MAX821/MAX822 19-1122 Rev 3 12/05 4-Pin P Voltage Monitors with Pin-Selectable Power-On Reset Timeout Delay General Description Features The MAX821/MAX822 microprocessor (P) supervisory Pin-Selectable, Precision Power-On Reset Delay: circuits monitor power supplies in P and digital sys- 1ms (max), 20ms (min), or 100ms (min) tems. They provide excellent circuit reliability and low Precision Monitoring of +3V to +5V Power-Supply cost by eliminating external components and adjust- Voltages ments when used with 5V-powered or 3V-powered cir- cuits. The MAX821/MAX822 also provide a power-on 2.5A Supply Current reset timeout delay that is pin selectable to 1ms (max), Guaranteed Over Temperature (-40C to +125C) 20ms (min), or 100ms (min). Guaranteed RESET Valid to V = 1V (MAX821) CC These devices perform a single function: they assert a reset signal whenever the V supply voltage falls CC Power-Supply Transient Immunity below a preset threshold, and they keep reset asserted No External Components for the pin-selected reset timeout delay after V has CC risen above the reset threshold. The only difference SOT143 Package between the two devices is that the MAX821 has an active-low RESET output (which is guaranteed to be in Ordering Information the correct state for V down to 1V), while the CC PART NOMINAL V (V) TOP MARK* MAX822 has an active-high RESET output. The reset TH comparator is designed to ignore fast transients on MAX821LUS-T 4.63 AZ V . Reset thresholds suitable for operation with a vari- CC MAX821MUS-T 4.38 BA ety of supply voltages are available. MAX821PUS-T 4.00 BM Low supply current makes the MAX821/MAX822 ideal MAX821TUS-T 3.08 BB for use in portable equipment. These devices come in a MAX821SUS-T 2.93 BC 4-pin SOT143 package. MAX821UUS-T 2.78 BL MAX821RUS-T 2.63 BD Applications MAX822LUS-T 4.63 BF Bar-Code Scanners MAX822MUS-T 4.38 BG Computers MAX822TUS-T 3.08 BH Controllers MAX822SUS-T 2.93 BJ MAX822RUS-T 2.63 BK Intelligent Instruments * The first two letters in the package top mark identify the part, Critical P and C Power Monitoring while the remaining two letters are the lot-tracking code. Portable/Battery-Powered Equipment Devices are available in both leaded and lead-free packaging. Specify lead-free by replacing -T with +T when ordering. Typical Operating Circuit Pin Configuration V V CC CC TOP VIEW 1 GND 4 V CC P MAX821 MAX822 MAX821 MAX822 RESET RESET 20ms INPUT (RESET) 100ms SRT 1ms 2 3 SRT (RESET) RESET GND GND SOT143 ( ) ARE FOR MAX822 ( ) ARE FOR MAX822 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.4-Pin P Voltage Monitors with Pin-Selectable Power-On Reset Timeout Delay ABSOLUTE MAXIMUM RATINGS Terminal Voltage (with respect to GND) Continuous Power Dissipation (T = +70C) A V ......................................................................-0.3V to 6.0V SOT143-4 (derate 4mW/C above +70C)...................320mW CC All Other Inputs.......................................-0.3V to (V + 0.3V) Operating Temperature Range .........................-40C to +125C CC Input Current, V , SRT......................................................20mA Storage Temperature Range .............................-65C to +160C CC Output Current, RESET or RESET.......................................20mA Lead Temperature (soldering, 10sec) .............................+300C 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 = full range, T = -40C to +125C, unless otherwise noted. Typical values are at T = +25C.) CC A A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS T = 0C to +70C 1.0 5.5 A V Range V CC T = -40C to +85C 1.2 5.5 A T = +25C 2.5 7.0 A MAX82 L/M/P, V = 5.5V, I = 0 CC OUT T = T to T 12 A MIN MAX Supply Current I A CC T = +25C 1.8 5.5 MAX82 R/S/T/U, A V = 5.5V, I = 0 CC OUT T = T to T 9 A MIN MAX T = +25C 4.56 4.63 4.70 A MAX82 L T = -40C to +125C 4.50 4.75 A T = +25C 4.31 4.38 4.45 A MAX82 M T = -40C to +125C 4.25 4.50 A T = +25C 3.97 4.00 4.04 A MAX82 P T = -40C to +125C 3.91 4.09 A T = +25C 3.04 3.08 3.11 A Reset Threshold (Note 1) V MAX82 T V TH T = -40C to +125C 3.00 3.15 A T = +25C 2.89 2.93 2.96 A MAX82 S T = -40C to +125C 2.85 3.00 A T = +25C 2.74 2.78 2.81 A MAX82 U T = -40C to +125C 2.70 2.85 A T = +25C 2.59 2.63 2.66 A MAX82 R T = -40C to +125C 2.55 2.70 A Reset Threshold Tempco 30 ppm/C V to Reset Delay (Note 1) V falling at 1mV/s 50 s CC CC SRT = GND 0.5 0.8 1 Reset Active Timeout Period t SRT = V 20 32 40 ms RP CC SRT = unconnected 100 160 200 SRT = GND -100 RESET = low for MAX821, SRT Input Current (Note 2) SRT = V 100 A CC RESET = high for MAX822 SRT = unconnected -1 1 V 0.07V IL CC RESET = low for MAX821, SRT Input Threshold V 0.9V V IH CC RESET = high for MAX822 V 0.5V OPEN CC 2 MAX821/MAX822