FreeCalypso > hg > freecalypso-reveng

annotate pirelli/vctcxo @ 220:2cc7a17c3859

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
pirelli/rfcal: new understanding
author Mychaela Falconia <falcon@freecalypso.org>
date Thu, 16 Nov 2017 04:19:58 +0000
parents ed7318a03e0c
children cbd944ebeff0
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
195
ed7318a03e0c pirelli/vctcxo: VCTCXO connections traced out
Michael Spacefalcon <falcon@ivan.Harhan.ORG>
parents:
diff changeset
1 Let's trace the TCXOEN signal from the Calypso. Calypso ball A12, no trace
ed7318a03e0c pirelli/vctcxo: VCTCXO connections traced out
Michael Spacefalcon <falcon@ivan.Harhan.ORG>
parents:
diff changeset
2 visible, guessing a micro-via right under the ball. L1 coord (3739,1053).
ed7318a03e0c pirelli/vctcxo: VCTCXO connections traced out
Michael Spacefalcon <falcon@ivan.Harhan.ORG>
parents:
diff changeset
3 Guess appears right: on L2 there is a connection from a micro-via to an inner
ed7318a03e0c pirelli/vctcxo: VCTCXO connections traced out
Michael Spacefalcon <falcon@ivan.Harhan.ORG>
parents:
diff changeset
4 via, the latter is at (3712,1055). Found it on L4: the via is in the middle of
ed7318a03e0c pirelli/vctcxo: VCTCXO connections traced out
Michael Spacefalcon <falcon@ivan.Harhan.ORG>
parents:
diff changeset
5 a trace going both ways! Right branch goes to (4548,1028); left branch goes to
ed7318a03e0c pirelli/vctcxo: VCTCXO connections traced out
Michael Spacefalcon <falcon@ivan.Harhan.ORG>
parents:
diff changeset
6 (1699,1349).
ed7318a03e0c pirelli/vctcxo: VCTCXO connections traced out
Michael Spacefalcon <falcon@ivan.Harhan.ORG>
parents:
diff changeset
7
ed7318a03e0c pirelli/vctcxo: VCTCXO connections traced out
Michael Spacefalcon <falcon@ivan.Harhan.ORG>
parents:
diff changeset
8 Following the branch at (4548,1028): found it on L2, microvia back to L1 at
ed7318a03e0c pirelli/vctcxo: VCTCXO connections traced out
Michael Spacefalcon <falcon@ivan.Harhan.ORG>
parents:
diff changeset
9 (4518,1048). Found it on L1, goes to some 2-pad footprint, can't tell if it's
ed7318a03e0c pirelli/vctcxo: VCTCXO connections traced out
Michael Spacefalcon <falcon@ivan.Harhan.ORG>
parents:
diff changeset
10 unpopulated or a faint black resistor. The other end goes to a via at
ed7318a03e0c pirelli/vctcxo: VCTCXO connections traced out
Michael Spacefalcon <falcon@ivan.Harhan.ORG>
parents:
diff changeset
11 (4676,919). Found it on L2, goes to inner via at (5135,684). Found it on L7,
ed7318a03e0c pirelli/vctcxo: VCTCXO connections traced out
Michael Spacefalcon <falcon@ivan.Harhan.ORG>
parents:
diff changeset
12 goes to surface via at (5132,716). Found it on L8 - goes to flash RY/BY# ball
ed7318a03e0c pirelli/vctcxo: VCTCXO connections traced out
Michael Spacefalcon <falcon@ivan.Harhan.ORG>
parents:
diff changeset
13 - WTF?
ed7318a03e0c pirelli/vctcxo: VCTCXO connections traced out
Michael Spacefalcon <falcon@ivan.Harhan.ORG>
parents:
diff changeset
14
ed7318a03e0c pirelli/vctcxo: VCTCXO connections traced out
Michael Spacefalcon <falcon@ivan.Harhan.ORG>
parents:
diff changeset
15 Following the branch at (1699,1349): found it on L2, immediately goes back to
ed7318a03e0c pirelli/vctcxo: VCTCXO connections traced out
Michael Spacefalcon <falcon@ivan.Harhan.ORG>
parents:
diff changeset
16 L1 at (1673,1353). Found it on L1, go to UL pad of the VCTCXO, passing by a
ed7318a03e0c pirelli/vctcxo: VCTCXO connections traced out
Michael Spacefalcon <falcon@ivan.Harhan.ORG>
parents:
diff changeset
17 cap to GND. The cap is populated.
