SNAS788C November 2019 – March 2022 LMX2694-SEP
PRODUCTION DATA
Refer to the PDF data sheet for device specific package drawings
To go below the VCO lower bound of 7550 MHz, the channel divider can be used. The channel divider consists of four segments, and the total division value is equal to the multiplication of them. Therefore, not all values are valid.
When the channel divider is used, there are limitations on the values. Table 7-8 shows how these values are implemented and which segments are used.
EQUIVALENT DIVISION VALUE | FREQUENCY LIMITATION | OUTPUT FREQUENCY (MHz) | CHDIV[4:0] | SEG0 | SEG1 | SEG2 | SEG3 | |
---|---|---|---|---|---|---|---|---|
MIN | MAX | |||||||
2 | None | 3775 | 7550 | 0 | 2 | 1 | 1 | 1 |
4 | 1887.5 | 3775 | 1 | 2 | 2 | 1 | 1 | |
6 | 1258.333 | 2516.667 | 2 | 2 | 3 | 1 | 1 | |
8 | fVCO ≤ 11.5 GHz | 943.75 | 1437.5 | 3 | 2 | 2 | 2 | 1 |
12 | 629.167 | 958.333 | 4 | 2 | 3 | 2 | 1 | |
16 | 471.875 | 718.75 | 5 | 2 | 2 | 4 | 1 | |
24 | 314.583 | 469.167 | 6 | 2 | 3 | 4 | 1 | |
32 | 235.938 | 359.375 | 7 | 2 | 2 | 8 | 1 | |
48 | 157.292 | 239.583 | 8 | 2 | 3 | 8 | 1 | |
64 | 117.969 | 179.688 | 9 | 2 | 2 | 8 | 2 | |
96 | 78.646 | 119.792 | 10 | 2 | 3 | 8 | 2 | |
128 | 58.984 | 89.844 | 11 | 2 | 2 | 8 | 4 | |
192 | 39.323 | 59.896 | 12 | 2 | 3 | 8 | 4 | |
Invalid | n/a | n/a | n/a | 13 - 31 | n/a | n/a | n/a | n/a |
The channel divider is powered up whenever an output (OUTx_MUX) is selected to the channel divider or SYSREF, regardless of whether it is powered down or not. When an output is not used, TI recommends selecting the VCO output to ensure that the channel divider is not unnecessarily powered up.
OUTA MUX | OUTB MUX | CHANNEL DIVIDER |
---|---|---|
Channel Divider | X | Powered up |
X | Channel Divider or SYSREF | Powered up |
All other cases | Powered down |