RFHCS362F Datasheet, PDF (33/60 Pages) Microchip Technology – Code Hopping Encoder with UHF ASK/FSK Transmitter

FIGURE 6-4: EXAMPLE LOOP FILTER
CIRCUIT
rfHCS362G/362F
LF
R1
C2
C1
rfHCS362G/362F
TABLE 6-4: EXAMPLE LOOP FILTER VALUES FOR TRANSMIT FREQUENCY = 433.92 MHz ⁽¹⁾
C1
C2
R1
Loop BW
Fn (natural
freq in Hz)
Phase Margin
(not counting
sampling delay)
2nd Order
damping
factor
Calculated
Lock Time
0.01 uF 390 pF
680
165 kHz
64 kHz
65 deg
1.37
3900 pF 100 pF 1.5K 360 kHz
103 kHz
63 deg
1.89
1500 pF 47 pF
2.7K 610 kHz
166 kHz
55 deg
2.10
1000 pF 18 pF
4.7K 1.05 MHz
203 kHz
50 deg
3.0
Note 1: Standard Operating Conditions (unless otherwise stated) TA = 25°C, RFEN = 1, VDDRF = 3V.
47 µs
29 µs
18 µs
15 µs
TABLE 6-5: EXAMPLE LOOP FILTER VALUES FOR TRANSMIT FREQUENCY = 315 MHz ⁽¹⁾
C1
C2
R1
Loop BW
Fn (natural
freq in Hz)
Phase Margin
(not counting
sampling delay)
2nd Order
damping
factor
Calculated
Lock Time
3900 pF 390 pF
680
190 kHz
112 kHz
55 deg
0.94
3900 pF 680 pF
680
175 kHz
112 kHz
47 deg
0.94
3900 pF 1000 pF 680
155 kHz
112 kHz
39 deg
0.94
Note 1: Standard Operating Conditions (unless otherwise stated) TA = 25°C, RFEN = 1, VDDRF = 3V.
27 µs
27 µs
27 µs
© 2002 Microchip Technology Inc.
Preliminary
DS41189A-page 33