CAT1232LP, CAT1832 5 V and 3.3 V Supply Monitor, Watchdog Timer, Manual Reset, with Active High & Low Resets FEATURES DESCRIPTION (cid:132) Selectable reset voltage tolerance The CAT1232LP and CAT1832 microprocessor supervisors can halt and restart a “hung-up” or — CAT1232LP for 5 V supply “stalled” microprocessor, restart a microprocessor — CAT1832 for 3.3 V supply after a power failure, and debounce a manual/push- (cid:132) Selectable watchdog period: button microprocessor reset switch. The devices are 150 ms, 600 ms or 1.2 s drop in replacements for the Maxim/Dallas (cid:132) Two reset outputs Semiconductor DS1232LP and DS1832 supervisors — Active high, push-pull reset output Precision reference and comparator circuits monitor — Active low, open-drain reset output the 5 V or 3.3 V system power supply voltage, VCC. (CAT1232LP) During power-up or when the power supply falls outside selectable tolerance limits, both the RESET — Active low, push-pull reset output (CAT1832) and R¯¯E¯S¯E¯T¯ become active. After the power supply (cid:132) Debounced manual push-button reset voltage rises above the RESET threshold voltage, the (cid:132) Compact SOIC and MSOP packages reset signals remain active for a minimum of 250ms, allowing the power supply and system processor to stabilize. The trip-point tolerance input, TOL, selects For Ordering Information details, see page 11. the trip level tolerance to be either 5% or 10% for the CAT1232LP 5 V supply and 10% or 20% for the APPLICATIONS CAT1832 3.3 V supply. (cid:132) Microprocessor Systems Each device has a push-pull, active HIGH reset (cid:132) Portable Equipment output. The CAT1232LP also has an open drain, active LOW reset output while the CAT1832 also has (cid:132) Controllers a push-pull, active LOW reset output. (cid:132) Single Board Computers A debounced manual reset input activates the reset (cid:132) Instrumentations outputs and holds them active for a minimum period of (cid:132) Telecommunications 250 ms after being released. Also included is a watchdog timer to reset a microprocessor that has stopped due to a software or hardware failure. Three watchdog time-out periods are selectable: 150 ms, 600 ms and 1.2 s. If the S¯¯T input is not strobed low before the watchdog time out period expires, the reset signals become active for a FUNCTIONAL DIAGRAM minimum of 250 ms. VCC RESET TOL Tolerance Selection + (CAT1232LP) VCC Reference – 40kΩ RESET PBRST Push Button Debounce RESET Reset & (CAT1832) TD WatchdogTimebase Selection WatchdogTimer ST WatchdogTransition Detector © 2009 SCILLC. All rights reserved. 1 Doc. No. MD-3018 Rev. F Characteristics subject to change without notice

CAT1232LP, CAT1832 PIN CONFIGURATION SOIC 8 Lead SOIC 16 Lead MSOP 8 Lead PDIP 8 Lead NC 1 16 NC P¯¯B¯R¯S¯T¯ 2 15 VCC P¯¯B¯R¯S¯T¯ 1 8 VCC NC 3 14 NC TD 2 CAT 7 S¯¯T TD 4 1 3 S¯¯T TOL 3 6 R¯¯E¯S¯E¯T¯ CAT NC 5 12 NC GND 4 5 RESET TOL 6 11 R¯¯E¯S¯E¯T¯ NC 7 10 NC GND 8 9 RESET PIN DESCRIPTION Pin Number Pin Number 8-Lead 16-Lead Package Package Name Function 1 2 P¯¯B¯R¯S¯T¯ Debounced manual pushbutton reset input Watchdog typical time delay selection: a) t = 150 ms for TD = GND 2 4 TD TD b) t = 600 ms for TD = Open TD c) t = 1200 ms for TD = V TD CC CAT1232LP TOL selects 5% (TOL = GND) or 10% (TOL = V ) trip CC 3 6 TOL point tolerance. CAT1832 TOL selects 10% (TOL = GND) or 20% TOL = V ) trip point tolerance. CC 4 8 GND Ground Active HIGH reset output. RESET is active 1. If V falls below the reset voltage trip point CC 5 9 RESET 2. If P¯¯B¯R¯S¯T¯ is low 3. If S¯¯T is not strobed low before the timeout period set by TD expires. 4. During power-up. 6 11 RESET Active LOW reset output. (See RESET) 7 13 S¯¯T Strobe Input 8 15 V Power Supply CC 1, 3. 5, 7, 10, NC No internal connection 12, 14, 16 ABSOLUTE MAXIMUM RATINGS (*) Parameters Ratings Units Parameters Ratings Units Voltage on V -0.5 to 7.0 V Maximum Junction Temperature 125 ºC CC Voltage on S¯¯T and TD -0.5 to V + 0.5 V Storage Temperature Range -65 to +150 ºC CC Voltage on P¯¯B¯R¯S¯T¯, Lead Soldering Temperature (10s) 300 ºC -0.5 to V + 0.5 V R¯¯E¯S¯E¯T¯and RESET CC Operating Temperature Range -40 to +85 ºC Note: * 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. Doc. No. MD-3018 Rev. F 2 © 2009 SCILLC. All rights reserved. Characteristics subject to change without notice

