19-1615; Rev 0; 1/00 SOT23, Low-Power µP Supervisory Circuits with Battery Backup Features ♦ Low +1.2V Operating Supply Voltage (VCC or VBATT) ♦ Precision Monitoring of +5.0V, +3.3V, +3.0V, and +2.5V Power-Supply Voltages ♦ Debounced Manual Reset Input (MAX6361) ♦ Battery-On Output Indicator (MAX6363) ♦ Auxiliary User-Adjustable RESET IN (MAX6364) ♦ Three Available Output Structures Push-Pull RESET, Open-Drain RESET, Push-Pull RESET ♦ RESET/RESET Valid Down to 1.2V Guaranteed (VCC or VBATT) ♦ Power-Supply Transient Immunity ♦ 150ms (min) Reset Timeout Period ♦ Small 6-Pin SOT23 Package Ordering Information Applications Computers Fax Machines PART TEMP. RANGE PIN-PACKAGE -40°C to +85°C 6 SOT23-6 Controllers Industrial Control MAX6361LUT_ _-T Intelligent Instruments POS Equipment MAX6361PUT_ _-T -40°C to +85°C 6 SOT23-6 Critical µP/µC Power Monitoring Portable/Battery-Powered Equipment MAX6361HUT_ _-T -40°C to +85°C 6 SOT23-6 MAX6363LUT_ _-T -40°C to +85°C 6 SOT23-6 MAX6363PUT_ _-T -40°C to +85°C 6 SOT23-6 MAX6363HUT_ _-T -40°C to +85°C 6 SOT23-6 MAX6364LUT_ _-T -40°C to +85°C 6 SOT23-6 MAX6364PUT_ _-T -40°C to +85°C 6 SOT23-6 MAX6364HUT_ _-T -40°C to +85°C 6 SOT23-6 Pin Configurations TOP VIEW RESET, RESET 1 GND 2 MAX6361 MR 3 6 BATT 5 OUT 4 VCC Note: These parts offer a choice of reset threshold voltages. From Table 1, select the suffix corresponding to the desired threshold voltage and insert it into the part number to complete it. When ordering from the factory, there is a 2500-piece minimum on the SOT package (tape-and-reel only). SOT23-6 Pin Configurations continued at end of data sheet. Selector Guide appears at end of data sheet. Typical Operating Circuit appears at end of data sheet. ________________________________________________________________ Maxim Integrated Products 1 For free samples and the latest literature, visit www.maxim-ic.com or phone 1-800-998-8800. For small orders, phone 1-800-835-8769. MAX6361/MAX6363/MAX6364 General Description The MAX6361/MAX6363/MAX6364 supervisory circuits reduce the complexity and number of components required for power-supply monitoring and battery control functions in microprocessor (µP) systems. The circuits significantly improve system reliability and accuracy compared to that obtainable with separate ICs or discrete components. Their functions include µP reset, backupbattery switchover, and power failure warning. The MAX6361/MAX6363/MAX6364 operate from supply voltages as low as +1.2V. The factory preset reset threshold voltage ranges from 2.32V to 4.63V (see Ordering Information). These devices provide a manual reset input (MAX6361), battery-on output (MAX6363), and an auxiliary adjustable reset input (MAX6364). In addition, each part type is offered in three reset output versions: an active-low push-pull reset, an active-low open-drain reset, and an active-high push-pull reset (see Selector Guide at end of data sheet). MAX6361/MAX6363/MAX6364 SOT23, Low-Power µP Supervisory Circuits with Battery Backup ABSOLUTE MAXIMUM RATINGS Terminal Voltages (with respect to GND) VCC, BATT, OUT...................................................-0.3V to +6V RESET (open drain)..............................................-0.3V to +6V BATT ON, MR, RESET IN .....................-0.3V to (VOUT + 0.3V) RESET, RESET......................................