L9217A Datasheet, PDF (1/30 Pages) Agere Systems – Low-Cost Line Interface with Reverse Battery and PPM

Data Sheet
November 2001
L9217A/G Low-Cost Line Interface
with Reverse Battery and PPM
Features
s Basic forward/reverse battery SLIC functionality at
a low cost
s Pin compatible with Agere Systems Inc. L9218/
L9219 SLIC
s Low active power (typical 154 mW during on-hook
transmission)
s Low-power scan mode for low-power, on-hook
power dissipation (57 mW typical)
s Distortion-free, on-hook transmission
s Convenient operating states:
— Forward powerup
— Reverse powerup
— Low-power scan
— Disconnect (high impedance)
— PPM operational states
s Minimal external components required
s Two gain options to optimize the codec interface
s Adjustable supervision functions:
— Off-hook detector with hysteresis
— Ring trip detector
s Adjustable loop current limit
s Adjustable overhead voltage
s Ramped rate of battery reversal
s Periodic pulse metering (PPM) compatible
s Thermal protection with thermal shutdown indica-
tion
Description
This general-purpose electronic subscriber loop
interface circuit (SLIC) is optimized for low cost, while
still providing a satisfactory set of features. This part
is a pin-for-pin replacement for the Agere L9218/
L9219 SLIC.
The L9217 requires a 5 V power supply and single
battery to operate. This device offers forward and
reverse battery operation. The rate of battery rever-
sal may be ramped to meet international require-
ments. Additionally, a low-power scan mode, wherein
all circuitry except the off-hook supervision is shut
down to conserve power, is available.
The dc current limit may be programmed via a single
external resistor. Both the loop supervision and ring
trip supervision functions are offered with user-
controlled thresholds via external resistors. Over-
head is adequate for 3.14 dBm into 900 Ω of on-hook
transmission.
The device is periodic pulse metering (PPM) compat-
ible, offering a convenient point for meter pulse injec-
tion and filter point for rejection of the meter pulse
signal. In the PPM active modes, overhead voltage is
automatically increased to accommodate on-hook
transmission of meter pulse signals. The level that
the overhead is increased to is set by a single exter-
nal resistor. In this way, the L9217 can accommodate
high-voltage meter pulse signals.
The L9217 is offered with a receive gain that is opti-
mized to interface to a first-generation type codec
(L9217A). It is also offered with a gain option that is
optimized to interface to a third- or fourth-generation
type codec (L9217G). In both cases, minimizing
external components is required at this interface.
Data control is via a parallel data control scheme.
The device is available in a 28-pin PLCC package. It
is built by using a 90 V complementary bipolar
(CBIC) process.