19-1508; Rev 1; 10/99 Dual/Triple-Voltage µP Supervisory Circuits The MAX6351 features both 3V and 5V active-low pushpull reset outputs. The MAX6353/MAX6356/MAX6359 offer a 5V active-low push-pull reset. The MAX6354/ MAX6357/MAX6360 offer a 3V active-low push-pull reset. The MAX6352/MAX6355/MAX6358’s reset is active-low open-drain. All of these devices are offered with a wide variety of voltage threshold levels, as shown in the Voltage Threshold Levels table below. They are available in 5and 6-pin SOT23 packages and operate over the extended (-40°C to +85°C) temperature range. Features ♦ Precision Monitoring of Multiple +2.5V, +3.0V, +3.3V, and +5V Power-Supply Voltages ♦ Precision Factory-Set Power-Supply Reset Thresholds ♦ 20µA Supply Current ♦ 100ms min Power-On Reset Pulse Width ♦ Fully Guaranteed Over Temperature ♦ Guaranteed RESET Valid to VCC5 = 1V or VCC3 = 1V ♦ Power-Supply Transient Immunity ♦ No External Components for Dual-Voltage Systems ♦ Small 5- and 6-Pin SOT23 Packages ♦ Debounced TTL/CMOS-Compatible Manual-Reset Input ♦ Watchdog Timer 46.4sec Start-Up Timeout 2.9sec Normal Timeout ♦ Low Cost Applications Computers Controllers Portable/Battery-Powered Equipment Intelligent Instruments Multivoltage Systems __________Voltage Threshold Levels PART NO. SUFFIX (_ _) VCC5 NOMINAL VOLTAGE THRESHOLD (V) VCC3 NOMINAL VOLTAGE THRESHOLD (V) LT 4.63 3.08 LS 4.63 2.93 LR 4.63 2.63 MT 4.38 3.08 MS 4.38 2.93 MR 4.38 2.63 TY 3.08 2.19 SY 2.93 2.19 Note: Standard versions are shown in bold and have a required order increment of 2500 pieces. Sample stock is generally held on the standard versions only. The required order increment for nonstandard versions is 10,000 pieces. Contact factory for availability. Ordering Information PART* TEMP. RANGE PIN-PACKAGE MAX6351_ _UT-T -40°C to +85°C 6 SOT23-6 MAX6352_ _UK-T MAX6353_ _UK-T MAX6354_ _UK-T -40°C to +85°C -40°C to +85°C -40°C to +85°C 5 SOT23-5 5 SOT23-5 5 SOT23-5 MAX6355_ _UT-T MAX6356_ _UT-T MAX6357_ _UT-T -40°C to +85°C -40°C to +85°C -40°C to +85°C 6 SOT23-6 6 SOT23-6 6 SOT23-6 MAX6358_ _UT-T MAX6359_ _UT-T MAX6360_ _UT-T -40°C to +85°C -40°C to +85°C -40°C to +85°C 6 SOT23-6 6 SOT23-6 6 SOT23-6 *The _ _ are placeholders for the threshold voltage levels of the devices. Substitute the part number suffix in the Voltage Threshold Levels table for the desired voltage level. There are two standard versions for each of the above part numbers. All devices are available in tape-and-reel only. Pin Configurations appear at end of data sheet. Selector Guide appears at end of data sheet. ________________________________________________________________ Maxim Integrated Products 1 For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800. For small orders, phone 1-800-835-8769. MAX6351–MAX6360 General Description The MAX6351–MAX6360 microprocessor (µP) supervisors with multiple reset voltages significantly improve system reliability and accuracy compared to separate ICs or discrete components. If any input supply voltage drops below its associated preset threshold, all reset outputs are asserted. In addition, the output(s) is valid as long as either input supply voltage remains greater than +1.0V. All devices in this series have an active-low debounced manual reset input. In addition, the MAX6358/MAX6359/ MAX6360 offer a watchdog timer input with a 46.4sec start-up timeout period and a 2.9sec timeout period. The MAX6355/MAX6356/MAX6357 offer an additional voltage monitor input to monitor a third voltage. MAX6351–MAX6360 Dual/Triple-Voltage µP Supervisory Circuits ABSOLUTE MAXIMUM RATINGS VCC5, VCC3 to GND .................................................