MIC803 3-Pin Microprocessor Supervisor Circuit with Open-Drain Reset Output General Description Features The MIC803 is a single-voltage supervisor with open-drain reset output that provides accurate power supply monitoring and reset generation in microprocessor based systems. The function of the device is to assert a reset signal if the power supply voltage drops below the Reset Threshold voltage, and retain this reset for the Reset Timeout Period once the power supply increases above the Reset Threshold voltage. * * * * * * * * * The MIC803 consumes only 4.5A of supply current and offers three reset delay periods of 20ms, 140ms and 1120ms (min). It features factory programmed reset threshold levels from 2.63V to 4.63V to accommodate 3.0V, 3.3V, and 5.0V power supplies. It is available in the compact 3-pin SC-70 and SOT-23 packages. 4.5A supply current (typical) at 3.6V Open-Drain /RESET output /RESET remains valid with VCC as low as 1V 20ms, 140ms, or 1120ms (min) reset timeout Options 2.63V to 4.63V Preset Voltage Threshold Options 2.5% Voltage Threshold Accuracy over temperature 3-pin SC70-3 package (2.0mm x 2.1mm) 3-pin SOT-23 package (2.3mm x 2.9mm) -40C to +125C Junction Temperature Range Applications * Critical microcomputer power monitoring * Portable equipment * Solid state drives * Printers/computers * Embedded controllers ____________________________________________________________________________________________________________ Typical Application VCC VCC VCC 100k MIC803 RESET GND P RESET GND Micrel Inc. * 2180 Fortune Drive * San Jose, CA 95131 * USA * tel +1 (408) 944-0800 * fax + 1 (408) 474-1000 * http://www.micrel.com December 2010 M9999-122310-A Micrel, Inc. MIC803 Ordering Information (1) Marking Nominal VTH (V) Min. tRESET (2) (ms) Junction Temperature Range Package MIC803-46D2VC3 AS 4.63 20 -40 to +125C SC70-3 MIC803-44D2VC3 AP 4.38 20 -40 to +125C SC70-3 MIC803-41D2VC3 AK 4.10 20 -40 to +125C SC70-3 MIC803-40D2VC3 A2 4.00 20 -40 to +125C SC70-3 MIC803-31D2VC3 AG 3.08 20 -40 to +125C SC70-3 MIC803-30D2VC3 AV 3.00 20 -40 to +125C SC70-3 MIC803-29D2VC3 AD 2.93 20 -40 to +125C SC70-3 MIC803-26D2VC3 AA 2.63 20 -40 to +125C SC70-3 MIC803-46D3VC3 AT 4.63 140 -40 to +125C SC70-3 MIC803-44D3VC3 AQ 4.38 140 -40 to +125C SC70-3 MIC803-41D3VC3 AM 4.10 140 -40 to +125C SC70-3 MIC803-40D3VC3 A5 4.00 140 -40 to +125C SC70-3 MIC803-31D3VC3 A4 3.08 140 -40 to +125C SC70-3 MIC803-30D3VC3 AX 3.00 140 -40 to +125C SC70-3 MIC803-29D3VC3 AE 2.93 140 -40 to +125C SC70-3 MIC803-26D3VC3 AB 2.63 140 -40 to +125C SC70-3 MIC803-46D4VC3 AU 4.63 1120 -40 to +125C SC70-3 MIC803-44D4VC3 AR 4.38 1120 -40 to +125C SC70-3 MIC803-41D4VC3 AN 4.10 1120 -40 to +125C SC70-3 MIC803-40D4VC3 A6 4.00 1120 -40 to +125C SC70-3 MIC803-31D4VC3 AJ 3.08 1120 -40 to +125C SC70-3 MIC803-30D4VC3 AZ 3.00 1120 -40 to +125C SC70-3 Part Number MIC803-29D4VC3 A3 2.93 1120 -40 to +125C SC70-3 MIC803-26D4VC3 AC 2.63 1120 -40 to +125C SC70-3 MIC803-46D2VM3 AS 4.63 20 -40 to +125C SOT23-3 MIC803-44D2VM3 AP 4.38 20 -40 to +125C SOT23-3 MIC803-41D2VM3 AK 4.10 20 -40 to +125C SOT23-3 MIC803-40D2VM3 A2 4.00 20 -40 to +125C SOT23-3 MIC803-31D2VM3 AG 3.08 20 -40 to +125C SOT23-3 MIC803-30D2VM3 AV 3.00 20 -40 to +125C SOT23-3 MIC803-29D2VM3 AD 2.93 20 -40 to +125C