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)

Instrument	Instrument SN range	Part Number	Output R/side	Components on ceramic hybrid
11A32	B010100 - B031028	165-2089-03	100 ohms	M377 chip only
11A32	B031029 - up	165-2089-05	100 ohms	M377 chip only
11A34	B010100 - B031044	165-2089-04	200 ohms	M377 chip only
11A34	B031045 - up	165-2089-06	200 ohms	M377 chip only
11A52	B010100 - B010179	165-2129-02	100 ohms	Diode bridge + 50 ohm input R + M377 chip
11A52	B010180 - up	165-2129-03	100 ohms	Diode bridge + 50 ohm input R + M377 chip

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	Display Invert
12	Display On
13	Analog Ground
14	+5V
15	Trigger Invert
16	Trigger On
17	+5V
18	Aux Trigger On
19	-Display
20	+Display
21	HF Adjust terminal 1
22	-Trigger
23	+Trigger
24	HF Adjust terminal 1
25	-Aux Signal
26	+Aux Signal
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

TTL 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