RFPIC12F675F-I/SS Microchip Technology, RFPIC12F675F-I/SS Datasheet - Page 51

• Manufacturer Part Number: RFPIC12F675F-I/SS
• Description: IC MCU 1KX14 RF FSK/ASK 20SSOP
• Manufacturer: Microchip Technology
• Series: PIC®r

Specifications of RFPIC12F675F-I/SS

• Package / Case: 20-SSOP
• Frequency: 380MHz ~ 450MHz
• Applications: RKE, Security Systems
• Modulation Or Protocol: ASK, FSK
• Data Rate - Maximum: 40 kbps
• Power - Output: 10dBm
• Current - Transmitting: 14mA
• Data Interface: PCB, Surface Mount
• Antenna Connector: PCB, Surface Mount
• Memory Size: 1024 x 14 words Flash, 128 x 8 Byte EEPROM, 64 x 8 Byte SRAM
• Voltage - Supply: 2V ~ 5.5V
• Operating Temperature: -40°C ~ 125°C
• Processor Series: RFPIC12F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 64 B
• Interface Type: USB
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 6
• Number Of Timers: 2
• Operating Supply Voltage: 2 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Development Tools By Supplier: ICE2000, DV164102, AC164101, AC164103
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 4-ch x 10-bit
• Program Memory Type: Flash
• Program Memory Size: 1.75 KB
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: XLT20SS-1 - SOCKET TRANSITION 18DIP 20SSOPAC164103 - MODULE RCVR RFPIC 433MHZAC164101 - MODULE TRANSMITTER RFPIC 433MHZDV164102 - KIT DEV RFPICKIT KIT 1AC124002 - MOD SKT PROMATEII 18SOIC/20SSOP
• Features: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: Q3188156

9.0
9.1
The transmitter is a fully integrated UHF ASK/FSK
transmitter consisting of crystal oscillator, Phase-
Locked Loop (PLL), Power Amplifier (PA) with open-
collector output, and mode control logic. There are 3
variations of this device to optimize its performance for
the most commonly used frequency bands.
TABLE 9-1:
The internal structure of the transmitter is shown in
Figure 9-1.
reference frequency set by the attached crystal. The
voltage controlled oscillator (VCO) converts the voltage
on the LF pin to a frequency. This frequency is divided
by 32 and compared to the crystal reference. If the
frequency or phase does not match the reference, the
charge pump corrects the voltage on the LF pin. The
VCO output signal is also amplified by the PA, whose
single ended output drives the user’s antenna.
The external components required are a crystal to set
the transmit frequency, a supply bypass capacitor, and
two to seven biasing/impedance matching components
to get maximum power to the antenna. The two control
signals from the microcontroller are connected exter-
nally for maximum design flexibility. The rfPIC12F675
is capable of transmitting data by Amplitude Shift
Keying (ASK) or Frequency Shift Keying (FSK).
The rfPIC12F675 is a radio frequency (RF) emitting
device. Wireless RF devices are governed by a
country’s regulating agency. For example, in the United
States it is the Federal Communications Committee
(FCC) and in Europe it is the European Conference of
Postal
(CEPT). It is the responsibility of the designer to ensure
that their end product conforms to rules and regulations
of the country of use and/or sale.
 2003 Microchip Technology Inc.
RF devices require correct board level implementa-
tion in order to meet regulatory requirements. Layout
considerations are listed at the end of each subsec-
tion. It is required to place a ground plane on the PCB
to reduce unwanted radio frequency emissions.
rfPIC12F675H
rfPIC12F675K
rfPIC12F675F
Device
and
UHF ASK/FSK TRANSMITTER
Transmitter Operation
A
Telecommunications
Colpitts
FREQUENCY BANDS
290-350 MHz
390-450 MHz
850-930 MHz
Frequency
oscillator
generates
Administrations
Modulation
ASK/FSK
ASK/FSK
ASK/FSK
Preliminary
the
FIGURE 9-1:
9.2
Pins V
respectively to the transmitter. These power pins are
separate from power supply pins V
microcontroller
ground plane with the shortest possible traces. The
microcontroller ground should be tied to the same RF
ground potential. However, the V
a different potential than the microcontroller as long as
the RFEN and DATA input levels are within specifica-
tion limits.
Layout Considerations - Provide low impedance
power and ground traces to minimize spurious
emissions. A two-sided PCB with a ground plane on
the bottom layer is highly recommended. Separate
bypass capacitors should be connected as close as
possible to each of the supply pins V
Connect both V
multiple PCB vias adjacent to the V
share these PCB vias with other ground traces. Filter
the V
spurs exceed regulatory limits.
DDRF
DATA
DDRF
DATA
Supply Voltage (V
RFEN
with an RC filter if the microcontroller noise
ASK
FSK
Divide
PS
by 32
and V
.
Both V
SSRF
TRANSMITTER BLOCK
DIAGRAM
SSRF
rfPIC12F675
pins to the ground plane using
Phase/Freq
FSK Switch
Controlled
RF Power
Oscillator
Oscillator
SSRF
Amplifier
Detector
Charge
Voltage
Divider
Control
Crystal
Pump
Clock
Logic
RF
supply power and ground
pins should be tied to the
DDRF
DDRF
SSRF
DD
DS70091A-page 49
supply can be at
, V
DD
and V
REFCLK
RFXTAL
LF
ANT
V
V
V
FSK
DDRF
SSRF
SSRF
pads. Do not
SSRF
and V
OUT
SS
)
DDRF
to the
.