MAX6746MAX6753 19-2530 Rev 6 4/11 P Reset Circuits with Capacitor-Adjustable Reset/Watchdog Timeout Delay General Description Features The MAX6746MAX6753 low-power microprocessor Factory-Set Reset Threshold Options from 1.575V (P) supervisory circuits monitor single/dual system to 5V in ~100mV Increments supply voltages from 1.575V to 5V and provide maxi- Adjustable Reset Threshold Options mum adjustability for reset and watchdog functions. These devices assert a reset signal whenever the V CC Single/Dual Voltage Monitoring supply voltage or RESET IN falls below its reset thresh- Capacitor-Adjustable Reset Timeout old or when manual reset is pulled low. The reset output remains asserted for the reset timeout period after V CC Capacitor-Adjustable Watchdog Timeout and RESET IN rise above the reset threshold. The reset Min/Max (Windowed) Watchdog Option function features immunity to power-supply transients. The MAX6746MAX6753 have 2% factory-trimmed Manual Reset Input Option reset threshold voltages in approximately 100mV incre- Guaranteed RESET Valid for V 1V CC ments from 1.575V to 5.0V and/or adjustable reset threshold voltages using external resistors. 3.7A Supply Current The reset and watchdog delays are adjustable with Push-Pull or Open-Drain RESET Output Options external capacitors. The MAX6746MAX6751 contain a Power-Supply Transient Immunity watchdog select input that extends the watchdog time- out period by 128x. The MAX6752/MAX6753 contain a Small 8-Pin SOT23 Packages window watchdog timer that looks for activity outside an expected window of operation. Ordering Information The MAX6746MAX6753 are available with a push-pull PART TEMP RANGE PIN-PACKAGE or open-drain active-low RESET output. The MAX6746 MAX6746KA -T -40C to +125C 8 SOT23 MAX6753 are available in an 8-pin SOT23 package and are fully specified over the automotive temperature MAX6746KA /V+T -40C to +125C 8 SOT23 range (-40C to +125C). MAX6747KA -T -40C to +125C 8 SOT23 MAX6747KA /V+T -40C to +125C 8 SOT23 Applications MAX6748KA-T -40C to +125C 8 SOT23 Medical Equipment Embedded Controllers MAX6749KA-T -40C to +125C 8 SOT23 Automotive Critical P Monitoring MAX6750KA -T -40C to +125C 8 SOT23 Intelligent Instruments Set-Top Boxes MAX6750KA /V+T -40C to +125C 8 SOT23 Portable Equipment Computers MAX6751KA -T -40C to +125C 8 SOT23 Battery-Powered MAX6752KA -T -40C to +125C 8 SOT23 Computers/Controllers MAX6753KA -T -40C to +125C 8 SOT23 MAX6753KA /V+T -40C to +125C 8 SOT23 Pin Configurations Note: represents the two number suffix needed when ordering the reset threshold voltage value for the TOP VIEW MAX6746/MAX6747 and MAX6750MAX6753. The reset threshold voltages are available in approximately 100mV incre- RESET IN (MR) 1 8 V CC ments. Table 2 contains the suffix and reset factory-trimmed voltages. All devices are available in tape-and-reel only. There SWT 2 7 RESET is a 2500-piece minimum order increment for standard ver- MAX6746 sions (see Table 3). Sample stock is typically held on standard MAX6751 SRT 3 6 WDI versions only. Nonstandard versions require a minimum order increment of 10,000 pieces. Contact factory for availability. GND 4 5 WDS Devices are available in both leaded and lead-free packaging. Specify lead-free by replacing -T with +T when ordering. SOT23-8 /V Denotes an automotive qualified part. ( ) ARE FOR MAX6746 AND MAX6747 ONLY. Selector Guide appears at end of data sheet. Pin Configurations continued at end of data sheet. Typical Operating Circuit appears at end of data sheet. Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com.P Reset Circuits with Capacitor-Adjustable Reset/Watchdog Timeout Delay ABSOLUTE MAXIMUM RATINGS V to GND...........................................................-0.3V to +6.0V Continuous Power Dissipation (T = +70C) CC A SRT, SWT, SET0, SET1, RESET IN, WDS, MR, 8-Pin SOT23 (derate 8.9mW/C above +70C)............714mW WDI, to GND .......................................-0.3V to (V + 0.3V) Operating Temperature Range .........................-40C to +125C CC RESET (Push-Pull) to GND......................-0.3V to (V + 0.3V) Storage Temperature Range ............................-65C to +150C CC RESET (Open Drain) to GND.............................-0.3V to +6.0V Junction Temperature......................................................+150C Input Current (All Pins) .....................................................20mA Lead Temperature (soldering, 10s) .................................+300C Output Current (RESET) ...................................................20mA Soldering Temperature (reflow) .......................................+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 (V = +1.2V to +5.5V, T = T to T , unless otherwise specified. Typical values are at V = +5V and T = +25C.) (Note 1) CC A MIN MAX CC A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS T = 0C to +125C 1.0 5.5 A Supply Voltage V V CC T = -40C to 0C 1.2 5.5 A V 5.5V 5 10 CC Supply Current I A CC V 3.3V 4.2 9 CC V 2.0V 3.7 8 CC See V V - V + TH TH TH V Reset Threshold V T = -40C to+125C V CC TH A selection table 2% 2% Hysteresis V 0.8 % HYST V falling from V + 100mV to V - CC TH TH V to Reset Delay 20 s CC 100mV at 1mV/s C = 1500pF 5.692 7.590 9.487 SRT Reset Timeout Period t ms RP C = 100pF 0.506 SRT SRT Ramp Current I V = 0 to 1.23V V = 1.6V to 5V 200 250 300 nA RAMP SRT CC SRT Ramp Threshold V V = 1.6V to 5V (V rising) 1.173 1.235 1.297 V RAMP CC RAMP C = 1500pF 5.692 7.590 9.487 Normal Watchdog Timeout Period SWT t ms WD (MAX6746MAX6751) C = 100pF 0.506 SWT C = 1500pF 728.6 971.5 1214.4 Extended Watchdog Timeout SWT t ms WD (MAX6746MAX6751) C = 100pF 64.77 SWT C = 1500pF 728.6 971.5 1214.4 SWT Slow Watchdog Period t ms WD2 (MAX6752/MAX6753) C = 100pF 64.77 SWT Fast Watchdog Timeout Period, C = 1500pF 91.08 121.43 151.80 SWT SET Ratio = 8, t ms WD1 (MAX6752/MAX6753) C = 100pF 8.09 SWT Fast Watchdog Timeout Period, C = 1500pF 45.53 60.71 75.89 SWT SET Ratio = 16, t ms WD1 (MAX6752/MAX6753) C = 100pF 4.05 SWT 2 MAX6746MAX6753