MAX6316-MAX6322 5-Pin P Supervisory Circuits with Watchdog and Manual Reset General Description The MAX6316-MAX6322 family of microprocessor (P) supervisory circuits monitors power supplies and microprocessor activity in digital systems. It offers several combinations of push/pull, open-drain, and bidirectional (such as Motorola 68HC11) reset outputs, along with watchdog and manual reset features. The Selector Guide below lists the specific functions available from each device. These devices are available in 26 factory-trimmed reset threshold voltages (from 2.5V to 5V, in 100mV increments), featuring four minimum power-on reset timeout periods (from 1ms to 1.12s), and four watchdog timeout periods (from 6.3ms to 25.6s). Thirteen standard versions are available with an order increment requirement of 2500 pieces (see Standard Versions table); contact the factory for availability of other versions, which have an order increment requirement of 10,000 pieces. The MAX6316-MAX6322 are offered in a miniature 5-pin SOT23 package. PART MAX6316LUK____-T MAX6316LUK____/V+T MAX6316MUK____-T MAX6317HUK____-T MAX6318HUK____-T MAX6318MHUK____-T Portable Computers Computers Controllers Intelligent Instruments Portable/Battery-Powered Equipment Embedded Control Systems Typical Operating Circuit and Pin Configurations appears at end of data sheet. MAX6316L TEMP RANGE -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C PIN-PACKAGE 5 SOT23 5 SOT23 5 SOT23 5 SOT23 5 SOT23 5 SOT23 Devices are available in both leaded and lead(Pb)-free packaging. Specify lead-free by replacing "-T" with "+T" when ordering. /V Denotes an automotive-qualified part. Ordering Information appears at end of data sheet. Selector Guide PART Integrated Configuration Enables Flexible Designs * Available in 26 Reset-Threshold Voltages - 2.5V to 5V, in 100mV Increments * Four Reset Timeout Periods - 1ms, 20ms, 140ms, or 1.12s (min) * Four Watchdog Timeout Periods - 6.3ms, 102ms, 1.6s, or 25.6s (typ) * Four Reset Output Stages - Active-High, Push/Pull - Active-Low, Push/Pull - Active-Low, Open-Drain - Active-Low, Bidirectional Integrated Features Increase Robustness * Guaranteed Reset Valid to VCC = 1V * Immune to Short-Negative VCC Transients Saves Board Space * No External Components * Small 5-Pin SOT23 Package * AEC-Q100 Qualified Ordering Information Applications Benefits and Features RESET OUTPUTS* WATCHDOG INPUT MANUAL RESET INPUT ACTIVE-LOW PUSH/PULL ACTIVE-HIGH PUSH/PULL ACTIVE-LOW BIDIRECTIONAL ACTIVE-LOW OPEN-DRAIN -- -- -- -- -- -- -- -- MAX6316M -- MAX6317H MAX6318LH -- -- MAX6318MH -- -- MAX6319LH -- MAX6319MH -- MAX6320P -- -- -- -- MAX6321HP -- -- MAX6322HP -- -- -- -- -- *The MAX6318/MAX6319/MAX6321/MAX6322 feature two types of reset output on each device. 19-0496; Rev 13; 5/17 -- -- -- -- MAX6316-MAX6322 5-Pin P Supervisory Circuits with Watchdog and Manual Reset Absolute Maximum Ratings Voltage (with respect to GND) VCC.......................................................................-0.3V to +6V RESET (MAX6320/MAX6321/MAX6322 only).....-0.3V to +6V All Other Pins........................................ -0.3V to (VCC + 0.3V) Input/Output Current, All Pins..............................................20mA Continuous Power Dissipation (TA = +70C) SOT23 (derate 7.1mW/C above +70C).....................571mW Operating Temperature Range.......................... -40C to +125C Junction Temperature.......................................................+150C Storage Temperature Range............................. -65C to +160C Lead Temperature (soldering, 10s).................................. +300C Soldering Temperature (reflow) Leaded Package...........................................................+240C Lead-Free Package......................................................