SS8037/8(G) Microprocessor Reset IC FEATURES DESCRIPTION The SS8037/8 are microprocessor (µP) supervisory circuits used to monitor the 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, +3.3V, +3.0V- powered circuits. Precision monitoring of +3V, +3.3V, and +5V power-supply voltages Fully specified over temperature Available in three output configurations Push-pull RESET output (SS8037L) Push-pull RESET output (SS8037H) Open-drain RESET output (SS8038L) Power-on reset pulse width of 140ms min Supply current of 10µA Guaranteed reset valid to VCC = +1V Power supply transient immunity No external components SOT23-3 package These circuits perform a single function: they assert a reset signal whenever the VCC supply voltage declines below a preset threshold, keeping it asserted for at least 140ms after VCC has risen above the reset threshold. Reset thresholds suitable for operation with a variety of supply voltages are available. The SS8038L has an open-drain output stage, while the SS8037H/L have push-pull outputs. The SS8038L’s open-drain RESET output requires a pull-up resistor that can be connected to a voltage higher than VCC. The SS8037L has an active-low RESET output, while the SS8037H has an active-high RESET output. The reset comparator is designed to ignore fast transients on VCC, and the outputs are guaranteed to be in the correct logic state for VCC down to 1V. APPLICATIONS Computers Controllers Intelligent instruments Critical µP and µC power monitoring Portable / battery-powered equipment Automotive Low supply current makes the SS8037/8 ideal for use in portable equipment. They are available in a 3-pin SOT23-3 package. This device is supplied with Pb-free lead finish (second-level interconnect). PIN CONFIGURATION TYPICAL APPLICATION 3 VCC V CC V CC R PULL-UP* SS8037/8 1 2 SOT23-3 RESET (RESET) GND µP RESET INPUT GND *SS8038 ONLY 10/6/2004 Rev.2.20 www.SiliconStandard.com 1 of 9 SS8037/8(G) ORDERING INFORMATION SS803xxxxxGT7x Pin Option GT7: Pb-free SOT-23-3 Threshold Voltage Option PART NUMBER THRESHOLD VOLTAGE OPTION SS8037L : Push-Pull Active Low Output SS8037H : Push-Pull Active High Output SS8038L : Open-Drain Output * xxx specifies the threshold voltage. e.g. 263 denotes the 2.63V threshold voltage. PIN OPTION 1: 1 2 RESET GND 3 VCC 2: RESET VCC GND 3: GND RESET VCC 4: GND VCC RESET 5: VCC GND RESET 6: VCC RESET GND *RESET for SS8037H SELECTION GUIDE AND MARKING INFORMATION PART/SUFFIX SS8038L463GT71 SS8038L438GT71 SS8038L400GT71 SS8038L308GT71 SS8038L293GT71 SS8038L263GT71 SS8037H463GT71 SS8037H438GT71 SS8037H400GT71 SS8037H308GT71 SS8037H293GT71 SS8037H263GT71 SS8037L463GT71 SS8037L438GT71 SS8037L400GT71 SS8037L308GT71 SS8037L293GT71 SS8037L263GT71 RESET THRESHOLD (V) 4.63 4.38 4.00 3.08 2.93 2.63 4.63 4.38 4.00 3.08 2.93 2.63 4.63 4.38 4.00 3.08 2.93 2.63 OUTPUT TYPE Open-Drain Open-Drain Open-Drain Open-Drain Open-Drain Open-Drain Push-Pull RESET Push-Pull RESET Push-Pull RESET Push-Pull RESET Push-Pull RESET Push-Pull RESET Push-Pull RESET Push-Pull RESET Push-Pull RESET Push-Pull RESET Push-Pull RESET Push-Pull RESET TOP MARK 689Fx 689Ex 689Dx 689Cx 689Bx 689Ax 688Lx 688Kx 688Jx 688Ix 688Hx 688Gx 688Fx 688Ex 688Dx 688Cx 688Bx 688Ax Note: T71: SOT23 pin-out option 1 Not all product options are released for mass production, please contact Silicon Standard for availability. 