CC1120 has a new footprint. Add datasheet and footprint generator

The only change from the 1120 footprint is to make the center pad a
bit smaller. The docs have a much more elaborate change, but that
involves putting vias in the middle of the solder paste area, which
seems like a bad plan unless we used a via-in-pad process.

Signed-off-by: Keith Packard <keithp@keithp.com>

diff --git a/datasheets/ti/cc1120-new.pdf b/datasheets/ti/cc1120-new.pdf
new file mode 100644 (file)
index 0000000..226d077
Binary files /dev/null and b/datasheets/ti/cc1120-new.pdf differ

diff --git a/packages/Makefile b/packages/Makefile
index 87ae78f9b3c83b2f4aef71a39a6b0b0ad5067419..194e7d20a886fa3b8a77a9bb64adc4bd76a5bdc2 100644 (file)
--- a/packages/Makefile
+++ b/packages/Makefile
@@ -26,6 +26,7 @@ FOOTPRINTS= \
        MPU6000.fp \
        UBLOX-MAX.fp \
        TI-QFN32.fp \
+       TI-QFN32-new.fp \
        NDK32.fp \
        sma-edge.fp \
        MO-220.fp \

diff --git a/packages/TI-QFN32-new.py b/packages/TI-QFN32-new.py
new file mode 100755 (executable)
index 0000000..46cf27f
--- /dev/null
+++ b/packages/TI-QFN32-new.py
@@ -0,0 +1,136 @@
+#!/usr/bin/python
+# Copyright 2011 by Bdale Garbee <bdale@gag.com>.  GPLv2
+#
+# Program to emit PCB footprint for QFN32 package used by TI CC1120
+#
+
+# dimensions in mm from the TI cc1111f32.pdf datasheet
+PinWidth = 0.3
+PinResist = PinWidth + (2 * 0.07)
+PinHeight = (5.8 - 4.1) / 2
+PinSpacing = 0.50
+Overall = 5.80
+GndSquare = 3.40
+CoreSquare = 3.30              # resist gaps and paste spots over ground tab
+PinSquare = 4.10
+
+import sys
+
+# we're going to use the 1/100 of a mil fundamental unit form
+def mm2mils100( mm ):
+       return int( mm / 25.4 * 1000.0 * 100.0 + 0.5 )
+
+print '# author: Bdale Garbee'
+print '# email: bdale@gag.com'
+print '# dist-license: GPL 2'
+print '# use-license: unlimited'
+
+print 'Element[0x0 "QFN36" "" "" 0 0 0 0 0 100 0x0]'
+print "("
+
+# pad under the chip, must be grounded
+print '   Pad[',\
+       mm2mils100(0), \
+       mm2mils100(0), \
+       mm2mils100(0), \
+       mm2mils100(0), \
+       mm2mils100(GndSquare), \
+       0, \
+       0, \
+       '"pin33" "33" "square,nopaste"]'
+
+# vias in the ground pad under the chip
+for viarow in range (-1,2):
+  for viacol in range (-1,2):
+    print '   Pin[',\
+       mm2mils100(2 * viacol * CoreSquare / 5), \
+       mm2mils100(2 * viarow * CoreSquare / 5), \
+       2900, \
+       2500, \
+       0, \
+       1500, \
+       '"pin33" "33" 0x0002]'
+
+# break pad under chip into a grid to control the resist and paste masks
+for viarow in range (-2, 3):
+  for viacol in range (-2, 3):
+    if (viarow in (-2, 0, 2)) and (viacol in (-2, 0, 2)):
+      # copper sub-square with resist over vias
+      print '   Pad[',\
+       mm2mils100(viacol * CoreSquare / 5), \
+       mm2mils100(viarow * CoreSquare / 5), \
+       mm2mils100(viacol * CoreSquare / 5), \
+       mm2mils100(viarow * CoreSquare / 5), \
+       mm2mils100((CoreSquare)/5), \
+       0, \
+       0, \
+       '"pin33" "33" "square,nopaste"]'
+    else:
+      # copper sub-square without resist
+      print '   Pad[',\
+       mm2mils100(viacol * CoreSquare / 5), \
+       mm2mils100(viarow * CoreSquare / 5), \
+       mm2mils100(viacol * CoreSquare / 5), \
+       mm2mils100(viarow * CoreSquare / 5), \
+       mm2mils100((CoreSquare)/5), \
+       0, \
+       mm2mils100((CoreSquare)/5), \
+       '"pin33" "33" "square,nopaste"]'
+      # copper spot to control paste mask generation
+      print '   Pad[',\
+       mm2mils100(viacol * CoreSquare / 5), \
+       mm2mils100(viarow * CoreSquare / 5), \
+       mm2mils100(viacol * CoreSquare / 5), \
+       mm2mils100(viarow * CoreSquare / 5), \
+       1500, \
+       0, \
+       mm2mils100((CoreSquare)/5), \
+       '"pin33" "33" "square"]'
+
+# pins
+for pin in range (1,9):
+    print '   Pad[',\
+       mm2mils100((-4.5 + pin) * PinSpacing), \
+       mm2mils100(-Overall/2 + PinWidth/2), \
+       mm2mils100((-4.5 + pin) * PinSpacing), \
+       mm2mils100(-Overall/2 + PinHeight - PinWidth/2), \
+       mm2mils100(PinWidth), \
+       mm2mils100(PinSpacing - PinWidth), \
+       mm2mils100(PinResist), \
+       '"pin%i"' % (25-pin), '"%i"' % (25-pin), '0x0000]'
+
+    print '   Pad[',\
+       mm2mils100((-4.5 + pin) * PinSpacing), \
+       mm2mils100(+Overall/2 - PinHeight + PinWidth/2), \
+       mm2mils100((-4.5 + pin) * PinSpacing), \
+       mm2mils100(+Overall/2 - PinWidth/2), \
+       mm2mils100(PinWidth), \
+       mm2mils100(PinSpacing - PinWidth), \
+       mm2mils100(PinResist), \
+       '"pin%i"' % pin, '"%i"' % pin, '0x0000]'
+
+    print '   Pad[',\
+       mm2mils100(Overall/2 - PinHeight + PinWidth/2), \
+       mm2mils100((-4.5 + pin) * PinSpacing), \
+       mm2mils100(Overall/2 - PinWidth/2), \
+       mm2mils100((-4.5 + pin) * PinSpacing), \
+       mm2mils100(PinWidth), \
+       mm2mils100(PinSpacing - PinWidth), \
+       mm2mils100(PinResist), \
+       '"pin%i"' % (17-pin), '"%i"' % (17-pin), '0x0000]'
+
+    print '   Pad[',\
+       mm2mils100(-Overall/2 + PinWidth/2), \
+       mm2mils100((-4.5 + pin) * PinSpacing), \
+       mm2mils100(-Overall/2 + PinHeight - PinWidth/2), \
+       mm2mils100((-4.5 + pin) * PinSpacing), \
+       mm2mils100(PinWidth), \
+       mm2mils100(PinSpacing - PinWidth), \
+       mm2mils100(PinResist), \
+       '"pin%i"' % (24+pin), '"%i"' % (24+pin), '0x0000]'
+
+print '   ElementArc[',\
+       mm2mils100(-2.6), \
+       mm2mils100(2.6), \
+       '500 500 0 360 1000 ]'
+print ")"