+260C Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Electrical Characteristics (VCC = 2.5V to 5.5V, TA = -40C to +125C, unless otherwise noted. Typical values are at TA = +25C.) (Note 1) PARAMETER Operating Voltage Range Supply Current Reset Threshold Temperature Coefficient Reset Threshold (Note 2) SYMBOL VCC ICC VCC to RESET Delay MIN VRST tRP tRD TYP 1.0 MAX UNITS 5.5 V MAX6316/MAX6317/MAX 6318/MAX6320/MAX6321 VCC = 5.5V 10 20 VCC = 3.6V 5 12 MAX6319/MAX6322: MR unconnected VCC = 5.5V 3 12 VCC = 3.6V 3 8 DVTH/C Reset Threshold Hysteresis Reset Active Timeout Period CONDITIONS TA = -40C to +125C 40 TA = +25C TA = -40C to +125C VTH - 1.5% VTH - 2.5% VTH VTH 3 ppm/C VTH + 1.5% VTH + 2.5% MAX63_ _ A_-T 1 1.4 2 MAX63_ _ B_-T 20 28 40 MAX63_ _ C_-T 140 200 280 MAX63_ _ D_-T 1120 1600 2240 VCC falling at 1mV/s A 40 V mV ms s PUSH/PULL RESET OUTPUT (MAX6316L/MAX6317H/MAX6318_H/MAX6319_H/MAX6321HP/MAX6322HP) RESET Output Voltage VOL VOH RESET Rise Time (MAX6316L, MAX6318LH, MAX6319LH) tR VOL RESET Output Voltage VOH VCC 1.0V, ISINK = 50A 0.3 VCC 2.7V, ISINK = 1.2mA 0.3 VCC 1.2V, ISINK = 100A 0.3 VCC 4.5V, ISINK = 3.2mA 0.4 VCC 2.7V, ISOURCE = 500A VCC 4.5V, ISOURCE = 800A 0.8 x VCC VCC - 1.5 Rise time is measured from 10% to 90% of VCC; CL = 5pF, VCC = 3.3V (Note 3) 5 VCC 2.7V, ISINK = 1.2mA VCC 4.5V, ISINK = 3.2mA 25 ns 0.3 0.4 VCC 1.8V, ISOURCE = 150A 0.8 x VCC VCC 4.5V, ISOURCE = 800A VCC - 1.5 VCC 2.7V, ISOURCE = 500A V V 0.8 x VCC Note 1: Overtemperature limits are guaranteed by design, not production tested. Note 2: A factory-trimmed voltage divider programs the nominal reset threshold (VTH). Factory-trimmed reset thresholds are available in 100mV increments from 2.5V to 5V (see Table 1 at end of data sheet). Note 3: Guaranteed by design. www.maximintegrated.com Maxim Integrated 2 MAX6316-MAX6322 5-Pin P Supervisory Circuits with Watchdog and Manual Reset Electrical Characteristics (continued) (VCC = 2.5V to 5.5V, TA = -40C to +125C, unless otherwise noted. Typical values are at TA = +25C.) (Note 1) PARAMETER SYMBOL Transitional Flip-Flop Setup Time tS CONDITIONS BIDIRECTIONAL RESET OUTPUT (MAX6316M/MAX6318MH/MAX6319MH) RESET Output Rise Time (Note 5) Active Pullup Enable Threshold RESET Active Pullup Current tR VPTH RESET Pullup Resistance (Note 4) Open-Drain Reset Output Leakage Current MAX 400 333 VCC = 3.0V, CL = 250pF 666 333 VCC = 5.0V, CL = 400pF 666 VCC = 5.0V 0.4 TA = -40C to +85C 4.2 4.7 5.2 3.6 4.7 5.8 VCC = 5.0V UNITS ns VCC = 5.0V, CL = 200pF TA = -40C to +125C VOL TYP VCC = 3.0V, CL = 120pF OPEN-DRAIN RESET OUTPUT (MAX6320P/MAX6321HP/MAX6322HP) RESET Output Voltage MIN ns 0.65 V 20 mA VCC > 1.0V, ISINK = 50A 0.3 VCC > 2.7V, ISINK = 1.2mA 0.3 VCC > 1.2V, ISINK = 100A 0.3 VCC > 4.5V, ISINK = 3.2mA 0.4 ILKG 1.0 k V A WATCHDOG INPUT (MAX6316/MAX6317H/MAX6318_H/MAX6320P/MAX6321HP) Watchdog Timeout Period WDI Pulse Width WDI Input Threshold WDI Input Current (Note 7) tWD tWDI VIL VIH IWDI MAX63_ _ _W-T 4.3 6.3 9.3 MAX63_ _ _X-T 71 102 153 MAX63_ _ _Y-T 1.12 1.6 2.4 MAX63_ _ _Z-T 17.9 25.6 38.4 VIL = 0.3 x VCC, VIH = 0.7 x VCC (Note 6) WDI = VCC, time average VWDI = 0V, time average 50 s ns 0.3 x VCC 120 -20 ms 0.7 x VCC 160 -15 V A MANUAL RESET INPUT (MAX6316_/MAX6317H/MAX6319_H/MAX6320P/MAX6322HP) VIL MR Input Threshold VIH VIL VIH MR Input Pulse Width MR Glitch Rejection VTH > 4.0V VTH < 4.0V TA = -40C to +85C TA = -40C to +125C MR Pullup Resistance MR to Reset Delay Note Note Note Note 4: 5: 6: 7: 0.8 2.0 0.3 x VCC VCC = 5V 0.7 x VCC 1 s 1.5 100 35 V 52 230 ns 75 k ns This is the minimum time RESET must be held low by an external pulldown source to set the active pullup flip-flop. Measured from RESET VOL to (0.8 x VCC), RLOAD = . WDI is internally serviced within the watchdog period if WDI is left unconnected. The WDI input current is specified as the average input current when the WDI input is driven high or low. The WDI input is designed for a three-stated-output device with a 10A maximum leakage current and capable of driving a maximum capacitive load of 200pF. The three-state device must be able to source and sink at least 200A when active. www.maximintegrated.com Maxim Integrated 3 MAX6316-MAX6322 5-Pin P Supervisory Circuits with Watchdog and Manual Reset Typical Operating Characteristics TA = +25C, unless otherwise noted.) 