-0.3V to +6V RST (MAX6352/55/58) ............................................. -0.3V to +6V RST, MR, WDI, RST5, RSTIN (MAX6351/53/56/59).............................-0.3V to (VCC5 + 0.3V) RST, RST3 (MAX6351/54/57/60) .................-3V to (VCC3 + 0.3V) Input/Output Current, All Pins .............................................20mA Continuous Power Dissipation (TA = +70°C) 5-Pin SOT23-5 (derate 7.1mW/°C above +70°C) ........571mW 6-Pin SOT23-6 (derate 7.1mW/°C above +70°C) ........571mW Operating Temperature Range ...........................-40°C to +85°C Storage Temperature Range .............................-65°C to +150°C Lead Temperature (soldering, 10sec) .............................+300°C 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 (VCC3 = VCC5 = +1.2V to +5.5V, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER Supply Voltage Range (Note 2) Supply Current SYMBOL VCC ICC5 + ICC3 CONDITIONS TA = -40°C to +85°C 1.2 5.5 20 VCC5 = 5.5V, VCC3 = 3.6V, all I/O pins open VTH5 MAX63_ _T_ MAX63_ _S_ MAX63_ _ _T MAX63_ _ _S VTH3 MAX63_ _ _R MAX63_ _ _Y Reset Threshold Tempco TA = +25°C 4.54 TA = -40°C to +85°C 4.5 TA = +25°C 4.3 TA = -40°C to +85°C 4.25 TA = +25°C 3.03 TA = -40°C to +85°C 3.00 TA = +25°C 2.88 TA = -40°C to +85°C 2.85 TA = +25°C 3.03 TA = -40°C to +85°C 3.00 TA = +25°C 2.88 TA = -40°C to +85°C 2.85 TA = +25°C 2.58 TA = -40°C to +85°C 2.55 TA = +25°C 2.16 TA = -40°C to +85°C 2.13 ∆VTH/°C Reset Timeout Period RESET Output Voltage Low 2 100mV overdrive tRP VOL 4.63 50 VCC5 > VTH5(MAX), VCC3 > VTH3(MAX) 100 UNITS V µA 4.72 4.75 4.38 4.46 3.08 3.14 4.50 V 3.15 2.93 2.98 3.00 3.08 3.14 3.15 2.93 2.98 2.63 2.68 2.19 2.22 3.00 V 2.70 2.25 20 Reset Threshold Hysteresis VCC to Reset Delay MAX 5.5 MAX63_ _M_ VCC3 Threshold (Note 3) TYP 1.0 MAX63_ _L_ VCC5 Threshold (Note 3) MIN TA = 0°C to +70°C ppm/°C VTH/500 V 20 µs 180 280 VCC5 or VCC3 ≥ 2.7V, ISINK = 1.2mA 0.3 VCC5 or VCC3 ≥ 4.5V, ISINK = 3.2mA 0.4 VCC5 or VCC3 < 1V, ISINK = 50µA, TA = 0°C to +70°C 0.3 VCC5 or VCC3 < 1.2V, ISINK = 50µA 0.3 _______________________________________________________________________________________ ms V V Dual/Triple-Voltage µP Supervisory Circuits (VCC3 = VCC5 = +1.2V to +5.5V, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER SYMBOL CONDITIONS MAX6351/MAX6353/ MAX6354/MAX6356/ MAX6357/MAX6359/ MAX6360 (_Y versions only), VCC5 > VTH5(MAX), VCC3 > VTH3(MAX) RESET Output Voltage High ISOURCE = 500µA MIN TYP MAX UNITS 0.8VCC VOH V MAX6351/MAX6353/ MAX6354/MAX6356/ MAX6357/MAX6359/ MAX6360 ISOURCE = 800µA (L_, M_ versions only), VCC5 > VTH5(MAX), VCC3 > VTH3(MAX) VCC - 1.5 WATCHDOG INPUT (MAX6358/MAX6359/MAX6360) Watchdog Timeout Period tWD WDI Pulse Width (Note 4) tWDI WDI Input Threshold (Note 5) VIL VIH First timeout period after reset 25.6 46.4 72.0 After first WDI falling edge 1.6 2.9 4.5 VIL = 0.4V, VIH = 0.8VCC 50 0.7VCC 120 VWDI = VCC WDI Input Current (Note 6) ns 0.3VCC VCC3 = 5V VWDI = 0 -20 0.8 sec 160 -15 V µA MANUAL RESET INPUT MR Input