CAT1232LP, CAT1832 ELECTRICAL CHARACTERISTICS Unless otherwise stated, 1.0 V - V - 5.5 V and over the operating temperature range of -40ºC to +85ºC. CC All voltages are referenced to ground. Symbol Parameter Conditions Min Typ Max Units V Supply Voltage 1.0 5.5 V CC V = 5.5 V, CAT1232LP 35 50 CC I Supply Current µA CC1 V = 3.6 V, CAT1832 20 35 CC ST and P¯¯B¯R¯S¯T¯ Input High (5) 2 V V + 0.3 V V IH Level (6) V - 0.4 V CC CC ST and P¯¯B¯R¯S¯T¯ Input Low VCC = 5.5 V, CAT1232LP -0.3 0.8 V V IL Level V = 3.6 V, CAT1832 0.5 CC V V Trip Point (TOL = GND) CAT1232LP 4.50 4.62 4.74 V CCTP CC V V Trip Point (TOL = V ) CAT1232LP 4.25 4.37 4.49 V CCTP CC CC V V Trip Point (TOL = GND) CAT1832 2.80 2.88 2.97 V CCTP CC V V Trip Point (TOL = V ) CAT1832 2.47 2.55 2.64 V CCTP CC CC t Watchdog Time-Out Period TD = GND 62.5 150 250 ms TD t Watchdog Time-Out Period TD = V 500 1200 2000 ms TD CC t Watchdog Time-Out Period TD floating 250 600 1000 ms TD V Output Voltage I = -500 µA (3) V -0.5 V V -0.1 V V OH CC CC I Output Current Output = 2.4 V (2) -350 µA OH I Output Current Output = 0.4 V 10 mA OL I Input Leakage (1) -1.0 1.0 µA IL R Internal Pull-Up Resistor (1) 32 40 55 kΩ PU C Input Capacitance 5 pF IN C Output Capacitance 7 pF OUT P¯¯B¯R¯S¯T¯ Manual Reset t P¯¯B¯R¯S¯T¯ = V 20 ms PB Minimum Low Time IL t Reset Active Time 250 600 1000 ms RST t S¯¯T Pulse Width (4) 20 ns ST V Fail Detect to RESET or t CC 5 8 µs RPD R¯¯E¯S¯E¯T¯ t V Slew Rate 20 µs F CC P¯¯B¯R¯S¯T¯ Stable LOW to RESET t 20 ms PDLY and R¯¯E¯S¯E¯T¯ Active V Detect to RESET or t CC t = 5 µs 250 600 1000 ms RPU R¯¯E¯S¯E¯T¯ Inactive RISE t V Slew Rate 4.25 V to 4.75 V 0 ns R CC Notes: (1) P¯¯B¯R¯S¯T¯ is internally pulled HIGH to V through a nominal 40 kΩ resistor (RPU). CC (2) R¯¯E¯S¯E¯T¯ is an open drain output on the CAT1232LP. (3) RESET remains within 0.5 V of V on power-down until V falls below 2 V. RESET remains within 0.5 V of ground on power-down until CC CC V falls below 2.0 V. CC (4) Must not exceed the minimum watchdog time-out period (t ). The watchdog circuit cannot be disabled. To avoid a reset, S¯¯T must be TD strobed. (5) Measured with V ≥ 2.7 V. CC (6) Measured with V < 2.7 V. CC © 2009 SCILLC. All rights reserved. 3 Doc. No. MD-3018 Rev. F Characteristics subject to change without notice

