STM795

STM690, STM704, STM795 STM802, STM804, STM805, STM806 3V Supervisor with Battery Switchover FEATURES SUMMARY ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ RST OR RST OUTPUTS NVRAM SUPERVISOR FOR EXTERNAL LPSRAM CHIP-ENABLE GATING (STM795 only) FOR EXTERNAL LPSRAM (7ns max PROP DELAY) MANUAL (PUSH-BUTTON) RESET INPUT 200ms (TYP) trec WATCHDOG TIMER - 1.6sec (TYP) AUTOMATIC BATTERY SWITCHOVER LOW BATTERY SUPPLY CURRENT - 0.4µA (TYP) POWER-FAIL COMPARATOR (PFI/PFO) LOW SUPPLY CURRENT - 40µA (TYP) GUARANTEED RST (RST) ASSERTION DOWN TO VCC = 1.0V OPERATING TEMPERATURE: –40°C to 85°C (Industrial Grade) Figure 1. Packages 8 1 SO8 (M) TSSOP8 3x3 (DS)* Table 1. Device Options Watchdog Input STM690T/S/R STM704T/S/R STM795T/S/R STM802T/S/R STM804T/S/R STM805T/S/R STM806T/S/R ✔ ✔ ✔ ✔ ✔ ActiveLow RST(1) ✔ ✔ ✔(2) ✔ ✔(2) ✔(2) ✔ ✔ ActiveHigh RST Manual Battery Reset Input Switch-over ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ Power-fail Comparator ✔ ✔ ✔ ChipEnable Gating Note: 1. All RST outputs push-pull (unless otherwise noted) 2. Open drain output. * Contact local ST sales office for availability. September 2004 1/31 STM690/704/795/802/804/805/806 TABLE OF CONTENTS FEATURES SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Figure 1. Packages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Table 1. Device Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 SUMMARY DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Figure 2. Logic Diagram (STM690/802/804/805) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Figure 3. Logic Diagram (STM704/806) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Figure 4. Logic Diagram (STM795). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Table 2. Signal Names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Figure 5. STM690/802/804/805 Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Figure 6. STM704/806 Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Figure 7. STM795 Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Pin Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Table 3. Pin Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Figure 8. Block Diagram (STM690/802/804/805) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Figure 9. Block Diagram (STM704/806) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Figure 10.Block Diagram (STM795) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Figure 11.Hardware Hookup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Reset Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Push-button Reset Input (STM704/806). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Watchdog Input (NOT available on STM704/795/806) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Back-up Battery Switchover. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Table 4. I/O Status in Battery Back-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Chip-Enable Gating (STM795 only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Chip Enable Input (STM795 only). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Chip Enable Output (STM795 only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Figure 12.Chip-Enable Gating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Figure 13.Chip Enable Waveform (STM795) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Power-fail Input/Output (NOT available on STM795) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Applications Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Figure 14.Power-fail Comparator Waveform (STM690/704/802/804/805/806) . . . . . . . . . . . . . . . . 11 Using a SuperCap™ as a Backup Power Source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Figure 15.Using a SuperCap™ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Negative-Going VCC Transients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 TYPICAL OPERATING CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Figure 16.VBAT-to-VOUT On-Resistance vs. Temperature. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Figure 17.Supply Current vs. Temperature (no load) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Figure 18.VPFI Threshold vs. Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Figure 19.Reset Comparator Propagation Delay vs. Temperature . . . . . . . . . . . . . . . . . . . . . . . . . 14 Figure 20.Power-up trec vs. Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 2/31 STM690/704/795/802/804/805/806 Figure 21.Normalized Reset Threshold vs. Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Figure 22.Watchdog Time-out Period vs. Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Figure 23.E to ECON On-Resistance vs. Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Figure 24.PFI to PFO Propagation Delay vs. Temperature. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Figure 25.RST Output Voltage vs. Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Figure 26.RST Output Voltage vs. Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Figure 27.RST Response Time (Assertion). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Figure 28.RESET Response Time (Assertion) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Figure 29.Power-fail Comparator Response Time (Assertion) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Figure 30.Power-fail Comparator Response Time (De-Assertion) . . . . . . . . . . . . . . . . . . . . . . . . . 19 Figure 31.VCC to Reset Propagation Delay vs. Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Figure 32.Maximum Transient Duration vs. Reset Threshold Overdrive. . . . . . . . . . . . . . . . . . . . . 20 Figure 33.E to ECON Propagation Delay vs. Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 MAXIMUM RATING. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Table 5. Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 DC and AC PARAMETERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Table 6. Operating and AC Measurement Conditions . . . . . . . . . . . . . . . . . . . . . . . . Figure 34.E to ECON Propagation Delay Test Circuit. . . . . . . . . . . . . . . . . . . . . . . . . Figure 35.AC Testing Input/Output Waveforms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 36.MR Timing Waveform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 37.Watchdog Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Table 7. DC and AC Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...... ...... ...... ...... ...... ...... . . . . 21 . . . . 22 . . . . 22 . . . . 22 . . . . 23 . . . . 23 PACKAGE MECHANICAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Figure 38.SO8 – 8-lead Plastic Small Outline, 150 mils body width, Package Mech. Drawing. . . . 26 Table 8. SO8 – 8-lead Plastic Small Outline, 150 mils body width, Package Mechanical Data . . 26 Figure 39.TSSOP8 – 8-lead, Thin Shrink Small Outline, 3x3mm body size, Outline . . . . . . . . . . . 27 Table 9. TSSOP8 – 8-lead, Thin Shrink Small Outline, 3x3mm body size, Mechanical Data . . . . 27 PART NUMBERING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Table 10. Ordering Information Scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Table 11. Marking Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 REVISION HISTORY. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Table 12. Document Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 3/31 STM690/704/795/802/804/805/806 SUMMARY DESCRIPTION The STM690/704/795/802/804/805/806 Supervisors are self-contained devices which provide microprocessor supervisory functions with the ability to non-volatize and write-protect external LPSRAM. A precision voltage reference and comparator monitors the VCC input for an out-of-tolerance condition. When an invalid VCC condition occurs, the reset output (RST) is forced low (or high in the case of RST). These devices also offer Figure 2. Logic Diagram (STM690/802/804/805) VCC VBAT a watchdog timer (except for STM704/795/806) as well as a power-fail comparator (except for STM795) to provide the system with an early warning of impending power failure. These devices are available in a standard 8-pin SOIC package or a space-saving 8-pin TSSOP package. Figure 4. Logic Diagram (STM795) VCC VBAT VOUT WDI PFI STM690/ 802/804/ 805 RST(RST)(1) PFO VCCSW STM795 E VOUT RST ECON VSS AI08846 VSS AI08848 Note: 1. For STM804/805, reset output is active-high and open drain. Table 2. Signal Names MR WDI Push-button Reset Input Watchdog Input Active-Low Reset Output Active-High Reset Output Chip Enable Input Conditioned Chip Enable Output VCC Switch Output Supply Voltage Output Supply Voltage Back-up Supply Voltage Power-fail Input Power-fail Output Ground Figure 3. Logic Diagram (STM704/806) VCC VBAT RST RST(1) VOUT MR PFI STM704 STM806 RST PFO E(2) ECON(2) Vccsw(2) VOUT VSS AI08847 VCC VBAT PFI PFO VSS Note: 1. Open drain for STM804/805 only. 2. STM795 4/31 STM690/704/795/802/804/805/806 Figure 5. STM690/802/804/805 Connections SO8/TSSOP8 VOUT VCC VSS PFI 1 2 3 4 8 7 6 5 VBAT RST(RST)(1) WDI PFO AI08849 Figure 6. STM704/806 Connections SO8/TSSOP8 VOUT VCC VSS PFI 1 2 3 4 8 7 6 5 VBAT RST MR PFO AI08850 Note: 1. For STM804/805, reset output is active-high