VIL MAX63_ _L_, MAX63_ _M_, VCC5 > VTH5(MAX) VIH MAX63_ _L_, MAX63_ _M_, VCC5 > VTH5(MAX) VIL MAX63_ _ _Y, VCC5 > VTH5(MAX) VIH MAX63_ _ _Y, VCC5 > VTH5(MAX) MR Pull-Up Resistance MR Minimum Pulse Width 2.3 0.3VCC 0.7VCC 32 MR Glitch Rejection MR to Reset Delay 63.5 100 10 tRP V tMD kΩ µs 100 ns 0.1 µs ADJUSTABLE RESET COMPARATOR INPUT (MAX6355/MAX6356/MAX6357) TA = +25°C 1.20 TA = -40°C to +85°C 1.19 RSTIN Input Threshold VRSTIN VCC5 > VTH5(MAX), VCC3 > VTH3(MAX) RSTIN Input Current IRSTIN 0 < VRISTIN < VCC5 - 0.3V RSTIN Hysteresis 1.22 1.24 1.25 -25 25 2.5 V nA mV Note 1: Overtemperature limits are guaranteed by design and not production tested. Note 2: The reset output is guaranteed to be in the correct state if either VCC3 or VCC5 is within its specified region of operation. Note 3: The reset output(s) is asserted if either VCC5 or VCC3 drops below its associated trip point. Note 4: Guaranteed by design. Not production tested. Note 5: WDI is internally serviced within the watchdog timeout period if WDI is left unconnected. Note 6: The WDI input current is specified as the average input current when the WDI input is driven high or low. _______________________________________________________________________________________ 3 MAX6351–MAX6360 ELECTRICAL CHARACTERISTICS (continued) Typical Operating Characteristics (VCC = +5V, TA = +25°C, unless otherwise noted.) RESET vs. VCC5 (VCC3 = 3V) 4.0 15 5.0 MAX6351/60-02 MAX6351/60-01 4.5 4.0 ICC3 (VCC5 = 5.0V, VCC3 = 3.3V) 5 ICC3 (VCC5 = 3.3V, VCC3 = 2.5V) 3.0 VTH 2.5 2.0 -40 -15 10 35 60 2.5 1.5 1.0 0.5 0.5 0 0 85 MAX6351 MAX6360 2.0 1.0 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 TEMPERATURE (°C) VCC5 (V) VCC5 (V) NORMALIZED RESET/WATCHDOG PERIOD vs. TEMPERATURE MAXIMUM VCC TRANSIENT DURATION vs. RESET THRESHOLD OVERDRIVE RESET DELAY vs. RESET THRESHOLD OVERDRIVE 1.05 1.00 0.95 0.90 250 200 150 100 200 150 100 DELAY FROM FALL OF VCC3 50 50 0.85 MAX6351/60-06 RESET OCCURS ABOVE LINE RESET DELAY (µs) 1.10 250 MAX6351/60-05 1.15 300 TRANSIENT DURATION (µs) MAX6351/60-04 1.20 DELAY FROM FALL OF VCC5 0 0 0.80 -60 -40 -20 0 20 40 60 80 0.01 100 0.1 1 RESET THRESHOLD OVERDRIVE, VRST - VCC (V) TEMPERATURE (°C) 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 RESET THRESHOLD OVERDRIVE, VRST - VCC (V) PULL-DOWN CHARACTERISTICS AND MANUAL RESET DELAY PULL-UP CHARACTERISTICS MAX6351/60-07 MAX6351/60-08 5V 5V PUSH-PULL OUTPUT 5V MR 0 0 5V OPEN-DRAIN OUTPUT 5V 0 OPEN-DRAIN OUTPUT 0 3V 3V PUSH-PULL OUTPUT 5V 3V PUSH-PULL OUTPUT 0 5V PUSH-PULL OUTPUT 5V 0 0 400ns/div 4 10k RST RST3 RST5 3.0 1.5 0 VCC5 OR VCC3 3.5 RESET (V) ICC5 (VCC5 = 3.3V, VCC3 = 2.5V) 10 VCC 4.5 3.5 RESET (V) SUPPLY CURRENT (µA) ICC5 (VCC5 = 5.0V, VCC3 = 3.3V) RESET vs. VCC5 (VCC3 = GND) 5.0 MAX6351/60-03 SUPPLY CURRENT vs. TEMPERATURE 20 NORMALIZED PERIOD MAX6351–MAX6360 Dual/Triple-Voltage µP Supervisory Circuits 40ns/div _______________________________________________________________________________________ Dual/Triple-Voltage µP Supervisory Circuits PIN MAX6352 MAX6353 MAX6354 MAX6355 MAX6356 MAX6357 MAX6358 MAX6359 MAX6360 NAME MAX6351 1 — — — RST5 Active-Low, 5V CMOS Reset Output FUNCTION — 1 1 1 RST Active-Low Reset Output. Open-drain for the MAX6352/MAX6355/MAX6358, 5V push-pull for the MAX6353/MAX6356/MAX6359, and 3V push-pull for the MAX6354/MAX6357/MAX6360. 