Radiometrix
Hartcran House, 231 Kenton Lane, Harrow, HA3 8RP, England
Issue: 4, 01 November 2004
Tel: +44 (0) 20 8909 9595, Fax: +44 (0) 20 8909 2233
Control44
4 bit Address - 4 bit Data encoder/decoder
Control44 is a 4 bit address, 4 bit data
encoder and decoder combined in a single IC.
This device can operate in either Encode or
Decode mode. It uses 1kbps differential
Manchester bit balancing with preamble and
checksum.CTR44 is specifically designed to
be used in RF remote control applications. It
is available in 20pin SSOP, 18pin SOIC and
PDIP packages.
Figure 1: Control44 in SO, DIL packages
Features
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Operating voltage (temperature):
3.0V-5.5V for standard version (-40°C to +125°C)
2.0V-5.5V for low voltage version (-40°C to +85°C)
Draws <2mA without external load
4 bit address and 4 bit data
16 different remotes with 4 controls each
Single packetised transmission for fast activation
Maximum usage of the range capability of an RF module
Adequate preamble to settle data slicer in the receiver.
Extra wake up preamble to allow for transmitter power up time requirements
Differential Manchester encoding of address, data and checksum
Synchronisation codes and checksum to reduce false triggering on noise
Suitable to be used with Narrow Band FM radio modules
Ceramic resonator or crystal oscillator up to 20MHz
Data rate up to 5.6kbps
Minimum external component requirement
4 wire, push button and latched push button modes
Custom address, data bit variations available subject to minimum order quantity
Applications
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Security and Alarm systems
Emergency assistance call system
Status reporting and monitoring systems
RF Remote control systems
Industrial controls
HVAC controls
Simple On/Off switching
Long range telecontrol with Narrow Band FM radios
Radiometrix Ltd
Control44
page 1
Encoder Mode
Control44 can be put into Encoder Mode by connecting Mode (pin 2) to supply.
5V
supply
RF
Vcc
GND
TXD
Transmitter
10k
4k7
NC 1
Mode(Vdd) 2
TXE 3
RST 4
VSS 5
A0 6
A1 7
A2 8
A3 9
18
17
16
15
14
13
12
11
10
TXD
SEND
OSC1
OSC2
Vdd (+5V)
DB3
DB2
DB1
DB0
NC
Mode
TXE
RST
VSS
A0
A1
A2
A3
TXD
SEND
OSC1
OSC2
Vdd
DB3
DB2
DB1
DB0
3.58MHz
10k
100nF
Control44
Figure 2: Control44 in Encoder Mode
Pin
1
2
3
4
5
6-9
10-13
14
15
16
17
18
Name
NC
Mode
TXE
RST
VSS
A3:A0
DB3:DB0
Vdd
OSC2
OSC1
SEND
TXD
Input/Output
Input
Output
Input
Supply
Input
Input
Supply
Output
Input
Input
Output
Description
RX=0V, TX=Vdd (no pull-up, only read at reset/power up)
Active Low RF Transmitter Enable (Open drain, require 10k pull-up)
4,6
Active Low Reset (Connect to user system reset or tie to Vdd)
Supply Ground
Least significant 4 bits of Address (Internal pull-ups to Vdd)
1,5
Least significant 4 bits of Data B (Internal pull-ups to Vdd)
5
4.5-5.5V supply (decouple with 0.1µF close to IC)
3.58MHz resonator
2
3.58MHz resonator
2
Active Low Send Packet (Encoder Enable)
3
Encoded Address and Data to TXD input of RF Transmitter
Control44
Decoder Mode
Control44 can be put into Decoder Mode by connecting Mode (pin 2) to Ground.
RF
Receiver
Vcc
GND
RXD
5V
supply
STB
Mode
NC
RST
VSS
A0
A1
A2
A3
RXD
Latch
OSC1
OSC2
Vdd
DB3
DB2
DB1
DB0
STB
Mode
NC
RST
VSS
A0
A1
A2
A3
RXD
Latch
OSC1
OSC2
Vdd
DB3
DB2
DB1
DB0
10k
470R
3.58MHz
Control44
Figure 3: Control44 in Decoder Mode
Control44
100nF
470R
470R
470R
470R
Radiometrix Ltd
Control44
page 2
Pin
1
2
3
4
5
6-9
10-13
14
15
16
17
18
Name
STB
Mode
NC
RST
VSS
A3:A0
DA3:DA0
Vdd
OSC2
OSC1
Latch
RXD
Input/Output
Output
Input
Input
Supply
Input
Output
Supply
Output
Input
Input
Input
Description
Positive going pulse on reception of valid data packet. 10µs duration
RX=0V, TX=Vdd (no pull-up, only read at reset/power up)
Active Low Reset (Connect to user system reset or tie to Vdd)
Supply Ground
Least significant 4 bits of Address (Internal pull-ups to Vdd)
1,5
Least significant 4 bits of Data A
5
4.5-5.5V supply (decouple with 0.1µF close to IC)
3.58MHz resonator
2
3.58MHz resonator
2
0V = latch DA3:D0 until next packet
Vdd = clear DA3:DA0 after 150ms (no pull-up)
Encoded Address and Data from RXD Output of RF Receiver
Notes:
1. Only 4 of the 6 address bits are accessible. A5,A4 are set to 0 in CTR44
2. OSC1,2 require a 3.58MHz ceramic resonator with internal capacitors like Murata
CSTLA3M58G55-B0. If a 2 pin resonator or crystal is used, then two 15pF-22pF caps are
needed: one from OSC1 to 0V another from OSC2 to 0V. 100Ω series resistor between OSC2 and
crystal may be required when driving low frequency crystal with High Speed (H) CTR44H
version.