and open drain. Figure 7. STM795 Connections SO8/TSSOP8 VOUT VCC VCCSW VSS 1 2 3 4 8 7 6 5 VBAT RST ECON E AI08851 5/31 STM690/704/795/802/804/805/806 Pin Descriptions MR . A logic low on /MR asserts the reset output. Reset remains asserted as long as MR is low and for trec after MR returns high. This active-low input has an internal pull-up. It can be driven from a TTL or CMOS logic line, or shorted to ground with a switch. Leave open if unused. WDI. If WDI remains high or low for 1.6sec, the internal watchdog timer runs out and reset is triggered. The internal watchdog timer clears while reset is asserted or when WDI sees a rising or falling edge. The watchdog function cannot be disabled by allowing the WDI pin to float. RST. Pulses low for trec when triggered, and stays low whenever VCC is below the reset threshold or when MR is a logic low. It remains low for trec after either VCC rises above the reset threshold, the watchdog triggers a reset, or MR goes from low to high. RST (Open Drain). Pulses high for trec when triggered, and stays high whenever VCC is above the reset threshold or when MR is a logic high. It remains high for trec after either VCC falls below the reset threshold, the watchdog triggers a reset, or MR goes from high to low. PFI. When PFI is less than VPFI or when VCC falls below VSW (2.4V), PFO goes low; otherwise, PFO remains high. Connect to ground if unused. PFO. When PFI is less than VPFI, or VCC falls below VSW, PFO goes low; otherwise, PFO remains high. Leave open if unused. VOUT. When VCC is above the switchover voltage (VSO), VOUT is connected to VCC through a Pchannel MOSFET switch. When VCC falls below VSO, VBAT connects to VOUT. Connect to VCC if no battery is used. Vccsw. When VOUT switches to battery, Vccsw is high. When VOUT switches back to VCC, Vccsw is low. It can be used to drive gate of external PMOS transistor for IOUT requirements exceeding 75mA. E. The input to the chip-enable gating circuit. Connect to ground if unused. ECON. ECON goes low only when E is low and reset is not asserted. If ECON is low when reset is asserted, ECON will remain low for 15µs or until E goes high, whichever occurs first. In the disabled mode, ECON is pulled up to VOUT. VBAT. When VCC falls below VSO, VOUT switches from VCC to VBAT. When VCC rises above VSO + hysteresis, VOUT reconnects to VCC. VBAT may exceed VCC. Connect to VCC if no battery is used. Table 3. Pin Description Pin STM795 – – 7 – – – 1 2 3 4 5 6 8 STM690 STM802 – 6 7 – 4 5 1 2 – 3 – – 8 STM704 STM806 6 – 7 – 4 5 1 2 – 3 – – 8 STM804 STM805 – 6 – 7 4 5 1 2 – 3 – – 8 MR WDI RST RST PFI PFO VOUT VCC Vccsw VSS E ECON VBAT Push-button Reset Input Watchdog Input Active-Low Reset Output Active-High Reset Output PFI Power-fail Input PFO Power-fail Output Supply Output for External LPSRAM Supply Voltage VCC Switch Output Ground Chip Enable Input Conditioned Chip Enable Output Backup-Battery Input Name Function 6/31 STM690/704/795/802/804/805/806 Figure 8. Block Diagram (STM690/802/804/805) VCC VBAT VOUT VSO COMPARE VRST COMPARE WDI WATCHDOG TIMER trec Generator RST(RST)(1) PFI VPFI COMPARE PFO AI07897 Note: 1. For STM804/805, reset output is active-high and open drain. Figure 9. Block Diagram (STM704/806) VCC VBAT VOUT VSO COMPARE VRST COMPARE MR trec Generator RST PFI VPFI COMPARE PFO AI07898 7/31 STM690/704/795/802/804/805/806 Figure 10. Block Diagram (STM795) VCC VBAT VCCSW VOUT VSO COMPARE VRST COMPARE trec Generator RST ECON OUTPUT CONTROL E PFI ECON VPFI COMPARE PFO AI08852 Figure 11. Hardware Hookup Regulator Unregulated Voltage VIN VCC VCC VCCSW(2) VOUT VCC VCC STM690/704/ 795/802/804/ 805/806 0.1µF WDI(1) LPSRAM E E 0.1µF From Microprocessor E(2) R1 PFI(3) R2 Push-Button MR(4) VBAT RST To Microprocessor Reset PFO(3) To Microprocessor NMI ECON(2) AI08853 Note: 1. 2. 3. 4. For STM690/802/804/805. For STM795 only. Not available on STM795. For STM704/806. 8/31 STM690/704/795/802/804/805/806 OPERATION Reset Output The STM690/704/795/802/804/805/806 Supervisor asserts a reset signal to the MCU whenever VCC goes below the reset threshold (VRST), a watchdog time-out occurs, or when the Push-button Reset Input (MR) is taken low. RST is guaranteed to be a logic low (logic high for STM804/805) for 0V < VCC < VRST if VBAT is greater than 1V. Without a back-up battery, RST is guaranteed valid down to VCC =1V. During power-up, once VCC exceeds the reset threshold an internal timer keeps RST low for the reset time-out period, trec. After this interval RST returns high. If VCC drops below the reset threshold, RST goes low. Each time RST is asserted, it