Radiometrix Ltd

Control124

page 3

Decoder Mode

Control124 can be put into Decoder Mode by connecting Mode (pin 2) to Ground.

MODE

RST

Vss

A3

A2

A1

A0

RXD

LATCH

OSC1

OSC2

Vdd

DB3

DB2

DB1

DB0

3.58MHz

5V

supply

Vss

DA0

DA1

DA2

DA3

DA7

DA6

DA5

DA4

STB

NC

470R

470R

470R

470R

470R

470R

100nF

470R

470R

470R

470R

470R

470R

NC

RF

Vcc

GND

RXD

Figure 3: Control124 in Decoder Mode

Pin

Name

Input/Outp

ut

Description

1

RST

Input

Active Low Reset (Connect to user system reset or tie to Vdd)

2

LATCH

Input

0V = latch DA3:D0 until next packet

Vdd = clear DA3:DA0 after 150ms (no pull-up)

3

RXD

Input

Encoded Address and Data from RXD Output of RF Receiver

4

STB

Output

Positive going pulse on reception of valid data packet. 10µs duration

5

MODE

Input

RX=0V, TX=Vdd (no pull-up, only read at reset/power up)

6

NC

-

-

7

NC

-

-

8

VSS

Supply

Supply Ground

9

OSC2

Output

10

OSC1

Input

11 - 18

DA0 - DA7

Output

19

VSS

Supply

Supply Ground

20

VDD

Supply

4.5-5.5V supply (decouple with 0.1µF close to IC)

2.0V-5.5V (low voltage version)

21 - 24

A0 - A3

Input

25 - 28

DB0 - DB3

Output

Notes:

1. 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) CTR124H

version.

2. Absolute maximum source/sink current from each DA0-DA7, DB0-DB3, A0-A3 pins is 25mA

Absolute maximum total current from DA0-DA7 port and DB0-DB3, A0-A3 port is 200mA

3. MODE pin is only read at reset/power up. Connect to either Vdd (Encoder) or 0V (Decoder).

4. Without external loads the CTR124 draws <2mA from 5V supply.

5. Standard version can be used down to 4V for <20MHz oscillator.

Low voltage version can be used down to 2V for <4MHz oscillator.

6. High Speed, CTR124H, version should not be used with Narrow Band FM radio modules.