

Intersignal Delay

Tone Output Duration

See Figures 2 and 3

40

5.55

90

90

5ms

1/sec

ms

ms

ms

TPT

FPT

PR

TB

TM

IDP

PDP

Pulse Mode

Pacifier Tone Duration

Pacifier Tone Frequency

Pulse Rate

Break Time :

ST3917A

ST3917B

Make Time :

ST3917A

ST3917B

Interdigital Pause

Predigital Pause :

ST3917A

ST3917B

See Figures 4 and 5

75

500

10

60

67

40

33

820

50

43

ms

Hz

PPS

ms

ms

ms

ms

ms

ms

ms

Option Selectable

Symbol

Parameter

Option 1

Option 2

SEL = GND

Option 3

SEL = ROW

Option 4

SEL = COL

Unit

Timed Hook Flash (see Figures 2 and3)

100

600

300

100

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

current and voltage.

5. Option 1 is with softswitch inhibition.

ELECTRICAL CHARACTERISTICS (continued)

ST3917A - ST3917B

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