-0.3V to (VOUT + 0.3V) Input Current VCC Peak ............................................................................1A VCC Continuous ............................................................250mA BATT Peak ....................................................................250mA BATT Continuous ............................................................40mA GND ................................................................................75mA Output Current OUT................................Short-Circuit Protection for up to 10s RESET, RESET, BATT ON ..............................................20mA Continuous Power Dissipation (TA = +70°C) 6-Pin SOT23 (derate 8.70mW/°C above +70°C) .........696mW Operating Temperature Range MAX636_ .........................................................-40°C to +85°C Storage Temperature Range .............................-65°C to +150°C Lead Temperature (soldering, 10s) .................................+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 (VCC = +2.4V to +5.5V, VBATT = 3V, TA = -40°C to +85°C, reset not asserted, typical values are at TA = +25°C, unless otherwise noted.) (Note 1) PARAMETER Operating Voltage Range, VCC or VBATT Supply Current (excluding IOUT) SYMBOL VCC, VBATT ICC CONDITIONS TYP 0 No load (Note 2) No load, VCC > VTH MIN MAX UNITS 5.5 V VCC = 2.8V 10 30 VCC = 3.6V 11 35 VCC = 5.5V 15 50 1 TA = -40°C to +85°C 3 ISUPPLY VBATT = 2.8V, VCC = 0 TA = +25°C BATT Standby Current IBATT 5.5V > VCC > (VBATT + 0.2V) TA = +25°C -0.1 0.02 TA = -40°C to +85°C -1.0 0.02 VCC = 4.75V, IOUT ≤ 150mA 1.25 VCC to OUT On-Resistance RON VCC = 3.15V, IOUT ≤ 65mA 2.25 ISUPPLY in Battery-Backup Mode (excluding IOUT) VCC = 2.38V, IOUT ≤ 25mA VOUT in Battery-Backup Mode Battery-Switchover Threshold (VCC - VBATT) Reset Threshold VTH VCC Falling Reset Delay Reset-Active Timeout Period 2 VBATT - 0.2 VBATT = 3.0V, IOUT ≤ 10mA VBATT - 0.15 VBATT = 2.25V, IOUT ≤ 5mA VBATT - 0.15 µA Ω V 20 Power-up Power-down mV -20 MAX636_UT46 4.50 4.63 4.75 MAX636_UT44 4.25 4.38 4.50 MAX636_UT31 3.00 3.08 3.15 MAX636_UT29 2.85 2.93 3.00 MAX636_UT26 2.55 2.63 2.70 MAX636_UT23 2.25 2.32 2.38 35 VCC falling at 10V/ms tRP µA 4.6 VBATT = 4.5V, IOUT ≤ 20mA VCC < VTH µA 150 _______________________________________________________________________________________ V µs 280 ms SOT23, Low-Power µP Supervisory Circuits with Battery Backup (VCC = +2.4V to +5.5V, VBATT = 3V, TA = -40°C to +85°C, reset not asserted, typical values are at TA = +25°C, unless otherwise noted.) (Note 1) PARAMETER SYMBOL VOL RESET Output Voltage Reset asserted, VBATT = 0 VOH Reset not asserted (MAX636_L only) VOH Reset asserted, VBATT = 0 RESET Output Voltage RESET Output Leakage Current CONDITIONS VOL Reset not asserted ILK MAX636_P only MIN TYP MAX ISINK = 1.6mA, VCC ≥ 2.1V 0.3 ISINK = 100µA, VCC ≥ 1.2V 0.4 ISOURCE = 500µA, VCC ≥ VTH(MAX) 0.8 · VCC ISOURCE = 200µA, VCC ≥ 1.2V 0.7 · VCC ISOURCE = 1mA, VCC ≥ 1.8V 0.8 · VCC UNITS V V ISINK = 1.6mA, VCC ≥ VTH(MAX) 0.3 1 µA MANUAL RESET (MAX6361 only) 0.3 · VCC VIL MR Input Voltage 0.7 · VCC VIH 20 Pull-Up Resistance kΩ 1 Minimum Pulse Width V V µs Glitch Immunity VCC = 3.3V 100 ns MR to Reset Delay VCC = 3.3V 120 ns BATT ON (MAX6363 only) Output Voltage VOL Output Short-Circuit Current 0.4 ISINK = 3.2mA, VBATT = 2.1V 60 Sink current, VCC = 5V Source current, VBATT ≥ 2V 10 V mA 30 100 1.235 1.285 V ±0.01 ±25 nA µA RESET IN (MAX6364 only) 1.185 Input Threshold RESET IN Leakage Current RESET IN to Reset Delay Overdrive voltage = 50mV, RESET IN falling 1.5 µs Note 1: Overtemperature limits are guaranteed by design and not production tested. Note 2: VBATT can be 0 anytime or VCC can go down to 0 if VBATT is active (except at startup). _______________________________________________________________________________________ 3 MAX6361/MAX6363/MAX6364 ELECTRICAL CHARACTERISTICS (continued) Typical Operating Characteristics (TA = +25°C, unless otherwise noted.) SUPPLY CURRENT vs. TEMPERATURE (NO LOAD) 14 VBATT = 0 VCC = 5.0V -20 VBATT = 2.0V 0.4 0.2 20 40 60 80 MAX6361 toc03 MAX6361 toc02 0.6 0 0 6 5 