UM807/821/822 μP Reset Circuits with Long Manual Reset Setup Period UM807/821/822 SOT143 General Description The UM807/821/822 are low-power microprocessor (μP) supervisory circuits used to monitor power supplies in μP and digital systems. They provide excellent circuit reliability and low cost by eliminating external components and adjustments when used with 5V-powered or 3V-powered circuits. The UM807/821/822 also provide a debounced manual reset input with long setup period. On all devices, the reset output asserts when the VCC supply voltage drops below its specified threshold. The reset output remains asserted for the reset timeout period (240ms typ) after VCC rises above the reset threshold. The reset output is one-shot pulse asserted for the reset timeout period (140ms min) when manual reset input is held low for a fixed setup timeout period. These devices ignore manual reset transitions of less than the fixed setup timeout period. _____________ The UM807 has an active-low RESET with open-drain output, the UM821 has an active-low _____________ RESET with push-pull output, and the UM822 has an active-high RESET with push-pull output. These devices, offered in small SOT143 package, are fully guaranteed over the extended temperature range (-40°C to +85°C). Applications Features Set-Top Boxes Consumer Electronics DVD Players Cable/DSL Modems MP3 Players Industrial Equipments Automotive Medical Devices No External Components VCC Transient Immunity Correct Logic Output Guaranteed to VCC=1.0V Precision VCC Monitoring of 3.0V, 3.3V and 5.0V Supplies 2μA Supply Current 140ms Minimum Power-On Reset Pulse Width Available in 3 Manual Reset Setup Periods (tMR): A: 10.08s B: 6.72s C: 1.68s Available in 3 Output Configurations: __________ Open-Drain Active-Low RESET Output(UM807); __________ Push-Pull Active-Low RESET Output(UM821) Push-Pull Active-High RESET Output(UM822) 4-Pin SOT143 Package Wide Operation Temperature: -40°C to +85°C ________________________________________________________________________ http://www.union-ic.com Rev.01 Jan.2015 1/17 UM807/821/822 GND 1 Top View 4 VCC 4 3 XXX RESET 2 (RESET) 1 3 M Pin Configurations 2 MR ( ) are for UM822 M: Month Code UM807/821/822 SOT143 Ordering Information UM8 XX Z T P XX: Output Type =07 Open-Drain Active Low =21 Push-Pull Active Low =22 Push-Pull Active High Z: Reset Threshold (V) =L 4.63 =M 4.38 =J 4.00 =T 3.08 =S 2.93 =R 2.63 =Z 2.32 T: Manual Reset Setup Period (s) =A 10.08 =B 6.72 =C 1.68 P: Package Type =E SOT143 ________________________________________________________________________ http://www.union-ic.com Rev.01 Jan.2015 2/17 UM807/821/822 Typical Operating Circuit +3.3V VCC VCC Rpullup* UM807 UM821 UM822 μP RESET (RESET) RESET MR GND GND RESET PULSE WIDTH 240ms MR SETUP PERIOD tMR tPW MR RESET RESET *UM807 ONLY ( ) are for UM822 ________________________________________________________________________ http://www.union-ic.com Rev.01 Jan.2015 3/17 UM807/821/822 Pin Description Pin Number Pin Name 1 GND Function Ground ______________ ______________ RESET (UM807/821) 2 RESET (UM822) _______ 3 MR Active-Low Push-Pull or Open-Drain Output. RESET changes from high to low when VCC drops below its reset threshold and remains low for the 240ms reset timeout period after VCC exceeds their reset ______________ threshold. RESET is one-shot pulsed low for the reset timeout period (140ms min) after the manual reset input is asserted longer than the specified setup period. For the open-drain output, use a