User's Manual

USER MANUAL 1.34
© 2013 EnOcean | www.enocean.com STM 300 / STM 300C / STM 300U User Manual | Page 15/42
STM 300 / STM 300C / STM 300U
Threshold Detector
VON
Turn on threshold
2.3
2.45
2.6
V
VOFF
Turn off threshold
Automatic shutdown if
VDD drops below VOFF
1.85
1.9
2.1
V
Voltage Limiter
STM 300 provides a voltage limiter which limits the supply voltage VDD of STM 300 to a
value VDDLIM which is slightly below the maximum VDD ratings by shunting of sufficient
current.
Threshold detector
STM 300 provides an ultra low power ON/OFF threshold detector. If VDD > VON, it turns on
the ultra low power regulator (UVDD), the watchdog timer and the WAKE# pins circuitry. If
VDD ≤ VOFF it initiates the automatic shut down of STM 300.
3.7 Charge control output (CCO)
After start-up STM 300 provides the output signal of the threshold detector at CCO.
CCO is supplied by UVDD. The output value remains stable also when STM 300 is in deep
sleep mode.
Behaviour of CCO
- At power up: TRISTATE until VDD>VON then HIGH
- if VDD>VON then HIGH
- if VDD<VON then LOW
- if VDD< VOFF then LOW or TRISTATE
For definition of VON and VOFF please refer to 3.6.
VDD
t
TRISTATE
VOFF
VON
VDD > VON VDD < VON
VDD < VOFF
TRISTATE
or LOW
CCO
VDD
1.8V
0V
~0.9V
VDD
t
TRISTATE
VOFF
VON
VDD > VON VDD < VON
VDD < VOFF
TRISTATE
or LOW
CCO
VDD
1.8V
0V
~0.9V