6 VCC = 3V 4 3 2 VCC = 1V 1 0 -40 -20 0 20 40 60 80 70 60 50 40 30 20 10 0 100 -40 -20 0 20 40 60 1.02 1.01 1.00 0.99 0.98 0.97 0.96 80 40 60 80 180 80 140 100 -40 -20 0 20 40 100 1.05 1.04 1.03 1.00 0.99 0.98 0.97 0.96 0.95 -40 -20 0 20 40 60 80 74HC05 PASSIVE 4.7k PULLUP 2V/div 4.7k 100pF VRST = 4.63V 40 VRST = 2.63V INPUT 30 74HC05 100pF 20 +5V VCC RESET MR GND 10 10 100 100 MAX6316toc07 +5V INPUT 50 100 1.01 MAX6316M/6318MH/6319MH BIDIRECTIONAL PULLUP CHARACTERISTICS VRST = 3.3V 80 1.02 MAXIMUM VCC TRANSIENT DURATION vs. RESET THRESHOLD OVERDRIVE RESET OCCURS ABOVE LINES 60 TEMPERATURE (C) TEMPERATURE (C) 60 0 MAX6316toc03 200 TEMPERATURE (C) 70 TRANSIENT DURATION (s) 20 NORMALIZED WATCHDOG TIMEOUT PERIOD MAX6316toc04 1.03 MAX6316toc06 NORMALIZED RESET TIMEOUT PERIOD 1.04 0 220 MAX6316/MAX6317/MAX6318/MAX6320/MAX6321 NORMALIZED WATCHDOG TIMEOUT PERIOD vs. TEMPERATURE 1.05 -20 240 TEMPERATURE (C) NORMALIZED RESET TIMEOUT PERIOD vs. TEMPERATURE -40 260 160 TEMPERATURE (C) 0.95 280 MAX6316toc05 5 80 VCC = 5V 300 PROPAGATION DELAY (ns) 7 VCC FALLING AT 1mV/s VRST - VCC = 100mV 90 320 MAX6316toc02 VCC = 5V 8 100 RESET PROPAGATION DELAY (s) SUPPLY CURRENT (A) 9 MAX6316toc01 10 MAX6316/MAX6317/MAX6319/MAX6320/MAX6322 MANUAL RESET TO RESET PROPAGATION DELAY vs. TEMPERATURE VCC FALLING TO RESET PROPAGATION DELAY vs. TEMPERATURE MAX6316/MAX6317/MAX6318/MAX6320/MAX6321 SUPPLY CURRENT vs. TEMPERATURE 1000 RESET, ACTIVE PULLUP 2V/div RESET INPUT 5V/div 200ns/div RESET THRESHOLD OVERDRIVE (mV) VRST - VCC www.maximintegrated.com Maxim Integrated 4 MAX6316-MAX6322 5-Pin P Supervisory Circuits with Watchdog and Manual Reset Pin Description PIN MAX6316L MAX6316M MAX6320P MAX6317H MAX6318LH MAX6318MH MAX6321HP MAX6319LH MAX6319MH MAX6322HP NAME FUNCTION MAX6316L/MAX6318LH/MAX6319LH: ActiveLow, Reset Output. CMOS push/pull output (sources and sinks current). 1 -- 1 1 RESET MAX6316M/MAX6318MH/MAX6319MH: Bidirectional, Active-Low, Reset Output. Intended to interface directly to microprocessors with bidirectional resets such as the Motorola 68HC11. MAX6320P/MAX6321HP/MAX6322HP: Open-Drain, Active-Low, Reset Output. NMOS output (sinks current only). Connect a pullup resistor from RESET to any supply voltage up to 6V. -- 1 3 3 RESET 2 2 2 2 GND 3 4 5 www.maximintegrated.com 3 4 5 -- 4 5 4 -- 5 Active-High, Reset Output. CMOS push/pull output (sources and sinks current). Inverse of RESET. Ground MR Active-Low, Manual Reset Input. Pull low to force a reset. Reset remains asserted for the duration of the Reset Timeout Period after MR transitions from low to high. Leave unconnected or connected to VCC if not used. WDI Watchdog Input. Triggers a reset if it remains either high or low for the duration of the watchdog timeout period. The internal watchdog timer clears whenever a reset asserts or whenever WDI sees a rising or falling edge. To disable the watchdog fea- ture, leave WDI unconnected or three-state the dri- ver connected to WDI. VCC Supply Voltage. Reset is asserted when VCC drops below the Reset Threshold Voltage (VRST). Reset remains asserted until VCC rises above VRST and for the duration of the Reset Timeout Period (tRP) once VCC rises above VRST. Maxim Integrated 5 MAX6316-MAX6322 5-Pin P Supervisory Circuits with Watchdog and Manual Reset VCC MAX6316-MAX6322 RESET (ALL EXCEPT MAX6317) RESET GENERATOR RESET (ALL EXCEPT MAX6316/MAX6320P) VCC 1.23V 52k MR (ALL EXCEPT MAX6318/MAX6321) WDI (ALL EXCEPT MAX6319/MAX6322) WATCHDOG TRANSITION DETECTOR WATCHDOG TIMER 52k GND Figure 1. Functional Diagram Detailed Description A microprocessor's (P) reset input starts or restarts the P in a known state. The reset output of the MAX6316- MAX6322 P supervisory circuits interfaces with the reset input of the P, preventing code-execution errors during power-up, power-down, and brownout conditions (see the Typical Operating Circuit). The