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

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