stays low for at least the reset time-out period (trec). Any time VCC goes below the reset threshold the internal timer clears. The reset timer starts when VCC returns above the reset threshold. Push-button Reset Input (STM704/806) A logic low on MR asserts reset. Reset remains asserted while MR is low, and for trec (see Figure 36., page 22) after it returns high. The MR input has an internal 40kΩ pull-up resistor, allowing it to be left open if not used. This input can be driven with TTL/CMOS-logic levels or with open-drain/ collector outputs. Connect a normally open momentary switch from MR to GND to create a manual reset function; external debounce circuitry is not required. If MR is driven from long cables or the device is used in a noisy environment, connect a 0.1µF capacitor from MR to GND to provide additional noise immunity. MR may float, or be tied to VCC when not used. Watchdog Input (NOT available on STM704/ 795/806) The watchdog timer can be used to detect an outof-control MCU. If the MCU does not toggle the Watchdog Input (WDI) within tWD (1.6sec typ), the reset is asserted. The internal watchdog timer is cleared by either: 1. a reset pulse, or 2. by toggling WDI (high-to-low or low-to-high), which can detect pulses as short as 50ns. If WDI is tied high or low, a reset pulse is triggered every 1.8sec (tWD + trec). The timer remains cleared and does not count for as long as reset is asserted. As soon as reset is released, the timer starts counting (see Figure 37., page 23). Note: Input frequency greater than 20ns (50MHz) will be filtered. Back-up Battery Switchover In the event of a power failure, it may be necessary to preserve the contents of external SRAM through VOUT. With a backup battery installed with voltage VBAT, the devices automatically switch the SRAM to the back-up supply when VCC falls. Note: If back-up battery is not used, connect both VBAT and VOUT to VCC. This family of Supervisors does not always connect VBAT to VOUT when VBAT is greater than VCC. VBAT connects to VOUT (through a 100Ω switch) when VCC is below VSW (2.4V) or VBAT (whichever is lower). This is done to allow the back-up battery (e.g., a 3.6V lithium cell) to have a higher voltage than VCC. Assuming that VBAT > 2.0V, switchover at VSO ensures that battery back-up mode is entered before VOUT gets too close to the 2.0V minimum required to reliably retain data in most external SRAMs. When VCC recovers, hysteresis is used to avoid oscillation around the VSO point. VOUT is connected to VCC through a 3Ω PMOS power switch. Note: The back-up battery may be removed while VCC is valid, assuming VBAT is adequately decoupled (0.1µF typ), without danger of triggering a reset. Table 4. I/O Status in Battery Back-up Pin VOUT VCC PFI PFO E ECON WDI MR RST RST VBAT Vccsw Status Connected to VBAT through internal switch Disconnected from VOUT Disabled Logic Low High impedance Logic High Watchdog timer is disabled Disabled Logic Low Logic High Connected to VOUT Logic High (STM795) 9/31 STM690/704/795/802/804/805/806 Chip-Enable Gating (STM795 only) Internal gating of the chip enable (E) signal prevents erroneous data from corrupting the external CMOS RAM in the event of an undervoltage condition. The STM795 uses a series transmission gate from E to ECON (see Figure 12). During normal operation (reset not asserted), the E transmission gate is enabled and passes all E transitions. When reset is asserted, this path becomes disabled, preventing erroneous data from corrupting the CMOS RAM. The short E propagation delay from E to ECON enables the STM795 to be used with most µPs. If E is low when reset asserts, ECON remains low for typically 10µs to permit the current WRITE cycle to complete. Chip Enable Input (STM795 only) The chip-enable transmission gate is disabled and E is high impedance (disabled mode) while reset is asserted. During a power-down sequence when VCC passes the reset threshold, the chip-enable transmission gate disables and E immediately becomes high impedance if the voltage at E is high. If E is low when reset asserts, the chip-enable transmission gate will disable 10µs after reset asserts (see Figure 13). This permits the current WRITE cycle to complete during power-down. Figure 12. Chip-Enable Gating VCC VRST COMPARE trec Generator RST VOUT ECON OUTPUT CONTROL E AI08802 Any time a reset is generated, the chip-enable transmission gate remains disabled and E remains high impedance (regardless of E activity) for the first half of the reset time-out period (trec/2). When the chip enable transmission gate is enabled, the impedance