CAT1232LP, CAT1832 TYPICAL CHARACTERISTICS For the CAT1232LP, V = 5 V and T = 25ºC unless otherwise stated. CC AMB Threshold Voltage vs. Temperature (10% TOL) Threshold Voltage vs. Temperature (5% TOL) 4.450 4.630 V) E( 4.445 V) 4.625 G ( A E TOL=GND(5%) LT TOL=Vcc(10%) AG O T V 4.440 L 4.620 D O L V O D H L S O RE 4.435 SH 4.615 H E T R H T 4.430 4.610 -50 0 50 100 -50 0 50 100 TEMPERATURE(°C) TEMPERATURE(ºC) Supply Current vs. Temperature Reset Active Time vs. Temperature 40 800 Vcc = 5.5V s) 700 TD=open A) 30 (m m E Vcc=5.5V NT( Vcc = 4.5V TIM 600 RE 20 VE UR CTI 500 Vcc=4.5V C A Y T PL 10 SE UP RE 400 S 0 300 -50 0 50 100 -50 0 50 100 TEMPERATURE(°C) TEMPERATURE(°C) Reset Active Time Waveform Transient Response Doc. No. MD-3018 Rev. F 4 © 2009 SCILLC. All rights reserved. Characteristics subject to change without notice

CAT1232LP, CAT1832 APPLICATION INFORMATION SUPPLY VOLTAGE MONITOR Reset Signal Polarity and Output Stage Structure Tolerance R¯¯E¯S¯E¯T¯ is an active LOW signal. It is developed with Trip Point Voltage (V) Select Trip Point an open drain driver in the CAT1232LP. A pull-up Voltage Tolerance Min Nominal Max resistor is required, typical values are 10 kΩ to 50 kΩ. CAT1232LP The CAT1832 uses a CMOS push-pull output stage 10 % 4.25 4.37 4.49 TOL = V for the R¯¯E¯S¯E¯T¯. CC CAT1232LP 5 % 4.50 4.62 4.74 RESET is an active High signal developed by a TOL = GND CMOS push-pull output stage and is the logical CAT1832 opposite to R¯¯E¯S¯E¯T¯. TOL = V 20 % 2.47 2.55 2.64 CC Trip Point Tolerance Selection CAT1832 10 % 2.80 2.88 2.97 TOL = GND The TOL input is used to select the V trip point CC threshold. This selection is made connecting the TOL input to ground or V . Connecting TOL to CC Manual Reset Operation Ground makes the V trip threshold 4.62 V for the CC Push-button input, P¯¯B¯R¯S¯T¯, allows the user to issue CAT1232LP and 2.88 V for the CAT1832. reset signals. The pushbutton input is debounced and Connecting TOL to V makes the V trip threshold is pulled high through an internal 40 kΩ resistor. CC CC 4.37 V for the CAT1232LP and 2.55 V for the CAT1832. When P¯¯B¯R¯S¯T¯ is held low for the minimum time of 20 ms, both resets become active and remain active After VCC has risen above the trip point set by TOL, for a minimum time period of 250 ms after PBRST RESET and R¯¯E¯S¯E¯T¯remain active for a minimum time returns high. period of 250 ms. No external pull-up resistor is required, since P¯¯B¯R¯S¯T¯ On power-down, once V falls below the reset CC is pulled high by an internal 40 kΩ resistor. threshold the RESET outputs will remain active and are guaranteed valid down to a V level of 1.0 V. CC P¯¯B¯R¯S¯T¯ can be driven from a TTL or CMOS logic line or short-ed to ground with a mechanical switch. Figure 1. Timing Diagram: Power Up Figure 2. Timing Diagram: Power Down t F tR VCC V CCTP(MAX) V V CCTP(MAX) CCTP VCCTP VCCTP(MIN) V CCTP(MIN) V CC t RPU t RESET RESET RPD V OH V OH VOL RESET RESET VOL © 2009 SCILLC. All rights reserved. 5 Doc. No. MD-3018 Rev. F Characteristics subject to change without notice

