micrf405 Micrel Semiconductor, micrf405 Datasheet - Page 23

• Manufacturer Part Number: micrf405
• Description: Micrf405 290mhz To 980mhz Ism Band Ask/fsk Transmitter
• Manufacturer: Micrel Semiconductor

April 2006
Micrel
VCO_Fr_Auto
VCO_freq
VCO_Fr_Chk
1
2
3
4
5
6
7
0
1
0
1
Comments
No calibration is done.
If VCO control voltage is below 0.35V or above AVDD-0.35V, the VCO frequency settings are altered until
the control voltage is within the window. No VC_LO or VC_HI interrupt flag is set. The new settings can be
read out; bits VCO_Freq_O[2:0] in interrupt register.
If PLL for some reason cannot obtain lock (i.e. if frequency is set wrongly), an interrupt will be given even
if VCO_Fr_Chk = 0.
1050.0
1000.0
Comments
VCO control voltage is not controlled
VCO control voltage is measured; if it is below 0.35V the VC_LO interrupt flag is set, if it is higher than
AVDD-0.35V the VC_HI flag is set
950.0
900.0
850.0
800.0
287
290
293
300
307
313
320
Figure 10. RF Frequency vs. Varactor Voltage and VCO Frequency Bit.
FreqBand=0
0
315MHz
Table 13. VCO Control Voltage Out of Range Detection.
VCO Tuning Range for Various VCO_Freq Settings
0.2
Table 15. Freq Ranges vs. VCO_freq and FreqBand.
Table 14. Automatic VCO Range Calibration.
0.4
290
293
300
307
313
320
326
0.6
0.8
Varactor Voltage [V]
1
430
435
440
450
460
470
480
1.2
23
FreqBand=1
433MHz
1.4
1.6
435
440
450
460
470
480
490
1.8
2
2.2
2.4
860
870
880
900
920
940
960
FreqBand=2 or 3
868, 915MHz
7
6
5
4
3
2
1
0
MICRF405
[phone]
M9999-041906
870
880
900
920
940
960
980