19-1508; Rev 3; 6/01 Dual/Triple-Voltage µP Supervisory Circuits __________Voltage Threshold Levels PART NO. SUFFIX (_ _) LT VCC5 NOMINAL VOLTAGE THRESHOLD (V) 4.63 VCC3 NOMINAL VOLTAGE THRESHOLD (V) 3.08 Features ♦ Precision Monitoring of Multiple +1.8V, +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 ♦ Debounced TTL/CMOS-Compatible Manual-Reset Input ♦ Watchdog Timer 46.4s Startup Timeout 2.9s Normal Timeout ♦ 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 ♦ Low Cost Applications Computers Controllers Portable/Battery-Powered Equipment Intelligent Instruments Multivoltage Systems LS 4.63 2.93 LR 4.63 2.63 MT 4.38 3.08 MS 4.38 2.93 PART* TEMP. RANGE PIN-PACKAGE -40°C to +85°C 6 SOT23-6 Ordering Information MR 4.38 2.63 MAX6351_ _UT-T TZ 3.08 2.32 2.19 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 TY 3.08 TW 3.08 1.67 TV 3.08 1.58 2.32 SZ 2.93 SY 2.93 2.19 SW 2.93 1.67 1.58 SV 2.93 UW 2.78 1.67 UV 2.78 1.58 RW 2.63 1.67 RV 2.63 1.58 Note: Standard versions are shown in bold. Sample stock is generally held on the standard versions only. Contact factory for availability. *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. All devices are available in tape-and-reel only. There is a 2500 piece minimum order increment for the SOT package. Pin Configurations appear at end of data sheet. Selector Guide appears at end of data sheet. ________________________________________________________________ Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. 1 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 outputs are 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 46.4s startup timeout period and a 2.9s timeout period. The MAX6355/MAX6356/MAX6357 offer an additional voltage monitor input to monitor a third voltage. 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 these devices are offered with a wide variety of voltage threshold levels, as shown in the Voltage Threshold Levels table. They are available in 5- and 6-pin SOT23 packages and operate over the extended (-40°C to +85°C) temperature range. MAX6351–MAX6360 Dual/Triple-Voltage µP Supervisory Circuits ABSOLUTE MAXIMUM RATINGS Input/Output Current, All Pins .............................................20mA Continuous Power Dissipation (TA = +70°C) 5-Pin SOT23 (derate 7.1mW/°C above +70°C)............571mW 6-Pin SOT23 (derate 8.7mW/°C above +70°C)............695mW Operating Temperature Range ...........................-40°C to +85°C Junction Temperature .....................................................+150°C Storage Temperature Range .............................-65°C to +150°C VCC5, VCC3 to GND .................................................-0.3V to +6V RST (MAX6352/MAX6355/MAX6358)...................... -0.3V to +6V RST, MR, WDI, RST5, RSTIN (MAX6351/MAX6353/ MAX6356/MAX6359) ..............................-0.3V to (VCC5 + 0.3V) RST, RST3 (MAX6351/MAX6354/ MAX6357/MAX6360) ..............................-0.3V to (VCC3 + 0.3V) 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 SYMBOL Supply Voltage VCC Supply Current ICC5 + ICC3 CONDITIONS TA = -40°C to +85°C 1.2 5.5 VCC5 = 5.5V, VCC3 = 3.6V, all I/O pins open MAX63_ _T_ VTH5 MAX63_ _S_ MAX63_ _U_ MAX63_ _R_ MAX63_ _ _T MAX63_ _ _S MAX63_ _ _R VTH3 MAX63_ _ _Z MAX63_ _ _Y MAX63_ _ _W MAX63_ _ _V 2 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 20 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 2.74 TA = -40°C to +85°C 2.70 TA = +25°C 2.58 TA = -40°C to +85°C 2.55 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 2.28 TA = -40°C to +85°C 2.25 TA = +25°C 2.16 TA = -40°C to +85°C 2.13 TA = +25°C 1.64 TA = -40°C to +85°C 1.62 TA = +25°C 1.55 TA = -40°C to +85°C 1.53 4.63 50 UNITS V µA 4.72 4.75 4.38 4.46 4.50 3.08 3.14 3.15 2.93 2.98 V 3.00 2.78 2.82 2.85 2.63 2.68 2.70 3.08 3.14 3.15 2.93 2.98 3.00 2.63 2.68 2.70 2.32 2.35 2.38 2.19 2.22 2.25 1.67 1.70 1.71 1.58 _______________________________________________________________________________________ 1.61 1.62 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 Reset Threshold Tempco SYMBOL CONDITIONS MIN TYP ∆VTH/°C Reset Threshold Hysteresis VCC to Reset Delay RESET Output Voltage Low tRP VOL RESET Output Voltage High (MAX6351/MAX6353/MAX6354/ MAX6356/MAX6357/MAX6359/ MAX6360 