EKM005 - TMUX4051 8-channel Analog Multiplexer

Part.no: 41023270 EKM005 is a breakout board for the analog multiplexer/demultiplexer TMUX4051 by Texas Instruments. TMUX4051 is an updated version of the classic CD4051 (and similar models in the various 74-series logic). The updated specs include lower RDSon, level shifters for the control inputs, wider supply voltage range and rail-to-rail signal handling. Combined with the very low switch capacitance and low leakage current makes the TMUX4051 a superior choice in every design where fast switching of analog or digital signals is needed.

The EKM005 module breaks out all the pins from the mux and also adds a configurable inverter for the Enable pin, which makes it possible to wire up two EKM005 in parallel for a total of 16 I/O. The added inverter makes the module a good substitute (not pin-compatible) for the obsolete CD4067 and 74HC4067.

TMUX4051 can be powered with a voltage range between 5V - 24V or a bipolar supply from ±2.5V - ±12V. The switches will handle the full supply range (rail-to-rail capable) while the control ports are level shifted to work with logic levels as low as 1.8V, even when powering the module with a bipolar voltage.

The switches are bidirectional, which means the module can be used for multiplexing (many inputs to one) or demultiplexing (one input to many). Please note that the switches are intended for use with small signals and the current capability is very limited (~10mA per switch).

Functions

Wide input voltage range (single or dual supply)
Low RDSon, leakage current and switch capacitance
Compatible with 1.8V logic
Very high bandwidth (up to 400MHz)
Enable input can function as fourth control bit for up to 16-channel operation

Specifications

Supply voltage: 5 – 24V / ±2.5 - ±12V
Switch RDSon: 60 - 240ohm
Channel matching: 2ohm
Leakage current: max 0.1µA
Logic levels: 1.8V - VDD
Dimensions: 20.32 x 15.24mm

Connections

Supply voltage

Pin	Description
V+	Positive supply input. Range is 5 - 24V or ±2.5 - ±12V
GND	Ground reference. Must always be connected 0V.
V-	Negative supply input, range is -2.5 - -12V. Must be connected to GND if single supply is used.

Control Inputs

Pin	Description
A, B, C	Binary control inputs for the 8 switches. Se table for addessing
D (En)	Enable input or fourth address bit.

EKM005 has a special feature to make the Enable input on TMUX4051 act as either Enable or as a fourth address bit. When configured as an address bit, two EKM005 can be wired up in parallel for 16-channels. In this configuration, one module should have the jumper in position "0" and the second in position "1". To change the solder jumper, first cut the trace between the center pad and "0". Then solder the center pad and "1" together. See tables below for addressing.

Solder jumper in position "0" (default):

D (En)	C	B	A	Switch connected to X
0	0	0	0	1
0	0	0	1	2
0	0	1	0	3
0	0	1	1	4
0	1	0	0	5
0	1	0	1	6
0	1	1	0	7
0	1	1	1	8
1	X	X	X	None (Hi-Z)

Jumper in position "1":

D (En)	C	B	A	Switch connected to X
0	0	0	0	1a
0	0	0	1	2a
0	0	1	0	3a
0	0	1	1	4a
0	1	0	0	5a
0	1	0	1	6a
0	1	1	0	7a
0	1	1	1	8a
1	0	0	0	1b
1	0	0	1	2b
1	0	1	0	3b
1	0	1	1	4b
1	1	0	0	5b
1	1	0	1	6b
1	1	1	0	7b
1	1	1	1	8b

#a = module 1 #b = module 2

Switches

TMUX4051 has 8 bi-directional switches that are connected to "X" depending on the address on inputs A, B, C (and D). The switches can be used like regular SPST switches with one leg connected together. Information can flow in either direction, so the module can be used either for collecting many signals to one pin (multiplex) or distributing one signal to many pins (demultiplex). Please note however that the current capability for the switches is very limited and can only be used for small signals. Maximum current through each switch is limited to around 10mA.

Default behavior for control input "D" is Enable. When "D" is high, no switch is connected to X and all the switches are Hi-Z (high impedance, not connected).