SOT23-3 MIC803-26D2VM3 AA 2.63 20 -40 to +125C SOT23-3 MIC803-46D3VM3 AT 4.63 140 -40 to +125C SOT23-3 MIC803-44D3VM3 AQ 4.38 140 -40 to +125C SOT23-3 MIC803-41D3VM3 AM 4.10 140 -40 to +125C SOT23-3 MIC803-40D3VM3 A5 4.00 140 -40 to +125C SOT23-3 MIC803-31D3VM3 A4 3.08 140 -40 to +125C SOT23-3 MIC803-30D3VM3 AX 3.00 140 -40 to +125C SOT23-3 MIC803-29D3VM3 AE 2.93 140 -40 to +125C SOT23-3 MIC803-26D3VM3 AB 2.63 140 -40 to +125C SOT23-3 December 2010 2 M9999-122310-A Micrel, Inc. MIC803 (2) Marking Nominal VTH (V) MIC803-46D4VM3 AU 4.63 MIC803-44D4VM3 AR 4.38 MIC803-41D4VM3 AN 4.10 MIC803-40D4VM3 A6 4.00 1120 -40 to +125C SOT23-3 MIC803-31D4VM3 AJ 3.08 1120 -40 to +125C SOT23-3 MIC803-30D4VM3 AZ 3.00 1120 -40 to +125C SOT23-3 MIC803-29D4VM3 A3 2.93 1120 -40 to +125C SOT23-3 MIC803-26D4VM3 AC 2.63 1120 -40 to +125C SOT23-3 Part Number Junction Temperature Range Package 1120 -40 to +125C SOT23-3 1120 -40 to +125C SOT23-3 1120 -40 to +125C SOT23-3 Min. tRESET (ms) Notes: 1. 1: All devices available in Tape and Reel only. 2. 2: -40 to +85C Temp. Range Part Numbering Convention: Pin Configuration 3-Pin SC70 3-Pin SOT-23 Pin Description Pin Number Pin Name 1 GND 2 /RESET 3 VCC December 2010 Pin Function Ground Pin /RESET goes low if VCC falls below the reset threshold (VTH), and remains asserted for one timeout period after VCC exceeds VTH Power Supply Input and monitored voltage 3 M9999-122310-A Micrel, Inc. MIC803 Absolute Maximum Ratings(1) Operating Ratings(2) Supply Voltage (VCC)....................................... -0.3V to 6.0V Reset Output (/RESET)................................... -0.3V to 6.0V Input Current (VCC) ......................................................20mA Output Current (/RESET) ............................................20mA Rate of Rise (VCC) ................................................... 100V/us Junction Temperature (TJ)..................................+150C Lead Temperature (soldering, 10sec.)....................... 260C Storage Temperature (TS)..........................-65C to +150C ESD Rating(3) .................................................................. 3kV Supply Voltage (VCC)........................................ 1.0V to 5.5V Reset Output Voltage (/RESET) ...................... 0.0V to 5.5V Junction Temperature (TJ) ........................ -40C to +125C Junction Thermal Resistance 3-Pin SC70 (JA) ..............................................260C/W 3-Pin SOT23 (JA)............................................203C/W Electrical Characteristics(4) For typical values, VCC = 5.0V for MIC803-46/44/41/40, VCC = 3.3V for MIC803-31/30/29, VCC = 3.0V for MIC803-26; TJ = 25C, Bold values indicate -40C < TJ < +125C; unless noted. Parameter Conditions Min Typ Max TJ = -40C to +85C 1.0 5.5 TJ = -40C to +125C 1.2 5.5 Units Power Supply Input Operating Voltage Range (VCC) TJ = -40C to +85C Supply Current (ICC) TJ = +85C to +125C VCC = 5.5V, no Load 5.5 15 VCC = 3.6V, no Load 4.5 10 VCC = 5.5V, no Load 18 VCC = 3.6V, no Load 13 V A Voltage Threshold MIC803-46 MIC803-44 MIC803-41 MIC803-40 Reset Threshold (VTH) MIC803-31 MIC803-30 MIC803-29 MIC803-26 December 2010 TJ = -40C to +85C 4.50 TJ = -40C to +125C 4.44 TJ = -40C to +85C 4.25 TJ = -40C to +125C 4.20 TJ = -40C to +85C 4.00 TJ = -40C to +125C 3.97 TJ = -40C to +85C 3.89 TJ = -40C to +125C 3.80 TJ = -40C to +85C 3.00 TJ = -40C to +125C 2.95 TJ = -40C to +85C 2.93 TJ = -40C to +125C 2.90 TJ = -40C to +85C 2.82 TJ = -40C to +125C 2.81 TJ = -40C to +85C 2.55 TJ = -40C to +125C 2.50 4 4.63 4.75 4.82 4.38 4.50 4.56 4.10 4.20 4.24 4.00 4.10 4.20 3.08 3.15 V 3.21 3.00 3.08 3.11 2.93 3.00 3.05 2.63 2.70 2.76 M9999-122310-A Micrel, Inc. MIC803 Electrical Characteristics (Continued) For typical values, VCC = 5.0V for MIC803-46/44/41/40, VCC = 3.3V for MIC803-31/30/29, VCC = 3.0V for MIC803-26; TJ = 25C, Bold values indicate -40C < TJ < +125C; unless noted. Parameter Conditions Min Typ Max Units Reset Time VCC to /RESET Delay (tD) VCC = VTH to (VTH - 100mV) D2 Reset Timeout Period (tRESET) D3 D4 15 TJ = -40C to +85C 20 TJ = +85C to +125C 16 TJ = -40C to +85C 140 TJ = +85C to +125C 112 TJ = -40C to +85C 1120 TJ = +85C to +125C 900 s 35 44 230 360 48 420 1800 ms 2400 3200 Reset Output /RESET Output Voltage (VOL) /RESET Output Leakage VCC 4.0V, ISINK = 3.2mA 0.4 V VCC > 2.5V, ISINK = 1.2mA 0.3 V VCC 1.0V, ISINK = 50A 0.3 V 1 A VCC > VTH, /RESET deasserted Notes: 1. Exceeding the absolute maximum rating may damage the device. 2. The device is not guaranteed to function outside its operating rating. 3. Devices are ESD sensitive. Handling precautions recommended. Human body model, 1.5k in series with 100pF. 4. Specification for packaged product only. December 2010 5 M9999-122310-A Micrel, Inc. MIC803 Typical Characteristics 30 6 5 4 3 300 V CC = VTH to VTH-100mV 25 20 15 10 5 0 -50 -20 10 40 70 100 V CC = 5.5V 280 260 240 220 200 -50 130 -20 TEMPERATURE (C) 10 40 70 100 130 -50 TEMPERATURE (C) Normalized Reset Threshold vs. Temperature 0.992 0.988 -20 10 40 70 TEMPERATURE (C) December 2010 100 130 70 100 130 V TH = 2.93V 6 4 2 0 -50 40 50 VTH = 2.93V MAXIMUM TRANSIENT DURATION (s) SUPPLY CURRENT (A) 0.996 10 Maximum Transient Duration vs Overdrive 8 1.000 -20 TEMPERATURE (C) VCC Operating Supply Current vs. Supply Voltage 1.004 NORMALIZED RESET THRESHOLD (V) RESET TIMEOUT PERIOD (ms) VCC = 3.6V VCC to /RESET DELAY (s) SUPPLY CURRENT (A) 7 Reset Timeout Period (D3) vs. Temperature VCC to /RESET Delay vs. Temperature VCC Operating Supply Current vs. Temperature 40 30 20 10 0 0 1 2 3 4 SUPPLY VOLTAGE (V) 6 5 6 0 200 400 600 800 1000 OVERDRIVE VOLTAGE, VTH - VCC (mV) M9999-122310-A Micrel, Inc. MIC803 Timing Diagram Functional Diagram MIC803 RESET (2) VCC (3) RESET GENERATOR + - VTH GND (1) December 2010 7 M9999-122310-A Micrel, Inc. MIC803 Application Information Microprocessor Reset The /RESET pin is asserted whenever VCC falls below the Reset Threshold Voltage, VTH. The /RESET pin remains asserted for the duration of the Reset Timeout Period (tRESET) after VCC has risen above the Reset Threshold Voltage. The reset function ensures the microprocessor is properly reset and powers up in a known condition after a power failure. /RESET will remain valid with VCC as low as 1.0V. The /RESET output is a simple open-drain N-channel MOSFET structure. A pull-up resistor must be used to pull this output up to some voltage. For most applications, this voltage will be the same power supply that supplies VCC to the MIC803. As shown in Figure 1, it is possible, however, to tie this