VBATT = 2.0V 4 VBATT = 2.8V 3 2 VBATT = 5.0V 1 IOUT = 25mA VCC = 0 0 -40 -20 0 20 40 60 80 -40 -20 60 80 RESET TIMEOUT PERIOD vs. TEMPERATURE VCC TO RESET PROPAGATION DELAY vs. TEMPERATURE MAX6361 toc04 VCC = 3.0V IOUT = 65mA 0.6 VCC = 4.5V IOUT = 150mA 0.3 210 135 205 200 195 VCC FALLING 120 0.25V/ms 105 90 75 60 45 1V/ms 30 10V/ms 15 190 0 20 40 60 80 0 -40 -20 0 TEMPERATURE (°C) RESET THRESHOLD vs. TEMPERATURE 4.5 4.0 3.5 3.0 MAX636_26 2.5 2.0 40 60 80 -40 0 20 40 TEMPERATURE (°C) 60 80 350 300 250 MAX636_46 200 RESET OCCURS ABOVE CURVE 150 100 40 60 VTH = 2.93V 9 8 VBATT = 2.8V 7 6 5 VBATT = 2.5V 4 3 2 VBATT = 2.3V 0 10 100 1k 10k RESET THRESHOLD OVERDRIVE VTH - VCC (mV) 80 10 1 MAX636_26 1 20 BATTERY SUPPLY CURRENT vs. SUPPLY VOLTAGE 0 -20 0 MAXIMUM TRANSIENT DURATION vs. RESET THRESHOLD OVERDRIVE 400 50 -20 TEMPERATURE (°C) MAX6361 toc08 MAX636_46 MAXIMUM TRANSIENT DURATION (µs) MAX6361 toc07 5.0 20 TEMPERATURE (°C) BATTERY SUPPLY CURRENT (µA) -20 MAX6361 toc06 VCC TO OUT ON-RESISTANCE vs. TEMPERATURE 0 4 40 TEMPERATURE (°C) 0.9 -40 20 TEMPERATURE (°C) VCC = 2.3V IOUT = 25mA -40 0 TEMPERATURE (°C) 1.2 VOUT TO OUT ON-RESISTANCE (Ω) 0.8 PROGAGATION DELAY (µs) -40 VBATT = 2.8V MAX6361 toc05 12 1.0 7 MAX6361 toc09 16 VCC = 0 BATTERY TO OUT ON-RESISTANCE vs. TEMPERATURE BATT TO OUT ON-RESISTANCE (Ω) 18 1.2 BATTERY SUPPLY CURRENT (µA) MAX6361 toc01 BATTERY SUPPLY CURRENT (BACKUP MODE) vs. TEMPERATURE RESET TIMEOUT PERIOD (ms) SUPPLY CURRENT (µA) 20 THRESHOLD (V) MAX6361/MAX6363/MAX6364 SOT23, Low-Power µP Supervisory Circuits with Battery Backup 0 1 2 VCC (V) _______________________________________________________________________________________ 3 4 SOT23, Low-Power µP Supervisory Circuits with Battery Backup MAX6361 toc10 1.235 2.8 PROPAGATION DELAY (µs) THRESHOLD (V) 1.236 MAX6361 toc11 MAX6364 RESET IN TO RESET PROPAGATION DELAY vs. TEMPERATURE MAX6364 RESET IN THRESHOLD vs. TEMPERATURE VOD = 50mV 2.5 2.2 1.9 1.6 1.3 1.0 1.234 -40 -20 0 20 40 60 -40 80 -20 0 20 40 60 80 TEMPERATURE (°C) TEMPERATURE (°C) Pin Description PIN NAME FUNCTION RESET Active-High Reset Output (for H versions). RESET remains high while VCC is below the reset threshold and for at least 150ms (tRP) after VCC rises above the reset threshold. RESET also asserts when MR or RESET IN is low. RESET Active-Low Reset Output (for L and P versions). RESET remains low while VCC is below the reset threshold and for at least 150ms (tRP) after VCC rises above the reset threshold. RESET also asserts when MR or RESET IN is low. 1 2 GND Ground MAX6361 Manual-Reset Input. Maintaining logic low on MR asserts a reset. Reset output remains asserted for at least 150ms (tRP) after MR transitions from low to high. Leave unconnected or connected to VCC if not used. MR 3 BATT ON MAX6363 Battery-On Output. BATT ON goes high in battery backup mode. RESET IN MAX6364 Reset Input. When RESET IN falls below 1.235V, reset is asserted. Reset output remains asserted as long as RESET IN is low and for at least 150ms (tRP) after RESET IN goes high. 4 VCC Supply Voltage. Reset is asserted when VCC drops below the reset threshold voltage (VTH). Reset remains asserted until VCC rises above VTH and for at least 150ms after VCC rises above VTH. 5 OUT Output. OUT sources from VCC when it is above the reset threshold (VTH), and from the greater of VCC or BATT when VCC is below VTH. 6 BATT Backup-Battery Input. When VCC falls below the reset threshold, BATT switches to OUT if VBATT is 20mV greater than VCC. When VCC rises 20mV above VBATT, VCC switches to OUT. The 40mV hysteresis prevents repeated switching if VCC falls slowly. Detailed Description The Typical Operating Circuit shows a typical connection for the MAX6361/MAX6363/MAX6364 