of E appears as a 40Ω resistor in series with the load at ECON. The propagation delay through the chip-enable transmission gate depends on VCC, the source impedance of the drive connected to E, and the loading on ECON. The chip enable propagation delay is production tested from the 50% point on E to the 50% point on ECON using a 50Ω driver and a 50pF load capacitance (see Figure 35., page 22). For minimum propagation delay, minimize the capacitive load at ECON and use a low-output impedance driver. Chip Enable Output (STM795 only) When the chip-enable transmission gate is enabled, the impedance of ECON is equivalent to a 40Ω resistor in series with the source driving E. In the disabled mode, the transmission gate is off and an active pull-up connects ECON to VOUT (see Figure 12). This pull-up turns off when the transmission gate is enabled. ECON Figure 13. Chip Enable Waveform (STM795) VCC VRST VBAT ½ trec trec 10µs trec ½ trec ECON RST E AI08855b 10/31 STM690/704/795/802/804/805/806 Power-fail Input/Output (NOT available on STM795) Figure 14., page 11). This occurs after VCC drops The Power-fail Input (PFI) is compared to an interbelow VSW (2.4V). When power returns, the pownal reference voltage (independent from the VRST comparator). If PFI is less than the power-fail er-fail comparator is enabled and PFO follows PFI. threshold (VPFI), the Power-Fail Output (PFO) will If the comparator is unused, PFI should be congo low. This function is intended for use as an unnected to VSS and PFO left unconnected. PFO may be connected to MR on the STM704/806 so dervoltage detector to signal a failing power supthat a low voltage on PFI will generate a reset outply. Typically PFI is connected through an external put. voltage divider (see Figure 11., page 8) to either the unregulated DC input (if it is available) or the Applications Information regulated output of the VCC regulator. The voltage These Supervisor circuits are not short-circuit prodivider can be set up such that the voltage at PFI tected. Shorting VOUT to ground - excluding powfalls below VPFI several milliseconds before the er-up transients such as charging a decoupling regulated VCC input to the STM690/704/795/802/ capacitor - destroys the device. Decouple both 804/805/806 or the microprocessor drops below VCC and VBAT pins to ground by placing 0.1µF cathe minimum operating voltage. pacitors as close to the device as possible. During battery back-up, the power-fail comparator is turned off and PFO goes (or remains) low (see Figure 14. Power-fail Comparator Waveform (STM690/704/802/804/805/806) VCC VRST VSW (2.4V) trec PFO PFO follows PFI PFO follows PFI RST AI08861a 11/31 STM690/704/795/802/804/805/806 Using a SuperCap™ as a Backup Power Source SuperCaps™ are capacitors with extremely high capacitance values (e.g., order of 0.47F) for their size. Figure 15 shows how to use a SuperCap as a back-up power source. The SuperCap may be connected through a diode to the VCC supply. Since VBAT can exceed VCC while VCC is above the reset threshold, there are no special precautions when using these supervisors with a SuperCap. Figure 15. Using a SuperCap™ 5V VCC VOUT To external SRAM Negative-Going VCC Transients The STM690/704/795/802/804/805/806 Supervisors are relatively immune to negative-going VCC transients (glitches). Figure 32., page 20 was generated using a negative pulse applied to VCC, starting at VRST + 0.3V and ending below the reset threshold by the magnitude indicated (comparator overdrive). The graph indicates the maximum pulse width a negative VCC transient can have without causing a reset pulse. As the magnitude of the transient increases (further below the threshold), the maximum allowable pulse width decreases. Any combination of duration and overdrive which lies under the curve will NOT generate a reset signal. Typically, a VCC transient that goes 100mV below the reset threshold and lasts 40µs or less will not cause a reset pulse. A 0.1µF bypass capacitor mounted as close as possible to the VCC pin provides additional transient immunity. STMXXX VBAT GND RST To µP AI08805 12/31 STM690/704/795/802/804/805/806 TYPICAL OPERATING CHARACTERISTICS Note: Typical values are at TA = 25°C. Figure 16. VBAT-to-VOUT On-Resistance vs. Temperature VBAT - to - VOUT ON-RESISTANCE [Ω] 220 VCC = 0V 200 180 160 140 120 100 –60 VBAT = 2V VBAT = 3V VBAT = 3.3V VBAT = 5V –40 –20 0 20 40 60 80 100 120 140 AI09140 TEMPERATURE [°C] Figure 17. Supply Current vs. Temperature (no load) 30 25 Supply Current [µA] 20 2.5V 3.3V 3.6V 5.0V 5.5V 15 10 5 0 –50 –40 –30 –20 –10 0 10 20 30 40 