CAT823, CAT824, CAT825 System Supervisory Voltage Reset with Watchdog and Manual Reset FEATURES DESCRIPTION Automatically restarts microprocessor after Power failure The CAT823, CAT824, and CAT825 provide basic reset and monitoring functions for the electronic systems. Each device monitors the system voltage and maintains a reset output until that voltage reaches the device’s specified trip value and then maintains the reset output active condition until the device’s internal timer, after a minimum timer of 140ms; to allow the systems power supply to stabilize. Monitors pushbutton for external override Accurate under voltage system monitoring Brownout detection system reset for use with 3.0, 3.3, and 5.0 volt systems Pin and function compatible with the MAX823/24/25 products The CAT823 and CAT824 also have a watchdog input which can be used to monitor a system signal and cause a reset to be issued if the signal fails to change state prior to a timeout condition. Operating Range from -40°C to +85°C Available in TSOT-23 5-lead and SC-70 packages For Ordering Information details, see page 13. The CAT823 and CAT825 also provide a manual reset input which can be used to initiate reset if pulled low. This input can be directly attached to a pushbutton or a processor signal. APPLICATIONS Microprocessor and Microcontroller based systems Intelligent Instruments Control Systems Critical µP Monitors Portable Equipment PIN FUNCTIONS PIN CONFIGURATION Pin Name TSOT-23 5-Lead SC-70 5-Lead RESET 1 GND 2 MR 3 5 VCC CAT823 4 WDI ¯¯¯¯¯¯ RESET RESET 1 GND 2 RESET 3 5 VCC WDI Ground ¯¯¯ MR Manual Reset input – Pulled high Internally by a 52kΩ resistor designed to be driven low by a mechanical pushbutton, open drain output or CMOS output. RESET RESET 1 GND 2 RESET 3 5 VCC CAT825 © Catalyst Semiconductor, Inc. Characteristics subject to change without notice 4 MR 1 CMOS Push-Pull Active Low Reset Output GND CAT824 4 Function CMOS Push-Pull Active High Reset Output WDI Watchdog Timer Input – Designed to be driven by a processor output or can be disabled by tri-stating or leaving open. VCC Power Supply Doc. No. MD-3027, Rev. B CAT823, CAT824, CAT825 BLOCK DIAGRAM VCC TIMEOUT COMPARATOR LEVEL SENSE & TIMER WDI* RESET VCC TOLERANCE BIAS VCC DIGITAL DELAY + VCC – VCC VOLTAGE REFERENCE RESET* 52kΩ LEVEL SENSE & DEBOUNCE MR* * Functions Available by Device Device ¯¯¯¯¯¯ RESET CAT823 x CAT824 x x CAT825 x x Doc. No. MD-3027, Rev. B RESET ¯¯¯ MR WDI x x x x 2 © Catalyst Semiconductor, Inc. Characteristics subject to change without notice CAT823, CAT824, CAT825 ABSOLUTE MAXIMUM RATINGS (1) Parameters Ratings Units 6 V -0.3 to (VCC + 0.3) V Input Current, VCC 20 mA Output Current RST, ¯¯¯¯ RST 20 mA SC-70 5-lead (derate 3.1mW/ºC above +70ºC) 247 mW TSOT-23 5-lead (derate 7.1mW/ºC above +70ºC) 571 mW Storage Temperature -65 to 150 ºC Operating Ambient Temperature -40 to +85 ºC Lead Soldering (10 seconds max) +300 ºC ESD Rating: Low Voltage Pins Human Body Model 2000 V 200 V Range Units 1.0 to 5.5 V Supply Voltage All other pins Continuous