Browse Prior Art Database

Channel Driver

IP.com Disclosure Number: IPCOM000051356D
Original Publication Date: 1981-Jan-01
Included in the Prior Art Database: 2005-Feb-10
Document File: 2 page(s) / 36K

Publishing Venue

IBM

Related People

Spencer, JW: AUTHOR

Abstract

This channel driver uses less circuit components than a known driver.

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Channel Driver

This channel driver uses less circuit components than a known driver.

The circuit functions in the following manner: When the identical driver inhibit 11 and latch enable 12 have their inputs 13, 14 in the logical 1 state (UP level), transistors T2 and T6 are in the OFF state. A logical 0 (DOWN level) applied to input 15 causes transistors T1 and T5 to turn OFF. The proper selection of resistors R2, R3, R4 and R5 along with Schottky diode SD1 causes transistor T1 to turn OFF faster than transistor T5. With transistor T1 off, transistors T3 and T4 turn ON, driving the emitter load resistor R7.

When transistor T5 turns off, its collector tries to approach a value determined by voltage V and resistors R5 and R6. The collector of transistor T7 clamps at the voltage sum = V5 + V6 + V7 + VR10. At this time, the output voltage Vout at terminal 16 should be greater than VD5 VD6 + VD7 - VBET7. However, if the voltage Vout at terminal 16 is less than VD5 + VD6 + VD7 - VBET7, the current through resistor R2 will be diverted through diode D9 and transistor T7, turning off transistors T3 and T4, thus preventing them from being damaged.

Transistor T6 and the associated circuits 11, 12 allow for simplified functional testing of the circuit when it is placed on a card with other components.

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