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Azur Electronics

This research on ECL was necessary for the repair of my HP 8016A Word Generator which had some faulty ECL IC's, for which data sheets and spares seemed to be unavailable on the web. I was aware of ECL and some of its features but had not used it before.

July 2009

This family of high speed logic integrated circuits was developed by Motorola in the 1960's. ECL stands for Emitter-Coupled Logic and the Motorola series was known as MECL.

There were 5 series of MECL IC's from Motorola: MECL I 1962-1977 30MHz switching and 8ns gate propagation delay; MECL II 1966-1979 70MHz switching and 4ns gate propagation delay (which increased to 180MHz and 2ns over the years); MECL III 1968-19?? 500MHz switching and 1ns gate propagation delay; MECL 10K (1971-) and MECL 10KH (1981-) were further improvements.

In 1999 Motorola divested its semiconductor business to ON Semiconductor.

TTL and CMOS IC's generally source current to the load in the high state (Logic '1') and sink current from the load in the low state (Logic '0'). They are powered by a single positive Vcc (+5V TTL) power supply.

In contrast ECL operates in the non-saturated transistor region so that current conditions are fairly constant whether high or low. This also helps to prevent power switching noise being introduced into the circuit. ECL also uses a -5.2V negative power supply Vee. [Modern versions of ECL are available that use positive power supplies, PECL, LVPECL, etc, which are outside the scope of this research].

ECL IC's use a differential amplifier input and emitter follower outputs which are biased to remain within their operating curves rather than switching off or saturating. This dramatically improves their switching speeds, typically to <1ns. 

Logic Levels:
Typically only 0.7V difference between high and low states, which can cause noise problems.

Logic '0' Low (VOL) can vary between -1.4V and -1.9V

Logic '1' High (VOH) can vary between -0.7V and -1.2V

This is with all outputs loaded with 50Ω to -2.0V

Inputs are generally (check data sheet) internally pulled down to Vee, so unused inputs can be left floating and assume a logic '0' state.

Other Voltage Levels are:

Vcc1 0V Ground (often just output stage to provide separation from input)

Vcc2 0V Ground (often just input stage to provide separation from output)

Vee -5.2V Negative Power, also tied to unused inputs

Vtt -2.0V Termination Voltage

Vbb -1.29V Bias Voltage

Memory Mot Part

Equipment Data

HP Part

16-Bit Coincident
Memory w/o Pulldowns
MC1037P 8016A Wanted 1820-1227
Quad Level Translator
(MECL to Saturated Logic)
MC1039P 8016A MOT 1820-0275
Dual 4 Input OR/NOR
MC1660L 3762A MOT 1820-0790
Quad 2 Input NOR
MC1662L 8016A MOT 1820-0796
Master-Slave Flip-Flop
MC1670L 3762A MOT 1820-0794
Quad 2 Input OR/NOR
MC10101L 8016A MOT 1820-0801
Quad 2 Input NOR
MC10102P 8016A MOT 1820-0802
Triple 2-3-2 Input OR/NOR
MC10105L 8016A MOT 1820-0803
Triple 4-3-3 Input NOR
MC10106L 8016A MOT 1820-0804
Triple 2 Input XOR/XNOR MC10107L 3762A MOT 1820-0805
Dual 4-5 Input OR/NOR
MC10109L 8016A MOT 1820-0806
Dual 3 Input 3 Output OR
MC10110L 8016A MOT 1820-0807
Dual 3 Input 3 Output NOR
MC10111L 8016A MOT 1820-0808
4 Wide 4-3-3-3 Input OR-AND
MC10119L 8016A MOT 1820-0813
MC10121P 8016A MOT 1820-0815
Dual D-Type Master-Slave Flip-Flop
MC10131P 8016A MOT 1820-0817
Dual J-K Master-Slave Flip-Flop MC10135L 3762A MOT 1820-0820
Universal Decade Counter MC10137P 3762A MOT 1820-0822
8-Line Multiplexer MC10164L 3762A MOT 1820-0829
Hex D-Type Master-Slave Flip-Flop MC10176P 3762A MOT 1820-1399
Dual 3 Input 3 Output OR MC10210P 3762A MOT 1820-1830
Dual 3 Input 3 Output NOR MC10211P 3762A MOT 1820-1482
High Speed Triple Line Receiver
MC10216P 8016A MOT 1820-1224
High Speed Dual D-Type
Master-Slave Flip-Flop  
MC10231P 8016A MOT 1820-1225
Motorola ECL IC's Used In HP Test Equipment 
P = Plastic DIL 16 Pin
C or L = Ceramic DIL 16 Pin
HP Part Numbers were often printed on the IC's instead of the industry standard (JEDEC) part numbers. I have a searchable PDF cross-reference list of 143 pages. This will help identify IC's from scrapped equipment.

I am trying to obtain Motorola ECL Databooks and some Datasheets for these IC's. Many are available from www.datasheetcatalog.com

An excellent reference is the "MECL System Design Handbook" from ON Semiconductor at www.onsemi.com/pub_link/Collateral/HB205-D.PDF

December 2016

I have come across some unusual ECL.  HP made their own range called EECL and was high speed up to 500MHz.  The logic levels are different though, with -0.8V logic 0 and 0V logic 1.  These devices are unobtainium!