much ado about the HP/Agilent/Avago/Broadcom
HDSP teeny tiny quad 5x7 LED display module

click here for datasheet:
HDSP-23xx Four Character 5.0 mm (0.20 inch) 5 x 7 Alphanumeric Displays
and Application Note 1016: Using the HDSP-2000 Alphanumeric Display Family

downloaded from
http://www.datasheet.hk/view_download.php?id=1223773&file=0103%5Chdsp-2301_1061981.pdf
Jonathan Chapman's glitchwrks.com has them running in red, green and the Soviet clone!

Driving HP HDSP-2000 Displays with the R6501Q SBC with BDX54C column drivers


Four 5x7 LEDs in a 0.3" DIP: so tiny and bright. Only recently have OLEDs surpassed the brightness and clarity.

There are many variations of these displays:
The HP QDSP-2020 / HDSP-200x series are 4 character @ 5x7 array in a 12 pin 0.3" DIP case.
They're the smallest case for 4 characters but there's no character generator.
They require external column drivers and constant scanning to refresh the display.

There are internal cathode row drivers for 1 column per character:
7 row drivers x 4 characters = 28 bits as a shift register.
3 pins control the shift register: clock, data in, data out (for cascading displays).
The blanking pin allows for PWM dimming (hold HIGH for full brightness).

There are 5 pins, one for each column.
An external driver needs to source nearly half an ampere if all 28 LEDs are on.

Dave McGuire suggests

tech info summary: 
        pinout
1-column 1     data in-12
2-column 2         gnd-11
3-column 3       clock-10
5-column 4         Vcc-9
5-column 5    blanking-8
6-do not use  data out-7

Recommended Operating Conditions (HDSP-2301/-2302/-2303)

Supply Voltage VCC 5.0 V
Column Input Voltage, Column On VCOL 3.5 V
column spply current Icc = 73 (typical) 95 (max) mA for VB = 2.4 V
Data Out Current, Low State IOL 1.6 mA
Data Out Current, High State IOH –0.5 mA

Clock Frequency fclock 3 MHz
Clock Transition Time tTHL 200 ns
Setup Time tsetup 45 ns
Hold Time thold 30 ns
Width of Clock tw(Clock) 75 ns

For more information, see Agilent Application Note 1016
The application note shows a PNP Darlington Pair used as column drivers, and notes 
[for] 32 modules of four digits each,
the transistors must source up to 32 times 410 mA or approximately 13 A.
Darlington PNP power transistors (2N6285) with the proper resistors
have been used to accomplish this task.
  • page 7, 16 shows 5: MJE700 PNP darlingtons
  • page 19 shows 5: MJE210 PNP transistors
  • page 21 shows 5: 2N6285 PNP darlingtons
  • page 24 shows 5: TIP 105 PNP darlingtons

    This display module has so many different part numbers!

    Application Note 1016: Using the HDSP-2000 Alphanumeric Display Family
    Table 1. The HDSP-2000 Alphanumeric Display Family

    Device Color Character Spacing Character Height Operating Temperature
    HDSP-2000
    HDSP-2001
    HDSP-2002
    HDSP-2003     		Red
    Yellow
    High Efficiency Red
    High Performance Green     		3.8 mm (0.15 in.) 4.5 mm (0.175 in.) -20 to +85 °C
    HDSP-2010 red 3.8 mm (0.15 in.) 4.5 mm (0.175 in.) -40 to +85 °C
    HDSP-2300
    HDSP-2301
    HDSP-2302
    HDSP-2303     		Red
    Yellow
    High Efficiency Red
    High Performance Green     		4.9 mm (0.192 in.) 5.0 mm (0.197 in.) -20 to +85 °C
    HDSP-2310
    HDSP-2311
    HDSP-2312     		Red
    Yellow
    High Efficiency Red     		4.9 mm (0.192 in.) 5.0 mm (0.197 in.) -55 to +85 °C
    HDSP-2450
    HDSP-2451
    HDSP-2452     		Red
    Yellow
    High Efficiency Red     		6.9 mm (0.27 in.) 8.9 mm (0.35 in.) -55 to +85 °C
    HDSP-2490
    HDSP-2491
    HDSP-2492
    HDSP-2493     		Red
    Yellow
    High Efficiency Red
    High Performance Green     		6.9 mm (0.27 in.) 8.9 mm (0.35 in.) -20 to +85 °C
    Siemens' version: MSD2000/MSD2300 (mil) and ISD2000/ISD2300 (ind) 0.15" and 0.20"

    http://www.decadecounter.com/ seems to be offline
    It listed:
  • Hewlett-Packard HDSP-2010 red intelligent LED display (12-pin red glass-on-ceramic DIP)
  • Hewlett-Packard HDSP-2030 red intelligent LED display (12-pin red glass-on-ceramic DIP)
  • Hewlett-Packard QDSP-2273 yellow intelligent LED display (12-pin glass-on-ceramic DIP)
  • Hewlett-Packard HDSP-2003 green intelligent LED display (12-pin glass-on-ceramic DIP)
  • Hewlett-Packard QDSP-2021 red intelligent display (12-pin glass-on-ceramic DIP)

    The HDSP-2302 High Efficiency Red seems to be IBM P/N QDSP-2278 and HP 5616 085
    The plain red is also P/N HP QDSP-2020.