50 60 70 80 90 100 AI09141 TEMPERATURE [°C] 13/31 STM690/704/795/802/804/805/806 Figure 18. VPFI Threshold vs. Temperature 1.255 1.250 1.245 1.240 1.235 VPFI THRESHOLD [V] VCC = 5V VCC = 3.3V VCC = 2.5V 1.230 VBAT = 3.0V 1.225 –50 –30 –10 10 30 50 70 90 110 130 AI09142 TEMPERATURE [°C] Figure 19. Reset Comparator Propagation Delay vs. Temperature PROPAGATION DELAY [µs] 24 22 20 18 16 14 12 10 –60 –40 –20 0 20 40 60 80 100 AI09143 VBAT = 3.0V 100mV OVERDRIVE TEMPERATURE [°C] Figure 20. Power-up trec vs. Temperature 215 210 trec [ms] 205 200 195 –50 –30 –10 10 30 50 70 90 110 130 AI09144 TEMPERATURE [°C] 14/31 STM690/704/795/802/804/805/806 Figure 21. Normalized Reset Threshold vs. Temperature NORMALIZED RESET THRESHOLD [V] 1.002 1.000 0.998 0.996 VBAT = 3.0V 0.994 –60 –40 –20 0 20 40 60 80 100 120 140 AI09145 TEMPERATURE [°C] Figure 22. Watchdog Time-out Period vs. Temperature 1.74 WATCHDOG TIME-OUT PERIOD [sec] 1.72 1.70 1.68 1.66 1.64 1.62 1.60 1.58 1.56 –50 –30 –10 10 30 50 70 90 110 130 AI09146 TEMPERATURE [°C] Figure 23. E to ECON On-Resistance vs. Temperature E to ECON ON-RESISTANCE [Ω] 90 80 70 VCC = 3V 60 50 40 30 –60 –40 –20 0 20 40 60 80 100 120 140 AI09147 TEMPERATURE [°C] 15/31 STM690/704/795/802/804/805/806 Figure 24. PFI to PFO Propagation Delay vs. Temperature 9 8 PROPAGATION DELAY [µs] 7 6 5 4 3 2 1 0 –60 –40 –20 0 20 40 60 80 100 120 140 AI09148 TEMPERATURE [°C] Figure 25. RST Output Voltage vs. Supply Voltage 6 5 RST OUTPUT VOLTAGE [V] 4 VCC 3 VRST 2 1 0 500 ms/div AI09149 16/31 STM690/704/795/802/804/805/806 Figure 26. RST Output Voltage vs. Supply Voltage 6 5 RST OUTPUT VOLTAGE [V] VCC 4 3 2 VRST 1 0 500 ms/div AI09150 Figure 27. RST Response Time (Assertion) 6 5 VCC VCC LEVEL [V] 4 3 VRST 2 1 0 2 µs/div AI09151 17/31 STM690/704/795/802/804/805/806 Figure 28. RESET Response Time (Assertion) 6 VCC 5 4 VCC LEVEL [V] 3 VRST 2 1 0 2µs/div AI09152 Figure 29. Power-fail Comparator Response Time (Assertion) 6 1.45 5 1.40 VPFO LEVEL [V] 4 1.35 PFO 3 1.30 PFI 2 1.25 1 1.20 0 2µs/div 1.15 AI09153 18/31 VPFI LEVEL [V] STM690/704/795/802/804/805/806 Figure 30. Power-fail Comparator Response Time (De-Assertion) 6 1.45 5 1.40 VPFO LEVEL (V) PFO 3 1.30 PFI 2 1.25 1 1.20 0 2 µs/div 1.15 AI09154 Figure 31. VCC to Reset Propagation Delay vs. Temperature 60 PROPAGATION DELAY [µs] 50 40 10V/ms 30 20 10 0 –60 –40 –20 0 20 40 60 80 100 1V/ms 0.25V/ms TEMPERATURE [°C] AI09155 VPFI LEVEL (V) 4 1.35 19/31 STM690/704/795/802/804/805/806 Figure 32. Maximum Transient Duration vs. Reset Threshold Overdrive 250 TRANSIENT DURATION [µs] 200 150 100 50 0 1 10 100 1000 10000 AI09156 RESET COMPARATOR OVERDRIVE, VRST – VCC [mV] Figure 33. E to ECON Propagation Delay vs. Temperature 3.5 E Rising E to ECON PROPAGATION DELAY [ns] 3.0 E Falling 2.5 2.0 1.5 1.0 0.5 0 –60 –40 –20 0 20 40 60 80 100 120 140 AI09157 TEMPERATURE [°C] 20/31 STM690/704/795/802/804/805/806 MAXIMUM RATING Stressing the device above the rating listed in the Absolute Maximum Ratings” table may cause permanent damage to the device. These are stress ratings only and operation of the device at these or any other conditions above those indicated in the Operating sections of this specification is not imTable 5. Absolute Maximum Ratings Symbol TSTG TSLD(1) VIO VCC/VBAT IO PD Parameter Storage Temperature (VCC Off) Lead Solder Temperature for 10 seconds Input or Output Voltage Supply Voltage Output Current Power Dissipation Value –55 to 150 260 –0.3 to VCC +0.3 –0.3 to 6.0 20 320 Unit °C °C V V mA mW plied. Exposure to Absolute Maximum Rating conditions for extended periods may affect device reliability. Refer also to the STMicroelectronics SURE Program and other relevant quality documents. Note: 1. Reflow at peak temperature of 255°C to 260°C for < 30 seconds (total thermal budget not to exceed 180°C for between 90 to 150 seconds). DC AND AC PARAMETERS This section summarizes the operating measurement conditions, and the DC and AC characteristics of the device. The parameters in the DC and AC characteristics Tables that follow, are derived from tests performed under the Measurement Conditions summarized in Table 6, Operating and AC Measurement Conditions. Designers should check that the operating conditions in their circuit match the operating conditions when relying on the quoted parameters. Table 6. Operating and AC Measurement Conditions Parameter VCC/VBAT Supply Voltage Ambient Operating Temperature (TA) Input Rise and Fall Times Input Pulse Voltages Input and Output Timing Ref. Voltages STM690/704/795/ 802/804/805/806 1.0 to 5.5 –40 to 85 ≤5 0.2 to 0.8VCC 0.3 to 0.7VCC Unit V °C ns V V 21/31 STM690/704/795/802/804/805/806 Figure 34. E to ECON Propagation Delay Test Circuit VCC VCC VBAT 3.6V STM690/704/ 795/802/804/ 805/806 25Ω Equivalent Source Impedance E 50Ω 50Ω Cable 50Ω ECON 50pF CL(1) GND AI08854 Note: 1. CL includes load capacitance and scope probe capacitance. Figure 35. AC Testing Input/Output Waveforms 0.8VCC 0.7VCC 0.3VCC AI02568 0.2VCC Figure 36. MR Timing Waveform MR tMLRL RST (1) tMLMH trec AI07837a Note: 1. RST for STM805. 