Ordering information, Electrical specifications, Theory of operation – Linx Technologies CMD-HHCP-xxx User Manual
Page 4

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Electrical Specifications
Parameter
Designation Min.
Typ.
Max.
Units
Notes
Power Supply
Operating Voltage
V
CC
2.1
3.0
3.6
VDC
Supply Current
l
CC
3.4
mA
Power-Down Current
l
PDN
5.0
nA
1
Transmitter Section
Transmit Frequency Range
F
C
CMD-HHCP-315-MD
315
MHz
CMD-HHCP-418-MD
418
MHz
CMD-HHCP-433-MD
433.92
MHz
Center Frequency Accuracy
–50
+50
kHz
Environmental
Operating Temperature Range
–40
+85
°C
1
Theory of Operation
The CMD-HHCP-***-MD Compact Handheld transmitter combines the LR
Series transmitter with an internal Splatch Series antenna and an on-board
DS Series encoder IC to form a simple, yet highly reliable, RF remote
control transmitter. The LR transmitter is a low-cost, high-performance,
synthesized ASK / OOK transmitter. The transmitter’s synthesized
architecture delivers outstanding stability and frequency accuracy while
minimizing the effects of antenna port loading and mismatching. This
reduces or eliminates frequency pulling, bit contraction, and other negative
effects common to SAW-based transmitter architectures, providing a
significantly higher level of performance and reliability.
When a button is pressed on the transmitter, power is applied to the
internal circuitry and the encoder IC is enabled. The encoder detects the
logic states of the address lines and button data lines. These states are
formatted into a three-word transmission cycle that continues until the
button is released. The encoder data is used to modulate the transmitter,
which, through the antenna, conveys the data into free space. On the
receiver side, a decoder IC or custom microcontroller is used to check
the transmitter’s address bits against the address settings of the receiving
device. If a match is confirmed, the decoder’s outputs are set to replicate
the transmitter’s button states. These outputs can then be used to activate
external circuitry required by the application.
The transmitter is compatible with several Linx receiver products, including
the LR, KH2, KH3, LT and OEM product families. For applications where
range is critical, the LR Series receiver is the best choice due to its
outstanding sensitivity. When the transmitter is combined with an LR Series
receiver and the DS Series decoder, ranges of up to 750 feet (230m) are
possible. Applications operating over shorter distances will also benefit
from the increased link reliability and superior noise immunity provided by
the LR Series receiver.
Electrical Specifications
Ordering Information
Part Number
Description
CMD-HHCP-***-xxx-MD
Compact Handheld Transmitter
EVAL-***-HHCP
HHCP Basic Evaluation Kit
*** = 315, 418 (Standard) or 433.92MHz
xxx = Custom color, leave blank for black
Ordering Information
Figure 3: Ordering Information
Figure 4: Electrical Specifications
1. Characterized, but not tested