MAX6316/ MAX6317/MAX6318/MAX6320/MAX6321 are also capable of asserting a reset should the P become stuck in an infinite loop. Reset Output The MAX6316L/MAX6318LH/MAX6319LH feature an active-low reset output, while the MAX6317H MAX6318_H/MAX6319_H/MAX6321HP/MAX6322HP feature an active-high reset output. RESET is guaranteed to be a logic low and RESET is guaranteed to be a logic high for VCC down to 1V. The MAX6316-MAX6322 assert reset when VCC is below the reset threshold (VRST), when MR is pulled low (MAX6316_/MAX6317H/MAX6319_H/MAX6320P/ MAX6322HP only), or if the WDI pin is not serviced www.maximintegrated.com within the watchdog timeout period (tWD). Reset remains asserted for the specified reset active timeout period (tRP) after VCC rises above the reset threshold, after MR transitions low to high, or after the watchdog timer asserts the reset (MAX6316_/MAX6317H/MAX6318_H/MAX6320P/ MAX6321HP). After the reset active timeout period (tRP) expires, the reset output deasserts, and the watchdog timer restarts from zero (Figure 2). VCC 1V VRST VRST 1V GND RESET tRP tRD RESET tRP tRD GND Figure 2. Reset Timing Diagram Maxim Integrated 6 MAX6316-MAX6322 5-Pin P Supervisory Circuits with Watchdog and Manual Reset Bidirectional RESET Output The MAX6316M/MAX6318MH/MAX6319MH are designed to interface with Ps that have bidirectional reset pins, such as the Motorola 68HC11. Like an opendrain output, these devices allow the P or other devices to pull the bidirectional reset (RESET) low and assert a reset condition. However, unlike a standard open-drain output, it includes the commonly specified 4.7k pullup resistor with a P-channel active pullup in parallel. This configuration allows the MAX6316M/MAX6318MH/ MAX6319MH to solve a problem associated with Ps that have bidirectional reset pins in systems where several devices connect to RESET (Figure 3). These Ps can often determine if a reset was asserted by an external device (i.e., the supervisor IC) or by the P itself (due to a watchdog fault, clock error, or other source), and then jump to a vector appropriate for the source of the reset. However, if the P does assert reset, it does not retain the information, but must determine the cause after the reset has occurred. The following procedure describes how this is done in the Motorola 68HC11. In all cases of reset, the P pulls RESET low for about four external-clock cycles. It then releases RESET, waits for two external-clock cycles, then checks RESET's state. If RESET is still low, the P concludes that the source of the reset was external and, when RESET eventually reaches the high state, it jumps to the normal reset vector. In this case, stored-state information is erased and processing begins from scratch. If, on the other hand, RESET is high after a delay of two externalclock cycles, the processor knows that it caused the reset itself and can jump to a different vector and use storedstate information to determine what caused the reset. A problem occurs with faster Ps; two external-clock cycles are only 500ns at 4MHz. When there are several devices on the reset line, and only a passive pullup resistor is used, the input capacitance and stray capacitance can prevent RESET from reaching the logic high state (0.85 x VCC) in the time allowed. If this happens, all resets will be interpreted as external. The P output stage is guaranteed to sink 1.6mA, so the rise time can not be reduced considerably by decreasing the 4.7k internal pullup resistance. See Bidirectional Pullup Characteristics in the Typical Operating Characteristics. The MAX6316M/MAX6318MH/MAX6319MH overcome this problem with an active pullup FET in parallel with the 4.7k resistor (Figures 4 and 5). The pullup transistor holds RESET high until the P reset I/O or the supervisory circuit itself forces the line low. Once RESET goes below VPTH, a comparator sets the transition edge flipflop, indicating that the next transition for RESET will be low to high. When RESET is released, the 