CAT1232LP, CAT1832 WATCHDOG TIMER AND S¯¯T INPUT A watchdog timer stops and restarts a microprocessor Watchdog Time-out Period (ms) TD Voltage that has stopped proper operation or become “hung”. Level Min Nominal Max The watchdog performs this function by monitoring the S¯¯T input. After the reset outputs go inactive the S¯¯T GND 62.5 150 250 input must be strobed with a high-to-low signal Floating 250 600 1000 transition prior to the minimum watchdog timeout V 500 1200 2000 period. However if the S¯¯T input is not strobed with a CC high-to-low signal transition prior to a watchdog timeout the reset outputs will become active for TRST 3.3V CAT1832 reseting and restarting the microprocessor. Once the resets return to the inactive state the watchdog timer 1 8 restarts the process. PBRST VCC 2 7 TD ST I/O µP The TD input allows the user to select from three 3 6 TOL RESET predetermined watchdog timeout periods. Always use 4 5 the minimum timeout period to determine the required GND RESET RESET frequency of S¯¯T high-to-low transitions and the maximum to determine the time prior to the reset outputs becoming active. S¯¯T pulse widths must be Figure 4. CAT1832 Application Circuit: 20 ns or greater. Pushbutton Reset The watchdog timer cannot be disabled. It must be strobed with a high-to-low signal transition to avoid a watchdog timeout and subsequent reset. 5V CAT1232LP 1 8 PBRST VCC MREQ 2 7 TD ST 10k µP Decoder 3 6 TOL RESET RESET Address Bus 4 5 GND RESET Figure 5. CAT1232LP Application Circuit: Watchdog Timer PBRST tPB Valid Valid Invalid Strobe Strobe Strobe tPDLY V ST IH V IL t ST tRST tRST tTD tTD (Min) (Min) RESET RESET V RESET OH V RESET OL Note: ST is ignored whenever a reset is active Figure 6. Timing Diagram: Pushbutton Reset Figure 7. Timing Diagram: Strobe Input Doc. No. MD-3018 Rev. F 6 © 2009 SCILLC. All rights reserved. Characteristics subject to change without notice

CAT1232LP, CAT1832 PACKAGE OUTLINE DRAWINGS SOIC 16-Lead 300 mils (W)(1)(2) D SYMBOL MIN NOM MAX A 2.36 2.49 2.64 A1 0.10 0.30 b 0.33 0.41 0.51 c 0.18 0.23 0.28 D 10.08 10.31 10.49 E1 E E 10.01 10.31 10.64 E1 7.39 7.49 7.59 e 1.27 BSC h 0.25 0.75 L 0.38 0.81 1.27 θ 0º 8º PIN #1 IDENTIFICATION TOP VIEW h c A θ b e L A1 SIDE VIEW END VIEW Notes: (1) All dimensions are in millimeters. (2) Complies with JEDEC MS-013. © 2009 SCILLC. All rights reserved. 7 Doc. No. MD-3018 Rev. F Characteristics subject to change without notice

CAT1232LP, CAT1832 PDIP 8-Lead 300mils (L)(1)(2) SYMBOL MIN NOM MAX A 5.33 A1 0.38 A2 2.92 3.30 4.95 b 0.36 0.46 0.56 E1 b2 1.14 1.52 1.78 c 0.20 0.25 0.36 D 9.02 9.27 10.16 E 7.62 7.87 8.25 e 2.54 BSC E1 6.10 6.35 7.11 eB 7.87 10.92 PIN # 1 L 2.92 3.30 3.80 IDENTIFICATION D TOP VIEW E A2 A A1 c b2 L eB e b SIDE VIEW END VIEW Notes: (1) All dimensions are in millimeters. (2) Complies with JEDEC MS-001. Doc. No. MD-3018 Rev. F 8 © 2009 SCILLC. All rights reserved. Characteristics subject to change without notice

CAT1232LP, CAT1832 MSOP 8-Lead (Z) (1)(2) SYMBOL MIN NOM MAX A 1.10 A1 0.05 0.10 0.15 A2 0.75 0.85 0.95 b 0.22 0.38 c 0.13 0.23 D 2.90 3.00 3.10 E 4.80 4.90 5.00 E E1 E1 2.90 3.00 3.10 e 0.65 BSC L 0.40 0.60 0.80 L1 0.95 REF L2 0.25 BSC θ 0º 6º TOP VIEW D A A2 DETAIL A A1 e b c SIDE VIEW END VIEW θ L2 L L1 DETAIL A Notes: (1) All dimensions are in millimeters. Angles in degrees. (2) Complies with JEDEC MO-187. © 2009 SCILLC. All rights reserved. 9 Doc. No. MD-3018 Rev. F Characteristics subject to change without notice