pull-up resistor to VCC. See Figure 1. Active-High Push-Pull Output. RESET changes from low to high when VCC drops below its reset threshold and remains high for the 240ms reset timeout period after VCC exceeds their reset threshold. RESET is one-shot pulsed high for the reset timeout period (140ms min) after the manual reset input is asserted longer than the specified setup period. See Figure 1. Manual Reset Input, Active Low. Internal 22kΩ pull-up to VCC. Pull _______ M R low for the typical input pulse width (tMR) to one-shot pulse _____________ RESET for the reset pulse width (tPW). See Figure 2. 4 VCC +5V, +3.3V, or +3V Supply Voltage Absolute Maximum Ratings (Note 1) Symbol VCC Parameter Supply Voltage RESET, RESET (push-pull) _____________ _______ TA TSTG V -0.3 to +6.0 MR PD -0.3 to (VCC+0.3) -0.3 to +6.0 RESET (open-drain) IO Unit -0.3 to +6.0 _____________ ICC Value _______ Input Current, VCC, M R _____________ 20 mA 20 mA Output Current, RESET, RESET Continuous Power Dissipation (Derate 4mW/°C above 70°C) Operating Temperature Range 320 mW -40 to +105 °C Storage Temperature Range -65 to +160 °C +300 °C Lead Temperature (soldering, 10s) Note 1: 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 are not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ________________________________________________________________________ http://www.union-ic.com Rev.01 Jan.2015 4/17 UM807/821/822 Electrical Characteristics (VCC = 5V for L/M/J versions, VCC = 3.3V for T/S versions, VCC = 3V for R version, and VCC = 2.5V for Z version, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 2) Symbol Parameter VCC Supply Voltage Range ICC Supply Current Conditions M version J version Reset Threshold T version S version R version Z version tRD tRP TA=+25℃ TA=-40℃ to + 85℃ TA=+25℃ TA=-40℃ to + 85℃ TA=+25℃ TA=-40℃ to + 85℃ TA=+25℃ TA=-40℃ to + 85℃ TA=+25℃ TA=-40℃ to + 85℃ TA=+25℃ TA=-40℃ to + 85℃ TA=+25℃ TA=-40℃ to + 85℃ 4.56 4.50 4.31 4.25 3.93 3.89 3.04 3.00 2.89 2.85 2.59 2.55 2.28 2.25 Reset Threshold Tempco VCC to Reset Delay (Note 3) Reset Active Timeout Period ______ tMR MR Minimum Pulse Width tPW RESET Pulse Width Typ Max Unit 5.5 V 2.0 5.0 μA 4.63 4.70 4.75 4.45 4.50 4.06 4.10 3.11 3.15 2.96 3.00 2.66 2.70 2.35 2.38 V 1.0 L version VTH+ Min A B C 4.38 4.00 3.08 2.93 2.63 2.32 150 ppm/°C 10 μs 140 240 560 ms 6.04 4.03 1.01 10.08 6.72 1.68 14.11 9.41 2.35 s 140 240 560 ms ______ MR Glitch Immunity (Note 4) VIH VIL VIH ______ VCC > VTH(MAX) UM807/821/822L_E/M_E/J_E 2.3 0.8 MR Input Threshold V VCC > VTH(MAX) UM807/821/822T_E/S_E/R_E/Z_E VIL ns 100 0.7×VCC 0.25×VCC ______ MR Pull-Up Resistance 10 20 30 kΩ ________________________________________________________________________ http://www.union-ic.com Rev.01 Jan.2015 5/17 UM807/821/822 Electrical Characteristics (Continued) (VCC = 5V for L/M/J versions, VCC = 3.3V for T/S versions, VCC = 3V for R version, and VCC = 2.5V for Z version, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 2) Symbol Parameter VOH RESET Output Voltage VOL VOH ____________ RESET Output Voltage VOL Conditions ISOURCE=150μA, 1.8V<VCC<VTH(MIN) UM822L_E/M_E/J_E/T_E/S_E/R_E/Z_E ISINK=1.2mA UM822T_E/S_E/R_E/Z_E ISINK=3.2mA UM822L_E/M_E/J_E ISOURCE=500μA, VCC>VTH(MAX) UM821T_E/S_E/R_E/Z_E ISOURCE=800μA, VCC>VTH(MAX) UM821L_E/M_E/J_E ISINK=1.2mA, VCC=VTH(MIN) UM807/821T_E/S_E/R_E/Z_E ISINK=3.2mA, VCC=VTH(MIN) UM807/821L_E/M_E/J_E ISINK=50μA, VCC>1.0V Min Typ Max Unit 0.3 V 0.8×VCC 0.4 0.8×VCC VCC-1.5 0.3 V 0.4 0.3 Note 2: Production _____________ testing done at TA = +25°C; limits over temperature guaranteed by design only. Note 3: RESET output for UM807/821; RESET output for UM822. Note 4: “Glitches” of 100ns or less typically will not generate a reset pulse. ________________________________________________________________________ http://www.union-ic.com Rev.01 Jan.2015 6/17 UM807/821/822 Typical Operating Characteristics (TA = +25°C, unless otherwise noted.) Supply Current vs. Temperature (UM821R_E) Power-down RESET Delay vs. Temperature (UM821R_E) VCC=3.3V Power-up RESET Timeout vs. Temperature ________________________________________________________________________ http://www.union-ic.com Rev.01 Jan.2015 7/17 UM807/821/822 Detailed Description RESET Timing The reset signal is asserted LOW for the UM821 and HIGH for the UM822 when the power supply voltage falls below the threshold trip voltage and remains asserted for at least 140ms after the power supply voltage has risen above the threshold. 5V VTH VCC VTH 0V tRP 5V RESET 0V 5V RESET 0V Figure 1. RESET vs. VCC Timing Diagram _______ _____________ Pull M R low for the typical input pulse width (tMR) to one-shot pulse RESET for the reset pulse width (tPW). HIGH MR LOW tMR VCC tPW RESET 0V VCC RESET 0V _______ Figure 2. RESET vs. MR Timing Diagram Reset Output A microprocessor’s (µP’s) reset input starts the µP in a known state. These μP supervisory circuits ________________________________________________________________________ http://www.union-ic.com Rev.01 Jan.2015 8/17 UM807/821/822 assert reset to prevent code execution errors during power-up, power-down, or brownout conditions. _____________ RESET is guaranteed to be a logic low for VCC > 1V. Once VCC exceeds the reset threshold, an _____________ _____________ internal timer keeps RESET low for the reset timeout period; after this interval, RESET goes high. _____________ If a brownout condition occurs (VCC dips below the reset threshold), RESET goes low. Any time _____________ VCC goes below the reset threshold, the internal timer resets to zero, and RESET goes low. The _____________ internal timer starts after VCC returns above the reset threshold, and RESET remains low for the reset timeout period. _______ The manual reset input (M R ) can also initiate a reset. See the Manual Reset Input section. _____________ The UM822 has an active-high RESET output that is the inverse of the UM807/821’s RESET output. The UM807 uses an open-drain output, and the UM821/822 have a push-pull output stage. _____________ Connect a pull-up resistor on the UM807’s RESET output to any supply between 0 and 6V. Manual Reset Input Each device in the UM807/821/822 family includes one manual reset input, which must be held _____________ logic-low for an extended setup period (tMR) before the RESET output asserts. When valid manual _____________ reset input conditions/setup periods are met, the RESET output is one-shot pulse asserted low for a fixed reset pulse width (140ms min). Existing front-panel pushbutton switches (i.e., power on/off, channel up/down, or mode select) can be used to drive the manual reset inputs. The extended manual reset setup period prevents nuisance system resets during normal front-panel usage or resulting from inadvertent short-term pushbutton closure. _______ This input has an internal 20kΩ pull-up resistor, so it can be left open if it is not used. M R can be driven with TTL or CMOS-logic levels, or with open-drain/collector outputs. Connect a normally _______ open momentary switch from M R to GND to create a manual-reset function; external debounce _______ circuitry is not required. If M R is driven from long cables or if the device is used in a noisy _______ environment, connecting a 0.1μF capacitor from M R to ground provides additional noise immunity. Reset Threshold Accuracy The UM807/821/822 are ideal for systems using a 5V±5% or 3V±5% power supply with ICs specified for 5V±10% or 3V±10%, respectively. They are designed to meet worst-case specifications over temperature. The reset is guaranteed to assert after the power supply falls out of regulation, but before power drops below the minimum specified operating voltage range for the system ICs. The thresholds are pre-trimmed and exhibit tight distribution, reducing the range over which an undesirable reset may occur. ________________________________________________________________________ http://www.union-ic.com Rev.01 Jan.2015 9/17 UM807/821/822 Applications Information Negative-Going VCC Transients In addition to issuing a reset to the µP during power-up, power-down, and brownout conditions, the UM807/821/822 are relatively immune to short-duration negative-going VCC transients (glitches). Figure 3 shows typical transient duration vs. reset comparator overdrive, for which the UM807/821/822 do not generate a reset pulse. The graph was generated using a negative-going pulse applied to VCC, starting above the actual reset threshold and ending below it by the magnitude indicated (reset comparator overdrive). The graph indicates the typical maximum pulse width a negative-going VCC transient may have without causing a reset pulse to be issued. As the magnitude of the transient increases (goes farther below the reset threshold), the maximum allowable pulse width decreases. Typically, for the UM8_ _L_E/M_E/J_E, a VCC transient that goes 125mV below the reset threshold and lasts 40µs or less will not cause a reset pulse to be issued. A 0.1µF capacitor mounted as close as possible to the VCC provides additional transient immunity. UM8_ _L_E/M_E/J_E UM8_ _T_E/S_E/R_E/Z_E Figure 3. Maximum Transient Duration without Causing a Reset Pulse vs. Reset Comparator Overdrive ______________ Ensuring a Valid RESET Output Down to VCC = 0V _____________ When VCC falls below 1V, the UM821 RESET output no longer sinks current—it becomes an open _____________ circuit. Therefore, high-impedance CMOS-logic inputs connected to RESET can drift to undetermined voltages. This presents no problem in most applications since most µP and other _____________ circuitry is inoperative with VCC below 1V. However, in applications where RESET must be valid _____________ down to 0V, adding a pull-down resistor to RESET pin will causes any stray leakage currents to _____________ flow to ground, holding RESET low (Figure 4). R1’s value is not critical; 100kΩ is large enough _____________ _____________ not to load RESET and small enough to pull RESET to ground. A 100kΩ pull-up resistor to VCC is also recommended for the UM822 if RESET is required to remain valid for VCC < 1V. ________________________________________________________________________ http://www.union-ic.com Rev.01 Jan.2015 10/17 UM807/821/822 UM821 ____________ Figure 4. RESET Valid to VCC = Ground Circuit Interfacing to μPs with Bidirectional Reset Pins μPs with bidirectional reset pins (such as the Motorola68HC11 series) can contend with the ______________ UM821/822 reset outputs. If, for example, the UM821 RESET output is