4.7k resistor pulls RESET up toward VCC. Once RESET rises above VPTH but is below (0.85 x VCC), the active P-channel pullup turns on. Once RESET rises above (0.85 x VCC) or the 2s one-shot times out, the active pullup turns off. The parallel combination of the 4.7k pullup and the VCC VCC WDI* MR** 68HC11 4.7k RESET CIRCUITRY RESET RESET RESET*** CIN MAX6316M MAX6318MH MAX6319MH * MAX6316M/MAX6318MH ** MAX6316M/MAX6319MH *** ACTIVE-HIGH PUSH/PULL MAX6318MH/MAX6319MH CIN CSTRAY RESET CIRCUITRY RESET CIN OTHER DEVICES Figure 3. MAX6316M/MAX6318MH/MAX6319MH Supports Additional Devices on the Reset Bus www.maximintegrated.com Maxim Integrated 7 MAX6316-MAX6322 5-Pin P Supervisory Circuits with Watchdog and Manual Reset VCC MAX6316M MAX6318MH MAX6319MH LASERTRIMMED RESISTORS VCC VREF 52k MR RESET GENERATOR WATCHDOG ON 2s ONE SHOT CIRCUITRY WDI (MAX6316M/ MAX6319MH) (MAX6316M/ MAX6318MH) VCC 2s ONE SHOT TRANSITION FLIP-FLOP R Q 4.7k FF S RESET ACTIVE PULLUP ENABLE COMPARATOR 0.65V 0.85VCC GND Figure 4. MAX6316/MAX6318MH/MAX6319MH Bidirectional Reset Output Functional Diagram www.maximintegrated.com Maxim Integrated 8 MAX6316-MAX6322 5-Pin P Supervisory Circuits with Watchdog and Manual Reset P-channel transistor on-resistance quickly charges stray capacitance on the reset line, allowing RESET to transition from low to high within the required two electronicclock cycles, even with several devices on the reset line. This process occurs regardless of whether the reset was caused by VCC dipping below the reset threshold, the watchdog timing out, MR being asserted, or the P or other device asserting RESET. The parts do not require an external pullup. To minimize supply current consumption, the internal 4.7k pullup resistor disconnects from the supply whenever the MAX6316M/MAX6318MH/ MAX6319MH assert reset. Open-Drain RESET Output The MAX6320P/MAX6321HP/MAX6322HP have an active-low, open-drain reset output. This output structure will sink current when RESET is asserted. Connect a pullup resistor from RESET to any supply voltage up to 6V (Figure 6). Select a resistor value large enough to regis- VCC tRP OR C RESET DELAY RESET 0.7V 0.8 x VCC tR tS RESET PULLED LOW BY C OR RESET GENERATOR ACTIVE PULLUP TURNS ON Figure 5. Bidirectional RESET Timing Diagram +3.3V MR* +5.0V 10k RESET 5V SYSTEM RESET*** MAX6320 MAX6321 MAX6322 GND * MAX6320/MAX6322 ** MAX6320/MAX6321 *** MAX6321/MAX6322 Figure 6. MAX6320P/MAX6321HP/MAX6322HP Open-Drain RESET Output Allows Use with Multiple Supplies www.maximintegrated.com Manual-Reset Input The MAX6316_/MAX6317H/MAX6319_H/MAX6320P/ MAX6322HP feature a manual reset input. A logic low on MR asserts a reset. After MR transitions low to high, reset remains asserted for the duration of the reset timeout period (tRP). The MR input is connected to VCC through an internal 52k pullup resistor and therefore can be left unconnected when not in use. MR can be driven with TTL-logic levels in 5V systems, with CMOS-logic levels in 3V systems, or with open-drain or open-collector output devices. A normally-open momentary switch from MR to ground can also be used; it requires no external debouncing circuitry. MR is designed to reject fast, negative-going transients (typically 100ns pulses). A 0.1F capacitor from MR to ground provides additional noise immunity. The MR input pin is equipped with internal ESD-protection circuitry that may become forward biased. Should MR be driven by voltages higher than VCC, excessive current would be drawn, which would damage the part. For example, assume that MR is driven by a +5V supply other than VCC. If VCC drops lower than +4.7V, MR's absolute maximum rating is violated [-0.3V to (VCC + 0.3V)], and undesirable current flows through the ESD structure from MR to VCC. To avoid this, use the same supply for MR as the supply monitored by VCC. This guarantees that the voltage at MR will never exceed VCC. Watchdog Input VCC WDI** ter a logic low (see Electrical Characteristics), and small enough to