STM6778 STMicroelectronics, STM6778 Datasheet - Page 5

• Manufacturer Part Number: STM6778
• Description: Dual/triple ultra-low voltage supervisors with push-button reset (with delay option)
• Manufacturer: STMicroelectronics

Specifications of STM6778

• Primary Supply (vcc1) Monitor. Fixed (factory-programmed) Reset Thresholds: 4.63 V to 1.58 V
• Fixed (factory-programmed) Reset Thresholds: 3.08 V to 0.79 V
• Tertiary Supply Monitor (using Externally Adjustable Rstin): 0.626 V internal reference
• Reset Delay Time (trec) On Power-up: 13.2 ms, 210 ms, 900 ms (typ)
• Operating Temperature: –40 °C to 85 °C (industrial grade)

STM6717/6718/6719/6720/STM6777/6778/6779/6780
1
Description
The STM6717/18/19/20 and STM6777/78/79/80 supervisors are a family of low-voltage/low-
supply current processor (micro or DSP) supervisors, designed to monitor two (or three)
system power supply voltages. They are targeted at applications such as set-top boxes
(STBs), portable, battery-powered systems, networking, and communication systems.
All device options have a push-button-type manual reset input (MR). The
STM6777/78/79/80 also includes an option which enables the user to delay the start of the
manual reset process from 6 µs (MRC pin left open) or more with external capacitor. The
delay is implemented by connecting the appropriately sized capacitor between the MRC pin
and V
Two of the three supplies monitored (V
factory-trimmed) thresholds (V
externally adjustable RSTIN threshold (0.626 V internal reference).
If any of the three monitored voltages drop below its factory-trimmed or adjustable
thresholds, or if MR is asserted to logic low, a RST is asserted (driven low). Once asserted,
RST is maintained at low for a minimum delay period (t
their respective thresholds and MR returns to high. These devices are guaranteed to be in
the correct reset output logic state when V
These devices are available in standard 5-pin or 6-pin SOT23 packages (see
page
1).
SS
(typical 4 s delay with a 3.3 µF capacitor, see
Doc ID 11469 Rev 8
RST1
and V
CC1
RST2
CC1
and V
). The third voltage is monitored using an
and/or V
CC2
) have fixed (customer-selectable,
Table 7 on page
rec
CC2
) after ALL supplies rise above
is greater than 0.8 V.
21).
Table 1 on
Description
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