Power Dissipations (TA = +70ºC) Machine Model RECOMMENDED OPERATING CONDITIONS Parameter VCC (TA = 0ºC to +70ºC) VCC (TA = -40ºC to +85ºC) All Other Pins Ambient Temperature 1.2 to 5.5 V -0.1 to (VCC + 0.1) V -40 to +85 ºC Notes: (1) Stresses above 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 outside of those listed in the operational sections of this specification is not implied. Exposure to any absolute maximum rating for extended periods may affect device performance and reliability. © Catalyst Semiconductor, Inc. Characteristics subject to change without notice 3 Doc. No. MD-3027, Rev. B CAT823, CAT824, CAT825 ELECTRICAL OPERATING CHARACTERISTICS DC Characteristics: VCC = 3.0V to 5.5V for L/M versions; VCC = 2.0V to 3.6V for the R/S/T/Y/Z version, -40ºC ≤ TA ≤ +85ºC unless otherwise noted. Typical Values at TA = 25ºC and VCC = 5V for L/M versions; VCC = 3.3V for the T/S versions; VCC = 3.0V for the R version; and VCC = 2.5V for the Y/Z versions. (1) Symbol Parameter ICC VRST Conditions Supply Current Reset Threshold Min Typ Max Units CAT823 (L/M Versions) CAT824 (L/M Versions) 6 17 µA CAT823 (R/S/T/Y/Z Versions) CAT824 (R/S/T/Y/Z Versions) 4 12 µA CAT825 (L/M Versions) 3 8 µA CAT825 (R/S/T/Y/Z Versions) 2 6 µA CAT82_L at -40ºC ≤ TA ≤ +85ºC 4.50 4.63 4.75 V CAT82_M at -40ºC ≤ TA ≤ +85ºC 4.25 4.38 4.50 V CAT82_T at -40ºC ≤ TA ≤ +85ºC 3.00 3.08 3.15 V CAT82_S at -40ºC ≤ TA ≤ +85ºC 2.85 2.93 3.00 V CAT82_R at -40ºC ≤ TA ≤ +85ºC 2.55 2.63 2.70 V CAT82_Z at -40ºC ≤ TA ≤ +85ºC 2.25 2.32 2.38 V CAT82_Y at -40ºC ≤ TA ≤ +85ºC 2.13 2.19 2.25 V Reset Threshold Tempco Reset Threshold Hysteresis (2) tRD VCC to Reset Delay tRP Reset Active Timeout Period VOH ¯¯¯¯¯¯ Output High RESET Voltage VOL ISOURCE ¯¯¯¯¯¯ Output Low RESET Voltage ppm/ºC CAT82_L/M 10 mV CAT82_R/S/T/Y/Z 5 mV VCC = VTH to (VTH - 100mV) 20 µs 140 200 CAT82_L/M, VCC = VRST max, ISOURCE = -120µA VCC - 1.5V CAT82_T/S/R/Z/Y, VCC = VRST max, ISOURCE = -30µA 0.8 x VCC 0.4 CAT82_T/S/R/Z/Y, VCC = VRST min, ISINK = 1.2mA 0.3 TA = 0ºC to +70ºC, VCC = 1V, VCC falling, ISINK = 50µA 0.3 TA = TMIN to TMAX, VCC = 1.2V, VCC falling, ISINK = 100µA 0.3 VCC > 1.8V, ISOURCE = -150µA Reset Output Voltage 400 CAT82_L/M, VCC = VRST min, ISINK = 3.2mA ms V CAT82_L/M, Reset = 0V, VCC = 5.5V ¯¯¯¯¯¯ Output RESET Short-Circuit Current CAT82_L/M, Reset = 0V, VCC = 3.6V VOH VOL 40 1.5 0.8 mA 0.8 x VCC CAT824L/M & CAT825L/M, VCC = VRST max, ISINK = 3.2mA 0.4 CAT824R/S/T/Y/Z & CAT825R/S/T/Y/Z, VCC = VRST max, ISINK = 1.2mA 0.3 V Notes: (1) Over-temperature limits are guaranteed by design and not production tested. (2) The RESET short-circuit current is the maximum pull-up current when reset is driven low by a bidirectional output. Doc. No. MD-3027 Rev. B 4 © Catalyst Semiconductor, Inc. Characteristics subject to change without notice CAT823, CAT824, CAT825 ELECTRICAL OPERATING CHARACTERISTICS (continued) DC Characteristics: VCC = 3.0V to 5.5V for L/M versions; VCC = 2.0V to 3.6V for the R/S/T/Y/Z version, -40ºC ≤ TA ≤ +85ºC unless otherwise noted. Typical Values at TA = 25ºC