register a logic high while supplying all input current and leakage paths connected to the RESET line. A 10k pullup is sufficient in most applications. The MAX6316_/MAX6317H/MAX6318_H/MAX6320P/ MAX6321HP feature a watchdog circuit that monitors the P's activity. If the P does not toggle the watchdog input (WDI) within the watchdog timeout period (tWD), reset asserts. The internal watchdog timer is cleared by reset or by a transition at WDI (which can detect pulses as short as 50ns). The watchdog timer remains cleared while reset is asserted. Once reset is released, the timer begins counting again (Figure 7). The WDI input is designed for a three-stated output device with a 10A maximum leakage current and the capability of driving a maximum capacitive load of 200pF. The three-state device must be able to source and sink at least 200A when active. Disable the watchdog function by leaving WDI unconnected or by three-stating the driver connected to WDI. When the watchdog timer is left open circuited, the timer is cleared internally at intervals equal to 7/8 of the watchdog period. Maxim Integrated 9 MAX6316-MAX6322 VCC RESET 5-Pin P Supervisory Circuits with Watchdog and Manual Reset tRST tRP tWD VCC MAX6316 MAX6318 MAX6319 tRP VCC WDI RESET GND 100k MAX6316/MAX6317 MAX6318/MAX6320 MAX6321 Figure 7. Watchdog Timing Relationship Figure 8. Ensuring RESET Valid to VCC = 0V on Active-Low Push/Pull and Bidirectional Outputs Applications Information Watchdog Input Current The WDI input is internally driven through a buffer and series resistor from the watchdog counter. For minimum watchdog input current (minimum overall power consumption), leave WDI low for the majority of the watchdog timeout period. When high, WDI can draw as much as 160A. Pulsing WDI high at a low duty cycle will reduce the effect of the large input current. When WDI is left unconnected, the watchdog timer is serviced within the watchdog timeout period by a low-high-low pulse from the counter chain. Negative-Going VCC Transients These supervisors are immune to short-duration, negativegoing VCC transients (glitches), which usually do not require the entire system to shut down. Typically, 200ns largeamplitude pulses (from ground to VCC) on the supply will not cause a reset. Lower amplitude pulses result in greater immunity. Typically, a VCC transient that goes 100mV under the reset threshold and lasts less than 4s will not trigger a reset. An optional 0.1F bypass capacitor mounted close to VCC provides additional transient immunity. Ensuring Valid Reset Outputs Down to VCC = 0V The MAX6316_/MAX6317H/MAX6318_H/MAX6319_H/ MAX6321HP/MAX6322HP are guaranteed to operate properly down to VCC = 1V. In applications that require valid reset levels down to VCC = 0V, a pulldown resistor to active-low outputs (push/pull and bidirectional only, Figure 8) and a pullup resistor to active-high outputs (push/pull only, Figure 9) will ensure that the reset line is valid while the reset output can no longer sink or source current. This www.maximintegrated.com MAX6317 MAX6318 MAX6319 MAX6321* MAX6322* GND VCC VCC 100k RESET *THIS SCHEMATIC DOES NOT WORK ON THE OPEN-DRAIN OUTPUTS OF THE MAX6321/MAX6322. Figure 9. Ensuring RESET Valid to VCC = 0V on Active-High Push/Pull Outputs scheme does not work with the open-drain outputs of the MAX6320/MAX6321/MAX6322. The resistor value used is not critical, but it must be large enough not to load the reset output when VCC is above the reset threshold. For most applications, 100k is adequate. Watchdog Software Considerations (MAX6316/MAX6317/MAX6318/ MAX6320/MAX6321) One way to help the watchdog timer monitor software execution more closely is to set and reset the watchdog input at different points in the program, rather than pulsing the watchdog input high-low-high or low-high-low. This technique avoids a stuck loop, in which the watchdog timer would continue to be reset inside the loop, keeping the watchdog from timing out. Maxim Integrated 10 MAX6316-MAX6322 