25-Pin D-Sub Connector

D Sub-miniature pin locations

25-Pin D-Sub Connector, Size 20 Contacts, Insert Arrangements

Mil-DTL-24308 25-pin Dsub Connector inserts
25 pin D Sub-miniature Connector, Standard Density

This connector may be terminated using any of the following terminal styles; Crimp, Solder, Insulation displacement contact (IDC), or Printed wiring board (PWB).
There are three general types; Standard density (size 20 contacts), High density (size 22D contacts), and Standard density (size 20 IDC contacts)

D-Sub Connector Insert Arrangements [D-Subminiature sizes]

Refer to MIL-DTL-24308; [Connectors, Electric, Rectangular, Non-environmental, Miniature, Polarized Shell, Rack and Panel]. The signal assignments are shown for the male connector, the female connector would have its pin outs mirrored.

D-Sub Connector Dimensions [D-Subminiature Case Out-line]
Military D-Sub Connector Manufacturers [MIL-C-24308 Vendors]

The 25-pin D-sub connector together with the 9-pin D-sub are the two most common connector sizes used with personal computers. The 25-pin DB connector was used as the PC Parallel Port connecting to printers or other devices before they started using smaller connectors. Like many connectors used on the back of PCs the connectors were color coded to assist in making interconnections. The red DB26 connector to the left is color coded to the standard color used for the 25-pin connector. A 25 pin Dsub connector is also used for a number of applications. The EIA-530 calls out a DB25 connector. In addition the RS232 specification [EIA232] calls out a 25 pin DSub. A common DB25 pin panel mount connector used as a serial port is shown to the left. The signal assignments for either of the two standards are provided on the electrical interface pages.

Of course 25-pin D connectors can be made to carry any type of signal including analog signals. Many devices use 3 terminal audio XLR connectors, as a positive and negative signal and ground. The two 25-pin D connector pin outs shown below each carry eight XLR signal pairs and is another example of the usage of a DB25 connector.

DB25 pin XLR Connector
DB25 Pin Yamaha Compatible DB25 Pin Tascam/Digidesign Compatible
1 Digital In 1/2 + 1 Digital Out 7/8 +
2 Digital In 3/4 + 2 Ground
3 Digital In 5/6 + 3 Digital Out 5/6 -
4 Digital In 7/8 + 4 Digital Out 3/4 +
5 Digital Out 1/2 + 5 Ground
6 Digital Out 3/4 + 6 Digital Out 1/2 -
7 Digital Out 5/6 + 7 Digital In 7/8 +
8 Digital Out 7/8 + 8 Ground
9 No Connect 9 Digital In 5/6 -
10 Ground 10 Digital In 3/4 +
11 No Connect 11 Ground
12 Ground 12 Digital In 1/2 -
13 Ground 13 No Connect
14 Digital In 1/2 - 14 Digital Out 7/8 -
15 Digital In 3/4 - 15 Digital Out 5/6 +
16 Digital In 5/6 - 16 Ground
17 Digital In 7/8 - 17 Digital Out 3/4 -
18 Digital Out 1/2 - 18 Digital Out 1/2 +
19 Digital Out 3/4 - 19 Ground
20 Digital Out 5/6 - 20 Digital In 7/8 -
21 Digital Out 7/8 - 21 Digital In 5/6 +
22 Ground 22 Ground
23 Ground 23 Digital In 3/4 -
24 Ground 24 Digital In 1/2 +
25 Ground 25 Ground

Unlike the other electrical standards listed above, the usage of the 25 pin connector shown above is undocumented. That is, there is no released specification that covers the pin assignments.

DB25 connector, male pin out
25 pin D-Sub Connector

Female DB25 connector, used as a panel mount serial port
DB25 pin D-Sub Connector

M24308 Up-grade Path
MIL-DTL-32139, 9-pin Single Row
MIL-DTL-83513, 9-pin Dual Row

Solder-Cup definition
IDC definition

25 pin D-sub Female connector, Plug
25 pin Dsub PC connector

PC motherboard

Distributor rolodex Electronic Components Electronic Equipment EDA CDROM Software Engineering Standards, BOB card Cabled Computer Bus Electronic Engineering Design Table Conversion DB9-to-DB25.
DistributorsComponents Equipment Software Standards Buses Design Reference

Modified 6/13/15
© 1998 - 2016 All rights reserved Larry Davis