family. OUT powers the static random-access memory (SRAM). OUT is internally connected to VCC if VCC is greater than the reset threshold, or to the greater of VCC or VBATT when VCC is less than the reset threshold. OUT can supply up to 150mA from VCC. When VCC is higher than VBATT, the BATT ON (MAX6363) output is low. When VCC is lower than VBATT, an internal MOSFET connects the backup battery to OUT. The on-resistance of the MOSFET is a function of backup-battery voltage and is shown in the Battery to Out On-Resistance vs. Temperature graph in the Typical Operating Characteristics section. _______________________________________________________________________________________ 5 MAX6361/MAX6363/MAX6364 Typical Operating Characteristics (continued) (TA = +25°C, unless otherwise noted.) MAX6361/MAX6363/MAX6364 SOT23, Low-Power µP Supervisory Circuits with Battery Backup Backup-Battery Switchover In a brownout or power failure, it may be necessary to preserve the contents of the RAM. With a backup battery installed at BATT, the MAX6361/MAX6363/ MAX6364 automatically switch the RAM to backup power when VCC falls. The MAX6363 has a BATT ON output that goes high when in battery-backup mode. These devices require two conditions before switching to battery-backup mode: 1) VCC must be below the reset threshold. 2) VCC must be below VBATT. Table 2 lists the status of the inputs and outputs in battery-backup mode. The device will not power up if the only voltage source is on BATT. OUT will only power up from VCC at startup. Manual Reset Input (MAX6361 only) Many µP-based products require manual reset capability, allowing the operator, a test technician, or external logic circuitry to initiate a reset. For the MAX6361, a logic low on MR asserts reset. Reset remains asserted while MR is low, and for a minimum of 150ms (tRP) after it returns high. MR has an internal 20kΩ pull-up resistor. This input can be driven with TTL/CMOS logic levels or with open-drain/collector outputs. Connect a normally open momentary switch from MR to GND to create a manual reset function; external debounce circuitry is not required. If MR is driven from long cables or the device is used in a noisy environment, connect a 0.1µF capacitor from MR to GND to provide additional noise immunity. Reset In (MAX6364 only) RESET IN is compared to an internal 1.235V reference. If the voltage at RESET IN is less than 1.235V, reset is asserted. The RESET IN comparator may be used as an undervoltage detector to signal a failing power supply. It can also be used as a secondary power-supply reset monitor. Applications Information Operation Without a Backup Power Source The MAX6361/MAX6363/MAX6364 were designed for battery-backed applications. If a backup battery is not used, connect VCC to OUT and connect BATT to GND. Replacing the Backup Battery If BATT is decoupled with a 0.1µF capacitor to ground, the backup power source can be removed while VCC remains valid without danger of triggering a reset pulse. The device does not enter battery-backup mode when VCC stays above the reset threshold voltage. Negative-Going VCC Transients These supervisors are relatively immune to short-duration, negative-going VCC transients. Resetting the µP when VCC experiences only small glitches is usually not desirable. The Typical Operating Characteristics section shows a graph of Maximum Transient Duration vs. Reset Threshold Overdrive for which reset is not asserted. The graph was produced using negative-going VCC pulses, starting at V CC and ending below the reset threshold by the magnitude indicated (reset threshold overdrive). The graph shows the maximum pulse width Table 1. Reset Threshold Ranges SUFFIX RESET THRESHOLD RANGES (V) MIN TYP MAX 46 4.50 4.63 4.75 44 4.25 4.38 4.50 31 3.00 3.08 3.15 29 2.85 2.93 3.00 26 2.55 2.63 2.70 23 2.25 2.32 2.38 Reset Output A µP’s reset input starts the µP in a known state. The MAX6361/MAX6363/MAX6364 µP supervisory circuits assert a reset to prevent code-execution errors during power-up, power-down, and brownout conditions. RESET is guaranteed to be a logic low or high depending on the device chosen (see Ordering Information). RESET or RESET asserts when VCC is below the reset threshold and for at least 150ms (tRP) after VCC rises above the reset threshold. RESET or RESET also asserts when MR is low (MAX6361) and when RESET IN is less than 1.235V (MAX6364). Table 2. Input and Output Status in Battery-Backup Mode PIN Disconnected from OUT OUT Connected to BATT BATT Connected to OUT. Current drawn from the battery is less than 1µA (at VBATT = 2.8V, excluding IOUT) when VCC = 0. RESET/RESET Asserted BATT ON High state MR, RESET IN 6 STATUS VCC Inputs ignored _______________________________________________________________________________________ SOT23, Low-Power µP Supervisory Circuits with Battery Backup PART MANUAL RESET INPUT, MR MAX6361LUT_ _ ✓ MAX6361PUT_ _ ✓ MAX6361HUT_ _ ✓ BATT ON RESET IN RESET PUSH-PULL RESET OPEN-DRAIN RESET PUSH-PULL ✓ ✓ ✓ MAX6363LUT_ _ ✓ MAX6363PUT_ _ ✓ MAX6363HUT_ _ ✓ ✓ ✓ ✓ MAX6364LUT_ _ ✓ MAX6364PUT_ _ ✓ MAX6364HUT_ _ ✓ ✓ ✓ ✓ Device Marking Codes PART TOP MARK PART TOP MARK PART TOP MARK MAX6361LUT23 AAEI MAX6361LUT26 AAEH MAX6363LUT23 AAFS MAX6364LUT23 AAGK MAX6363LUT26 AAFR MAX6364LUT26 MAX6361LUT29* AAGJ AAEG MAX6363LUT29* AAFQ MAX6364LUT29* MAX6361LUT31 AAGI AAEF MAX6363LUT31 AAFP MAX6364LUT31 AAGH AAGG MAX6361LUT44 AAEE MAX6363LUT44 AAFO MAX6364LUT44 MAX6361LUT46* AAED MAX6363LUT46* AAFN MAX6364LUT46* AAGF MAX6361PUT23 AAEO MAX6363PUT23 AAFY MAX6364PUT23 AAGQ MAX6361PUT26 AAEN MAX6363PUT26 AAFX MAX6364PUT26 AAGP MAX6361PUT29* AAEM MAX6363PUT29* AAFW MAX6364PUT29* AAGO MAX6361PUT31 AAEL MAX6363PUT31 AAFV MAX6364PUT31 AAGN MAX6361PUT44 AAEK MAX6363PUT44 AAFU MAX6364PUT44 AAGM MAX6361PUT46* AAEJ MAX6363PUT46* AAFT MAX6364PUT46* AAGL MAX6361HUT23 AAEU MAX6363HUT23 AAGE MAX6364HUT23 AAGW MAX6361HUT26 AAET MAX6363HUT26 AAGD MAX6364HUT26 AAGV MAX6361HUT29 AAES MAX6363HUT29 AAGC MAX6364HUT29 AAGU MAX6361HUT31 AAER MAX6363HUT31 AAGB MAX6364HUT31 AAGT MAX6361HUT44 AAEQ MAX6363HUT44 AAGA MAX6364HUT44 AAGS MAX6361HUT46* AAEP MAX6363HUT46* AAFZ MAX6364HUT46* AAGR *Sample stock generally held on standard versions only. Contact factory for availability of nonstandard versions. that a negative-going VCC transient can typically have without triggering a reset pulse. As the amplitude of the transient increases (i.e., goes further below the reset threshold), the maximum allowable pulse width decreases. Typically, a VCC transient that goes 100mV below the reset threshold and lasts for 30µs will not trigger a reset pulse. A 0.1µF bypass capacitor mounted close to the VCC pin provides additional transient immunity. _______________________________________________________________________________________ 7 MAX6361/MAX6363/MAX6364 Selector Guide Pin Configurations (continued) TOP VIEW Typical Operating Circuit UNREGULATED DC VOLTAGE RESET, RESET 1 6 BATT VCC R1 GND 2 MAX6363 BATT ON 3 2.4V TO 5.5V 5 OUT 4 VCC 0.1µF VCC RESET RESET µP RESET IN GND R2 MAX6364 BUS MAX6361/MAX6363/MAX6364 SOT23, Low-Power µP Supervisory Circuits with Battery Backup OUT SOT23-6 RESET, RESET 1 GND 2 MAX6364 RESET IN 3 3.6V Li+ BATTERY 6 BATT 5 OUT 4 VCC BATT VCC GND 0.1µF SRAM GND Chip Information TRANSISTOR COUNT: 720 SOT23-6 Package Information 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 © 2000 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.