STM6720SVWB6F Datasheet, PDF (8/30 Pages) STMicroelectronics – Dual/triple ultra-low voltage supervisors

Description
STM6717/6718/6719/6720/STM6777/6778/6779/6780
1.1.4
1.1.5
1.1.6
1.1.7
V_CC1. It can be driven from a TTL or CMOS logic line, or with open drain/collector outputs,
or connected to V_SS through a switch. If unused, leave this pin open or connect it to V_CC1.
Connect a normally open momentary switch from MR to V_SS; external debounce circuitry is
not required. (If MR is driven from long cables or if the device is used in noisy environments,
connecting a 0.1µF capacitor from MR to V_SS provides additional noise immunity.
Manual reset delay input (MRC) - STM6777/78/79/80)
This pin is either left open or connected to V_SS via a capacitor. By selecting the appropriate
capacitor, the manual reset process, initiated by pressing the push-button manual reset
input, can be delayed by any value from 6 µs or more (see Table 7 on page 21).
Primary supply voltage monitoring input (V_CC1)
It also is the input for the primary reset threshold monitor. Available fixed (customer-
selectable, factory-programmed) reset thresholds include 4.63 V to 1.58 V.
Secondary supply voltage monitoring input (V_CC2)
This function is available on the STM6717/18/19/20/77/78. Fixed (customer-selectable,
factory-programmed) reset thresholds include 3.08 V to 0.79 V.
Adjustable reset comparator input (RSTIN; STM6719/20/79/80)
This is a high impedance input. RST is driven low when the voltage at the RSTIN pin falls
below 0.626 V (internal reference voltage at this comparator). The monitored voltage reset
threshold is set with an external resistor-divider network.
Table 3. Pin functions
STM6717
STM6718
Pin
STM6719 STM6777
STM6720 STM6778
STM6779
STM6780
Name
Function
1
1
1
1
RST Active-low reset output
3
3
3
3
MR Push-button reset input
—
—
5
4
MRC Manual reset delay input
5
6
6
6
V_CC1 Primary supply voltage input
4
4
4
—
V_CC2 Secondary supply voltage input
—
5
—
5
RSTIN Adjustable reset comparator input
2
2
2
2
V_SS Ground
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Doc ID 11469 Rev 8