10/6/2004 Rev.2.20 www.SiliconStandard.com 2 of 9 SS8037/8(G) SELECTION GUIDE AND MARKING INFORMATION (cont.) PART/SUFFIX SS8038L463GT72 SS8038L438GT72 SS8038L400GT72 SS8038L308GT72 SS8038L293GT72 SS8038L263GT72 SS8037H463GT72 SS8037H438GT72 SS8037H400GT72 SS8037H308GT72 SS8037H293GT72 SS8037H263GT72 SS8037L463GT72 SS8037L438GT72 SS8037L400GT72 SS8037L308GT72 SS8037L293GT72 SS8037L263GT72 RESET THRESHOLD (V) 4.63 4.38 4.00 3.08 2.93 2.63 4.63 4.38 4.00 3.08 2.93 2.63 4.63 4.38 4.00 3.08 2.93 2.63 OUTPUT TYPE TOP MARK Open-Drain Open-Drain Open-Drain Open-Drain Open-Drain Open-Drain Push-Pull RESET Push-Pull RESET Push-Pull RESET Push-Pull RESET Push-Pull RESET Push-Pull RESET Push-Pull RESET Push-Pull RESET Push-Pull RESET Push-Pull RESET Push-Pull RESET Push-Pull RESET 687Fx 687Ex 687Dx 687Cx 687Bx 687Ax 686Lx 688Kx 6 686Jx 686Ix 686Hx 686Gx 686Fx 686Ex 686Dx 686Cx 686Bx 686Ax Note: T72: SOT23 pin-out option 2 Not all product options are released for mass production, please contact Silicon Standard for availability. PART/SUFFIX SS8038L463GT73 SS8038L438GT73 SS8038L400GT73 SS8038L308GT73 SS8038L293GT73 SS8038L263GT73 SS8037H463GT73 SS8037H438GT73 SS8037H400GT73 SS8037H308GT73 SS8037H293GT73 SS8037H263GT73 SS8037L463GT73 SS8037L438GT73 SS8037L400GT73 SS8037L308GT73 SS8037L293GT73 SS8037L263GT73 RESET THRESHOLD (V) 4.63 4.38 4.00 3.08 2.93 2.63 4.63 4.38 4.00 3.08 2.93 2.63 4.63 4.38 4.00 3.08 2.93 2.63 OUTPUT TYPE Open-Drain Open-Drain Open-Drain Open-Drain Open-Drain Open-Drain Push-Pull RESET Push-Pull RESET Push-Pull RESET Push-Pull RESET Push-Pull RESET Push-Pull RESET Push-Pull RESET Push-Pull RESET Push-Pull RESET Push-Pull RESET Push-Pull RESET Push-Pull RESET 691Fx 691Ex 691Dx 691Cx 691Bx 691Ax 690Lx 690Kx 690Jx 690Ix 690Hx 690Gx 690Fx 690Ex 690Dx 690Cx 690Bx 690Ax Note: T73: SOT23 pin-out option 3 Not all product options are released for mass production, please contact Silicon Standard for availability. 10/6/2004 Rev.2.20 www.SiliconStandard.com 3 of 9 SS8037/8(G) ABSOLUTE MAXIMUM RATINGS All terminal voltages with respect to GND VCC.……………………………..…….…….-0.3V to +6.0V RESET, RESET (push-pull)....…....-0.3V to (VCC + 0.3V) RESET (open drain)...….......................-0.3V to +6.0V Input Current, VCC ............................….................20mA Output Current, RESET, RESET ........................20mA Continuous Power Dissipation (TA = +70°C) 3-Pin SOT23 (derate 4mW/°C above +70°C)….320mW Operating Temperature Range …........