3. If a low going pulse of between 10µs and 50ms is applied to SEND pin then a single packet will
be transmitted
4. After asserting TXE low (active), the encoder allows 55ms for NBFM TX to power up and settle
5. Absolute maximum source/sink current from each DB3:DB0 pin is 25mA
6. TXE is an open drain output (no pull-up). Connect it to Vdd via a 10kΩ pull-up resistor
7. MODE pin is only read at reset/power up. Connect to either Vdd (Encoder) or 0V (Decoder).
8. Without external loads the CTR44 draws <2mA from 5V supply.
9. Standard version can be used down to 3V for <10MHz oscillator.
Low voltage version can be used down to 2V for <4MHz oscillator.
10. High Speed, CTR44H, version should not be used with Narrow Band FM radio modules.
Encoded Data Packet Format
Transmission format is 1kbps differential Manchester encoding when using 3.58MHz resonator.
Oscillator frequency can decreased to suit narrow band RF module data rate requirements. CTR44H IC
running at 20MHz can be used with wideband radio modules for fast data transmission.
0
0
0
1
0
1
0
1
1
1ms
500µs
Figure 4: 1kbps differential Manchester coding of ‘1’ and ‘0’
Radiometrix Ltd
Control44
page 3
Control44 transmits a 6-byte burst, with 8 bits of preamble and 4 bits postamble. When firing up the
transmitter from cold Control44 puts in an extra 55ms especially for Narrow Band FM transmitter and
receiver requiring longer power-up to stable data time.
Figure 5: Push button transmission with 55ms power-up preamble
The large amount of sync code, address and checksum reduce the likelihood of false calling on noise to
an insignificant degree, while the breaking up of the data sequences with bit7 zeros is to reduce the
likelihood of the decoder mistaking particular sequences in the data for sync codes.
Differential Manchester encoding coverts the 0000 into 11001100 which is the bit pattern equivalent to preamble
required to settle adaptive data slicer in the RF receiver module.
Preamble =
Sync1 =
Sync2 =
DataA =
DataB =
Address =
Checksum =
11001100
this byte is not decoded.
10111111
111100(A7)(B7)
0(DA6-DA0)
Reserved for future use and custom variants
0(DB6-DB0)
0(A5-A0)0
sum of (DA7-DA0) + (DB7-DB0) + Adr(whole byte) truncated to 8 bits
This allows 6 bits of address and 2 data bytes per 60ms burst when 3.58MHz resonator is used.
Preamble
00000000000000
11001100
Sync1
10111111
Sync2
111100(DA7)(DB7)
Data A
0(DA6:DA0)
Data B
0(DB6:DB0)
Address
0(A5:A0)0
Check Sum
DA7:DA0+DB7:DB0
+A7:A0
Postamble
0000
Figure 6: Control44 data packet
In the following example, Control44 in Encoder mode is set with the following.
DB3
1
DB2
0
DB1
1
DB0
0
A3
1
A2
0
A1
0
A0
1
The Control44 will packetise the address and data into the following format. Reserved DataA is
transmitted as 00hex. Any custom variants requiring more than 8 bits of data will make use of this
slot..
Preamble
11001100
Radiometrix Ltd
Sync1
10111111
Sync2
11110000
DataA
00000000
DataB
00001010
Address
00010010
Checksum
00011100
Postamble
0000
page 4
Control44
Figure 7: Synchronisation codes, DataA, DataB, Address, Checksum and Postamble
Application Modes
Mode
4 wires
Pushbutton
Latched
Pushbutton
Setup
Latch = 0V (connect)
SEND = 0V (connect)
Latch = Vdd (connect)
SEND =0V (push button)
Latch = 0V (connect)
SEND = 0V (push
button)
Description
Continuous transmission like wire connection
Decoder outputs active only when transmitter is
keyed
Decoder outputs hold state of last transmission
Ordering Information
CTR44-000-SS
CTR44-000-SO
CTR44-000-DIL
CTR44L-000-SS
CTR44L-000-SO
CTR44L-000-DIL
CTR44H-000-SS
CTR44H-000-SO
CTR44H-000-DIL
Control 44 (≤4MHz)- No Frequency - Shrink Small Outline
Control 44 (≤4MHz)- No Frequency - Small Outline
Control 44 (≤4MHz)- No Frequency - Plastic Dual In Package
Control 44 Low Voltage (≤4MHz) - No Frequency - Shrink Small Outline
Control 44 Low Voltage (≤4MHz) - No Frequency - Small Outline
Control 44 Low Voltage (≤4MHz) - No Frequency - Plastic Dual In Package
Control 44 High Speed (4MHz-20MHz) - No Frequency - Shrink Small Outline
Control 44 High Speed (4MHz-20MHz) - No Frequency - Small Outline
Control 44 High Speed (4MHz-20MHz) - No Frequency - Plastic Dual In Package
Radiometrix Ltd
Control44
page 5
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