22/31 STM690/704/795/802/804/805/806 Figure 37. Watchdog Timing VCC RST trec WDI tWD AI07891 Table 7. DC and AC Characteristics Sym VCC, VBAT(2) Alternative Description Operating Voltage Test Condition(1) TA = –40 to +85°C Excluding IOUT (VCC < 5.5V) Excluding IOUT (VCC < 3.6V) Excluding IOUT (VBAT = 2.3V, VCC = 2.0V, MR = VCC) Excluding IOUT (VBAT = 3.6V) IOUT1 = 5mA(5) VOUT1 VOUT Voltage (Active) IOUT1 = 75mA IOUT1 = 250µA, VCC > 2.5V(5) IOUT2 = 250µA, VBAT = 2.3V IOUT2 = 1mA, VBAT = 2.3V VCC – 0.03 VCC – 0.3 VCC – 0.0015 VBAT – 0.1 Min 1.1(3) 40 35 25 Typ Max 5.5 60 50 35 Unit V µA µA µA VCC Supply Current ICC VCC Supply Current in Battery Back-up Mode IBAT(4) VBAT Supply Current in Battery Back-up Mode 0.4 VCC – 0.015 VCC – 0.15 VCC – 0.0006 VBAT – 0.034 VBAT – 0.14 3 100 1.0 µA V V V V V VOUT2 VOUT Voltage (Battery Back-up) VCC to VOUT On-resistance VBAT to VOUT On-resistance Input Leakage Current (MR) ILI Input Leakage Current (PFI) Input Leakage Current (WDI) ILO VIH VIL Output Leakage Current Input High Voltage (MR, WDI) Input Low Voltage (MR, WDI) STM704/806 only; MR = 0V; VCC = 3V 0V = VIN = VCC 0V = VIN = VCC STM804/805/795; 0V = VIN = VCC(6) VRST (max) < VCC < 5.5V VRST (max) < VCC < 5.5V 20 –25 –1 –1 0.7VCC 4 Ω Ω 75 2 350 +25 +1 +1 µA nA µA µA V 0.3VCC V 23/31 STM690/704/795/802/804/805/806 Alternative Test Condition(1) VCC = VRST (max), ISINK = 3.2mA VCC = VRST (max), IOUT = 1.6mA, E = 0V IOL = 40µA; VCC = 1.0V; VBAT = VCC; TA = 0°C to 85°C IOL = 200µA; VCC = 1.2V; VBAT = VCC Output High Voltage (RST, RST)(7) VOH Output High Voltage (ECON) Output High Voltage (PFO) VOHB VOH Battery Back-up (ECON, Vccsw, RST) ISOURCE = 1mA, VCC = VRST (max) VCC = VRST (max), IOUT = 1.6mA, E = VCC ISOURCE = 75µA, VCC = VRST (max) ISOURCE = 100µA, 2.4 0.8VCC 0.8VCC 0.8VBAT Sym Description Output Low Voltage (PFO, RST, RST, Vccsw) Min Typ Max 0.3 0.2VCC Unit V V VOL Output Low Voltage (ECON) 0.3 V VOL Output Low Voltage (RST) 0.3 V V V V V Power-fail Comparator (NOT available on STM795) PFI Falling (VCC < 3.6V) STM802/ 804/806 STM690/ 704/805 1.212 1.187 1.237 1.237 10 2 VCC = 3.6V, PFO = 0V 0.1 0.75 2.0 1.262 1.287 20 V V mV µs mA VPFI PFI Input Threshold PFI Hysteresis tPFD ISC Battery Switchover PFI to PFO Propagation Delay PFO Output Short to GND Current PFI Rising (VCC < 3.6V) Power-down Battery Back-up Switchover Voltage (8,9) VSO VSW Hysteresis Power-up VBAT > VSW VBAT < VSW VBAT > VSW VBAT < VSW VSW VBAT VSW VBAT 2.4 40 V V V V V mV 24/31 STM690/704/795/802/804/805/806 Alternative Test Condition(1) Sym Description Min Typ Max Unit Reset Thresholds STM690T/ 704T/795T/ 805T STM802T/ 804T/806T STM690S/ 704S/795S/ 805S STM802S/ 804S/806S STM690R/ 704R/795R/ 805R STM802R/ 804R/806R trec RST Pulse Width VCC Falling VCC Rising VCC Falling VCC Rising VCC Falling VCC Rising VCC Falling VCC Rising VCC Falling VCC Rising VCC Falling VCC Rising 3.00 3.00 3.00 3.00 2.85 2.85 2.88 2.88 2.55 2.55 2.59 2.59 140 3.075 3.085 3.075 3.085 2.925 2.935 2.925 2.935 2.625 2.635 2.625 2.635 200 3.15 3.17 3.12 3.14 3.00 3.02 3.00 3.02 2.70 2.72 2.70 2.72 280 V V V V V V V V V V V V ms VRST(10) Reset Threshold VCC < 3.6V Push-button Reset Input (STM704/806) tMLMH tMLRL tMR tMRD MR Pulse Width MR to RST Output Delay 100 20 60 500 ns ns Watchdog Timer (NOT available on STM704/795/806) tWD Watchdog Timeout Period WDI Pulse Width Chip-Enable Gating (STM795 only) E-to-ECON Resistance E-to-ECON Propagation Delay Reset-to-ECON High Delay ISC ECON Short Circuit Current VCC = 3.6V, Disable Mode, ECON = 0V 0.1 VCC = VRST (max) VCC = VRST (max) 46 2 10 0.75 2.0 7 Ω ns µs mA VRST (max) < VCC < 3.6V VRST (max) < VCC < 3.6V 1.12 100 1.60 20 2.24 s ns Note: 1. Valid for Ambient Operating Temperature: TA = –40 to 85°C; VCC = VRST (max) to 5.5V; and VBAT = 2.8V (except where noted). 2. VCC supply current, logic input leakage, Watchdog functionality, Push-button Reset functionality, PFI functionality, state of RST and RST tested at VBAT = 3.6V, and VCC = 5.5V. The state of RST or RST and PFO is tested at VCC = VCC (min). Either VCC or VBAT can go to 0V if the other is greater than 2.0V. 3. VCC (min) = 1.0V for TA = 0°C to +85°C. 4. Tested at VBAT = 3.6V, VCC = 3.5V and 0V. 5. Guaranteed by design. 