and VCC = 5V for L/M versions; VCC = 3.3V for the T/S versions; VCC = 3.0V for the R version; and VCC = 2.5V for the Y/Z versions. Symbol Parameter Conditions Min Typ Max 1.12 1.60 3.20 Units WATCHDOG INPUT (CAT823 & CAT824) tWD Watchdog Timeout Period tWDI WDI Pulse Width VIL VIH VIL = 0.4V, VIH = 0.8 x VCC 0.7 x VCC WDI = VCC, Time Average WDI = 0V, Time Average 120 -20 s ns 0.3 x VCC WDI Input Voltage (3) WDI Input Current (4) 50 160 -15 V µA MANUAL RESET INPUT(CAT823 & CAT825) VIL VIH tPB tPDLY 0.3 x VCC ¯¯¯ MR Input Voltage 0.7 x VCC ¯¯¯ MR Pulse Width ¯¯¯ MR low to Reset Delay ¯¯¯ MR Noise Immunity ¯¯¯ MR Pullup Resistance (internal) 1 µs 5 Pulse Width with No Reset 100 35 V 52 µs ns 75 kΩ Notes: (3) WDI is internally serviced within the watchdog period if WDI is left open. (4) The WDI input current is specified as an average input current when the WDI input is driven high or low. The WDI input if connected to a three-stated output device can be disabled in the tristate mode as long as the leakage current is less than 10µA and a maximum capacitance of less than 200pF. To clock the WDI input in the active mode the drive device must be able to source or sink at least 200µA when active. © Catalyst Semiconductor, Inc. Characteristics subject to change without notice 5 Doc. No. MD-3027, Rev. B CAT823, CAT824, CAT825 TYPICAL ELECTRICAL OPERATING CHARACTERISTICS TABLES Normalized Reset Threshold Voltage vs. Temperature VCC Supply Current vs. Temperature NORMALIZED RESET THRESHOLD (V) 9 SUPPLY CURRENT (µA 8 7 6 5 4 3 2 1 -40 -20 0 20 40 60 1.04 1.02 1.00 0.98 0.96 0.94 -40 80 100 120 -20 0 20 40 60 80 100 TEM PERATURE (ºC) TEMPERATURE (°C) TEMPERATURE (ºC) Doc. No. MD-3027 Rev. B 1.06 6 © Catalyst Semiconductor, Inc. Characteristics subject to change without notice CAT823, CAT824, CAT825 FUNCTIONAL DESCRIPTION PROCESSOR RESET The CAT823-825 detect supply voltage (VCC) conditions that are below the specified voltage trip value (VRST) and provide a reset output to maintain ¯¯¯¯¯¯ (and correct system operation. On power-up, RESET RESET if available) are kept active for a minimum delay tRP of 140ms after the supply voltage (VCC) rises above VRST to allow the power supply and processor to stabilize. When VCC drops below the voltage trip ¯¯¯¯¯¯ (and value (VRST), the reset output signals RESET ¯¯¯¯¯¯ (and RESET if RESET) are pulled active. RESET available) is specifically designed to provide the reset input signals for processors. This provides reliable and consistent operation as power is turned on, off or during brownout conditions by maintaining the processor operation in known conditions. MANUAL RESET The CAT823 and CAT825 each have a Manual Reset ¯¯¯) input to allow for alternative control of the reset (MR outputs. The ¯¯¯ MR input is designed for direct connection to a pushbutton (see Figure 1). The ¯¯¯ MR input is internally pulled up by 52kΩ resistor and must be pulled low to cause the reset outputs to go active. Internally, this input is debounced and timed such that ¯¯¯¯¯¯ (and RESET) signals of at least 140ms