mc68194 ON Semiconductor, mc68194 Datasheet - Page 8

• Manufacturer Part Number: mc68194
• Description: Carrier Band Modem Cbm
• Manufacturer: ON Semiconductor

Symbol
RXIN, RXIN*
FDBK, FDBK*
THRESHOLD
GAIN
CARDET
RPW, CPW
SET−PW
UP*, DOWN*
VCX
VCM−C1, VCM−C2
JAB−RC
XTAL,1 XTAL2
V
V
V
V
V
V
GND−TTL, GND−VCM,
GND−LOGIC, GND−OSC,
GND−RCV, GND−SUBS, GND
CC
CC
CC
CC
CC
CC
−VCM
−TXOUT
−OSC
−RCV
−TTL
ECL/O
Type
O
O
O
I
I
I
I
I
I
I
Name/Description
RECEIVER INPUTS — A differential input signal pair for the receiver amplifier/limiter.
These inputs may be used differentially or single ended.
DC FEEDBACK BYPASS — These two points are provided to bypass dc feedback
around the receiver amplifier.
THRESHOLD ADJUST — The receiver threshold detect is trimmed with this pin.
GAIN — This output can be used to monitor the receiver amplifier output signal. Used
only for test purposes.
CARRIER DETECT — This output can be used to filter the internal signal that is
sampled to sense carrier detect.
PULSE−WIDTH RESISTOR/CAPACITOR — A resistor and capacitor set a one−shot
pulse width used in the clock recovery circuitry.
PULSE WIDTH TEST POINT — Output test point used for adjusting clock recovery
one−shot pulse width.
PLL PHASE DETECTOR OUTPUTS — UP* and DOWN* are the pump−up and
pump−down outputs, respectively, of the PLL digital phase detector. They are MECL
levels referenced to +5.0 volts and are used to drive inputs to an active filter or charge
pump for the PLL.
VCM CONTROL — The control voltage applied to the PLL voltage controlled
multivibrator.
VCM CAPACITOR — VCM capacitor inputs. VCM frequency is 4X RXCLK.
JABBER−INHIBIT RC — A resistor−capacitor network connected to this pin sets the
jabber−inhibit time constant.
CLOCK CRYSTAL — Oscillator circuit inputs may be used with a crystal or an external
clock source. Oscillator frequency is 4X data rate.
VCM POWER — 5.0 ± 5% volts for VCM.
TXOUT POWER — 5.0 ± 5% volts for TXOUT/TXOUT*.
OSCILLATOR POWER — 5.0 ± 5% volts for oscillator.
RECEIVER POWER — 5.0 ± 5% volts for receiver amplifier/limiter.
LOGIC POWER — 5.0 ± 5% volts for remaining logic.
TTL POWER — 5.0 ± 5% volts for TTL output buffers.
GROUND — Reference voltage for TTL buffers, VCM, internal logic, oscillator, receiver/
limiter, substrate respectively. Two additional grounds are used to isolate signals.
Signal Description (Cont.)
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