only) VOH VCC5 > VTH5 (MAX), VCC3 > VTH3 (MAX) UNITS ppm/°C VTH/500 V 20 µs 100mV overdrive Reset Timeout Period MAX 20 100 180 280 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; TA = -40°C to +85°C 0.3 (_W, _V versions only), ISOURCE = 350µA VCC5 > VTH5(MAX), VCC3 > VTH3(MAX) 0.8 × VCC (_Y versions only), VCC5 > VTH5(MAX), VCC3 > VTH3(MAX) ISOURCE = 500µA 0.8 × VCC (_T, _S, _R versions only), ISOURCE = 800µA VCC5 > VTH5(MAX), VCC3 > VTH3(MAX) VCC - 1.5 ms V V WATCHDOG INPUT (MAX6358/MAX6359/MAX6360) Watchdog Timeout Period tWD WDI Pulse Width (Note 4) tWDI WDI Input Voltage (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 = 0.8 x VCC 50 VCC5 = 5V VWDI = 0 ns 0.3 x VCC 0.7 x VCC VWDI = VCC WDI Input Current (Note 6) 120 -20 s 160 -15 V µA MANUAL RESET INPUT MR Input Voltage 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) 0.8 2.3 0.3 x VCC V 0.7 x VCC _______________________________________________________________________________________ 3 MAX6351–MAX6360 ELECTRICAL CHARACTERISTICS (continued) ELECTRICAL CHARACTERISTICS (continued) (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 MR Pullup Resistance MR Minimum Pulse Width tRP MIN TYP MAX UNITS 32 63.5 100 kΩ µs 1 MR Glitch Rejection MR to Reset Delay tMD 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 < VRSTIN < VCC5 - 0.3V 1.22 1.24 V 1.25 -25 RSTIN Hysteresis 25 2.5 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. Typical Operating Characteristics (VCC = +5V, TA = +25°C, unless otherwise noted.) RESET vs. VCC5 (VCC3 > VTH3) 4.0 4.5 4.0 ICC5 (VCC5 = 3.3V, VCC3 = 2.5V) 10 ICC3 (VCC5 = 5.0V, VCC3 = 3.3V) ICC3 (VCC5 = 3.3V, VCC3 = 2.5V) 3.5 3.0 VTH 2.5 2.0 -15 10 35 TEMPERATURE (°C) 60 85 2.5 2.0 1.5 1.0 1.0 MAX6356L_ 0 -40 3.0 1.5 0.5 0 RESET (V) RESET (V) 3.5 5 4 4.5 15 RESET vs. VCC5 (VCC3 = GND) 5.0 MAX6351/60-02 MAX6351/60-01 ICC5 (VCC5 = 5.0V, VCC3 = 3.3V) 5.0 MAX6351/60-03 SUPPLY CURRENT vs. TEMPERATURE 20 SUPPLY CURRENT (µA) MAX6351–MAX6360 Dual/Triple-Voltage µP Supervisory Circuits 0.5 0 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 VCC5 (V) 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 VCC5 (V) _______________________________________________________________________________________ Dual/Triple-Voltage µP Supervisory Circuits 1.05 1.00 0.95 0.90 200 150 100 MAX6351/60-06 150 100 DELAY FROM FALL OF VCC3 50 50 0.85 200 RESET DELAY (µs) 250 1.10 250 MAX6351/60-05 RESET OCCURS ABOVE LINE TRANSIENT DURATION (µs) 1.15 NORMALIZED PERIOD 300 MAX6351/60-04 1.20 RESET DELAY vs. RESET THRESHOLD OVERDRIVE MAXIMUM VCC TRANSIENT DURATION vs. RESET THRESHOLD OVERDRIVE NORMALIZED RESET/WATCHDOG PERIOD vs. TEMPERATURE 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) MAX6351/60-07 MAX6351/60-08 5V 5V MR 0 0 5V OPEN-DRAIN OUTPUT 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) MANUAL RESET INPUT TO OUTPUT DELAY PULLUP CHARACTERISTICS 5V PUSH-PULL OUTPUT 0 RPULLUP = 100kΩ OPEN-DRAIN OUTPUT 0 RPULLUP = 100kΩ CLOAD = 10pF 0 3V 3V PUSH-PULL OUTPUT 5V 3V PUSH-PULL OUTPUT 0 5V PUSH-PULL OUTPUT 5V 0 400ns/div 5V CLOAD = 10pF 0 40ns/div _______________________________________________________________________________________ 5 MAX6351–MAX6360 Typical Operating Characteristics (continued) (VCC = +5V, TA = +25°C, unless otherwise noted.) Dual/Triple-Voltage µP Supervisory Circuits MAX6351–MAX6360 Pin Description PIN MAX6352 MAX6353 MAX6354 MAX6355 MAX6356 MAX6357 MAX6358 MAX6359 MAX6360 NAME MAX6351 1 — — — RST5 Active-Low, 5V CMOS Reset Output — 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/+2.5V/+1.8V 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 1.22V. Set the reset threshold with an external resistive divider. Connect to VCC5 if unused. VRSTIN must be below VCC5. — 6 FUNCTION — 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 +5.0/+3.3V/+3.0V Supply Input. Powers the device when it is above VCC3 and monitors its own voltage. _______________________________________________________________________________________ Dual/Triple-Voltage µP Supervisory Circuits 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. The output reset state is guaranteed to remain viable while either VCC5 or VCC3 is above +1V. Threshold Levels All the possible input voltage threshold level combinations are indicated by a two-letter code in the Voltage Threshold Levels table. 