Analog Devices ADRV9002

Preliminary Technical Data UG-1828
Rev. PrB | Page 75 of 277
CLOCK GENERATION
CLOCK GENERATION
In ADRV9001 all clocks for the converters and main digital are generated by CLKGEN. CLKGEN receives from two clocks, a high
performance (HP) clock PLL and a low power (LP) PLL. The high performance clock PLL has a programmable frequency range of
7.2 GHz to 8.8 GHz. The low power clock PLL can generate a programmable range of 3.3 GHz to 5 GHz frequency. CLKGEN also has
the clocks be divided and retimed with reset pulses from the clock PLLs.
CLK PLL AND
PHASE SYNC
7200 TO
8847.36MHz
CLK GEN
TO MAIN
DIGITAL
/1,/2,/3,/4 /2 TO /31
/2 TO /31
/2 TO /31
LPCLK PLL AND
PHASE SYNC
3300 TO
5000MHz
24159-070
Figure 69. ADRV9001 Clock Generation
CONFIGURABLE
DECIMATORS
HP BBPLL
8.8G TO 7.2G
HP BBPLL
3.3G TO 5G
DESIRED
SAMPLE RATE
HP ADC
LP ADC
/4
/12
/8
/6
24159-071
Figure 70. CLKPLL Can Be Programmed to Provide Arbitrary Clock Speed
Low Power Clock PLL (LP CLKPLL)
By default, LP CLKPLL works at a fixed frequency at 4423.68 MHz. However, the user can set it to have a tuning operation range. The
operating frequency range of LP CLKPLL is from 3.3 GHz to 5 GHz. User only must provide their final sampling frequency at the
interface, and the final frequency of LP CLKPLL are determined internally. This is all done before the chip is programmed. A profile is
generated based on the user’s provided sampling frequency.
Note LP CLKPLL uses less power than HP CLKPLL but produces more jitter noise. User must take this trade-off into consideration for
their end application. Note that, in most profiles, LP CLKPLL meets the performance requirements.
Table 28 lists the supported data sample rate with different standards. The LTE 40 MHz at 16-bit, this is not supported by the
LP CLKPLL.
Table 28. Sample Rate Supported By LP CLKPLL
Standard Sample Rate
DMR I/Q 2.40E + 04
TETRA 1.44E + 05
TETRA 2.88E + 05
LTE 1.5 1.92E + 06
LTE 3 3.84E + 06
LTE 5 7.68E + 06
LTE 10 1.54E + 07
LTE 15 2.30E + 07
LTE 20 3.07E + 07
LTE 40 @12 bits 6.14E + 07