2 2 2 2 GND Ground 3 3 3 3 MR Manual-Reset Input. Pull low to force a reset. RST, RST5, and RST3 remain active as long as MR is low and for the timeout period after MR goes high. Leave unconnected or connect to VCC5 if unused. V MR must be below VCC5. 4 4 4 4 VCC3 +3.3V/+3.0V Supply Input. Powers the device when it is above VCC5 and monitors its own voltage. 5 — — — RST3 Active-Low, 3V CMOS Reset Output RSTIN Undervoltage Reset Comparator Input. Asserts reset when the monitored voltage falls below 1.23V. Set the reset threshold with an external resistordivider. Connect to VCC5 if unused. VRSTIN must be below VCC5. — — 5 — — — — 5 WDI Watchdog Input. If WDI remains either high or low longer than the timeout period, then reset is triggered. The timer clears when reset is asserted or whenever WDI sees a rising or falling edge. Leave floating to disable it if unused. 6 5 6 6 VCC5 +5V Supply Input. Powers the device when it is above VCC3 and monitors its own voltage. _______________________________________________________________________________________ 5 MAX6351–MAX6360 Pin Description MAX6351–MAX6360 Dual/Triple-Voltage µP Supervisory Circuits Detailed Description Supply Voltages The MAX6351–MAX6360 microprocessor (µP) supervisory circuits maintain system integrity by alerting the µP to fault conditions. These ICs monitor multiple-supply systems and derive their internal power from the highest voltage source present at VCC5 and VCC3. In addition, the output reset state is guaranteed to remain viable while either VCC5 or VCC3 is above +1V. MR GLITCH FILTER VTH5 RST (1) 4 VCC3 RESET GENERATOR VTH3 Reset Outputs The MAX6351 provides a 5V active-low reset and a 3V active-low reset. The MAX6353/MAX6356/MAX6359 provide a 5V active-low push-pull reset and the MAX6354/ MAX6357/MAX6360 provide a 3V active-low push-pull reset. The MAX6353/MAX6355/MAX6358 provide an active-low open-drain reset. The higher input voltages of VCC5 and VCC3 maintain the sinking capability of the low reset-output state. The reset outputs are maintained as long as either supply is above +1V. 3 (5) 6 VCC5 Threshold Levels All the possible input voltage threshold level combinations are indicated by a two-letter code in Voltage Threshold Levels. The two standard combinations are LS and SY. LS parts monitor one +5V ±5% supply and one +3.3V ±10% supply. SY parts monitor one +3.3V ±10% supply and one +2.5V ±10% supply. The other combinations also monitor +5V ±10% supplies, +3.3V ±5% supplies, and +3V ±5% supplies. Negative-Going VCC Transients The MAX6351–MAX6360 are designed to ignore short negative-going VCC5 and VCC3 transients. See Typical Operating Characteristics for a glitch immunity graph. RST3 (5) RST5 (1) Third Input Voltage (MAX6355/MAX6356/MAX6357) The MAX6355/MAX6356/MAX6357 provide an additional input to monitor a third voltage. The threshold voltage at RSTIN is typically 1.22V. To monitor a voltage higher than 1.22V, connect a resistor-divider to the circuit as shown in Figure 2. The threshold at V3 is: (5) (RSTIN) R1 + R2 V3TH = 1.22 R2 Note that RSTIN is powered by VCC5, and its voltage must therefore remain lower than VCC5. 