8

Am7945 Data Sheet

Supply Currents, BAT = –48 V

On-hook supply current

Open Circuit state

OHT state

Standby state

Active state

1.7

4.9

2.2

6.3

2.5

7.5

3.0

8.5

mA

On-hook supply current

Open Circuit state

OHT state

Standby state

Active state

0.7

2.0

0.77

2.1

2.0

3.5

2.0

5.0

On-hook supply current

Open Circuit state

OHT state

Standby state

Active state

0.18

1.9

0.45

4.2

1.0

4.7

1.5

5.7

50 Hz to 3.4 kHz

30

40

dB

5

50 Hz to 3.4 kHz

28

35

50 Hz to 3.4 kHz

28

50

Effective internal resistance

CAS pin to GND

85

170

255

k

Ω

4

RFI rejection

100 kHz to 30 MHz (See Figure E)

1.0

mVrms

Off-Hook Detector

Current threshold

–12

+12

%

Ground-Key Detector Thresholds, Active State, BAT = –48 V

Ground-key resistance threshold

B(RING) to GND

2.0

5.0

10.0

k

Ω

Ground-key current threshold

B(RING) to GND

9

mA

Ring-Trip Detector Input

Bias current

–0.5

–0.05

µA

Offset voltage

Source resistance = 2 M

Ω

–50

0

+50

mV

6

Logic Inputs (C3–C1, E0, E1)

Input High voltage

2.0

V

Input Low voltage

0.8

Input High current

All inputs except C3 and E1

–75

40

µA

Input C3

–75

200

Input E1

–75

45

Input Low current

–0.4

mA

Logic Output (DET)

Output Low voltage

0.4

V

Output High voltage

2.4

ELECTRICAL CHARACTERISTICS (continued)

Description

Test Conditions (See Note 1)

Min

Typ

Max

Unit

Note

I

DET

375

R

D

---------

=