RESET minimum will be generated. The min 140ms tRP delay commences as the Manual Reset input is released from the low level. (see Figure 2) Figure 1. Pushbutton RESET MR Supply Voltage RESET CAT825 VCC GND RESET Figure 2. Timing Diagram – Pushbutton RESET tPB MR tPDLY VIH VIL tRP RESET VOH VOL RESET © Catalyst Semiconductor, Inc. Characteristics subject to change without notice 7 Doc. No. MD-3027, Rev. B CAT823, CAT824, CAT825 WATCHDOG TIMER The CAT823 and CAT824 provide a Watchdog input ¯¯¯¯¯¯ (WDI). The watchdog timer function forces RESET (and RESET in the CAT824) signals active when the WDI input does not have a transition from low-to-high or high-to-low within 1.12 seconds. Timeout of the ¯¯¯¯¯¯ (RESET on the watchdog starts when RESET CAT824) becomes inactive. If a transition occurs on the WDI input pin prior to the watchdog time-out, the watchdog timer is reset and begins to time-out again. If the watchdog timer is allowed to time-out, then the reset output(s) will go active for tRP and once released will repeat the watchdog timeout process. reliable is a dedicated I/O output transitioned by a specific software instruction. The watchdog can be disabled by floating (or tristating) the WDI input (see Figure 4). If the watchdog is disabled the WDI pin will be pulled low for the first th 7/8 ’s of the watchdog period (tWD) and pulled high for the last 1/8th of the watchdog period. This pulling low of the WDI input and then high is used to detect an open or tri-state condition and will continue to repeat until the WDI input is driven high or low. For most efficient operation of devices with the watchdog function the WDI input should be held low the majority of the time and only strobed high as required to reset the watchdog timer. Figure 3 below shows a typical implementation of a watchdog function. Any processor signal that repeats dependant on the normal operation of the processor or directed by the software operating on the processor can be used to strobe the watchdog input. The most Figure 3. Watchdog Timer WDI MR Supply Voltage CAT823 VCC PIC µC GND RESET DECODER ADDRESS MCLR Figure 4. Watchdog Disable Circuit Tristate VCC VCC RESET GND 150kΩ CAT823 OUTPUT MR WDI Doc. No. MD-3027 Rev. B µC 110kΩ 8 © Catalyst Semiconductor, Inc. Characteristics subject to change without notice CAT823, CAT824, CAT825 Figure 5. Timing Diagram – Strobe Input INVALID STROBE VALID STROBE INDETERMINATE STROBE WDI tWD MIN. MAX. RESET Figure 6. Timing Diagram – Power Down VCC VRST (MAX) VRST VRST (MIN) tRD RESET VOH RESET Slews with VCC VOL RESET (CAT824 & CAT825) Figure 7. Timing Diagram – Power Up VRST (MAX) VRST VRST (MIN) VCC tRP RESET VOH VOL RESET © Catalyst Semiconductor, Inc. Characteristics subject to change without notice 9 RESET (CAT824 & CAT825) Doc. No. MD-3027, Rev. B CAT823, CAT824, CAT825 APPLICATION NOTES OUTPUT VALID CONDITIONS µP’s with Bidirectional Reset Pins ¯¯¯¯¯¯ output can be pulled low by processors The RESET like the 68HC11 allowing for a system reset issued by the processor. The maximum pullup