3 MR GLITCH FILTER (5) 6 VCC5 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 MAX6352/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. Negative-Going VCC Transients The MAX6351–MAX6360 are designed to ignore short negative-going V CC 5 and V CC 3 transients. See the Maximum VCC Transient Duration vs. Reset Threshold Overdrive graph in the Typical Operating Characteristics. Third Input Voltage (MAX6355/MAX6356/MAX6357) VTH5 RST (1) 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 resistive divider to the circuit as shown in Figure 2. The threshold at VEXT is: 4 VCC3 RESET GENERATOR VTH3 RST5 (1) Note that RSTIN is powered by VCC5, and its voltage must therefore remain lower than or equal to VCC5. Watchdog Input (MAX6358/MAX6359/MAX6360) The MAX6358/MAX6359/MAX6360 include a dualmode watchdog timer to monitor µP activity. The flexible timeout architecture provides a startup mode, allowing complicated systems to complete lengthy boots, and a normal mode, allowing the supervisor to provide quick alerts when processor activity fails. (5) (RSTIN) 1.22V (5) (WDI) R1 + R2 VEXT_TH = 1.22V R2 RST3 (5) WATCHDOG TIMER VEXT R1 MAX6355 MAX6356 MAX6357 RSTIN 2 MAX6351–MAX6360 GND 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/MAX6356/MAX6357, WDI FOR THE MAX6358/ MAX6359/MAX6360, AND VCC5 FOR THE MAX6352/MAX6353/MAX6354. Figure 1. Functional Diagram R2 VCC5 ≥ VRSTIN Figure 2. Monitoring a Third Voltage _______________________________________________________________________________________ 7 MAX6351–MAX6360 Detailed Description MAX6351–MAX6360 Dual/Triple-Voltage µP Supervisory Circuits During the normal operating mode, the supervisor will issue a reset pulse for the reset timeout period (140ms min) if the µP does not update the WDI with a valid transition (HIGH to LOW or LOW to HIGH) within the standard timeout period (1.6s min). After each reset event (VCC power-up, manual reset, or watchdog reset), there is an initial watchdog startup timeout period of 25.6s. The startup mode provides an extended period for the system to power up and fully initialize all µP and system components before assuming responsibility for routine watchdog updates. The normal watchdog timeout period (1.6s min) begins at the conclusion of the startup timeout period or after the first transition on WDI before the conclusion of the startup period (Figure 3). Applications Information VCC3 VCC5 RST VCC5 RST3 RST5 VCC3 100k MAX6351 MAX6356 MAX6353 MAX6357 MAX6354 MAX6359 MAX6360 GND Figure 4. Ensuring a Valid Reset Low to VCC5 and VCC3 = 0 Ensuring a Valid RESET Output Down to VCC = 0 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 4. Note that this configuration does not work for the open-drain outputs of the MAX6352/ MAX6355/MAX6358. Interfacing to µPs with Bidirectional Reset Pins 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. VCC3 VCC5 VCC5 VCC3 RST RESET MAX6351–MAX6360 GND GND tWDI-NORMAL 1.6s MAX tWDI-STARTUP 25.6s MAX Chip Information WDI TRANSISTOR COUNT: 855 1.6s MAX RESET 140ms Figure 3. Normal Watchdog Startup Sequence 8 µP 4.7k RST3 RST5 Figure 5. Interfacing to µPs with Bidirectional Reset I/O VTH VCC BUFFERED RESET TO OTHER SYSTEM COMPONENTS _______________________________________________________________________________________ Pin Configurations TOP VIEW RST5 1 GND 2 MAX6351 MR 3 6 VCC5 RST* 1 5 RST3 GND 2 4 VCC3 MR 3 SOT23-6 RST* 1 GND 2 MAX6355 MAX6356 MAX6357 MR 3 5 VCC5 MAX6352 MAX6353 MAX6354 *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 GND 2 MAX6358 MAX6359 MAX6360 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 — — ✔ ✔ — ✔ — — ✔ — — ✔ ✔ _______________________________________________________________________________________ 9 Dual/Triple-Voltage µP Supervisory Circuits 6LSOT.EPS MAX6351–MAX6360 Package Information 10 ______________________________________________________________________________________ Dual/Triple-Voltage µP Supervisory Circuits SOT5L.EPS 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. 11 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2001 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products. MAX6351–MAX6360 Package Information (Continued)