M48A-000-DIL RADIOMETRIX, M48A-000-DIL Datasheet - Page 2

• Manufacturer Part Number: M48A-000-DIL
• Description: IC, CONTROLLER, SERIAL MODEM, 20DIP
• Manufacturer: RADIOMETRIX

Specifications of M48A-000-DIL

• Baud Rate: 4800baud
• Supply Voltage Range: 4.5V To 5.5V
• Operating Temperature Range: -40°C To +85°C
• Digital Ic Case Style: DIP
• No. Of Pins: 20
• Controller Type: MOSFET
• Data Format: Asynchronous

User Interface
M48A is an 18pin PIC16F648A (SO, DIL), running proprietary software. It requires a 4.5v minimum supply.
Figure 2: package type, 18-Lead Plastic Dual In-line (PDIP - 300mil wide body)
Pin description (SO, DIL):
NOTES:
Radiometrix Ltd
RX FLOW
Pin
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
TX FLOW
Vss (0V)
Aux out
RSTXD
RSRXD
LAMP
1. M48 is intended for use with USX/UHX, RMX and LM series radios.
2. All conncetions are 5v cmos logic level except TXE, which is a an open drain
3. Some Radiometrix transmitters require 3v logic levels on their transit data inputs:
4. In RX operation, Tone_out becomes a high impedance
5. After pulling TXE low (active), the coder allows about 50mS for TX to power up and settle
6. RSTXD (pin 7) has no pullup. If the device is only used for transmit, then tie this pin to VCC
7. Vcc must be a 5v regulated supply (4.5 - 5.5v).
8. An approximately 5.1kbps multiphase coded comms protocol is used
9. Without external loads the chip draws less than 5mA from 5v
10. TX_FLOW goes low when the tx buffer is 3/4 full.
11. RX_FLOW goes low whenever valid data is present in the receive buffer.
RST
TXE
If other radios are used, then to reliably recover the data format an external peak sampling data
recovery circuit is recommended, such as QR96.
(but do not exceed +5v on this pin)
In such cases a divider (4K7 series, 10K to ground) on the RXD pin is needed
(this, and other timings, can be modified via the setup mode)
At this oscillator frequency the pic will not operate reliably at 3v
it returns to high state when the buffer is empty
Name
AUX OUT
LAMP
TXE
RST
0V
TX FLOW
RSTXD
RSRXD
RXFLOW
DFLT_0
DFLT_1
TX inhibit
RX inhibit
Vcc
OSC2
OSC1
TONE IN
TONE OUT
1
2
3
4
5
6
7
8
9
I/O
out
out
out
in
supply
out
in
out
out
in
in
in
in
supply
out
in
in
out
Function
Serial output to radio module (1200/2400/4800/9600 baud true RS232)
High when in transmit
Low = enable transmitter
Drive low to reset device. Otherwise pullup to Vcc
Supply ground
Low indicates tx buffer near full (3/4 full)
Inverted RS232 datastream in
Inverted RS232 datastream out
Low indicates data received or in rx FIFO buffer
Default timing set
Default timing set
high = normal mode, low = inhibits transmit (data in still goes to buffer)
high = normal mode, low = prevents serial data being output
5V (regulated power supply); Decouple with 100nuF close to IC
Connect to 19.6608MHz crystal via 100Ω resistor
Connect to 19.6608MHz crystal
Baseband input from receiver data output
Baseband output to transmitter data input
18
17
16
15
14
13
12
11
M48A Modem Data Sheet
TONE OUT
TONE IN
OSC1
OSC2
RX Inhibit
Vdd (+5V)
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