MICRF104BM Micrel Inc, MICRF104BM Datasheet - Page 6

• Manufacturer Part Number: MICRF104BM
• Description: IC ASK TRANSMITTER UHF 14SOIC
• Manufacturer: Micrel Inc

Specifications of MICRF104BM

• Frequency: 300MHz ~ 470MHz
• Applications: RKE
• Modulation Or Protocol: ASK, OOK
• Data Rate - Maximum: 20 kbps
• Power - Output: -2dBm
• Current - Transmitting: 12mA
• Data Interface: PCB, Surface Mount
• Antenna Connector: PCB, Surface Mount
• Voltage - Supply: 1.8 V ~ 4 V
• Operating Temperature: 0°C ~ 85°C
• Package / Case: 14-SOIC (0.154", 3.90mm Width)
• Peak Reflow Compatible (260 C): No
• Supply Voltage Max: 4V
• Transceiver Type: RF Transmitter
• Data Rate Max: 20Kbps
• Leaded Process Compatible: No
• Mounting Type: Surface Mount
• No. Of Drivers: 1
• Supply Current: 35mA
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Features: -
• Memory Size: -
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant, Contains lead / RoHS non-compliant

MICRF104
Functional Diagram
Functional Description
The block diagram illustrates the basic structure of the RF
portion of the MICRF104.
principal functional blocks of the IC, namely the (1, 2, 3, 4, 5)
UHF Synthesizer, (6a/b) Buffer, (7) Antenna tuner, (8) Power
amplifier, (9) TX bias control, (10) Reference bias and (11)
Process tuner.
The UHF synthesizer generates the carrier frequency with
quadrature outputs. The in-phase signal (I) is used to drive
the PA and the quadrature signal (Q) is used to compare the
antenna signal phase for antenna tuning purpose.
MICRF104
VDDPWR
REF.OSC
VDDRF
STBY
VSS
EN
PC
VDD
Oscillator (1)
Reference
Detector
Phase
Identified in the figure are the
Reference
Bias
(2)
Shutdown
(10)
Figure 2. MICRF104 Block Diagram (RF Circuit)
Thermal
Enable
1.2V
Oscillator
Prescaler
Divide
(3)
by 32
Reference
Bandgap
Error
Amplifier
(5)
Logic
VCO (4)
6
Control
The Antenna tuner block senses the phase of the transmit
signal at the antenna port and controls the varactor capacitor
to tune the antenna.
The Power control unit senses the antenna signal and con-
trols the PA bias current to regulate the antenna signal to the
transmit power.
The Process tune circuit generates process independent
bias currents for different blocks.
A PCB antenna loop coupled with a resonator and a resistor
divider network are all the components required to construct
Bias
TX
Driver
(9)
Buffer
Buffer
(6a)
(6b)
Antenna
Control
Tuning
(7)
Power
Amp
DC/DC Converter
RF Transmitter
(8)
Varactor
Device
(11)
November 8, 2001
SW
ASK
ANTP
ANTM
VSS
5V
Micrel