-40°C to +105°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 = full range, TA = -40°C to +105°C, unless otherwise noted. Typical values are at TA = +25°C, VCC = 5V for 463/438/400 versions, VCC= 3.3V for 308/293 versions, and VCC = 3V for 263 version.) (Note 1) PARAMETER SYMBOL VCC Range Supply Current (SOT-23) ICC CONDITION 5.5 TA = -40°C +105°C 1.2 5.5 TA = -40°C +105°C SS803xx438x SS803xx400x VTH SS803xx308x SS803xx293x SS803xx263x 10/6/2004 Rev.2.20 TYP MAX UNITS 1.0 SS803xx463x Reset Threshold MIN TA = 0°C +70°C VCC<5.5V, 803xx463/438/400x 22 30 VCC<3.6V, 803xx308/293/263x 10 23 TA = +25°C 4.56 TA = -40°C to +85°C 4.50 4.63 TA = +85°C to +105°C 4.40 TA = +25°C 4.31 TA = -40°C to +85°C 4.25 TA = +85°C to +105°C 4.16 TA = +25°C 3.93 TA = -40°C to +85°C 3.89 4.10 TA = +85°C to +105°C 3.80 4.20 TA = +25°C 3.04 TA = -40°C to +85°C 3.00 TA = +85°C to +105°C 2.92 TA = +25°C 2.89 TA = -40°C to +85°C 2.85 3.00 TA = +85°C to +105°C 2.78 3.08 µA 4.70 4.75 4.86 4.38 4.45 4.50 4.56 4.00 3.08 4.06 3.11 V 3.15 3.23 2.93 2.63 2.96 TA = +25°C 2.59 TA = -40°C to +85°C 2.55 2.70 TA = +85°C to +105°C 2.50 2.76 www.SiliconStandard.com V 2.66 4 of 9 SS8037/8(G) ELECTRICAL CHARACTERISTICS (Cont.) (VCC = full range, TA = -40°C to +105°C, unless otherwise noted. Typical values are at TA = +25°C, VCC = 5V for 463/438/400 versions, VCC= 3.3V for 308/293 versions, and VCC = 3V for 263 version.) (Note 1) PARAMETER SYMBOL Reset Threshold Tempco VCC to Reset Delay (Note 2) CONDITION MIN 40 7 VCC = VTH to (VTH – 100mV) Reset Active Timeout Period RESET Output Current Low (push-pull active low, and open-drain active-low, SS8037L and SS8038L) RESET Output Current High (push-pull active low, SS8037L) RESET Output Current Low (push-pull active high, SS8037H) RESET Output Current High (push-pull active high, SS8037H) RESET Open-Drain Output Leakage Current (SS8038L) IOL IOH IOL IOH VCC = VTH max, SS803xx463/438/400 280 VCC = VTH max, SS803xx308/293/263 140 VCC = 2.5V, V RESET = 0.5V VCC = 5V, V RESET = 4.5V, SS8037L463/438/400 VCC = 3.3V, V RESET = 2.8V, SS8037L308/293 VCC = 3V, V RESET = 2.5V, SS8037L263 VCC = 5V, VRESET = 0.5V, SS8037H463/438/400 VCC = 3.3V, VRESET = 0.5V, SS8037H308/293 VCC = 3V, VRESET = 0.5V, SS8037H263 VCC = 2.5V, VRESET = 2V TYP MAX UNITS ppm/°C µs 640 ms 550 8 mA 4.5 mA 3 2 16 mA 12 10 2 VCC > VTH, RESET de-asserted mA 1 µA Note 1: Production testing done at TA = +25°C; limits over temperature guaranteed by design. Note 2: RESET output is for SS8037L/38L; RESET output is for SS8037H. 10/6/2004 Rev.2.20 www.SiliconStandard.com 5 of 9 SS8037/8(G) TYPICAL PERFORMANCE CHARACTERISTICS (VCC = full range, TA = -40°C to +105°C, unless otherwise noted. Typical values are at TA = +25°C, VCC = 5V for 463/438/400 versions, VCC= 3.3V for 308/293 versions, and VCC = 3V for 263 version.) Supply Current vs.Temperature (No Load) Power-up Reset Timeout vs. Temperature 600 803xx463/438/400, Vcc=5V 15 10 803xx308/293/263, Vcc=3.3V 5 803xxx463/438/400/308/293/263, Vcc=1V Power-up Reset Timeout (ms) Supply Current (µA) 20 803xx463/438/400 500 400 300 803xx308/293/263 200 100 0 0 -40 -20 0 20 40 60 -40 80 -20 Temperature (°C) 20 40 60 80 Temperature (°C) Power-down Reset Delay vs. Temperature (803xx308/293/263) Power-down Reset Delay vs. Temperature (803xx463/438/400) 140 VOD = VTH - VCC 60 50 VOD = 10mV 40 VOD = 20mV 30 20 VOD = 100mV 10 VOD = 200mV 0 -40 -20 0 20 40 Power-Down Reset Delay (u s) 70 Power-down Reset Delay (us) 0 VOD = VTH - VCC 120 100 VOD = 10mV 80 VOD = 20mV 60 40 VOD = 