Document
STM690, STM704, STM795 STM802, STM804, STM805, STM806
3 V supervisor with battery switchover
Features
■ RST or RST outputs ■ NVRAM supervisor for external LPSRAM ■ Chip enable gating (STM795 only) for external
LPSRAM (7 ns max prop delay) ■ Manual (push-button) reset input ■ 200 ms (typ) trec ■ Watchdog timer - 1.6 s (typ) ■ Automatic battery switchover ■ Low battery supply current - 0.4 µA (typ) ■ Power-fail comparator (PFI/PFO) ■ Low supply current - 40 µA (typ) ■ Guaranteed RST (RST) assertion
down to VCC = 1.0 V ■ Operating temperature:
–40 °C to 85 °C (industrial grade) ■ RoHS compliance
– Lead-free components are compliant with the RoHS directive
8 1
SO8 (M)
TSSOP8 3x3 (DS)(1)
1. Contact local ST sales office for availability.
Table 1. Device summary
Watchdog Active- low Active- high
Input
RST(1)
RST(1)
STM690T/S/R
✓
✓
STM704T/S/R
✓
STM795T/S/R
✓(2)
STM802T/S/R
✓
STM804T/S/R
✓
STM805T/S/R
✓
✓ ✓(2) ✓(2)
STM806T/S/R
✓
1. All RST outputs push-pull (unless otherwise noted). 2. Open drain output.
Manual reset input ✓
✓
Battery Power-fail Chip enable switchover comparator gating
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
August 2010
Doc ID 10519 Rev 9
1/42
www.st.com
1
Contents
Contents
STM690, STM704, STM795, STM802, STM804, STM805, STM806
1
Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.1 Pin descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1.1.1 MR (manual reset) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1.1.2 1.1.3
WDI (watchdog input) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 RST (active-low reset) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1.1.4 1.1.5 1.1.6
RST (active-high reset - open drain) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 PFI (power-fail input) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 PFO (power-fail output) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1.1.7 1.1.8 1.1.9 1.1.10 1.1.11
VOUT (supply output voltage) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Vccsw (VCC switch output) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 E (chip enable input) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 ECON (conditional chip enable) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 VBAT (backup battery input) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2
Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
2.1 Reset output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
2.2 Push-button reset input (STM704/806) . . . . . . . . . . . . . . . . . . . . . . . . . . 14
2.3 Watchdog input (NOT available on STM704/795/806) . . . . . . . . . . . . . . . 14
2.4 Backup battery switchover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.5 Chip enable gating (STM795 only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.6 Chip enable input (STM795 only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.7 Chip enable output (STM795 only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.8 Power-fail input/output (NOT available on STM795) . . . . . . . . . . . . . . . . 17
2.9 Applications information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.10 Using a SuperCap™ as a backup power source . . . . . . . . . . . . . . . . . . . 19
2.11 Negative-going VCC transients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
3
Typical operating characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
4
Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
5
DC and AC parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
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Doc ID 10519 Rev 9
STM690, STM704, STM795, STM802, STM804, STM805, STM806
Contents
6
Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
7
Part numbering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
8
Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Doc ID 10519 Rev 9
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List of tables
List of tables
STM690, STM704, STM795, STM802, STM804, STM805, STM806
Table 1. Table 2. Table 3. Table 4. Table 5. Table 6. Table 7. Table 8.
Table 9. Table 10. Table 11. Table 12.
Device summary . . . . . . . . . ..