Electronic Components Datasheet Search |
|
RXD-418-KH2 Datasheet(PDF) 5 Page - List of Unclassifed Manufacturers |
|
RXD-418-KH2 Datasheet(HTML) 5 Page - List of Unclassifed Manufacturers |
5 / 11 page Page 9 Page 8 TYPICAL APPLICATIONS The figure below shows an example of a basic remote control receiver utilizing the KH2 Series receiver module. When a key is pressed on the transmitter, a corresponding line on the receiver goes high. A schematic for the transmitter / encoder circuit may be found in the KH Series Transmitter Data Guide. These circuits are implemented in the KH Series Basic Evaluation Kit. They can be easily modified for a custom application and clearly demonstrate the ease of using the Linx KH Series modules for remote control applications. The ten-position DIP switch is used to set the address to either ground or floating. Since the floating state is a valid state, no pull-up resistors are needed. The data line outputs can only source about 1mA of current, so transistor buffers are used to drive the buzzer and LED. 1mA is sufficient to activate most microcontrollers, but the manufacturer’s data guides should be consulted to make sure. The KH2 Series receiver / decoder module is also suitable for use with Linx OEM handheld transmitters. These transmitters are FCC certified, making product introduction extremely quick. Information on these transmitters can be found on the Linx website at www.linxtechnologies.com. Q1 2N2222 R2 2.2k R4 10k BZ1 BUZZER VCC Q2 2N2222 R3 2.2k R5 10k LED1 RED LED R6 220 OHM VCC B1 CR2032 3V LITHIUM VCC S4 NC 1 D0 2 D1 3 GND 4 VCC 5 PDN 6 D2 7 D3 8 D4 9 DATA 10 VT 11 D5 12 D6 13 D7 14 A0 15 A1 16 A2 17 A3 18 A4 19 A5 20 A6 21 A7 22 A8 23 A9 24 RSSI 25 NC 26 GND 27 ANT 28 RXD-XXX-KH2 1 2 3 20 19 18 4 5 6 17 16 15 7 8 9 14 13 12 10 11 S1 SW-DIP-10 GND ANT1 GND GND VCC GND GND GND Figure 12: Basic Remote Control Receiver Figure 13: Linx OEM Transmitters Figure 14: Linx OEM Keyfobs USING THE RSSI PIN The receiver’s Received Signal Strength Indicator (RSSI) line serves a variety of functions. This line has a dynamic range of 80dB (typical) and outputs a voltage proportional to the incoming signal strength. It should be noted that the RSSI levels and dynamic range will vary slightly from part to part. It is also important to remember that RSSI output indicates the strength of any in-band RF energy and not necessarily just that from the intended transmitter; therefore, it should be used only to qualify the level and presence of a signal. The RSSI output can be utilized during testing or even as a product feature to assess interference and channel quality by looking at the RSSI level with all intended transmitters shut off. The RSSI output can also be used in direction- finding applications, although there are many potential perils to consider in such systems. Finally, it can be used to save system power by “waking up” external circuitry when a transmission is received or crosses a certain threshold. The RSSI output feature adds tremendous versatility for the creative designer. INTERFERENCE CONSIDERATIONS The RF spectrum is crowded and the potential for conflict with other unwanted sources of RF is very real. While all RF products are at risk from interference, its effects can be minimized by better understanding its characteristics. Interference may come from internal or external sources. The first step is to eliminate interference from noise sources on the board. This means paying careful attention to layout, grounding, filtering, and bypassing in order to eliminate all radiated and conducted interference paths. For many products, this is straightforward; however, products containing components such as switching power supplies, motors, crystals, and other potential sources of noise must be approached with care. Comparing your own design with a Linx evaluation board can help to determine if and at what level design-specific interference is present. External interference can manifest itself in a variety of ways. Low-level interference will produce noise and hashing on the output and reduce the link’s overall range. High-level interference is caused by nearby products sharing the same frequency or from near-band high-power devices. It can even come from your own products if more than one transmitter is active in the same area. It is important to remember that only one transmitter at a time can occupy a frequency, regardless of the coding of the transmitted signal. This type of interference is less common than those mentioned previously, but in severe cases it can prevent all useful function of the affected device. Although technically it is not interference, multipath is also a factor to be understood. Multipath is a term used to refer to the signal cancellation effects that occur when RF waves arrive at the receiver in different phase relationships. This effect is a particularly significant factor in interior environments where objects provide many different signal reflection paths. Multipath cancellation results in lowered signal levels at the receiver and, thus, shorter useful distances for the link. |
Similar Part No. - RXD-418-KH2 |
|
Similar Description - RXD-418-KH2 |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.COM |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Datasheet Upload | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |