STM706T/S/R, STM706P, STM708T/S/R 3V Supervisor FEATURES SUMMARY ■ ■ ■ ■ ■ ■ ■ ■ ■ Figure 1. Packages PRECISION VCC MONITOR – STM706/708 T: 3.00V ≤ VRST ≤ 3.15V S: 2.88V ≤ VRST ≤ 3.00V R; STM706P: 2.59V ≤ VRST ≤ 2.70V RST AND RST OUTPUTS 200ms (TYP) trec WATCHDOG TIMER - 1.6sec (TYP) MANUAL RESET INPUT (MR) 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) 8 1 SO8 (M) TSSOP8 3x3 (DS) Table 1. Device Options Watchdog Input Watchdog Output Active-Low RST(1) STM706T/S/R ✔ ✔ ✔ STM706P(2) ✔ ✔ STM708T/S/R ✔ Active-High RST(1) Manual Reset Input Power-fail Comparator ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ Note: 1. Push-Pull Output 2. The STM706P is identical to the STM706R, except its reset output is active-high. February 2005 1/26 STM706T/S/R; STM706P; STM708T/S/R TABLE OF CONTENTS FEATURES SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Figure 1. Packages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Table 1. Device Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 SUMMARY DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Figure 2. Logic Diagram (STM706T/S/R and STM706P) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Figure 3. Logic Diagram (STM708T/S/R) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Table 2. Signal Names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Figure 4. STM706T/S/R and STM706P SO8 Connections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Figure 5. STM706T/S/R and STM706P TSSOP8 Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Figure 6. STM708T/S/R SO8 Connections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Figure 7. STM708T/S/R TSSOP8 Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Pin Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Table 3. Pin Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Figure 8. Block Diagram (STM706T/S/R and STM706P) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Figure 9. Block Diagram (STM708T/S/R) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Figure 10.Hardware Hookup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Reset Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Push-button Reset Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Watchdog Input (STM706T/S/R and STM706P). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Watchdog Output (STM706T/S/R and STM706P) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Power-fail Input/Output. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Ensuring a Valid Reset Output Down to VCC = 0V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Figure 11.Reset Output Valid to Ground Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Interfacing to Microprocessors with Bi-directional Reset Pins . . . . . . . . . . . . . . . . . . . . . . . . 10 Figure 12.Interfacing to Microprocessors with Bi-directional Reset I/O . . . . . . . . . . . . . . . . . . . . . . 10 TYPICAL OPERATING CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Figure 13.Supply Current vs. Temperature (no load) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Figure 14.VPFI Threshold vs. Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Figure 15.Reset Comparator Propagation Delay vs. Temperature . . . . . . . . . . . . . . . . . . . . . . . . . 11 Figure 16.Power-up trec vs. Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Figure 17.Normalized Reset Threshold vs. Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Figure 18.Watchdog Time-out Period vs. Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Figure 19.PFI to PFO Propagation Delay vs. Temperature. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Figure 20.Output Voltage vs. Load Current (VCC = 5V; VBAT = 2.8V; TA = 25°C). . . . . . . . . . . . . . 