1.22V (5) (WDI) WATCHDOG TIMER V3 R1 MAX6355 MAX6356 MAX6357 RSTIN 2 GND MAX6351–MAX6360 NOTE: PIN 1 IS RST5 FOR THE MAX6351 AND RST FOR THE MAX6352–MAX6360. PIN 5 IS RST3 FOR THE MAX6351, RSTIN FOR THE MAX6355/56/57, WDI FOR THE MAX6358/59/60, AND VCC FOR THE MAX6352/53/54. Figure 1. Functional Diagram 6 R2 VCC5 ≥ VRSTIN Figure 2. Monitoring a Third Voltage _______________________________________________________________________________________ Dual/Triple-Voltage µP Supervisory Circuits Interfacing to µPs with Bidirectional Reset Pins The MAX6358/MAX6359/MAX6360 include a WDI to provide a reset if the µP goes into an infinite loop. After a reset, the start-up timeout period and the initial timeout period is nominally 46.4sec to allow the µP time to initialize. After the first transition on the WDI and after any toggle of the watchdog thereafter, the timeout period is nominally 2.9sec. Microprocessors with bidirectional reset pins will contend with the push-pull outputs of these devices. To prevent this, connect a 4.7kΩ resistor between RESET and the µP’s reset I/O port, as shown in Figure 5. Buffer RESET as shown in the figure if this reset is used by other components in the system. Applications Information Ensuring a Valid RESET Output Down to VCC = 0 VCC5 In some systems, it is necessary to ensure a valid reset even if VCC falls to 0. In these applications, use the circuit shown in Figure 3. Note that this configuration does not work for the open-drain outputs of the MAX6352/ MAX6355/MAX6358. RSTIN Monitoring a Negative Voltage To monitor a negative supply rail using RSTIN or the MAX6355/MAX6356/MAX6357, use the circuit shown in Figure 4. In this configuration, a reset is issued when the negative supply falls below VINTH. MAX6355 MAX6356 MAX6357 R1 R2 VIN VINTH = 1.22 VCC5 ≥ - R2 (V 5 - 1.22) R1 CC VINR1 R2 VCC5 ≥ VRSTIN Figure 4. Monitoring a Negative Voltage BUFFERED RESET TO OTHER SYSTEM COMPONENTS +3.3V/+3V +5V VCC3 VCC5 RST VCC5 RST3 RST5 VCC3 VCC5 100k VCC3 RST RST3 RST5 MAX6351–MAX6360 MAX6351–MAX6360 GND Figure 3. Ensuring a Valid Reset Low to VCC5 and VCC3 = 0 µP 4.7k RESET GND GND Figure 5. Interfacing to µPs with Bidirectional Reset I/O Chip Information TRANSISTOR COUNT: 855 _______________________________________________________________________________________ 7 MAX6351–MAX6360 Watchdog Input (MAX6358/MAX6359/MAX6360) MAX6351–MAX6360 Dual/Triple-Voltage µP Supervisory Circuits Pin Configurations TOP VIEW RST5 1 GND 2 MAX6351 MR 3 6 VCC5 RST* 1 5 RST3 GND 2 4 VCC3 MR 3 5 MAX6352 MAX6353 MAX6354 SOT23-6 RST* 1 GND 2 MAX6355 MAX6356 MAX6357 MR 3 VCC5 *MAX6352: OPEN-DRAIN OUTPUT *MAX6353: 5V PUSH-PULL OUTPUT *MAX6354: 3V PUSH-PULL OUTPUT 4 VCC3 6 VCC5 5 WDI 4 VCC3 SOT23-5 6 VCC5 5 RSTIN 4 VCC3 RST* 1 *MAX6355: OPEN-DRAIN OUTPUT *MAX6356: 5V PUSH-PULL OUTPUT *MAX6357: 3V PUSH-PULL OUTPUT MAX6358 MAX6359 MAX6360 GND 2 MR 3 SOT23-6 *MAX6358: OPEN-DRAIN OUTPUT *MAX6359: 5V PUSH-PULL OUTPUT *MAX6360: 3V PUSH-PULL OUTPUT SOT23-6 Selector Guide PART PIN COUNT NUMBER OF SUPPLIES MONITORED 5V RESET 3V RESET OPEN-DRAIN RESET WATCHDOG TIMER MANUAL RESET MAX6351 6 2 ✔ ✔ — ✔ MAX6352 5 2 — — ✔ MAX6353 5 2 — ✔ — ✔ — — ✔ MAX6354 5 2 — — ✔ MAX6355 6 3 — ✔ MAX6356 6 3 — ✔ — ✔ — — ✔ MAX6357 6 3 — 6 2 — ✔ MAX6359 6 2 — ✔ — ✔ ✔ MAX6358 — ✔ ✔ MAX6360 6 2 — — ✔ ✔ — ✔ — — ✔ — — ✔ ✔ Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. 8 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 1999 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.