View MB3793-27A_2976885.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

ds04-27404-1e fujitsu semiconductor data sheet assp f o r p o w e r supply applications bipolar power voltage monitoring ic with watchdog timer mb3793 -27a n description the mb3793 is an integrated circuit to monitor power voltage; it incorporates a watchdog timer. a reset signal is output when the power is cut or falls abruptly. when the power recovers normally after resetting, a power-on reset signal is output to microprocessor units (mpus). an internal watchdog timer with two inputs for system operation diagnosis can provide a fall-safe function for various applicaiton systems. there is also a mask option that can detect voltages of 4.9 to 2.4 v in 0.1-v steps. n features ? precise detection of power voltage fall: 2.5% ? detection voltage with hysteresis ? low power dispersion: i cc = 31 m a (reference) ? internal dual-input watchdog timer ? watchdog-timer halt function (by inhibition pin) ? independently-set wacthdog and reset times n package 8-pin, plastic sop (fpt-8p-m01) 8-pin, plastic sol (fpt-8p-m02) 8-pin, plastic ssop (fpt-8p-m03) 8-pin, plastic dip (di p -8p-m01)
2 mb3793 -27a n pin assignment n pin description pin no. symbol descriptions pin no. symbol descriptions 1 reset outputs reset pin 5 v cc power supply pin 2ctw watchdog timer monitor time setting pin 6 inh inhibit pin 3ctp power-on reset hold time setting pin 7 ck2 inputs clock 2 pin 4 gnd ground pin 8 ck1 inputs clock 1 pin reset ctw ctp gnd ck1 ck2 inh v cc (fpt-8p-m01) (fpt-8p-m02) (fpt-8p-m03) (dip-8p-m01) (top view) 1 2 3 4 8 7 6 5
3 mb3793 -27a n block diagram i 1 = 3 m a . . i 2 = 30 m a . . r 1 = 295 k w . . 3 1 6 2 8 7 5 4 ctp to v cc of all blocks pulse generator 1 watchdog timer reference voltage generator to gnd of all blocks pulse generator 2 output circuit logic circuit reset inh ctw ck1 ck2 v cc gnd comp.s - + v s v ref = 1.24 v . . r 2 = 240 k w . .
4 mb3793 -27a n block description 1. comp. s comp. s is a comparator with hysteresis to compare the reference voltage with a voltage (v s ) that is the result of dividing the power voltage (v cc ) by resistors 1 and 2. when v s falls below 1.24 v, a reset signal is output. this function enables the mb3793 to detect an abnomality within 1 m s when the power is cut or falls abruptly. 2. output circuit the output circuit contains a reset output control comparator that compares the voltage at the ctp pin to the threshold voltage to release the reset output if the ctp pin voltage exceeds the threshold value. since the reset (reset ) output buffer has cmos organization, no pull-up resistor is needed. 3. pulse generator the pulse generator generates pulses when the voltage at the ck1 and ck2 clock pins changes to high from low level (positive-edge trigger) and exceeds the threshold voltage; it sends the clock signal to the watchdog timer. 4. watchdog timer the watchdog timer can monitor two clock pulses. short-circuit the ck1 and ck2 clock pins to monitor a single clock pulse. 5. inhibition pin the inhibition (inh) pin forces the watchdog timer on/off. when this pin is high level, the watchdog timer is stopped. 6. logic circuit the logic circuit contains flip-flops. flip-flop rsff1 controls the charging and discharging of the power-on reset time setting capacitor (c tp ). flip-flop rsff2 turns on/off the circuit that accelerates charging of the power-on reset time setting capacitor (c tp ) at a reset. the rsff2 operates only at a reset; it does not operate at a power-on reset when the power is turned on.