5-Pin P Supervisory Circuits with Watchdog and Manual Reset Figure 10 shows an example of a flow diagram where the I/O driving the watchdog input is set high at the beginning of the program, set low at the end of every subroutine or loop, then set high again when the program returns to the beginning. If the program should hang in any subroutine, the problem would be quickly corrected, since the I/O is continually set low and the watchdog timer is allowed to time out, causing a reset or interrupt to be issued. As described in the Watchdog Input Current section, this scheme results in higher time average WDI current than does leaving WDI low for the majority of the timeout period and periodically pulsing it low-high-low. START SET WDI HIGH PROGRAM CODE POSSIBLE INFINITE LOOP PATH SUBROUTINE OR PROGRAM LOOP SET WDI LOW RETURN Figure 10. Watchdog Flow Diagram Pin Configurations Typical Operating Circuit TOP VIEW VIN RESET 1 GND 2 5 VCC MAX6316 MAX6320 MR 3 RESET 1 GND 2 4 WDI GND 2 5 VCC MAX6318 MAX6321 RESET 3 RESET MAX6316 4 WDI MANUAL RESET MR GND WDI P I/O GND SOT23 SOT23 RESET 1 RESET MAX6317 MR 3 VCC VCC 5 VCC RESET 1 GND 2 4 WDI SOT23 www.maximintegrated.com 5 VCC MAX6319 MAX6322 RESET 3 4 MR SOT23 Maxim Integrated 11 MAX6316-MAX6322 5-Pin P Supervisory Circuits with Watchdog and Manual Reset Table 1. Factory-Trimmed Reset Thresholds PART MIN TA = +25C TA = -40C to +125C TYP MAX MIN MAX MAX63___50_ _-T 4.925 5.000 5.075 4.875 5.125 MAX63___49_ _-T 7.827 4.900 4.974 4.778 5.023 MAX63___48_ _-T 4.728 4.800 4.872 4.680 4.920 MAX63___47_ _-T 4.630 4.700 4.771 4.583 4.818 MAX63___46_ _-T 4.561 4.630 4.699 4.514 4.746 MAX63___45_ _-T 4.433 4.500 4.568 4.388 4.613 MAX63___44_ _-T 4.314 4.390 4.446 4.270 4.490 MAX63___43_ _-T 4.236 4.300 4.365 4.193 4.408 MAX63___42_ _-T 4.137 4.200 4.263 4.095 4.305 MAX63___41_ _-T 4.039 4.100 4.162 3.998 4.203 MAX63___40_ _-T 3.940 4.000 4.060 3.900 4.100 MAX63___39_ _-T 3.842 3.900 3.959 3.803 3.998 MAX63___38_ _-T 3.743 3.800 3.857 3.705 3.895 MAX63___37_ _-T 3.645 3.700 3.756 3.608 3.793 MAX63___36_ _-T 3.546 3.600 3.654 3.510 3.690 MAX63___35_ _-T 3.448 3.500 3.553 3.413 3.588 MAX63___34_ _-T 3.349 3.400 3.451 3.315 3.485 MAX63___33_ _-T 3.251 3.300 3.350 3.218 3.383 MAX63___32_ _-T 3.152 3.200 3.248 3.120 3.280 MAX63___31_ _-T 3.034 3.080 3.126 3.003 3.157 MAX63___30_ _-T 2.955 3.000 3.045 2.925 3.075 MAX63___29_ _-T 2.886 2.930 2.974 2.857 3.000 MAX63___28_ _-T 2.758 2.800 2.842 2.730 2.870 MAX63___27_ _-T 2.660 2.700 2.741 2.633 2.768 MAX63___26_ _-T 2.591 2.630 2.669 2.564 2.696 MAX63___25_ _-T 2.463 2.500 2.538 2.438 2.563 Table 2. Standard Versions RESET THRESHOLD (V) MINIMUM RESET TIMEOUT (ms) TYPICAL WATCHDOG TIMEOUTS (s) MAX6316LUK29CY-T 2.93 140 1.6 ACDE MAX6316LUK46CY-T 4.63 140 1.6 ACDD MAX6316MUK29CY-T 2.93 140 1.6 ACDG MAX6316MUK46CY-T 4.63 140 1.6 ACDF MAX6317HUK46CY-T 4.63 140 1.6 ACDQ MAX6318LHUK46CY-T 4.63 140 1.6 ACDH MAX6318MHUK46CY-T 4.63 140 1.6 ACDJ MAX6319LHUK46C-T 4.63 140 -- ACDK MAX6319MHUK46C-T 4.63 140 -- ACDM PART www.maximintegrated.com SOT TOP MARK Maxim Integrated 12 MAX6316-MAX6322 5-Pin P Supervisory Circuits with Watchdog and Manual Reset Table 2. Standard Versions (continued) RESET THRESHOLD (V) MINIMUM RESET TIMEOUT (ms) TYPICAL WATCHDOG TIMEOUTS (s) SOT TOP MARK MAX6320PUK29CY-T 2.93 140 1.6 ACDO MAX6320PUK46CY-T 4.63 140 1.6 ACDN MAX6321HPUK46CY-T 4.63 140 1.6 ACGL MAX6322HPUK46C-T 4.63 140 1.6 ACGN PART Note: Thirteen standard versions are available, with a required order increment of 2500 pieces. Sample stock is generally held on standard versions only. The required order increment for nonstandard versions is 10,000 pieces. Contact factory for availability. Table 3. Reset/Watchdog Timeout Periods RESET TIMEOUT PERIODS SUFFIX MIN TYP MAX A 1 1.6 2 B 20 30 40 C 140 200 280 D 1.12 1.60 2.24 W 4.3 6.3 9.3 X 71 102 153 Y 1.12 1.6 2.4 Z 17.9 25.6 38.4 UNITS ms s WATCHDOG TIMEOUT Chip Information ms s SUBSTRATE IS INTERNALLY CONNECTED TO V+ Ordering Information (continued) PART MAX6319LHUK___-T MAX6319MHUK___-T MAX6320PUK____-T MAX6320PUK____/V+T MAX6321HPUK___-T MAX6322HPUK___-T TEMP RANGE -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C PIN-PACKAGE 5 SOT23 5 SOT23 5 SOT23 5 SOT23 5 SOT23 5 SOT23 Devices are available in both leaded and lead(Pb)-free packaging. Specify lead-free by replacing "-T" with "+T" when ordering. /V Denotes an automotive-qualified part. Note: These devices are available with factory-set VCC reset thresholds from 2.5V to 5V, in 0.1V increments. Insert the desired nominal reset threshold (25 to 50, from Table 1) into the blanks following the letters UK. All devices offer factory-programmed reset timeout periods. Insert the letter corresponding to the desired reset timeout period (A, B, C, or D from Table 3) into the blank following the reset threshold suffix. Parts that offer a watchdog feature (see Selector Guide) are factory-trimmed to one of four watchdog timeout periods. Insert the letter corresponding to the desired watchdog timeout period (W, X, Y, or Z from Table 3) into the blank following the reset timeout suffix. Package Information For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages. Note that a "+", "#", or "-" in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. www.maximintegrated.com PACKAGE TYPE PACKAGE CODE OUTLINE NO. LAND PATTERN NO. 5 SOT23 U5+2 21-0057 90-0174 Maxim Integrated 13 MAX6316-MAX6322 5-Pin P Supervisory Circuits with Watchdog and Manual Reset Revision History REVISION NUMBER REVISION DATE PAGES CHANGED 0 1/98 Initial release. 1 4/98 Update to show MAX6319 as an existing part. 1, 2, 12 2 7/98 Update specifications, Selector Guide, and Table 2. 1, 12, 14 3 1/99 Include extended temperature range in EC table globals, Table 1, Ordering Information. 4 11/99 Update available products and versions in Table 2 and Ordering Information. 1, 12, 14 5 9/02 Addition of RESET rise time specification to Electrical Characteristics table. 1, 2 6 12/05 Add lead-free option to Ordering Information. 7 11/07 Add automotive temperature to Ordering Information, Electrical Characteristics table, Table 1, and updated Package Information. 8 8/09 Updated Ordering Information. DESCRIPTION -- 1, 2, 3, 12, 13, 14 1, 13, 14 1, 2, 3, 12, 13, 14 13 9 6/10 Added automotive part and soldering temperatures. 10 10/11 Added automotive-qualified part ordering option for MAX6316 family 2, 13 1 11 2/13 Changed /V-T suffix to /V+T in Ordering Information 1 12 4/15 Updated the General Description and Benefits and Features sections 1 13 5/17 Added AEC-Q100 qualification 1 Corrected typo 1 13.1 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated's website at www.maximintegrated.com. Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits) shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance. Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc. (c) 2017 Maxim Integrated Products, Inc. 14 Mouser Electronics Authorized Distributor Click to View Pricing, Inventory, Delivery & Lifecycle Information: Maxim Integrated: MAX6320PUK29CY+T MAX6320PUK46CY+T MAX6316LUK25AY+T MAX6316LUK26CY+T MAX6316LUK26DY+T MAX6316LUK29AX+T MAX6316LUK29BX+T MAX6316LUK29BX/V+T MAX6316LUK29BY+T MAX6316LUK29CX+T MAX6316LUK29CY+T MAX6316LUK29DY+T MAX6316LUK45BX+T MAX6316LUK45CX+T MAX6316LUK45CY+T MAX6316LUK46BY+T MAX6316LUK46CX+T MAX6316LUK46CY+T MAX6316MUK29CY+T MAX6316MUK31CY+T MAX6316MUK46AY+T MAX6316MUK46BY+T MAX6316MUK46CY+T MAX6317HUK46CY+T MAX6318LHUK27CY+T MAX6318LHUK30CZ+T MAX6318LHUK33CY+T MAX6318LHUK46AX+T MAX6318LHUK46BX+T MAX6318LHUK46CY+T MAX6318LHUK49BX+T MAX6318MHUK29CY+T MAX6319LHUK29B+T MAX6319LHUK31A+T MAX6319LHUK46C+T MAX6319MHUK46C+T MAX6320PUK29DY+T MAX6320PUK33BX+T MAX6320PUK45CY+T MAX6321HPUK25BZ+T MAX6321HPUK46CY+T MAX6322HPUK29C+T MAX6322HPUK46C+T MAX6320PUK29CX+T MAX6320PUK46BY+T MAX6302ESA+ MAX6316LUK46CZ+T MAX6316LUK47CZ+T MAX9317AECJ+ MAX6320PUK31BX/V+T MAX6320PUK43CY/V+T MAX6320PUK46BY/V+T MAX6320PUK30BY+T MAX6322HPUK29A+T MAX6316LUK31BX/V+T