6

Lucent Technologies Inc.

Data Sheet

March 1997

L7554 Low-Power SLIC

Functional Description

Table 2. Input State Coding

Table 3. Supervision Coding

°C)

Stresses in excess of the absolute maximum ratings can cause permanent damage to the device. These are abso-

lute stress ratings only. Functional operation of the device is not implied at these or any other conditions in excess

of those given in the operational sections of the data sheet. Exposure to absolute maximum ratings for extended

periods can adversely affect device reliability.

Note: The IC can be damaged unless all ground connections are applied before, and removed after, all other connections. Furthermore, when

powering the device, the user must guarantee that no external potential creates a voltage on any pin of the device that exceeds the

device ratings. Some of the known examples of conditions that cause such potentials during powerup are the following: 1) an inductor

B0

B1

B2

State/Definition

1

1

1

Powerup, Forward Battery. Normal talk and battery feed state. Pin PT is positive with respect to

PR. On-hook transmission is enabled.

1

1

0

Powerup, Reverse Battery. Normal talk and battery feed state. Pin PR is positive with respect to

PT. On-hook transmission is enabled.

0

1

1

Ground Start. Tip drive amplifier is turned off. The device presents a high-impedance (>100 k

Ω)

to the PT pin and a current-limited battery to the PR pin. Output pin RGDET indicates current flow-

ing in the ring lead.

0

1

0

Low-Power Scan, Reverse Battery. Except for off-hook supervision, all circuits are shut down to

conserve power. Pin PR is positive with respect to PT. On-hook transmission is disabled.

0

0

1

Low-Power Scan, Forward Battery. Except for off-hook supervision, all circuits are shut down to

conserve power. Pin PT is positive with respect to PR. On-hook transmission is disabled.

0

0

0

Disconnect. The Tip and Ring amplifiers are turned off and the SLIC goes to a high-impedance

state (>100 k

Ω).

Pin NLC

Pin NRDET

Pin RGDET

0 = off-hook

1 = on-hook

0 = ring trip

1 = no ring trip

1 = ring ground

0 = no ring ground

Parameter

Symbol

Value

Unit

5 V Power Supply

7.0

V

Battery (Talking) Supply

–75

V

Logic Input Voltage

—

–0.5 to +7.0

V

Analog Input Voltage

—

–7.0 to +7.0

V

Maximum Junction Temperature

165

°C

Storage Temperature Range

–40 to +125

°C

Relative Humidity Range

5 to 95

%

Ground Potential Difference (BGND to AGND)

—

±3

V

PT or PR Fault Voltage (dc)

V

PT or PR Fault Voltage (10 x 1000

µs)

V

Current into Ring Trip Inputs

±240

µA