5 mb3793 -27a n absolute maximum ratings (ta = +25 c) * : the voltage is based on the ground voltage (0 v). warning: semiconductor devices can be permanently damaged by application of stress (voltage, current, temperature, etc.) in excess of absolute maximum ratings. do not exceed these ratings. n recommended operating conditions * : the watchdog timer monitor time range depends on the rating of the setting capacitor. warning: the recommended operating conditions are required in order to ensure the normal operation of the semiconductor device. all of the device's electrical characteristics are warranted when the device is operated within these ranges. always use semiconductor devices within their recommended operating condition ranges. operation outside these ranges may adversely affect reliability and could result in device failure. no warranty is made with respect to uses, operating conditions, or combinations not represented on the data sheet. users considering application outside the listed conditions are advised to contact their fujitsu representatives beforehand. parameter symbol conditions rating unit min. max. power supply voltage* v cc C0.3 +7 v input voltage* ck1 v ck1 C0.3 +7 v ck2 v ck2 inh i inh reset output current reset i ol i oh C10+10ma power dissipation p d ta +85 c 200 mw storage temperature tstg C55 +125 c parameter symbol conditions value unit min. typ. max. power supply voltage v cc 1.2 6.0 v reset (reset ) output current i ol i oh C5+5ma power-on reset hold time setting capacity c tp 0.00110 m f watchdog-timer monitoring time setting capacity c tw 0.001 1 m f operating temperature ta C40 +85 c
6 mb3793 -27a n electrical characteristics 1. dc characteristics (v cc = +3.3 v, ta = +25 c) * : the values enclosed in parentheses ( ) are setting assurance values. 2. ac characteristics (v cc = +3.3 v, ta = +25 c) *1:the voltage range is 10% to 90% at testing the reset output transition time. *2:the values enclosed in parentheses ( ) are setting assurance values. parameter symbol conditions value unit min. typ. max. power supply current i cc1 after exit from reset 31 55 m a detection voltage v sl v cc falling ta = + 2 5 c 2.63 2.70 2.77 v ta = C 4 0 c to +85 c (2.59)* 2.70 (2.81)* v sh v cc rising ta = + 2 5 c 2.69 2.76 2.87 v ta = C 4 0 c to +85 c (2.65)* 2.76 (2.87)* detection voltage hysteresis difference v shys v sh C v sl 35 65 95 mv clock-input threshold voltage v cih ck rising (0.7)* 1.3 1.9 v v cil ck falling 0.5 1.0 (1.5)* v clock-input hysteresis v chts (0.1)* 0.3 (0.6)* v inhibition-input voltage v iih 2.2 v v iil 00.8 input current (ck1, ck2, inh) i ih v ck = 5 v 0 1.0 m a i il v ck = 0 v C1.0 0 m a reset output voltage v oh i reset = C5 ma 2.8 3.10 v v ol i reset = +5 ma 0.12 0.4 v reset-output minimum power voltage v ccl i reset = +50 m a0.81.2v parameter symbol conditions value unit min. typ. max. power-on reset hold time t pr c tp = 0.1 m f 30 75 120 ms v cc input pulse width t pi c tp = 0.1 m f (8)* 2 m s v cc delay time t pd c tp = 0.1 m f2 (10)* 2 m s watchdog timer monitor time t wd c tw = 0.01 m f, c tp = 0.1 m f 81624ms watchdog timer reset time t wr c tp = 0.1 m f25.59ms clock input pulse width t ckw 500 ns clock input pulse cycle t ckt 20 m s reset (reset ) output transition time rising t r * 1 c l = 50 pf 500 ns falling t f * 1 c l = 50 pf 500 ns
7 mb3793 -27a n diagram 1. basic operation (positive clock pulse) ctp reset inh ctw ck1 ck2 v sh v cc v sl v th v h v l (1) (2) (3) (4)(5) (5) (6) (7) (8) (9) (10) (11) (12) (13) t pr t wd t pr t wr t ckw t ckt
8 mb3793 -27a 2. basic operation (negative clock pulse) ctp reset inh ctw ck1 ck2 v sh v cc v sl v th v h v l t pr t wd t pr t wr t ckw t ckt (1) (2) (3) (4)(5) (5) (6) (7) (8) (9) (10) (11) (12) (13)
9 mb3793 -27a 3. single-clock input monitoring (positive clock pulse) ctp reset ctw ck1 v th v h v l ck2 t wr t wd t ckt t ckw note: the mb3793 can monitor only one clock. the mb3793 checks the clock signal at every other input pulse. therefore, set watchdog timer monitor time t wd to the time that allows the mb3793 to monitor the period twice as long as the input clock pulse.
