User's Manual

USER MANUAL
© 2013 EnOcean | www.enocean.com TCM 300x / TCM 320x User Manual | Page 36/53
TCM 300 / TCM 300C / TCM 300U
TCM 320 / TCM 320C / TCM 320U
4.9 Backward compatibility to TCM 220C
In Mode 0 TCM 320C is backward compatible to its predecessor TCM 220C.
There are a few minor restrictions of compatibility which are listed here:
Parameter
TCM
220C
TCM 320C
Maximum current consumption
34 mA
43 mA
Maximum output current of outputs
25 mA
2 mA
(external driver transistor may be needed)
Thickness of module
4.6 mm
5.5 mm
Maximum voltage rating at pin7
(TCM 320C: ADIO6; TCM 220C: IN_5)
6 V
3.6 V
Minimum HIGH voltage level
at input pins
1.55 V
2.0 V
Post master function for systems with
smart acknowledge
No
Yes, 15 mail boxes
Pull-down 10 kΩ required at Pin 13, 14
No
Yes
4.10 Using RVDD
If RVDD is used in an application circuit a serial ferrite bead shall be used and wire length
should be as short as possible (<3 cm). The following ferrite beads have been tested:
74279266 (0603), 74279205 (0805) from Würth. During radio transmission and reception
only small currents may be drawn (I<100 µA).
Pulsed current drawn from RVDD has to be avoided. If pulsed currents are necessary, suffi-
cient blocking has to be provided.
4.11 Voltage dips
The modules are supporting the handling of supply voltage dips (as requested e.g. by
EN60669-2-1). As soon as the supply voltage drops below the VON
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threshold level the
current consumption is reduced. TCM 300 will enter short term sleep mode (worst case 35
µA), TCM 320 will enter standby mode (1.8 mA) for 200 ms. As long as the voltage at VDD
does not drop below VOFF during that phase the module will restore the output state as set
before the voltage dip. The minimal difference between VON and VOFF is 0.35 V.
The electric charge needed to bridge this interval is:
1.8 mA x 200 ms = 360 µC for TCM 320
0.035 mA x 200 ms = 7 µC for TCM 300
This electric charge can be stored in an external capacitor. The required capacity (do not
forget to add component specific tolerances and some extra margin) calculates as:
360 µC / 0.35 V = 1028 µF for TCM 320
7 µC / 0.35 V = 20 µF for TCM 300
If other external circuitry has to be supplied the calculations have to be done accordingly,
using the total current consumption of module and external circuitry.
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For a detailed definition of VON and VOFF please refer to „Dolphin Core Description“.