STM1831 STMicroelectronics, STM1831 Datasheet - Page 8

• Manufacturer Part Number: STM1831
• Description: Voltage detector with sense input and external delay capacitor
• Manufacturer: STMicroelectronics

Operation
2
8/24
Operation
The STM1831 voltage detector monitors system voltages from 1.6 V to 5.7 V in 100 mV
increments, has a voltage hysteresis (V
capacitor C
The STM1831 asserts a reset output (RST) whenever V
(V
hysteresis (V
output deassertion is adequately delayed (see
details). Leave the C
Figure 5.
t
t
t
The t
Equation 1
and considering R
Equation 2
DET
REL
CD
DET
CD
). The reset output stays asserted until V
detect delay time
release delay time (measured when external capacitor C
delay by external capacitor C
delay can be calculated based on
D
.
Timing waveforms
DET
V SEN
RST
+ V
C D
CD
D
HYS
= 2 MΩ (typ.) and V
V DET
pin open if unused (i.e. t
). If the external capacitor is connected to the C
t DET
Doc ID 18180 Rev 1
t
CD
t
CD
=
D
–
≅
.
R
1.39 10
HYS
CD
TCD
×
Equation
) and an output delay programmable by external
×
C
D
= 1.5 V (typ.) at V
CC
CD
Figure 5
6
×
t REL + t CD
×
In 1
goes above the detect voltage with
= 0 ms).
C
V DET + V HYST
⎛
⎝
D
V TCD
1:
(
–
s F
,
V
------------- -
V
with calculations below for more
CC
TCD
CC
)
goes below the detect voltage
⎞
⎠
CC
D
is disconnected)
= 3.0 V:
D
pin, the reset
STM1831
AM00854