The Tektronix 2221A is a portable, 100 MHz, 100 MS/s combination analog / digital storage scope, an update of the slower 2221.

Tektronix 2221A
100 MHz portable DSO
Tektronix 2221

Produced from 1991 to (?)

ROM Images
File Pos. Checksum
160-6188-04.bin U9120 15fca141
160-6188-06.bin U9120 6adb2e6d
160-6188-07.bin U9120 c3925d83
160-6192-04.bin U9121 fa0c5bd4
160-6192-06.bin U9121 5430cb6a
160-6192-07.bin U9121 66044407
(All manuals in PDF format unless noted otherwise)

Recommended cart is the K212.

Key Specifications

Analog bandwidth 100 MHz (80 MHz in 2 mV/Div range), 20 MHz limit switchable
Rise time (analog mode) 3.5 ns (4.4 ns in 2 mV/Div range)
Sampling rate 100 MS/s single channel, 50 MS/s in ALT or CHOP
Memory depth 4 K samples single channel, 2 K per channel in ALT or CHOP
Resolution 8 bits
Deflection 2 mV/Div to 5 V/Div, 1-2-5
Glitch capture > 100 ns
CRT 8 x 10 cm, P31 phosphor, 14 kV acceleration
Outputs analog X/Y plotter output, 500 mV/Div, pen lift relay contact
Power 90-250 V, 85 W, fan-cooled
Weight 8.2 kg (18 lb.)
  • Reference waveform memory
  • Cursors and readout
  • Signal averaging
  • TV line and field trigger
  • Variable holdoff
  • Opt.10 – GPIB (board 671-0304-00)
  • Opt.12 – RS232 (board 671-0303-00)


Documents Referencing 2221A

(no results)


The 2230 is controlled by an Intel 8088 microprocessor with firmware in a pair of 27512 EPROMs, and six TMS4426 16K×4 DRAMs. The A/D converter is a Sony CX20052A (8 bit, 20 MHz, ECL output). A pair of MCM2016H 2K×8, 70 ns RAMs serve as acquisition memory.

Custom Tek chips used include 155-0274-00 (A1U130, A1U180), 155-0273-00 (A2U30, A2U80), and 155-0022-00 (A10U2101). There is also a semi-custom part (A10U9208 Display Controller, 156-2452-00).



Some Parts Used in the 2221A

Part Part Number(s) Class Description Used in
T4655 154-0861-00 154-0861-10 154-0930-00 CRT CRT 2220 2221 2221A 2230 2232