Clock Generation And Multichip Synchronization; Clock Generation - Analog Devices ADRV9001 User Manual

Preliminary Technical Data

CLOCK GENERATION AND MULTICHIP SYNCHRONIZATION

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.
8.8G TO 7.2G
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 needs to 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 has worse performance in terms of jitter noise. User needs to take this trade-off
into consideration for their end application.
Table 27 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 27. Sample Rate Supported By LP CLKPLL
Standard
DMR I/Q
TETRA
TETRA
LTE 1.5
LTE 3
LTE 5
LTE 10
LTE 15
LTE 20
LTE 40 @12 bits
7200 TO
8847.36MHz
CLK PLL AND
PHASE SYNC
3300 TO
5000MHz
LPCLK PLL AND
PHASE SYNC
Figure 69. ADRV9001 Clock Generation
HP BBPLL
HP ADC
/4
HP BBPLL
3.3G TO 5G
LP ADC
Figure 70. CLKPLL Can Be Programmed to Provide Arbitrary Clock Speed
CLK GEN
/1,/2,/3,/4 /2 TO /31
/2 TO /31
/2 TO /31
/12
/8
/6
Sample Rate
2.40E + 04
1.44E + 05
2.88E + 05
1.92E + 06
3.84E + 06
7.68E + 06
1.54E + 07
2.30E + 07
3.07E + 07
6.14E + 07
Rev. PrA | Page 75 of 253
TO MAIN
DIGITAL
CONFIGURABLE
DECIMATORS
DESIRED
SAMPLE RATE
UG-1828