SLIC Products

5

PIN DESCRIPTIONS

Pin Names

Type

Description

AGND/DGND

Gnd

Analog and digital ground are connected internally to a single pin.

A(TIP)

Output

Output of A(TIP) power amplifier.

B2EN

Input

BGND

Gnd

Battery (power) ground

B(RING)

Output

Output of B(RING) power amplifier.

C3–C1

Input

Decoder. TTL compatible. C3 is MSB and C1 is LSB.

D1

Input

Relay1 control. TTL compatible. Logic Low activates the Relay1 relay driver.

D2

Input

(Option) Relay2 control. TTL compatible. Logic Low activates the Relay2 relay driver.

DET

Output

Detector. Logic Low indicates that the selected detector is tripped. Logic inputs C3–C1 and E1

select the detector. Open-collector with a built-in 15 k

Ω pull-up resistor.

E1

Input

(Option) A logic High selects the off-hook detector. A logic Low selects the ground-key detector.

TTL compatible.

HPA

Capacitor

High-pass filter capacitor. A(TIP) side of high-pass filter capacitor.

HPB

Capacitor

High-pass filter capacitor. B(RING) side of high-pass filter capacitor.

RD

Resistor

Detect resistor. Threshold modification and filter point for the off-hook detector.

RDC

Resistor

DC feed resistor. Connection point for the DC-feed current programming network, which also

for reverse polarity.

RDCR

—

Connection point for feedback during ringing.

RINGIN

Input

Ring Signal Input. Pin for ring signal input. Square-wave shaped by external RC filter. Requires

50% duty cycle. CMOS-compatible input.

RSGH

Input

Saturation Guard High. Pin for resistor to adjust Open Circuit voltage when operating from

RSGL

Input

Saturation Guard Low. Pin for resistor to adjust the anti-saturation cut-in voltage when operating

RSN

Input

The metallic current (AC and DC) between A(TIP) and B(RING) is equal to 1000 x the current

into this pin. The networks that program receive gain, two-wire impedance, and feed resistance

all connect to this node.

RTRIP1

Input

Ring-trip detector. Ring-trip detector threshold set and filter pin.

RTRIP2

Input

state, this switch is open.

RYE

Output

Common Emitter of RYOUT1/RYOUT2. Emitter output of RYOUT1 and RYOUT2. Normally

connected to relay ground.

RYOUT1

Output

Relay/switch driver. Open-collector driver with emitter internally connected to RYE.

RYOUT2

Output

(Option) Relay/switch driver. Open-collector driver with emitter internally connected to RYE.

VBAT1

Battery

Battery supply and connection to substrate.

VBAT2

Battery

Power supply to output amplifiers. Connect to off-hook battery through a diode.

VCC

Power

Positive analog power supply.

VNEG

Power

Negative analog power supply. This pin is the return for the internal VEE regulator.

VTX

Output

Transmit Audio. This output is a 0.5066 gain version of the A(TIP) and B(RING) metallic AC volt-

age. VTX also sources the two-wire input impedance programming network.