6. The leakage current measured on the RST pin (STM804/805) or RST pin (STM795) is tested with the reset output not asserted (output high impedance). 7. Not valid for STM795/804/805 (open drain). 8. When VBAT > VCC > VSW, VOUT remains connected to VCC until VCC drops below VSW. 9. When VSW > VCC > VBAT, VOUT remains connected to VCC until VCC drops below the battery voltage (VBAT) – 75mV. 10. The reset threshold tolerance is wider for VCC rising than for VCC falling due to the 10mV (typ) hysteresis, which prevents internal oscillation. 25/31 STM690/704/795/802/804/805/806 PACKAGE MECHANICAL Figure 38. SO8 – 8-lead Plastic Small Outline, 150 mils body width, Package Mech. Drawing h x 45˚ A2 B e D A C ddd 8 E 1 H A1 α L SO-A Note: Drawing is not to scale. Table 8. SO8 – 8-lead Plastic Small Outline, 150 mils body width, Package Mechanical Data mm Symb Typ A A1 B C D ddd E e H h L α N – – – – – – – 1.27 – – – – Min 1.35 0.10 0.33 0.19 4.80 – 3.80 – 5.80 0.25 0.40 0° 8 Max 1.75 0.25 0.51 0.25 5.00 0.10 4.00 – 6.20 0.50 0.90 8° Typ – – – – – – – 0.050 – – – – Min 0.053 0.004 0.013 0.007 0.189 – 0.150 – 0.228 0.010 0.016 0° 8 Max 0.069 0.010 0.020 0.010 0.197 0.004 0.157 – 0.244 0.020 0.035 8° inches 26/31 STM690/704/795/802/804/805/806 Figure 39. TSSOP8 – 8-lead, Thin Shrink Small Outline, 3x3mm body size, Outline D 8 5 E1 E c 1 4 α A1 A CP b e A2 L L1 TSSOP8BM Note: Drawing is not to scale. Table 9. TSSOP8 – 8-lead, Thin Shrink Small Outline, 3x3mm body size, Mechanical Data mm Symb Typ A A1 A2 b c CP D e E E1 L L1 α N – – 0.85 – – – 3.00 0.65 4.90 3.00 0.55 0.95 – Min – 0.05 0.75 0.25 0.13 – 2.90 – 4.65 2.90 0.40 – 0° 8 Max 1.10 0.15 0.95 0.40 0.23 0.10 3.10 – 5.15 3.10 0.70 – 6° Typ – – 0.034 – – – 0.118 0.026 0.193 0.118 0.022 0.037 – Min – 0.002 0.030 0.010 0.005 – 0.114 – 0.183 0.114 0.016 – 0° 8 Max 0.043 0.006 0.037 0.016 0.009 0.004 0.122 – 0.203 0.122 0.030 – 6° inches 27/31 STM690/704/795/802/804/805/806 PART NUMBERING Table 10. Ordering Information Scheme Example: STM690 T M 6 E Device Type STM690/704/795/802/804/805/806 Reset Threshold Voltage T = STM690/704/795/805 = VRST = 3.00V to 3.15V STM802/804/806 = VRST = 3.00V to 3.12V S = STM690/704/795/805 = VRST = 2.85V to 3.00V STM802/804/806 = VRST = 2.88V to 3.00V R = STM690/704/795/805 = VRST = 2.55V to 2.70V STM802/804/806 = VRST = 2.59V to 2.70V Package M = SO8 DS(1) = TSSOP8 Temperature Range 6 = –40 to 85°C Shipping Method E = Tubes (Pb-Free - ECO PACK®) PACK®) F = Tape & Reel (Pb-Free - ECO Note: 1. Contact local ST sales office for availability. For other options, or for more information on any aspect of this device, please contact the ST Sales Office nearest you. 28/31 STM690/704/795/802/804/805/806 Table 11. Marking Description Part Number STM690T STM690S STM690R STM704T STM704S STM704R STM795T STM795S STM795R STM802T STM802S STM802R STM804T STM804S STM804R STM805T STM805S STM805R STM806T STM806S STM806R Reset Threshold 3.075 2.925 2.625 3.075 2.925 2.625 3.075 2.925 2.625 3.075 2.925 2.625 3.075 2.925 2.625 3.075 2.925 2.625 3.075 2.925 2.625 Package SO8 TSSOP8 SO8 TSSOP8 SO8 TSSOP8 SO8 TSSOP8 SO8 TSSOP8 SO8 TSSOP8 SO8 TSSOP8 SO8 TSSOP8 SO8 TSSOP8 SO8 TSSOP8 SO8 TSSOP8 SO8 TSSOP8 SO8 TSSOP8 SO8 TSSOP8 SO8 TSSOP8 SO8 TSSOP8 SO8 TSSOP8 SO8 TSSOP8 SO8 TSSOP8 SO8 TSSOP8 SO8 TSSOP8 Topside Marking 690T 690S 690R 704T 704S 704R 795T 795S 795R 802T 802S 802R 804T 804S 804R 805T 805S 805R 806T 806S 806R 29/31 STM690/704/795/802/804/805/806 REVISION HISTORY Table 12. Document Revision History Date October 31, 2003 22-Dec-03 16-Jan-04 07-Apr-04 25-May-04 02-Jul-04 29-Sep-04 Version 1.0 2.0 2.1 2.2 3.0 4.0 5.0 First Issue Reformatted; update characteristics (Figure 1, 3, 4, 11, 13, 14, 36; Table 1, 3, 4, 7, 9, 11) Add Typical Operating Characteristics (Figure 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33) Update characteristics (Figure 13, 25, 26, 27, 28, 31; Table 1, 3, 7) Update characteristics (Table 3, 7) Update package availability, pin description; promote document (Figure 1, 14; Table 3, 10) Clarify root part numbers, pin descriptions, update characteristics (Figure 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 14, 34; Table 1, 3, 6, 7, 10) Revision Details 30/31 STM690/704/795/802/804/805/806 Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specifications mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics. The ST logo is a registered trademark of STMicroelectronics. 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