resistor to some other voltage. This will allow the MIC803 to monitor one voltage while level-shifting the /RESET output to some other voltage. The pull-up voltage must be limited to 5.5V. The resistor must be small enough to supply current to the inputs and leakage paths that are driven by the /RESET output. Figure 2. /RESET at falling VCC Wire OR'ing The /RESET Output Since the /RESET output is open-drain, several reset sources can be wire-ORed, in parallel, to allow resets from multiple sources. VCC Transients The MIC803 is relatively immune to negative-going VCC glitches below the Reset Threshold. See the Typical Characteristic Curve, Maximum Transient Duration vs Overdrive on page 6 of the datasheet. As shown in Figure 3, the Overdrive Voltage is the difference between the Threshold Voltage and the minimum point of the VCC glitch. Typically, an overdrive of 100mV, with duration of 15s or less will not cause a reset. If additional transient immunity is needed, a 0.1F bypass capacitor can be placed as close as possible to the MIC803 on the VCC pin. Figure 1. MIC803 used in a Multiple Supply System /RESET Valid at Low Voltage As VCC drops to 0V, the MIC803 will no longer be able to pull the /RESET output low, and the pull-up resistor will pull the output high. The value of the pull-up resistor and the voltage it is connected to will affect the point at which this happens. December 2010 Figure 3. VCC Transient 8 M9999-122310-A Micrel, Inc. MIC803 Package Information 3-Pin SC-70 (C3) December 2010 9 M9999-122310-A Micrel, Inc. MIC803 3-Pin SOT-23 (M3) MICREL, INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA TEL +1 (408) 944-0800 FAX +1 (408) 474-1000 WEB http://www.micrel.com Micrel makes no representations or warranties with respect to the accuracy or completeness of the information furnished in this data sheet. This information is not intended as a warranty and Micrel does not assume responsibility for its use. Micrel reserves the right to change circuitry, specifications and descriptions at any time without notice. No license, whether express, implied, arising by estoppel or otherwise, to any intellectual property rights is granted by this document. Except as provided in Micrel's terms and conditions of sale for such products, Micrel assumes no liability whatsoever, and Micrel disclaims any express or implied warranty relating to the sale and/or use of Micrel products including liability or warranties relating to fitness for a particular purpose, merchantability, or infringement of any patent, copyright or other intellectual property right. Micrel Products are not designed or authorized for use as components in life support appliances, devices or systems where malfunction of a product can reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that (a) are intended for surgical implant into the body or (b) support or sustain life, and whose failure to perform can be reasonably expected to result in a significant injury to the user. A Purchaser's use or sale of Micrel Products for use in life support appliances, devices or systems is a Purchaser's own risk and Purchaser agrees to fully indemnify Micrel for any damages resulting from such use or sale. (c) 2010 Micrel, Incorporated. December 2010 10 M9999-122310-A