14 Figure 21.Output Voltage vs. Load Current (VCC = 0V; VBAT = 2.8V; TA = 25°C). . . . . . . . . . . . . . 14 Figure 22.RST Output Voltage vs. Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Figure 23.RST Output Voltage vs. Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Figure 24.Power-fail Comparator Response Time (Assertion) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Figure 25.Power-fail Comparator Response Time (De-Assertion) . . . . . . . . . . . . . . . . . . . . . . . . . 16 2/26 STM706T/S/R; STM706P; STM708T/S/R Figure 26.Maximum Transient Duration vs. Reset Threshold Overdrive. . . . . . . . . . . . . . . . . . . . . 17 MAXIMUM RATING. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Table 4. Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 DC and AC PARAMETERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Table 5. Operating and AC Measurement Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Figure 27.AC Testing Input/Output Waveforms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Figure 28.Power-fail Comparator Waveform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Figure 29.MR Timing Waveform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Figure 30.Watchdog Timing (STM706T/S/R and STM706P) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Table 6. DC and AC Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 PACKAGE MECHANICAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Figure 31.SO8 – 8-lead Plastic Small Outline, 150 mils body width, Package Mechanical. . . . . . . 21 Table 7. SO8 – 8-lead Plastic Small Outline, 150 mils body width, Package Mechanical Data . . 21 Figure 32.TSSOP8 – 8-lead, Thin Shrink Small Outline, 3x3mm body size, Outline . . . . . . . . . . . 22 Table 8. TSSOP8 – 8-lead, Thin Shrink Small Outline, 3x3mm body size, Mechanical Data . . . . 22 PART NUMBERING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Table 9. Ordering Information Scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Table 10. Marking Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 REVISION HISTORY. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Table 11. Document Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 3/26 STM706T/S/R; STM706P; STM708T/S/R SUMMARY DESCRIPTION The STM70x Supervisors are self-contained devices which provide microprocessor supervisory functions. 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 a watchdog timer (except for STM708T/S/R) as well as a power-fail comparator to provide the system with an early warning of impending power failure. The STM706P is identical to the STM706R, except its reset output is active-high. These devices are available in a standard 8-pin SOIC package or a space-saving 8-pin TSSOP package. Figure 2. Logic Diagram (STM706T/S/R and STM706P) Table 2. Signal Names VCC WDI MR WDO STM706T/S/R, STM706P RST (RST)(1) Push-button Reset Input WDI Watchdog Input WDO Watchdog Output RST Active-Low Reset Output RST(1) Active-High Reset Output VCC Supply Voltage PFI Power-fail Input PFO Power-fail Output VSS Ground NC No Connect PFO PFI VSS AI08841 Note: 1. For STM706P and STM708T/S/R only. Note: 1. For STM706P only. Figure 3. Logic Diagram (STM708T/S/R) VCC RST MR STM708T/S/R RST PFI PFO VSS 4/26 MR AI08842 STM706T/S/R; STM706P; STM708T/S/R Figure 4. STM706T/S/R and STM706P SO8 Connections Figure 6. STM708T/S/R SO8 Connections SO8 SO8 MR VCC VSS PFI 1 2 3 4 8 7 6 5 WDO RST(RST)(1) WDI PFO MR VCC VSS PFI 1 2 3 4 8 7 6 5 RST RST NC PFO AI08839 AI08837 Note: 1. For STM706P reset output is active-high. Figure 5. STM706T/S/R and STM706P TSSOP8 