CAT1232LP, CAT1832 SOIC 8-Lead 150mils (V) (1)(2) SYMBOL MIN NOM MAX A 1.35 1.75 A1 0.10 0.25 b 0.33 0.51 c 0.19 0.25 E1 E D 4.80 5.00 E 5.80 6.20 E1 3.80 4.00 e 1.27 BSC h 0.25 0.50 L 0.40 1.27 PIN # 1 θ 0º 8º IDENTIFICATION TOP VIEW D h A1 θ A c e b L SIDE VIEW END VIEW Notes: (1) All dimensions are in millimeters. Angles in degrees. (2) Complies with JEDEC MS-012. Doc. No. MD-3018 Rev. F 10 © 2009 SCILLC. All rights reserved. Characteristics subject to change without notice

CAT1232LP, CAT1832 EXAMPLE OF ORDERING INFORMATION(1) Prefix Device # Suffix CAT 1232LP V – G T3 Company ID Package Lead Finish Tape & Reel L: PDIP Blank: Matte-Tin T: Tape & Reel Product Number V: SOIC 8-Lead G:NiPdAu 2: 2,000/Reel 1232LP W: SOIC 16-Lead (5) 3: 3,000/Reel 1832 Z: MSOP ORDERING PART NUMBER Package Parts per Tube Parts Per Reel Reel Size (inch) CAT1232LPL-G 8-lead, PDIP 50 — — CAT1232LPV-GT3 8-lead, SOIC — 3,000 13 CAT1232LPZ-GT3 8-lead, MSOP — 3,000 13 CAT1232LPW-T2 16-lead, SOIC — 2,000 13 CAT1832L-G 8-lead, PDIP 50 — — CAT1832V-GT3 8-lead, SOIC — 3,000 13 CAT1832Z-GT3 8-lead, MSOP — 3,000 13 Notes: (1) All packages are RoHS-compliant (Lead-free, Halogen-free). (2) The standard lead finish is NiPdAu. (3) The device used in the above example is a CAT1232LPV-GT3 (SOIC 8-Lead, NiPdAu, Tape & Reel). (4) For additional package and temperature options, please contact your nearest ON Semiconductor Sales office. (5) The SOIC 16-Lead package is only available in Matte-Tin finish. © 2009 SCILLC. All rights reserved. 11 Doc. No. MD-3018 Rev. F Characteristics subject to change without notice

CAT1232LP, CAT1832 REVISION HISTORY Date Rev. Description 13-Jun-05 00 Initial Issue Update Electrical Characteristics 26-Jul-05 0A Add Typical Characteristics Update Document Title 37-Mar-06 0B Update Ordering Information Add Ordering Information detail to page 1 27-Nov-06 0C Update Sample of Ordering Information Update Package Outline Drawings 13-Nov-07 D Update Example of Ordering Information Change document number from 25088, Rev. OC 06-Nov-08 E Change logo and fine print to ON Semiconductor 09-Mar-09 F Update Example of Ordering Information ON Semiconductor and are registered trademarks of Semiconductor Components Industries, LLC (SCILLC). SCILLC reserves the right to make changes without further notice to any products herein. SCILLC makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does SCILLC assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation special, consequential or incidental damages. “Typical” parameters which may be provided in SCILLC data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. All operating parameters, including “Typicals” must be validated for each customer application by customer's technical experts. SCILLC does not convey any license under its patent rights nor the rights of others. SCILLC 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 SCILLC product could create a situation where personal injury or death may occur. Should Buyer purchase or use SCILLC products for any such unintended or unauthorized application, Buyer shall indemnify and hold SCILLC and its officers, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if such claim alleges that SCILLC was negligent regarding the design or manufacture of the part. SCILLC is an Equal Opportunity/Affirmative Action Employer. This literature is subject to all applicable copyright laws and is not for resale in any manner. PUBLICATION ORDERING INFORMATION LITERATURE FULFILLMENT: Literature Distribution Center for ON Semiconductor N. American Technical Support: 800-282-9855 Toll Free ON Semiconductor Website: www.onsemi.com P.O. Box 5163, Denver, Colorado 80217 USA USA/Canada Phone: 303-675-2175 or 800-344-3860 Toll Free USA/Canada Europe, Middle East and Africa Technical Support: Order Literature: http://www.onsemi.com/orderlit Fax: 303-675-2176 or 800-344-3867 Toll Free USA/Canada Phone: 421 33 790 2910 Email: orderlit@onsemi.com Japan Customer Focus Center: For additional informa tion, please contact your local Phone: 81-3-5773-3850 Sales Representative Doc. No. MD-3018 Rev. F 12 © 2009 SCILLC. All rights reserved. Characteristics subject to change without notice

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