S42 Hardware User Guide
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Page 18 of 62
3.1.1
Power-up Slew-Rate
Parameter
Min
Max
Unit
VSUP rise time rate
(1)
0
60
ms
(1)
0V to 1,7V
Table 2: Power up Rise Time Requirements
3.2
Reset
S42 are equipped with circuitry for generating reset from three sources:
•
A reset is held active, when VSUP falls below the threshold of the brownout detector
(V
BOR =
1,2V … 1,7V), and is released when VSUP rises above V
BOR
+ V
HYST
.
The brownout detector also holds the reset active during power up, until VSUP >
V
BOR
.
•
A reset is generated, when VSUP is > V
BOR
and increases 300 mV or more, within
300 ms or less.
•
By holding pin B-1 (EXT-
RES#) at ≤ VSUP*0,3V for t
HOLDRESETNORMAL
≥ 0,2µs, an
external reset (
pin reset
) is generated. This pin has a fixed internal pull-up resistor
(R
PU
= 11k
Ω ... 16kΩ). EXT-RES# may be left open if not used.
S42
E-6,F-6
VSUP
GND
+3V3
EXT-RES#
B-1
Reset-Switch is optional
Please Note: EXT-RES# of S42 has approx. 13k internal pullup.
470R*
Reset signal is optional
Host MCU
GPIO
VDD
* resistor can be omitted,
if GPIO is open drain type
Figure 3: S42 Example Reset
The following table shows the pin states of S42 during reset active.
