5962R9672301VXC(1999) Ver la hoja de datos (PDF) - Intersil

Número de pieza

componentes Descripción

Fabricante

5962R9672301VXC
(Rev.:1999)

Radiation Hardened Triple Line Transmitter, Triple Line Receiver, Triple Party-Line Receiver

Intersil 

HS-245RH, HS-246RH, HS-248RH

Test Circuits and Applications (Continued)

+5V

IN

1/3

HS-245RH

+5V

(+)

1/3 HS-246RH

50Ω

50

Ω

(-)

RECEIVER

OUT

(NOTE)

ENABLE

(+)

NOTE: HS-245RH should be driven by open-collector

(-)

gates. (Totem-pole output may cause slight reduction in

“on” data current). For more detailed information, refer to

Design Information section of this data sheet.

FIGURE 3. TYPICAL APPLICATION

+5V

-5V

“PARTY-LINE”

RECEIVER

1/3

HS-248RH

-5V

OUTPUT

Voltage Mode Transmission

Data rates of up to 10 million bits per second can be

obtained with standard TTL logic; however, the transmission

distance must be very short. For example, a typical 50 foot

low capacitance cable will have a capacitance of

approximately 750pF which requires a current of greater

than 50mA to drive 5V into this cable at 10MHz; therefore,

voltage mode transmitters are undesirable for long

transmission lines at high data rates due to the large current

required to charge the transmission line capacitance.

Current Mode Transmission

An alternate method of driving high data rates down long

transmission lines is to use a current mode transmitter.

Current mode logic changes the current in a low impedance

transmission line and requires very little change in voltage.

For example, a 2mA change in transmitter current will

produce a 100mV change in receiver voltage independent of

the series transmission line resistance. The rise time at the

receiver for a typical 50 foot cable (750pF) is approximately

30ns for a 2mA pulse.

An emitter coupled logic gate is frequently used for a current

mode transmitter. However, ECL gates are not compatible

with TTL and DTL logic and they require considerable power.

The Intersil HS-245RH is a TTL/DTL compatible current

mode transmitter designed for high data rates on long

transmission lines. Data rates of 15 megabits per second

can be obtained with 50 feet of transmission line when using

the companion HS-246RH receiver. Data rates of 2 megabits

per second are easily obtained on transmission lines as long

as 1,000 feet. The Intersil transmitter and receivers feature

very low power, typically 25mW for the transmitter and

15mW for the receiver.

Intersil Transmitter/Receivers

The Intersil transmitter/receiver family consists of a triple line

transmitter, two triple line receivers with internal terminations

and a triple party-line receiver. The general characteristics of

the transmitter and receivers are outlined in Table A.

3

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