asserted high and the μP wants to pull it low, indeterminate logic levels may result. To correct such cases, connect a 4.7kΩ ______________ resistor between the UM821 RESET (or UM822 RESET) output and the μP reset I/O (Figure 5). Buffer the reset output to other system components. BUFFER Buffered RESET to Other System Components VCC VCC VCC UM821 RESET GND µP 4.7k RESET GND Figure 5. Interfacing to μPs with Bidirectional Reset I/O ________________________________________________________________________ http://www.union-ic.com Rev.01 Jan.2015 11/17 UM807/821/822 ______________ UM807 Open-Drain RESET Output Allows Use with Multiple Supplies Generally, the pull-up connected to the UM807 will connect to the supply voltage that is being monitored at the IC’s VCC pin. However, some systems may use the open-drain output to level-shift from the monitored supply to reset circuitry powered by some other supply (Figure 6). Note that as ______________ the UM807’s VCC decreases below 1V, so does the IC’s ability to sink current at RESET . Also, ______________ with any pull-up, RESET will be pulled high as VCC decays toward 0. The voltage where this occurs depends on the pull-up resistor value and the voltage to which it is connected. 5.0V 3.3V VCC Rpull-up VCC 5V System UM807 RESET RESET GND GND ______________ Figure 6. UM807 Open-Drain RESET Output Allows Use with Multiple Supplies ________________________________________________________________________ http://www.union-ic.com Rev.01 Jan.2015 12/17 UM807/821/822 Package Information UM807/821/822 SOT143 Outline Drawing e C 3 1 2 L E1 4 E L1 Symbol e1 Top View End View A1 A A2 D b2 b Side View A A1 A2 b b2 C D E E1 e e1 L1 L DIMENSIONS MILLIMETERS Min Max 0.763 1.220 0.013 0.150 0.750 1.070 0.300 0.510 0.760 0.930 0.080 0.200 2.800 3.040 2.200 2.640 1.200 1.400 1.920BSC 0.200BSC 0.540REF 0.400 0.600 INCHES Min Max 0.031 0.049 0.001 0.006 0.030 0.043 0.012 0.020 0.030 0.037 0.003 0.008 0.112 0.122 0.088 0.211 0.048 0.056 0.077BSC 0.008BSC 0.022 0.016 0.024 Land Pattern 1.92 0.80 0.20 0.90 0.50 NOTES: 1. Compound dimension: 2.90×1.30; 2. Unit: mm; 3. General tolerance ±0.05mm unless otherwise specified; 4. The layout is just for reference. XXX M Tape and Reel Orientation ________________________________________________________________________ http://www.union-ic.com Rev.01 Jan.2015 13/17 UM807/821/822 Selection Table Part Number RESET Threshold (V) Timeout Period (ms) UM807LAE 4.63 240 UM807MAE 4.38 240 UM807JAE 4.00 240 UM807TAE 3.08 240 UM807SAE 2.93 240 UM807RAE 2.63 240 UM807ZAE 2.32 240 UM807LBE 4.63 240 UM807MBE 4.38 240 UM807JBE 4.00 240 UM807TBE 3.08 240 UM807SBE 2.93 240 UM807RBE 2.63 240 UM807ZBE 2.32 240 UM807LCE 4.63 240 UM807MCE 4.38 240 UM807JCE 4.00 240 UM807TCE 3.08 240 UM807SCE 2.93 240 UM807RCE 2.63 240 UM807ZCE 2.32 240 Manual Reset Setup Period (s) 10.08 6.72 1.68 Output Type Open-Drain, Active Low Open-Drain, Active Low Open-Drain, Active Low Open-Drain, Active Low Open-Drain, Active Low Open-Drain, Active Low Open-Drain, Active Low Open-Drain, Active Low Open-Drain, Active Low Open-Drain, Active Low Open-Drain, Active Low Open-Drain, Active Low Open-Drain, Active Low Open-Drain, Active Low Open-Drain, Active Low Open-Drain, Active Low Open-Drain, Active Low Open-Drain, Active Low Open-Drain, Active Low Open-Drain, Active Low Open-Drain, Active Low Marking Code Package Type Shipping Qty SOT143 3000pcs/7Inch Tape & Reel 7LA 7MA 7JA 7TA 7SA 7RA 7ZA 7LB 7MB 7JB 7TB 7SB 7RB 7ZB 7LC 7MC 7JC 7TC 7SC 