current that can be sourced by the CAT82_L/M is 1.5mA (and by the CAT82_T/R/S/Z/Y is 800µA) allowing the processor to pull the output low even when the CAT82x is pulling it high. ¯¯¯¯¯¯ output uses a push-pull output which can The RESET maintain a valid output down to a VCC of 1.0 volts. To sink current below 0.8V a resistor can be connected ¯¯¯¯¯¯ to Ground (see Figure 8.) from RESET This ¯¯¯¯¯¯ arrangement will maintain a valid value on the RESET output during both power up and down but will draw ¯¯¯¯¯¯ output is in the high state. A current when the RESET resistor value of about 100kΩ should be adequate in most situations to maintain a low condition valid output down to VCC equal to 0V. Power Transients Generally short duration negative-going transients of less than 2µs on the power supply at VRST minimum will not cause a reset condition. However the lower the voltage of the transient the shorter the required time to cause a reset output. These issues can usually be remedied by the proper location of bypass capacitance on the circuit board. ¯¯¯¯¯¯ Valid to 0 Volts VCC Figure 8. RESET WDI MR CAT823 VCC Doc. No. MD-3027 Rev. B 100kΩ GND µC RESET RESET 10 © Catalyst Semiconductor, Inc. Characteristics subject to change without notice CAT823, CAT824, CAT825 PACKAGE OUTLINE DRAWING TSOT-23 5-Lead (TD) (1)(2) SYMBOL D MIN NOM MAX A1 0.01 0.05 0.10 A2 0.80 0.87 0.90 b 0.30 c 0.12 A e E1 E 1.00 0.45 0.15 D 2.90 BSC E 2.80 BSC E1 1.60 BSC e 0.95 TYP L 0.30 0.40 L1 0.60 REF L2 0.25 BSC θ 0º 0.20 0.50 8º TOP VIEW A2 A b θ L A1 c L2 L1 SIDE VIEW END VIEW For current Tape and Reel information, download the PDF file from: http://www.catsemi.com/documents/tapeandreel.pdf. Notes: (1) All dimensions in millimeters. Angles in degrees. (2) Complies with JEDEC standard MO-193. © Catalyst Semiconductor, Inc. Characteristics subject to change without notice 11 Doc. No. MD-3027, Rev. B CAT823, CAT824, CAT825 SC-70 5-Lead (SD) (1)(2) SYMBOL D e e E1 E MIN MAX A 0.80 1.10 A1 0.00 0.10 A2 0.80 1.00 b 0.15 0.30 c 0.10 0.18 D 1.80 2.00 2.20 E 1.80 2.10 2.40 E1 1.15 1.25 1.35 e L TOP VIEW NOM 0.65 BSC 0.26 0.36 L1 0.42 REF L2 0.15 BSC 0.46 θ 0° 8° θ1 4° 10° θ1 A2 A θ θ1 b L L1 A1 SIDE VIEW c L2 END VIEW For current Tape and Reel information, download the PDF file from: http://www.catsemi.com/documents/tapeandreel.pdf. Notes: (1) All dimensions in millimeters. Angles in degrees. (2) Complies with JEDEC MO-203. Doc. No. MD-3027 Rev. B 12 © Catalyst Semiconductor, Inc. Characteristics subject to change without notice CAT823, CAT824, CAT825 EXAMPLE OF ORDERING INFORMATION (1) Prefix Device # CAT 823 Optional Company ID Product Number Suffix L 823 824 825 TD I Package TD: TSOT-23 5-Lead SD: SC-70 5-Lead Reset Threshold Voltage L: 4.63V M: 4.38V T: 3.08V S: 2.93V R: 2.63V Z: 2.32V Y: 2.19V -G T3 Lead Finish G:NiPdAu Tape & Reel T: Tape & Reel 3: 3,000/Reel Temperature Range I = Industrial (-40ºC to 85ºC) TOP MARKING INFORMATION (For all Thresholds) Device # CAT823 CAT824 CAT825 CAT823 CAT824 CAT825 Package TSOT-23 TSOT-23 TSOT-23 SC-70 SC-70 