MAX6854/MAX6855/MAX6856/MAX6858/MAX6860MAX6869 19-3139 Rev 4 12/05 Nanopower P Supervisory Circuits with Manual Reset and Watchdog Timer General Description Features The MAX6854/MAX6855/MAX6856/MAX6858/MAX6860 Ultra-Low 170nA (typ) Supply Current MAX6869 ultra-low-current (170nA, typ) microprocessor Reset Thresholds from +1.575V to +4.625V in (P) supervisory circuits combine voltage monitoring, Approximately 100mV Increments watchdog timer, and manual reset input functions in a 5- Six Minimum Reset Timeout Period Options from pin SOT23 package. These devices assert a reset signal 10ms to 1200ms whenever the monitored voltage drops below the factory- trimmed reset threshold voltage, manual reset is assert- Manual Reset Option ed, or the watchdog timer expires. The reset output Watchdog Timer Option remains asserted for a minimum timeout period after V CC Pin-Selectable 10ms/150ms (min) Reset Timeout rises above the reset threshold and manual reset is Period (MAX6861/MAX6862/MAX6863) deasserted. Factory-trimmed reset threshold voltages are offered from +1.575V to +4.625V in approximately Immune to Short V Transients CC 100mV increments (see the Threshold Suffix Guide). Guaranteed Reset Valid to V = +1.1V CC Each device is offered with six minimum reset timeout Three Reset Output Options: options, ranging from 10ms to 1200ms. Push-Pull RESET The MAX6854/MAX6855/MAX6856/MAX6858/MAX6860 Push-Pull RESET MAX6869 are offered in a variety of configurations (see Open-Drain RESET the Selector Guide). The MAX6854/MAX6855/MAX6856/ No External Components MAX6861MAX6869 provide a manual reset input, MR. The MAX6864MAX6869 offer a watchdog timer that Small 5-Pin SOT23 Package monitors activity at the WDI input to prevent code execu- Pin Compatible to the TPS3836/TPS3837/TPS3838 tion errors. The MAX6864MAX6869 offer watchdog (MAX6861/MAX6862/MAX6863) timeout options of 3.3s or 209s (typ). The MAX6861/ MAX6862/MAX6863 feature a pin-selectable reset delay period of 10ms or 150ms (min). Push-pull active-low, push-pull active-high, and open-drain active-low reset Ordering Information outputs are available. PART TEMP RANGE PIN-PACKAGE Applications MAX6854UK D -T -40C to +85C 5 SOT23-5 Portable/Battery-Powered Equipment MAX6855UK D -T -40C to +85C 5 SOT23-5 PDAs/Cell Phones Insert reset threshold suffix (see Table 2, Threshold Suffix MP3 Players/Pagers Guide) after UK. Insert the number corresponding to the desired reset timeout period (see Table 4, Reset Timeout Glucose Monitors/Patient Monitors Period) after D. Note: Sample stock is generally held on standard versions only (see Table 5, Standard Versions Table). Standard versions Typical Operating Circuit have an order increment of 2500 pieces. Nonstandard versions have an order increment of 10,000 pieces. Contact factory for V CC availability of nonstandard versions. 0.1F Devices are available in both leaded and lead-free packaging. Specify lead-free by replacing -T with +T when ordering. V V CC CC RESET RESET Pin Configurations and Selector Guide appear at end of P MAX6864 data sheet. MAX6867 Ordering Information continued at end of data sheet. MR WDI I/O MANUAL RESET GND GND Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com.Nanopower P Supervisory Circuits with Manual Reset and Watchdog Timer ABSOLUTE MAXIMUM RATINGS Operating Temperature Range ...........................-40C to +85C V , Open-Drain RESET to GND ..........................-0.3V to +6.0V CC Junction Temperature .....................................................+150C MR, Push-Pull RESET, RESET, WDI, CT, I.C............................................-0.3V to (V + 0.3V) Storage Temperature Range .............................-65C to +150C CC Lead Temperature (soldering, 10s) .................................+300C Input Current, Output Current (all pins)............................20mA Continuous Power Dissipation (T = +70C) A 5-Pin SOT23 (derate 7.1mW/C above +70C)............571mW 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 = -40C to +85C, unless otherwise specified. Typical values are at V = 2.5V, T = +25C.) (Note 1) CC A CC A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS T 0C 1.1 5.5 A Supply Voltage V V CC T = -40C to +85C 1.2 5.5 A V = 5.0V 210 400 CC V > V , no load, CC TH nA reset output V = 3.3V 190 380 CC Supply Current I CC deasserted (Note 2) V = 1.8V 170 370 CC V < V , no load, reset output asserted 715 A CC TH V - V + TH TH V Reset Threshold V V falling (see Table 2) V V CC TH CC TH 2.5% 2.5% Reset Threshold Hysteresis V Reset asserted to reset deasserted 0.5 %V HYST TH D1 10 15 25 D2 40 60 80 D3 150 225 300 V = V + 150mV CC TH Reset Timeout Period t ms RP (Figures 2 and 3) D4 1200 1800 2400 D5 300 450 600 D6 600 900 1200 V falling from (V + 100mV) to CC TH V to Reset Delay t 40 s CC RD (V - 100mV) at 10mV/s TH V 1.1V, I = 50A, CC SINK 0.3 RESET asserted, T 0C A V 1.2V, I = 100A, CC SINK V 0.3 OL RESET asserted V 2.12V, I = 1.2mA, CC SINK RESET Output Voltage 0.3 V RESET asserted V 1.71V, I = 200A, CC SOURCE 0.8 x V CC RESET deasserted, push-pull RESET only V OH V 2.38V, I = 500A, CC SOURCE 0.8 x V CC RESET deasserted, push-pull RESET only Open-Drain RESET Leakage I RESET deasserted 25 nA LKG Current 2 MAX6854/MAX6855/MAX6856/MAX6858/MAX6860MAX6869