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Tektronix 7A16P
150/200 MHz vertical amplifier

Compatible with 7000-series scopes

Produced from 1978 to 1987

ROM Images
File Pos. Checksum
(All manuals in PDF format unless noted otherwise)
Manuals – Specifications – Links – Pictures

The Tektronix 7A16P is a single-channel programmable vertical amplifier for 7000-series digitizing mainframes. All functions of the 7A16P can be remotely programmed via the GPIB 7000-series main interface bus, with exception of the variable gain control and the probe identify switch.

The 7A16P is special among the 7000-series vertical amplifiers in that it offers a switchable 1 MΩ/50 Ω input impedance, a feature otherwise only found in the 7A42. The 7A16P is also unique as it has two input BNC connectors, but is strictly a single channel plugin, having a switch that routes one of the BNC connectors to the amplifier circuits. This feature is handy in remote-controlled digitizing applications.

The plug-in was mainly intended for use in the 7612D and the 7912 family, but can also be used in the 7854 if paired with a 021-0374-00 GPIB interface and internally modified by adding cables for an 18-pin header and setting jumpers correctly. It is not recommended to use the 7A16P in any conventional 7000-series mainframe since it expects +5.1 V at pins B27 and A9 of the mainframe interface, and shorts them together. A9 is the 5 V light pin on conventional mainframes, and its current rating might be too low for successful operation of the 7A16P.

Key Specifications

Bandwidth DC – 150 MHz at 1 MΩ, 250 MHz at 50 Ω
Deflection 10 mV/Div to 5 V/Div in 1–2–5 sequence
Input impedance 1 MΩ // 15 pF or 50 Ω
  • Two BNC inputs
  • 20 MHz bandwidth limit switch
  • Invert switch
  • Probe multiplier / Identify switch sensing inputs


Documents Referencing 7A16P

Document Class Title Authors Year Links
Tekscope 1979 V11 N1.pdf Article An Intelligent, Programmable Transient Digitizer Dale Aufrecht 1979


The input stage of the 7A16P contains miniature relays that switch between the two available input connectors, and select AC or DC coupling modes. Another relay is used to connect a 50 Ω shunt if the corresponding input impedance is selected. Further relays then select an optional 10x attenuator before the signal enters the input buffer, which contains an AC-coupled MOSFET common-drain amplifier and a DC-coupled operational amplifier configured in a feed-beside scheme. Gain switching is accommodated by several junction FETs that can insert another 10x attenuator in front of the MOSFET buffer, and 2× / 5× low-impedance attenuators after the input buffer.

The digital circuitry is built around a Motorola 6800 processor with several MC6821 Peripheral Interface Adapters that drive the switches of the analog circuit, and interface with the modified 7000-series internal GPIB bus.


Early 7A16P (SN B041606 and below) contain power supply monitoring circuitry that checks for the presence of the -5.2 V rail (A27) that is only present in digitizer mainframes. While the rail is not used in any other circuitry, it will prevent the plugin to work in regular 7K mainframes or the 7854.

Late 7A16Ps contain pin headers to connect to a 021-0374-00, which requires a modification in earlier units (see below).

Operation with 021-0374-00

When operated with the 021-0374-00, the 7A16P's modified GPIB bus is directly connected to it through an 18-pin, dual-row pin header and 17 leads. Following the labeling from the 021-0374-00 manual, the cable is connected as follows:

Pin Color Connected to Function
1 U1200 pin 10 I/O 0
2 U1200 pin 11 I/O 1
3 U1200 pin 12 I/O 2
4 U1200 pin 13 I/O 3
5 U1200 pin 14 I/O 4
6 U1200 pin 15 I/O 5
7 U1200 pin 16 I/O 6
8 U1200 pin 17 I/O 7
9 U500 pin 5 ATN
10 U1620 pin 6 NDAC
11 U1620 pin 8 NRFD
12 U1520 pin 9 DAV
13 U1620 pin 11 EOI
14 U1330 pin 13 IFC
15 U1200 pin 7 REN
16 U1620 pin 3 SND
17 U720 pin 8 SRQ

Additionally, jumper P1622 in the 7A16P should be set according to the 021-0374-00 manual. This connects the regular +5 V supply on A1 to the lights pin A9. In a 7854 mainframe, this will cause no direct harm if the rear "Control Illumination" switch is not in the "high" position since the 7854 uses series diodes to drop the light voltage if set to medium. However, the full lights current for all plugins will run through the 7A16P, so setting the switch to "high" is recommended.



Some Parts Used in the 7A16P

Part Part Number(s) Class Description Used in
155-0078-00 155-0078-xx 155-0273-00 155-0274-00 Monolithic integrated circuit broadband amplifier 464 465 466 468 475 475A 475M 485 7834 7844 7854 7904 R7903 R7912 7912AD 7912HB 7104 7A16A 7A16P 7A24 7A26 7A42 067-0587-01 067-0680-00 AM503 PG502 PG508 DC510 DC5010 FG5010
155-0135-00 155-0135-00 Monolithic integrated circuit custom legend generator 7A16P
155-0164-00 155-0164-00 Hybrid integrated circuit time slot switch 7A16P 7B90P 7A29P
Motorola 6800 156-0426-00 Monolithic integrated circuit 8-bit microprocessor 021-0206-00 021-0374-00 067-0902-00 067-1137-99 222 222A 222PS 2424L 2445 2465 2467 4051 7912 7912AD 7A16P 7A29P 7B81P 7B90P 833 834 CG5001 CG551AP CG5010 CG5011 DF1 DF2 DM5010 MI5010 SI5010 PS5004 PS5010 SG5010 Keithley 181 Keithley 175 Keithley 175A Keithley 192 Keithley 195A Keithley 197 Keithley 220 Keithley 230 Keithley 485 Keithley 580
Motorola 6820 156-0427-00 Monolithic integrated circuit "Peripheral Interface Adapter (PIA)" 021-0206-00 7A16P 7B81P 7B90P Keithley 175A Keithley 197 Keithley 485 Keithley 580
Motorola 6821 156-0427-03 156-1205-00 Monolithic integrated circuit "Peripheral Interface Adapter (PIA)" 067-1137-99 7A16P 7A29P 7B90P