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

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3
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