SC-70 Top Marking TS TB TD RG TB TD ORDERING PART NUMBER CAT823LTDI-G CAT823MTDI-G CAT823TTDI-G CAT823STDI-G CAT823RTDI-G CAT823ZTDI-G CAT823YTDI-G CAT823LSDI-G CAT823MSDI-G CAT823TSDI-G CAT823SSDI-G CAT823RSDI-G CAT823ZSDI-G CAT823YSDI-G CAT824LTDI-G(4) CAT824MTDI-G(4) CAT824TTDI-G(4) CAT824TSDI-G(4) CAT824RTDI-G(4) CAT824ZTDI-G(4) CAT824YTDI-G(4) CAT824LSDI-G(4) CAT824MSDI-G(4) CAT824TSDI-G(4) CAT824SSDI-G(4) CAT824RSDI-G(4) CAT824ZSDI-G(4) CAT824YSDI-G(4) CAT825LTDI-G CAT825MTDI-G CAT825TTDI-G CAT825STDI-G CAT825RTDI-G CAT825ZTDI-G CAT825YTDI-G CAT825LSDI-G CAT825MSDI-G CAT825TSDI-G CAT825SDI-G CAT825RSDI-G CAT825ZSDI-G CAT825YSDI-G Notes: (1) All packages are RoHS-compliant (Lead-free, Halogen-free). (2) The standard lead finish is NiPdAu. (3) This device used in the above example is a CAT823LTDI -GT3 (4.63V, TSOT-23 5-Lead, Industrial Temperature, NiPdAu, Tape & Reel, 3,000/Reel, (4) Contact factory for package availability. © Catalyst Semiconductor, Inc. Characteristics subject to change without notice 13 Doc. No. MD-3027, Rev. B REVISION HISTORY Date 10-Sep-07 Rev. A 23-May-08 B Reason Initial Release Update Package Outline Drawings Update Top Mark Information Copyrights, Trademarks and Patents © Catalyst Semiconductor, Inc. Trademarks and registered trademarks of Catalyst Semiconductor include each of the following: Adaptive Analog™, Beyond Memory™, DPP™, EZDim™, LDD™, MiniPot™, Quad-Mode™ and Quantum Charge Programmable™ Catalyst Semiconductor has been issued U.S. and foreign patents and has patent applications pending that protect its products. CATALYST SEMICONDUCTOR MAKES NO WARRANTY, REPRESENTATION OR GUARANTEE, EXPRESS OR IMPLIED, REGARDING THE SUITABILITY OF ITS PRODUCTS FOR ANY PARTICULAR PURPOSE, NOR THAT THE USE OF ITS PRODUCTS WILL NOT INFRINGE ITS INTELLECTUAL PROPERTY RIGHTS OR THE RIGHTS OF THIRD PARTIES WITH RESPECT TO ANY PARTICULAR USE OR APPLICATION AND SPECIFICALLY DISCLAIMS ANY AND ALL LIABILITY ARISING OUT OF ANY SUCH USE OR APPLICATION, INCLUDING BUT NOT LIMITED TO, CONSEQUENTIAL OR INCIDENTAL DAMAGES. Catalyst Semiconductor products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other applications intended to support or sustain life, or for any other application in which the failure of the Catalyst Semiconductor product could create a situation where personal injury or death may occur. Catalyst Semiconductor reserves the right to make changes to or discontinue any product or service described herein without notice. Products with data sheets labeled "Advance Information" or "Preliminary" and other products described herein may not be in production or offered for sale. Catalyst Semiconductor advises customers to obtain the current version of the relevant product information before placing orders. Circuit diagrams illustrate typical semiconductor applications and may not be complete. Catalyst Semiconductor, Inc. Corporate Headquarters 2975 Stender Way Santa Clara, CA 95054 Phone: 408.542.1000 Fax: 408.542.1200 www.catsemi.com Document No: MD-3027 Revision: B Issue date: 05/23/08