7RC 7ZC ________________________________________________________________________ http://www.union-ic.com Rev.01 Jan.2015 14/17 UM807/821/822 Selection Table (Continued) Part Number RESET Threshold (V) Timeout Period (ms) UM821LAE 4.63 240 UM821MAE 4.38 240 UM821JAE 4.00 240 UM821TAE 3.08 240 UM821SAE 2.93 240 UM821RAE 2.63 240 UM821ZAE 2.32 240 UM821LBE 4.63 240 UM821MBE 4.38 240 UM821JBE 4.00 240 UM821TBE 3.08 240 UM821SBE 2.93 240 UM821RBE 2.63 240 UM821ZBE 2.32 240 UM821LCE 4.63 240 UM821MCE 4.38 240 UM821JCE 4.00 240 UM821TCE 3.08 240 UM821SCE 2.93 240 UM821RCE 2.63 240 UM821ZCE 2.32 240 Manual Reset Setup Period (s) 10.08 6.72 1.68 Output Type Push-Pull, Active Low Push-Pull, Active Low Push-Pull, Active Low Push-Pull, Active Low Push-Pull, Active Low Push-Pull, Active Low Push-Pull, Active Low Push-Pull, Active Low Push-Pull, Active Low Push-Pull, Active Low Push-Pull, Active Low Push-Pull, Active Low Push-Pull, Active Low Push-Pull, Active Low Push-Pull, Active Low Push-Pull, Active Low Push-Pull, Active Low Push-Pull, Active Low Push-Pull, Active Low Push-Pull, Active Low Push-Pull, Active Low Marking Code Package Type Shipping Qty SOT143 3000pcs/7Inch Tape & Reel 1LA 1MA 1JA 1TA 1SA 1RA 1ZA 1LB 1MB 1JB 1TB 1SB 1RB 1ZB 1LC 1MC 1JC 1TC 1SC 1RC 1ZC ________________________________________________________________________ http://www.union-ic.com Rev.01 Jan.2015 15/17 UM807/821/822 Selection Table (Continued) Part Number RESET Threshold (V) Timeout Period (ms) UM822LAE 4.63 240 UM822MAE 4.38 240 UM822JAE 4.00 240 UM822TAE 3.08 240 UM822SAE 2.93 240 UM822RAE 2.63 240 UM822ZAE 2.32 240 UM822LBE 4.63 240 UM822MBE 4.38 240 UM822JBE 4.00 240 UM822TBE 3.08 240 UM822SBE 2.93 240 UM822RBE 2.63 240 UM822ZBE 2.32 240 UM822LCE 4.63 240 UM822MCE 4.38 240 UM822JCE 4.00 240 UM822TCE 3.08 240 UM822SCE 2.93 240 UM822RCE 2.63 240 UM822ZCE 2.32 240 Manual Reset Setup Period (s) 10.08 6.72 1.68 Output Type Push-Pull, Active High Push-Pull, Active High Push-Pull, Active High Push-Pull, Active High Push-Pull, Active High Push-Pull, Active High Push-Pull, Active High Push-Pull, Active High Push-Pull, Active High Push-Pull, Active High Push-Pull, Active High Push-Pull, Active High Push-Pull, Active High Push-Pull, Active High Push-Pull, Active High Push-Pull, Active High Push-Pull, Active High Push-Pull, Active High Push-Pull, Active High Push-Pull, Active High Push-Pull, Active High Marking Code Package Type Shipping Qty SOT143 3000pcs/7Inch Tape & Reel 2LA 2MA 2JA 2TA 2SA 2RA 2ZA 2LB 2MB 2JB 2TB 2SB 2RB 2ZB 2LC 2MC 2JC 2TC 2SC 2RC 2ZC ________________________________________________________________________ http://www.union-ic.com Rev.01 Jan.2015 16/17 UM807/821/822 IMPORTANT NOTICE The information in this document has been carefully reviewed and is believed to be accurate. Nonetheless, this document is subject to change without notice. Union assumes no responsibility for any inaccuracies that may be contained in this document, and makes no commitment to update or to keep current the contained information, or to notify a person or organization of any update. Union reserves the right to make changes, at any time, in order to improve reliability, function or design and to attempt to supply the best product possible. Union Semiconductor, Inc Add: Unit 606, No.570 Shengxia Road, Shanghai 201210 Tel: 021-51093966 Fax: 021-51026018 Website: www.union-ic.com ________________________________________________________________________ http://www.union-ic.com Rev.01 Jan.2015 17/17