Connections TSSOP8 TSSOP8 (1) RST(RST) WDO MR VCC 1 2 3 4 8 7 6 5 Figure 7. STM708T/S/R TSSOP8 Connections WDI PFO PFI VSS RST RST MR VCC 1 2 3 4 8 7 6 5 NC PFO PFI VSS AI08840 AI08838 Note: 1. For STM706P reset output is active-high. 5/26 STM706T/S/R; STM706P; STM708T/S/R 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 (or WDO) 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. WDO. WDO goes low when a transition does not occur on WDI within 1.6sec, and remains low until a transition occurs on WDI (indicating the watchdog interrupt has been serviced). WDO also goes low when VCC falls below the reset threshold; however, unlike the reset output, WDO goes high as soon as VCC exceeds the reset threshold. Note: For those devices with a WDO output, a watchdog timeout will not trigger reset unless WDO is connected to MR. 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. 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, PFO goes low; otherwise, PFO remains high. Connect to ground if unused. PFO. When PFI is less than VPFI, PFO goes low; otherwise, PFO remains high. Leave open if unused. Table 3. Pin Description Pin STM706P STM706T/S/R STM708T/S/R Name Function SO8 TSSOP8 SO8 TSSOP8 SO8 TSSOP8 1 3 1 3 1 3 MR Push-button Reset Input 6 8 6 8 – – WDI Watchdog Input 8 2 8 2 – – WDO Watchdog Output – – 7 1 7 1 RST Active-Low Reset Output 7 1 – – 8 2 RST Active-High Reset Output 2 4 2 4 2 4 VCC Supply Voltage 4 6 4 6 4 6 PFI PFI Power-fail Input 5 7 5 7 5 7 PFO PFO Power-fail Output 3 5 3 5 3 5 VSS Ground – – – – 6 8 NC No Connect 6/26 STM706T/S/R; STM706P; STM708T/S/R Figure 8. Block Diagram (STM706T/S/R and STM706P) WDI Transitional Detector WDI VCC WATCHDOG TIMER VRST WDO COMPARE VCC trec Generator MR RST(RST)(1) PFI VPFI COMPARE PFO AI08829 Note: 1. For STM706P only. Figure 9. Block Diagram (STM708T/S/R) VCC VRST COMPARE RST VCC trec Generator MR PFI VPFI COMPARE RST PFO AI08830 7/26 STM706T/S/R; STM706P; STM708T/S/R Figure 10. Hardware Hookup Regulator Unregulated Voltage VIN VCC VCC 0.1µF STM706T/S/R; STM706P; STM708T/S/R (1) WDO(1) To Microprocessor IRQ PFI PFO To Microprocessor NMI MR RST WDI R1 From Microprocessor R2 Push-button (2) To Microprocessor Reset RST AI08843 Note: 1. For STM706T/S/R and STM706P. 2. For STM706P and STM708T/S/R. 8/26 STM706T/S/R; STM706P; STM708T/S/R OPERATION Reset Output The STM70x Supervisor asserts a reset signal to the MCU whenever VCC goes below the reset threshold (VRST), a watchdog time-out occurs (if WDO is connected to MR), or when the Push-button Reset Input (MR) is taken low. RST is guaranteed to be a logic low (logic high for STM706P and STM708T/S/R) for VCC < VRST down to VCC =1V for TA = 0°C to 85°C. 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 A logic low on MR asserts reset. Reset remains asserted while MR is low, and for trec (see Figure 29., page 19) 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 (STM706T/S/R and STM706P) 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), the Watchdog Output pin (WDO) is asserted. The internal 1.6sec 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. See Figure 30., page 19 for STM706T/S/R and STM706P. 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. Watchdog Output (STM706T/S/R and STM706P) When VCC drops below the reset threshold, WDO will go low even if the watchdog timer has not yet timed out. However, unlike the reset output, WDO goes high as soon as VCC exceeds the reset threshold. WDO may be used to generate a reset pulse by connecting it to the MR input. Power-fail Input/Output The Power-fail Input (PFI) is compared to an internal reference voltage (independent from the VRST comparator). If PFI is less than the power-fail threshold (VPFI), the Power-Fail Output (PFO) will go low. This function is intended for use as an undervoltage detector to signal a failing power supply. Typically PFI is connected through an external voltage divider (see Figure 10., page 8) to either the unregulated DC input (if it is available) or the regulated output of the VCC regulator. The voltage divider can be set up such that the voltage at PFI falls below VPFI several milliseconds before the regulated VCC input to the STM70x or the microprocessor drops below the minimum operating voltage. If the comparator is unused, PFI should be connected to VSS and PFO left unconnected. PFO may be connected to MR on the STM70x so that a low voltage on PFI will generate a reset output. Ensuring a Valid Reset Output Down to VCC = 0V When VCC falls below 1V, the state of the RST output can no longer be guaranteed, and becomes essentially an open circuit. If a high value pulldown resistor is added to the RST pin, the output will be held low during this condition. A resistor value of approximately 100kΩ will be large enough to not load the output under operating conditions, but still sufficient to pull RST to ground during this low voltage condition (see Figure 11). Figure 11. Reset Output Valid to Ground Circuit STM70x RST R1 AI08844 9/26 STM706T/S/R; STM706P; STM708T/S/R Interfacing to Microprocessors with Bidirectional Reset Pins Microprocessors with bi-directional reset pins can contend with the STM70x reset output. For example, if the reset output is driven high and the micro wants to pull it low, signal contention will result. To prevent this from occurring, connect a 4.7kΩ resistor between the reset output and the micro’s reset I/O as in Figure 12. Figure 12. Interfacing to Microprocessors with Bi-directional Reset I/O Buffered Reset to other System Components VCC VCC STM70x Microprocessor 4.7k RST RST GND GND AI08845 TYPICAL OPERATING CHARACTERISTICS Note: Typical values are at TA = 25°C. Figure 13. Supply Current vs. Temperature (no load) 30 Supply Current (µA) 25 20 15 VCC = 2.7V VCC = 3.0V VCC = 3.6V VCC = 4.5V VCC = 5.5V 10 5 0 –40 –20 0 20 40 Temperature (°C) 10/26 60 80 100 120 AI09141b STM706T/S/R; STM706P; STM708T/S/R Figure 14. VPFI Threshold vs. Temperature 1.270 1.265 VCC = 2.5V VCC = 3.0V VCC = 3.3V VCC = 3.6V VPFI Threshold (V) 1.260 1.255 1.250 1.245 1.240 1.235 1.230 1.225 –40 –20 0 20 40 60 80 100 120 Temperature (°C) AI09142b Figure 15. Reset Comparator Propagation Delay vs. Temperature 30 28 Propagation Delay (µs) 26 24 22 20 18 16 14 12 10 –40 –20 0 20 40 Temperature (°C) 60 80 100 120 AI09143b 11/26 STM706T/S/R; STM706P; STM708T/S/R Figure 16. Power-up trec vs. Temperature 240 235 trec (ms) 230 VCC = 3.0V 225 VCC = 4.5V VCC = 5.5V 220 215 210 –40 –20 0 20 40 60 80 100 120 Temperature (°C) AI09144b Figure 17. Normalized Reset Threshold vs. Temperature Normalized Reset Threshold 1.004 1.002 1.000 0.998 0.996 –40 –20 0 20 40 60 Temperature (°C) 12/26 80 100 120 AI09145b STM706T/S/R; STM706P; STM708T/S/R Figure 18. Watchdog Time-out Period vs. Temperature Watchdog Time-out Period (sec) 1.90 1.85 1.80 1.75 VCC = 3.0V VCC = 4.5V VCC = 5.5V 1.70 1.65 1.60 –40 –20 0 20 40 60 80 100 Temperature (°C) 120 AI09146b Figure 19. PFI to PFO Propagation Delay vs. Temperature PFI to PFO Propagation Delay (µs) 4.0 VCC = 3.0V VCC = 3.6V 3.0 VCC = 4.5V VCC = 5.5V 2.0 1.0 0.0 –40 –20 0 20 40 Temperature (°C) 60 80 100 120 AI09148b 13/26 STM706T/S/R; STM706P; STM708T/S/R Figure 20. Output Voltage vs. Load Current (VCC = 5V; VBAT = 2.8V; TA = 25°C) 5.00 VOUT (V) 4.98 4.96 4.94 0 10 20 30 40 IOUT (mA) 50 AI10496 Figure 21. Output Voltage vs. Load Current (VCC = 0V; VBAT = 2.8V; TA = 25°C) 2.80 2.78 VOUT (V) 2.76 2.74 2.72 2.70 2.68 2.66 0.0 0.2 0.4 IOUT (mA) 14/26 0.6 0.8 1.0 AI10497 STM706T/S/R; STM706P; STM708T/S/R Figure 22. RST Output Voltage vs. Supply Voltage 5 5 VRST (V) 4 4 3 3 2 2 1 1 0 VCC (V) VRST VCC 0 500ms/div AI09149b Figure 23. RST Output Voltage vs. Supply Voltage 5 VRST VCC VRST (V) 4 4 3 3 2 2 1 1 VCC (V) 5 0 0 500ms/div AI09150b 15/26 STM706T/S/R; STM706P; STM708T/S/R Figure 24. Power-fail Comparator Response Time (Assertion) 5V 1V/div PFO 0V 1.3V PFI 500mV/div 0V 500ns/div AI09153b Figure 25. Power-fail Comparator Response Time (De-Assertion) 5V 1V/div PFO 0V 1.3V PFI 500mV/div 0V 500ns/div 16/26 AI09154b STM706T/S/R; STM706P; STM708T/S/R Figure 26. Maximum Transient Duration vs. Reset Threshold Overdrive 6000 Transient Duration (µs) 5000 4000 Reset occurs above the curve. 3000 2000 1000 0 0.001 0.01 0.1 1 10 Reset Comparator Overdrive, VRST – VCC (V) AI09156b 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 im- 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. Table 4. Absolute Maximum Ratings Symbol TSTG TSLD(1) Parameter Storage Temperature (VCC Off) Lead Solder Temperature for 10 seconds Value Unit –55 to 150 °C 260 °C –0.3 to VCC +0.3 V VIO Input or Output Voltage VCC Supply Voltage –0.3 to 7.0 V IO Output Current 20 mA PD Power Dissipation 320 mW 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). 17/26 STM706T/S/R; STM706P; STM708T/S/R 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 5, 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 5. Operating and AC Measurement Conditions Parameter STM70x Unit VCC Supply Voltage 1.0 to 5.5 V Ambient Operating Temperature (TA) –40 to 85 °C ≤5 ns Input Pulse Voltages 0.2 to 0.8VCC V Input and Output Timing Ref. Voltages 0.3 to 0.7VCC V Input Rise and Fall Times Figure 27. AC Testing Input/Output Waveforms 0.8VCC 0.7VCC 0.3VCC 0.2VCC AI02568 Figure 28. Power-fail Comparator Waveform VCC VRST trec PFO RST AI08860a 18/26 STM706T/S/R; STM706P; STM708T/S/R Figure 29. MR Timing Waveform MR tMLRL RST (1) tMLMH trec AI07837a Note: 1. RST for STM706P and STM708T/S/R. Figure 30. Watchdog Timing (STM706T/S/R and STM706P) VCC RST trec tWD WDI WDO AI08833 Table 6. DC and AC Characteristics Sym Alternative Description VCC Operating Voltage ICC VCC Supply Current Test Condition(1) Min Typ 1.2(2) Max Unit 5.5 V VCC < 3.6V 35 50 µA VCC < 5.5V 40 60 µA +1 µA Input Leakage Current (WDI) 0V = VIN = VCC –1 Input Leakage Current (PFI) 0V = VIN = VCC –25 2 +25 nA VRST (max) < VCC < 3.6V 25 80 250 µA 4.5V < VCC < 5.5V 75 125 300 µA 4.5V < VCC < 5.5V 2.0 V VRST (max) < VCC < 3.6V 0.7VCC V VRST (max) < VCC < 5.5V 0.7VCC V ILI Input Leakage Current (MR) VIH Input High Voltage (MR) VIH Input High Voltage (WDI) VIL Input Low Voltage (MR) VIL Input Low Voltage (WDI) 4.5V < VCC < 5.5V 0.8 V VRST (max) < VCC < 3.6V 0.6 V VRST (max) < VCC < 5.5V 0.3VCC V 19/26 STM706T/S/R; STM706P; STM708T/S/R Sym Alternative Test Condition(1) Description Min Typ Max Unit VOL Output Low Voltage (PFO, RST, RST, WDO) VCC = VRST (max), ISINK = 3.2mA 0.3 V V Output Low Voltage (RST) ISINK = 50µA, VCC = 1.0V, TA = 0°C to 85°C 0.3 VOL ISINK = 100µA, VCC = 1.2V 0.3 V Output High Voltage (RST, RST, WDO) ISOURCE = 1mA, VCC = VRST (max) 2.4 V Output High Voltage (PFO) ISOURCE = 75µA, VCC = VRST (max) 0.8VCC V PFI Falling (STM70xP/R, VCC = 3.0V; STM70xS/T, VCC = 3.3V) 1.20 VOH Power-fail Comparator VPFI PFI Input Threshold tPFD PFI to PFO Propagation Delay 1.25 1.30 2 V µs Reset Thresholds (3) VRST Reset Threshold STM706P/70xR 2.55 2.63 2.70 V STM70xS 2.85 2.93 3.00 V STM70xT 3.00 3.08 3.15 V Reset Threshold Hysteresis trec 20 RST Pulse Width 140 200 mV 280 ms Push-button Reset Input tMLMH tMLRL tMR tMRD VRST (max) < VCC < 3.6V 500 ns 4.5V < VCC < 5.5V 150 ns MR Pulse Width VRST (max) < VCC < 3.6V 750 ns 4.5V < VCC < 5.5V 250 ns 2.24 s MR to RST Output Delay Watchdog Timer (STM706T/S/R and STM706P) tWD STM706P/70xR, VCC = 3.0V Watchdog Timeout Period 1.12 1.60 STM70xS/70XT, VCC = 3.3V 4.5V < VCC < 5.5V 50 ns VRST (max) < VCC < 3.6V 100 ns WDI Pulse Width Note: 1. Valid for Ambient Operating Temperature: TA = –40 to 85°C; VCC = VRST (max) to 5.5V (except where noted). 