micrf507ymltr Micrel Semiconductor, micrf507ymltr Datasheet - Page 29

• Manufacturer Part Number: micrf507ymltr
• Description: 470mhz To 510mhz Low-power Fsk Transceiver With +10dbm Power Amplifier
• Manufacturer: Micrel Semiconductor

This filter is designed for the 490MHz band with 50Ω
terminations. Component values may have to be tuned to
compensate for layout parasitics.
Frequency Modulation
The MICRF507 supports two methods of FSK modulation,
selected with the Modulation field as shown in Table 18:
VCO modulation (enabled when Modulation1 is bit set to
0) and divider modulation (Modulation1 bit set to 1). The
Modulation0 bit must always remain 0.
March 2010
Micrel, Inc.
ANT (pin 5)
Set Modulation[1:0] to
Means of modulation
Register fields to set
PLL bandwidth required
Bitstream constraints
Instantaneous frequency
waveform (spectrum)
determined by
Figure 18. LC Filter
12pF
C4
39pF
C5
12nH
L1
VCO Modulation
00
VCO modulation using modulator
Refclk_K, Mod_clkS, Mod_I, Mod_A,
Mod_F
Lower than 1/10 of bit rate
DC balance required
Register fields affecting modulator
12pF
Table 19. Modulation Modes
C6
29
Bits from the microcontroller to be transmitted enter at the
DATAIXO pin. See Table 19.
The modulation index ß must be a minimum of 2. It is
given by
in which f
rate. Another constraint on f
where f
receiver and the transmitter:
The calculated f
receiver bandwidth, see “Switched Capacitor Filter”
section.
Modulation1 Modulation0
0
0
1
1
OFFSET
f
β
DEV
DEV
=
≥ r
2
Frequency Divider Modulation
10
Divider modulation by switching between
A0/M0/NO and A1/M1/N1
A0, M0, N0, A1, M1, N1
Higher than 2x bit rate
None
PLL transient response
is the single-sided deviation and r
f
b
is the total frequency offset between the
DEV
r
DEV
+ f
b
Table 18. Modulation Field
OFFSET
0
1
0
1
should be used to calculate the needed
State
Closed loop VCO-modulation
Not in use
Modulation by A,M and N
Not in use
DEV
is
M9999-032210-B
MICRF507
b
is the bit