100mV 20 0 60 80 -40 -20 Temperature (°C) 0 20 40 60 80 Temperature (°C) Normalized Reset Threshold vs. Temperature 1.002 Normalized Threshold 1 0.998 0.996 0.994 0.992 0.99 0.988 -40 -20 0 20 40 60 80 Temperature (°C) 10/6/2004 Rev.2.20 www.SiliconStandard.com 6 of 9 SS8037/8(G) PIN DESCRIPTION PIN NAME 1 GND FUNCTION Ground RESET Output remains low while VCC is below the reset threshold, and for at least 140ms after VCC rises above the reset threshold. RESET Output remains high while VCC is below the reset threshold, and for at least 140ms after VCC rises above the reset threshold. (SS8037L/38L) 2 RESET (SS8037H) VCC 3 Supply Voltage (+5V, +3.3V, +3.0V) APPLICATIONS INFORMATION A microprocessor’s (µP’s) reset input starts the µP in a known state. The SS8037L/H and 8038L assert reset to prevent code-execution errors during power-up, power-down, or brownout conditions. They assert a reset signal whenever the VCC supply voltage declines below a preset threshold, keeping it asserted for at least 140ms after VCC has risen above the reset threshold. The SS8038L uses an open-drain output, and the SS8037L/37H have push-pull output stages. Connect a pull-up resistor on the SS8308L’s RESET output to any supply between 0 and 5.5V. 600 Maximum Transient Duration(us) 500 400 300 200 803xx 463/438/400 100 803xx308/293/263 0 1 10 100 1000 Reset Comparator Overdrive, VTH - V CC (mV) Figure 1. Maximum Transient Duration Without Causing a Reset Pulse vs. Reset Comparator Overdrive Fig 2. RESET Valid to V CC = Ground Circuit Figure 1 shows typical transient duration vs. reset comparator overdrive, for which the SS8037L/H/8038L do not generate a reset pulse. The graph was generated using a negative-going pulse applied to VCC, starting 0.5V above the actual reset threshold and ending below it by the magnitude indicated (reset comparator overdrive). The graph indicates the maximum pulse width a negative-going VCC transient can have without causing a reset pulse. As the magnitude of the transient increases (goes farther below the reset threshold), the maximum allowable pulse width decreases. Typically, for the SS803xx 463 and SS803xx438, a V CC transient that goes 100mV below the reset threshold and lasts 7µs or less will not cause a reset pulse. A 0.1µF bypass capacitor mounted as close as possible to the VCC pin provides additional transient immunity. Ensuring a Valid Reset Output Down to VCC = 0 When VCC falls below 1V, the SS8037 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 causes any stray leakage currents to flow to ground, holding RESET low (Figure 2). R1’s value is not critical; 100kΩ is large enough not to load RESET and small enough to pull RESET to ground. VCC A 100kΩ pull-up resistor to VCC is also recommended for the SS8038L if RESET is required to remain valid for VCC < 1V. SS8037 RESET GND 10/6/2004 Rev.2.20 Negative-Going VCC Transients In addition to issuing a reset to the µP during power-up, power-down, and brownout conditions, the SS8037L/H/8038L are relatively immune to shortduration negative-going VCC transients (glitches). R1 100k www.SiliconStandard.com 