2. VCC (min) = 1.0V for TA = 0°C to +85°C. 3. For VCC falling. 20/26 STM706T/S/R; STM706P; STM708T/S/R PACKAGE MECHANICAL Figure 31. SO8 – 8-lead Plastic Small Outline, 150 mils body width, Package Mechanical h x 45˚ A2 A C B ddd e D 8 E H 1 A1 α L SO-A Note: Drawing is not to scale. Table 7. SO8 – 8-lead Plastic Small Outline, 150 mils body width, Package Mechanical Data mm inches Symb Typ Min Max Typ Min Max A – 1.35 1.75 – 0.053 0.069 A1 – 0.10 0.25 – 0.004 0.010 B – 0.33 0.51 – 0.013 0.020 C – 0.19 0.25 – 0.007 0.010 D – 4.80 5.00 – 0.189 0.197 ddd – – 0.10 – – 0.004 E – 3.80 4.00 – 0.150 0.157 e 1.27 – – 0.050 – – H – 5.80 6.20 – 0.228 0.244 h – 0.25 0.50 – 0.010 0.020 L – 0.40 0.90 – 0.016 0.035 α – 0° 8° – 0° 8° N 8 8 21/26 STM706T/S/R; STM706P; STM708T/S/R Figure 32. TSSOP8 – 8-lead, Thin Shrink Small Outline, 3x3mm body size, Outline D 8 5 c E1 1 E 4 α A1 A L A2 L1 CP b e TSSOP8BM Note: Drawing is not to scale. Table 8. TSSOP8 – 8-lead, Thin Shrink Small Outline, 3x3mm body size, Mechanical Data mm inches Symb Typ Min Max Typ Min Max A – – 1.10 – – 0.043 A1 – 0.05 0.15 – 0.002 0.006 A2 0.85 0.75 0.95 0.034 0.030 0.037 b – 0.25 0.40 – 0.010 0.016 c – 0.13 0.23 – 0.005 0.009 CP – – 0.10 – – 0.004 D 3.00 2.90 3.10 0.118 0.114 0.122 e 0.65 – – 0.026 – – E 4.90 4.65 5.15 0.193 0.183 0.203 E1 3.00 2.90 3.10 0.118 0.114 0.122 L 0.55 0.40 0.70 0.022 0.016 0.030 L1 0.95 – – 0.037 – – α – 0° 6° – 0° 6° N 22/26 8 8 STM706T/S/R; STM706P; STM708T/S/R PART NUMBERING Table 9. Ordering Information Scheme Example: STM706 T M 6 E Device Type STM706 STM708 Reset Threshold Voltage T: 3.00V ≤ VRST ≤ 3.15V S: 2.88V ≤ VRST ≤ 3.00V R, STM706P: 2.59V ≤ VRST ≤ 2.70V Package M = SO8 DS = TSSOP8 Temperature Range 6 = –40 to 85°C Shipping Method E = Tubes F = Tape & Reel For other options, or for more information on any aspect of this device, please contact the ST Sales Office nearest you. 23/26 STM706T/S/R; STM706P; STM708T/S/R Table 10. Marking Description Part Number Reset Threshold STM706P 2.63V Package Topside Marking SO8 706P TSSOP8 SO8 STM706T 3.08V 706T TSSOP8 SO8 STM706S 2.93V 706S TSSOP8 SO8 STM706R 2.63V 706R TSSOP8 SO8 STM708T 3.08V 708T TSSOP8 SO8 STM708S 2.93V 708S TSSOP8 SO8 STM708R 2.63V 708R TSSOP8 24/26 STM706T/S/R; STM706P; STM708T/S/R REVISION HISTORY Table 11. Document Revision History Date Version Revision Details October 2003 1.0 First Issue 12-Dec-03 2.0 Reformatted; update characteristics (Figure 2, 3, 8, 9, 10, 28, 29, 30; Table 6, 7, 8, 9) 16-Jan-04 2.1 Add Typical Operating Characteristics (Figure 13, 14, 15, 16, 17, 18, 19, 22, 23, 24, 25, 26) 09-Apr-04 3.0 Reformatted; update characteristics (Figure 15, 19, 22, 23, 26; Table 6) 25-May-04 4.0 Update characteristics (Table 3, 6) 02-Jul-04 5.0 Datasheet promoted; waveform corrected (Figure 28) 21-Sep-04 6.0 Clarify root part numbers; (Figure 2, 3, 4, 5, 6, 7, 8, 9, 10, 30; Table 1, 3, 6, 9) 25-Feb-05 7.0 Update Typical Characteristics (Figure 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26) 25/26 STM706T/S/R; STM706P; STM708T/S/R 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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