HC-5509B3999-003 Datasheet, PDF (6/10 Pages) Intersil Corporation – SLIC Subscriber Line Interface Circuit

HC-5509B3999-003
Pin Descriptions (Continued)
SOIC
SYMBOL
DESCRIPTION
24
VFB Feedback input to the tip feed amplifier; may be used in conjunction with transmit output signal and the spare op amp
to accommodate 2-Wire line impedance matching.
25
TF₂
Tip Feed - A low impedance analog output connected to the TIP terminal through a feed resistor. Functions with the
RF terminal to provide loop current, and to feed voice signals to the telephone set and to sink longitudinal currents.
Must be tied to TF₁.
NA
TF₁
Tie directly to TF₂ in the PLCC application.
26
RF₁
Ring Feed - A low impedance analog output connected to the RING terminal through a feed resistor. Functions with
the TF terminal to provide loop current, feed voice signals to the telephone set, and to sink longitudinal currents. Tie
directly to RF₂.
NA
RF₂
Tie directly to RF₁ in the PLCC application.
27
VB-
The battery voltage source. The most negative supply.
28
BG
Battery Ground - To be connected to zero potential. All loop current and some quiescent current flows into this ground
terminal.
NC
No internal connection.
NOTE:
1. All grounds (AG, BG, DG) must be applied before V_B+ or V_B-. Failure to do so may result in premature failure of the part. If a user wishes to run
separate grounds off a line card, the AG must be applied first.
6