7 of 9 SS8037/8(G) VCC VCC VCC RPULL-UP µP 8038 RESET MOTOROLA INPUT 68HCXX RESET GND GND Figure 3. Interfacing to µPs with bidirectional reset I/O +5.0V +3.3V VCC VCC RPULL-UP 8038 RESET GND Interfacing to µPs with Bidirectional Reset Pins Since the RESET output on the SS8038L is open drain, this device interfaces easily with µPs that have bidirectional reset pins, such as the Motorola 68HC11. Connecting the µP supervisor’s RESET output directly to the microcontroller’s (µC’s) RESET pin with a single pull-up resistor allows either device to assert reset (Figure 3). 8038L Open-Drain RESET Output Allows Use with Multiple Supplies Generally, the pull-up connected to the SS8038L 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 4). Note that as the SS8038L’s V CC 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. 5V SYSTEM RESET INPUT GND Figure 4. SS8038L open-drain RESET output allows use with multiple supplies Benefits of Highly Accurate Reset Threshold Most µP supervisor ICs have reset threshold voltages between 5% and 10% below the value of nominal supply voltages. This ensures a reset will not occur within 5% of the nominal supply, but will occur when the supply is 10% below nominal. When using ICs rated at only the nominal supply ±5%, this leaves a zone of uncertainty where the supply is between 5% and 10% low, and where the reset may or may not be asserted. The SS803xx463/803xx308 use highly accurate circuitry to ensure that reset is asserted close to the 5% limit, and long before the supply has declined to 10% below nominal. 10/6/2004 Rev.2.20 www.SiliconStandard.com 8 of 9 SS8037/8(G) PHYSICAL DIMENSIONS C D L E H e θ1 A A2 A1 Feed Direction SOT23 Package Orientation b SOT 23 (T7) Package Note: 1.Package body sizes exclude mold flash protrusions or gate burrs 2.Tolerance ±0.1000 mm (4mil) unless otherwise specified 3.Coplanarity: 0.1000mm 4.Dimension L is measured in gage plane MIN DIMENSIONS IN MILLIMETERS NOM MAX A 1.00 1.10 1.30 A1 0.00 ----- 0.10 A2 0.70 0.80 0.90 b 0.35 0.40 0.50 C 0.10 0.15 0.25 D 2.70 2.90 3.10 E 1.40 1.60 1.80 SYMBOLS e ----- 1.90(TYP) ----- H 2.60 2.80 3.00 L 0.37 ------ ----- 1º 5º 9º Θ1 Information furnished by Silicon Standard Corporation is believed to be accurate and reliable. However, Silicon Standard Corporation makes no guarantee or warranty, express or implied, as to the reliability, accuracy, timeliness or completeness of such information and assumes no responsibility for its use, or for infringement of any patent or other intellectual property rights of third parties that may result from its use. Silicon Standard reserves the right to make changes as it deems necessary to any products described herein for any reason, including without limitation enhancement in reliability, functionality or design. No license is granted, whether expressly or by implication, in relation to the use of any products described herein or to the use of any information provided herein, under any patent or other intellectual property rights of Silicon Standard Corporation or any third parties. 10/6/2004 Rev.2.20 www.SiliconStandard.com 9 of 9