Specifications

8
Different switching for applications
A general purpose relay is used to turn on/off the DUT
(device under test), instruments, motors, pumps and
LEDs, or to form an attenuation network with L, C, R
components.
A multiplexer is used for switching signal to
instrumentation by connecting many test points to an
instrument, or a DUT to many instruments. The
instruments can include multimeters, oscilloscopes,
spectrum analyzers, and counters, etc. There are one-
wire, two-wire, three-wire or four-wire multiplexers. A
one-wire multiplexer is very useful in high frequency
(30 MHz - 26 GHz) applications and common ended
signal switching. The two-wire multiplexer is very
useful for floating measurements where you need to
switch both the "high" and "low" paths. The three-wire
multiplexer is mostly used for the guarded
measurements that have very high CMRR (Common
Mode Rejection Ratio). The four-wire multiplexer is
mainly used for 4-wire precision ohm measurements.
A matrix switch is used when one or more instruments
are connected to one or more test points at the same
time. By using a matrix switch, you can connect any
point on a column to any point on a row. A matrix
switch offers maximum flexibility, but you need to use
more relays and be careful to avoid crosstalk between
channels.
A digital I/O module has both input & output bits for
digital sensing and is mainly used to control external
devices, such as motors, LEDs, and microwave relays.
The digital I/O can also be used to send and receive
digital patterns to/from the DUT, and to communicate
with other devices.
Six high density modules
Now test engineers have a 40-channel 2-wire
multiplexer in roughly the same space as only one of
the HP 3488A's 10-channel switching modules. The six
high density modules reduce cost by compacting a large
number of channels on a single module. There are also
two multifunction modules for applications a that
require variety of functions in limited space. The
N2264A includes 12 general purpose relay channels, 3
high current channels and 16-bit digital I/O. The
N2265A includes a 4 x 4 matrix switch and 16-bit of
digital I/O. With these two modules and HP 3499B, the
half-rack-width mainframe, you will have a compact
switching unit in a small space and at a low cost!
Flexible channel capacity
The 19 modules in HP 3499 family provide a large
variety of channel selections to match your test system
application (10-200 channels in one mainframe). The
total channel count ranges from 10, 20, to 40 channels
per module. You can customize your HP 3499A/B with
these modules to match the channel count and
switching topologies to meet your individual needs.
Customize your HP 3499A/B with plug-in modules
We invested a lot of time and energy in studying actual switching applications and tailoring the switching
modules for different applications. Six high density modules (HP N2260A, N2261A, N2262A, N2263A,
N2264A and N2265A) plus the 13 existing modules (HP 44470A/D, 44471A/D, 44472A, 44473A, 44474A,
44475A, 44476A/B, 44477A, and 44478A/B) for the HP 3488A can cover a wide variety of signals with
superior flexibility.