Nokia 9000i - PLL Circuit; UHF VCO Buffers

After Sales
Technical Documentation
RAE/RAK–1N
RF
Page 3– 25
Amendment 1 04/97
UHF VCO buffers
The UHF VCO output signal is divided into the 1st mixer of the receiver
and the upconversion mixer of the transmitter. The UHF VCO signal is
amplified after division. There is one buffer for TX and one for RX.
Table 20. UHF VCO buffer specification
Parameter Minimum Typical /
Nominal
Maximum Unit / Notes
Supply voltage 4.2 4.5 4.8 V
Supply current 5.5 6.5 mA
Frequency range See UHF VCO specification MHz
Input power –3 dBm
Harmonics –10 dBc
Output amplitude 700 mVrms / 1 kohm
PLL Circuit
The PLL is Philips UMA1018 in GSM and National LMX2331 in PCN.
The circuit is a dual frequency synthesizer including both the UHF and
VHF synthesizers.
Table 21. PLL UMA1018 (UMA1020) specification
Parameter Minimum Typical /
Nominal
Maximum Unit / Notes
Supply voltage 2.7 5.5 V
Supply current GSM
PCN
8.5
12.1
mA
mA
Principal input freq. GSM
PCN
500
200
1200
2000
MHz, Vdd = 4.5 V
MHz, Vdd = 3.0 V
Auxiliary input freq. GSM
PCN
20
20
300
510
MHz, Vdd = 4.5 V
MHz, Vdd = 3.0V
Input reference frequency 3 40 MHz, Vdd = 4.5 V
Input signal level GSM
PCN
50
–10
–15
500
500
4
4
mVrms
dBm main divider
dBm aux. divider
mVrms ref. divider