Browse Prior Art Database

Universal Supply Hi-Speed Off-Chip Receivers

IP.com Disclosure Number: IPCOM000034046D
Original Publication Date: 1989-Jan-01
Included in the Prior Art Database: 2005-Jan-26
Document File: 2 page(s) / 57K

Publishing Venue

IBM

Related People

Beranger, H: AUTHOR [+3]

Abstract

A receiver is described which offers the following features: - The receiver is usable with low voltage supply (e.g., 3.4 - .4 V OR 5 V +- .5V). - The receiver threshold is designed for a very low sensitivity to temperature, supply and process (+ - 80 mV overall spread). - The receiver exhibits very short average delay (0.5 ns nominal). The principles of implementation are the following: The circuitry which defines the threshold is common to a bench of receivers and consists of a local reference circuit called here VRG, at 1.05 V for the General-Purpose Interface (GPI) bipolar standard. The receiver itself, depicted in Fig. 1, is basically a current switch circuit, which source of current is also driven from an external voltage reference circuit (called VR3).

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 75% of the total text.

Page 1 of 2

Universal Supply Hi-Speed Off-Chip Receivers

A receiver is described which offers the following features:

- The receiver is usable with low voltage supply

(e.g., 3.4 - .4 V OR 5 V +- .5V).

- The receiver threshold is designed for a very low

sensitivity to temperature, supply and process (+ - 80

mV overall spread).

- The receiver exhibits very short average delay

(0.5 ns nominal). The principles of implementation are the following: The circuitry which defines the threshold is common to a bench of receivers and consists of a local reference circuit called here VRG, at 1.05 V for the General-Purpose Interface (GPI) bipolar standard. The receiver itself, depicted in Fig. 1, is basically a current switch circuit, which source of current is also driven from an external voltage reference circuit (called VR3). The current source is a kind of a mirror stage. Instead of a pure current mirror (T33 copies T35), which is subject to bad VBE tracking, T33 and T35 currents are balanced thanks to R34 and R36 resistors. Reference circuit generators are shown in Fig. 2. VR3 generator is a kVBE supply, which Vbe variations induced by the VPP supply are compensated thanks to the R51 resistor. VRG generator (GPI 1.05 V nom) has an internal reference voltage at T54 emitter which is partly temperature compensated. The compensation is due to the higher temperature coefficient for T54 VBE operating at a low current with respect to T55 operating at a higher current. The voltage across R53 ...