SLIC Products

5

PIN DESCRIPTIONS

Pin Names

Type

Description

AGND/DGND

Gnd

Analog and Digital ground

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

Switchhook 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) Ground-Key Enable. 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

Detector resistor. Detector threshold set and filter pin.

RDC

Resistor

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

and positive 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

RSN

Input

Receive Summing Node. 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

conservation in any nonringing 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 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 intern VEE regulator.

VTX

Output

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

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