MRF24J40-I/ML Microchip Technology, MRF24J40-I/ML Datasheet - Page 135

• Manufacturer Part Number: MRF24J40-I/ML
• Description: IC TXRX IEEE/ZIGBEE 2.4GHZ 40QFN
• Manufacturer: Microchip Technology

Specifications of MRF24J40-I/ML

• Package / Case: 40-QFN
• Frequency: 2.4GHz
• Data Rate - Maximum: 250kbps
• Modulation Or Protocol: 802.15.4
• Applications: ISM, ZigBee™
• Power - Output: 0dBm
• Sensitivity: -95dBm
• Voltage - Supply: 2.4 V ~ 3.6 V
• Current - Receiving: 18mA
• Current - Transmitting: 18mA
• Data Interface: PCB, Surface Mount
• Antenna Connector: PCB, Surface Mount
• Operating Temperature: -40°C ~ 85°C
• Number Of Receivers: 1
• Number Of Transmitters: 1
• Wireless Frequency: 2.4 GHz
• Interface Type: 4 Wire SPI
• Noise Figure: 8 dB
• Output Power: + 0 dBm
• Operating Supply Voltage: 2.5 V, 3.3 V
• Maximum Operating Temperature: 85 C
• Mounting Style: SMD/SMT
• Maximum Supply Current: 22 mA
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Memory Size: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

4.0
4.1
Figure 4-1 is an example of the circuit diagram of a
balun to match to a 50 Ω antenna. A balun is the imped-
ance transformer from unbalanced input of the PCB
antenna and the balanced input of the RF transceiver
(pins RFP and RFN).
FIGURE 4-1:
FIGURE 4-2:
© 2010 Microchip Technology Inc.
APPLICATIONS
Antenna/Balun
50Ω ANT
0.3 pF
C17
EXAMPLE BALUN CIRCUIT DIAGRAM
BALUN CIRCUIT MEASURED IMPEDANCE
4.7 nH
L4
0.5 pF
C16
Preliminary
0.5 pF
C15
Figure 4-2 shows the measured impedance of the
balun where the center of the band is very close to 50 Ω .
When using low tolerance components (i.e., ±5%)
along with an appropriate ground, the impedance will
remain close to the 50 Ω measurement.
0.5 pF
10 nH
5.6 nH
C14
L3
L2
+V
10 nH
L1
C2
0.5 pF
0.01 μF
C12
MRF24J40
RFP
RFN
DS39776C-page 135