M377

The M377 is a Tek-made amplifier integrated circuit designed by John Addis. It is used in the 11A16, 11A32, 11A33, 11A34, and 11A52.

About the M377, John Addis says:

The M377 was a single channel plugin on a chip with 0 V common mode input and output voltages, excellent variable gain control, two four pole bandwidth limits, three outputs which could be separately inverted and turned on or off.

It was the first wideband analog IC with level shift on chip (allowing 0 V common mode input and output and without PNP transistors), first wideband amplifier with any on-chip bandwidth limit selection, first to have more than two fixed gain settings (it has six), and first to require only one transient response adjustment (no thermals), and the first to have a highly linear relationship between a control voltage and gain. It also had excellent overdrive recovery.

The packaged M377 die has the following Tek part numbers:

• 165-2129-03
• 165-2089-06
• 155-2089-05 (11A33)

165-2089-xx Pinout

Pin Function 1 GP0 (gain select bit 0) 2 GS' 3 +15V 4 +Vin 5 Analog ground 6 -Vin 7 Analog ground 8 Var Gain 9 -5V 10 -5V 11 Disp Inv' 12 Disp On 13 Analog Ground 14 +5V 15 Trig Inv' 16 Trig On 17 +5V 18 Aux Trig On 19 -Display 20 +Display 21 HF Adjust terminal 1 22 -Trigger 23 +Trigger 24 HF Adjust terminal 1 25 -Aux Sig 26 +Aux Sig 27 HF Adjust terminal 2 28 Ground 29 Ground 30 Ground 31 +5V 32 -5V 33 BP1 (bandpass select bit 1) 34 BP0 (bandpass select bit 0) 35 GP2 (gain select bit 2) 36 GP1 (gain select bit 1) Pin function legend Power pins Ground pins HF signals digital control signals analog control signals M377 in an 11A52, as U310 and U410. Each M377 chip has a differential output impedance of 200 Ω. The two chips' outputs are in parallel, driving the output pins of the plug-in with a differential impedance of 100 Ω, or 50 Ω per side. Two M377 chips (packaged as part number 165-2129-03) in an 11A52. M377 die Links Article in Electronic Engineering Magazine on M377 by John Addis