ed7318a03e0c pirelli/vctcxo: VCTCXO connections traced out
Michael Spacefalcon <falcon@ivan.Harhan.ORG>
parents:
diff changeset
18
ed7318a03e0c pirelli/vctcxo: VCTCXO connections traced out
Michael Spacefalcon <falcon@ivan.Harhan.ORG>
parents:
diff changeset
19 Let's trace the signal from the VCTCXO to the Rita. VCTCXO pin is unknown, but
ed7318a03e0c pirelli/vctcxo: VCTCXO connections traced out
Michael Spacefalcon <falcon@ivan.Harhan.ORG>
parents:
diff changeset
20 the input to Rita corresponds to a surface via at (2161,488) - at this point on
ed7318a03e0c pirelli/vctcxo: VCTCXO connections traced out
Michael Spacefalcon <falcon@ivan.Harhan.ORG>
parents:
diff changeset
21 L1 there is an unpopulated cap(?) to GND and a series component (cap?) to the
ed7318a03e0c pirelli/vctcxo: VCTCXO connections traced out
Michael Spacefalcon <falcon@ivan.Harhan.ORG>
parents:
diff changeset
22 actual Rita input. Found it on L2, goes back to L1 at (2123,1284). On L1 it
ed7318a03e0c pirelli/vctcxo: VCTCXO connections traced out
Michael Spacefalcon <falcon@ivan.Harhan.ORG>
parents:
diff changeset
23 falls right into the UR pad of the VCTCXO! Conclusion: the signal from VCTCXO
ed7318a03e0c pirelli/vctcxo: VCTCXO connections traced out
Michael Spacefalcon <falcon@ivan.Harhan.ORG>
parents:
diff changeset
24 to Rita passes through a single series component, just like in Rita datasheet.
ed7318a03e0c pirelli/vctcxo: VCTCXO connections traced out
Michael Spacefalcon <falcon@ivan.Harhan.ORG>
parents:
diff changeset
25
ed7318a03e0c pirelli/vctcxo: VCTCXO connections traced out
Michael Spacefalcon <falcon@ivan.Harhan.ORG>
parents:
diff changeset
26 The LR pad of the VCTCXO is GND. Thus the control input must be the LL pad.
ed7318a03e0c pirelli/vctcxo: VCTCXO connections traced out
Michael Spacefalcon <falcon@ivan.Harhan.ORG>
parents:
diff changeset
27 The input signal to here passes first through a series component, then passes
ed7318a03e0c pirelli/vctcxo: VCTCXO connections traced out
Michael Spacefalcon <falcon@ivan.Harhan.ORG>
parents:
diff changeset
28 by a comp to ground, and then goes into the VCTCXO input. The entry point to
ed7318a03e0c pirelli/vctcxo: VCTCXO connections traced out
Michael Spacefalcon <falcon@ivan.Harhan.ORG>
parents:
diff changeset
29 the whole arrangement is a surface via at (1669,1488). Found it on L2, inner
ed7318a03e0c pirelli/vctcxo: VCTCXO connections traced out
Michael Spacefalcon <falcon@ivan.Harhan.ORG>
parents:
diff changeset
30 via at (1655,1467). Found it on L4, goes to (2932,855). Found it on L2,
ed7318a03e0c pirelli/vctcxo: VCTCXO connections traced out
Michael Spacefalcon <falcon@ivan.Harhan.ORG>
parents:
diff changeset
31 surface via to L1 at (2950,837). That's Iota ball J4 (AFC), and there is also
ed7318a03e0c pirelli/vctcxo: VCTCXO connections traced out
Michael Spacefalcon <falcon@ivan.Harhan.ORG>
parents:
diff changeset
32 a branch from there that goes to an unpopulated cap(?) footprint to GND.