W-Linx Technology TXE-433-KH dimensions PIN Assignments, PIN Descriptions, Pin # Name Description

PIN ASSIGNMENTS

1	LADJ/GND ANT		24
2	D0	GND	23
3	D1	A9	22
4	GND	A8	21
5	VCC	A7	20
6	TE	A6	19
7	D2	A5	18
8	D3	A4	17
9	D4	A3	16
10	D5	A2	15
11	D6	A1	14
12	D7	A0	13

Figure 6: KH Series Transmitter Pinout (Top View)

PIN DESCRIPTIONS

Pin #	Name	Description
		Level Adjust. This line can be used to adjust the output
1	GND / LADJ	power level of the transmitter. Connecting to GND will give
		the highest output, while placing a resistor to GND will
		lower the output level.
		Data Input Lines. When TE goes high, the module will
2, 3,	D0 - D1	encode the state of these lines for transmission. Upon
7-12		receipt of a valid transmission, the receiver / decoder will
		replicate these lines on its output lines.
4	GND	Analog Ground
5	VCC	Supply Voltage
		Transmit Enable Line. When this line goes high, the
6	TE	module will encode the states of the address and data lines
		into a packet and transmit the packet three times.
		Address Lines. The state of these lines must match the
13-22	A0-A9	state of the receiver’s address lines in order for a
		transmission to be accepted.
23	GND	Analog Ground
24	ANT	50-ohm RF Output

MODULE DESCRIPTION

The KH Series transmitter / encoder module combines a high-performance Surface Acoustic Wave (SAW) based transmitter with an on-board encoder. When combined with a Linx KH Series receiver / decoder, a highly reliable RF link capable of transferring control or command data over line-of-sight distances in excess of 300 feet is formed. The module accepts up to 8 parallel inputs, such as switches or contact closures, and provides ten tri-state address lines for security and creation of 59,049 (310) unique transmitter / receiver relationships. The KH’s compact surface-mount package integrates easily into existing designs and is friendly to hand production or automated assembly.

			Address Inputs
		TX Enable		A0-A9
	SAW
50Ω RF OUT	Oscillator		Divider		Parallel
				OSC	Inputs
(ANT)		Sync
					D0-D7
Keyed Output			Counter	GATE
	RF Amplifier	Buffer	TRI-Detect
Output Isolation
& Filter
RF STAGE		ENCODER STAGE

Figure 7: KH Series Transmitter Block Diagram

THEORY OF OPERATION

The KH Series transmitter operation is straightforward. When the Transmit Enable (TE) line is taken high, the on-board encoder IC is activated. The encoder detects the logic states of the data and address lines. These states are formatted into a 3-word transmission, which continues until the TE line is taken low. The encoder creates a serial data packet that is used to modulate the transmitter.

The transmitter section is based on a simple, but highly-optimized, architecture that achieves a high fundamental output power with low harmonic content. This ensures that most approval standards can be met without external filter components. The KH Series transmitter is exceptionally stable over variations in time, temperature, and physical shock as a result of the precision SAW device that is incorporated as the frequency reference.

The transmitted signal may be received by any Linx KH Series receiver / decoder module or Linx LC or LR Series receiver combined with the appropriate decoder IC. Once data is received, it is decoded using a decoder IC or custom microcontroller. The transmitted address bits are checked against the address settings of the receiving device. If a match is confirmed, the decoder’s outputs are set to replicate the transmitter’s inputs.

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