Datasheet

STM6600, STM6601 Pin descriptions
Doc ID 15453 Rev 11 11/52
EN or EN - enable output
This output is intended to enable system power (see Figure 1). EN is asserted high after
a valid turn-on event has been detected and confirmed (i.e. push-button has been pressed
and held for t
DEBOUNCE
or more and V
CC
> V
TH+
voltage level has been detected - see
Figure 13). EN is released low if any of the conditions below occur:
a) the push-button is released before PS
HOLD
is driven high (valid for STM6600, see
Figure 9) or t
ON_BLANK
expires before PS
HOLD
is driven high during startup (valid
for both STM6600 and STM6601, see Figure 10 and 12).
b) PS
HOLD
is driven low during normal operation (see Figure 14).
c) an undervoltage condition is detected for more than t
SRD
+ t
INT_Min
+ t
DEBOUNCE
(see Figure 21).
d) a long push of the buttons is detected (only for the device with option “EN
deasserted by long push” - see Figure 19) or PS
HOLD
is not driven high during
t
ON_BLANK
after a long push of the buttons (only for the device with option “RST
asserted by long push” - see Figure 18).
Described logic levels are inverted in case of EN
output. Output type is push-pull by default.
RST
- reset output
This output pulls low for t
REC
:
a) during startup. PB
has been pressed (falling edge on the PB detected) and held
for at least t
DEBOUNCE
and V
CC
> V
TH+
(see Figure 7, 8, 9, 10, 11, 12 and 13 for
more details).
b) after long push detection (valid only for the device with option “RST
asserted by
long push”). PB
has been pressed (falling edge on the PB detected) and held for
more than t
DEBOUNCE
+ t
SRD
(additional Smart Reset
™
delay time can be adjusted
by the external capacitor C
SRD
) - see Figure 18.
Output type is active low and open drain by default. Open drain output type requires a pull-
up resistor. A 10 kΩ is sufficient in most applications.
INT
- interrupt output
While the system is under normal operation (PS
HOLD
is driven high, power for application is
asserted), the INT
is driven low if:
a) V
CC
falls below V
TH-
threshold (i.e. undervoltage is detected - see Figure 20 and
21).
b) the falling edge on the PB
is detected and the push-button is held for t
DEBOUNCE
or
more. INT
is driven low after t
DEBOUNCE
and stays low as long as PB is held. The
INT
signal is held high during power-up.
The state of the PB
OUT
output can be used to determine if the interrupt was caused by
either the assertion of the PB
input, or was due to the detection of an undervoltage condition
on V
CC
.
INT
output is asserted low for at least t
INT_Min
.
Output type is active low and open drain by default. Open drain output type requires a pull-
up resistor. A 10 kΩ is sufficient in most applications.
GND - ground