10 mb3793 -27a 4. inhibition operation (positive clock pulse) ctp reset inh ctw ck1 ck2 v sh v cc v sl v th v h v l t pr t wd t pr t wr t ckw (1) (2) (3) (4)(5) (5) (6) (7) (11) (8) (9) (10) (12) (13)
11 mb3793 -27a 5. clock pulse input supplementation (positive clock pulse) n operation sequence 1. positive clock pulse input see 1. basic operation (positive clock pulse) under n diagram. 2. negative clock pulse input see 2. basic operation (negative clock pulse) under n diagram. the mb3793 operates in the same way whether it inputs positive or negative pulses. 3. clock monitoring to use the mb3793 while monitoring only one clock, connect clock pins ck1 and ck2. although the mb3793 operates basically in the same way as when monitoring two clocks, it monitors the clock signal at every other input pulse. see 3. single-clock input monitoring (positive clock pulse) under n diagram. 4. description of operations the numbers given to the following items correspond to numbers (1) to (13) used in n diagram. (1) the mb3793 outputs a reset signal when the supply voltage (v cc ) reaches about 0.8 v (v ccl ) (2) if v cc reaches or exceeds the rise-time detected voltage v sh , the mb3793 starts charging the power-on reset hold time setting capacitor c tp . at this time, the output remains in a reset state. the v sh value is about 2.76 v. (3) when c tp has been charged for a certain period of time t pr (until the ctp pin voltage exceeds the threshold voltage (v th ) after the start of charging), the mb3793 cancels the reset (setting the reset pin to h level from l level). ctw ck1 *1 *2 ck2 v h v l note: the mb3793 watchdog timer monitors clock1 (ck1) and clock2 (ck2) pulses alternately. when a ck2 pulse is detected after detecting a ck1 pulse, the monitoring time setting capacity (c tw ) switches to charging from discharging. when two consecutive pulses occur on one side of this alternation before switching, the second pulse is ignored. in the above figure, pulse *1 and *2 are ignored.
12 mb3793 -27a the v th value is about 2.4 v with v cc = 3.3 v the power-on reset hold timer monitor time t pr is set with the following equation: t pr (ms) a c tp ( m f) the value of a is about 750 with v cc = 3.3 v and about 700 with v cc = 3.0 v. the mb3793 also starts charging the watchdog timer monitor time setting capacitor (c tw ). (4) when the voltage at the watchdog timer monitor time setting pin c tw reaches the h level threshold voltage v h , the c tw switches from the charge state to the discharge state. the value of v h is always about 1.24 v regardless of the detected voltage. (5) if the ck2 pin inputs a clock pulse (positive edge trigger) when the c tw is being discharged in the ck1-ck2 order or simultaneously, the c tw switches from the discharge state to the charge state. the mb3793 repeats operations (4) and (5) as long as the ck1/ck2 pin inputs clock pulses with the system logic circuit operating normally. (6) if no clock pulse is fed to the ck1 or ck2 pin within the watchdog timer monitor time t wd due to some problem with the system logic circuit, the ctw pin is set to the l level threshold voltage v l or less and the mb3793 outputs a reset signal (setting the reset pin to l level from h level). the value of v l is always about 0.24 v regardless of the detected voltage. the watchdog timer monitor time t wd is set with the following equation: t wd (ms) b c tw ( m f) the value of b is hardly affected by the power supply voltage; it is about 1600 with v cc = 3.0 to 3.3 v. (7) when a certain period of time t wr has passed (until the ctp pin voltage reaches or exceeds vth again after recharging the c tp ), the mb3793 cancels the reset signal and starts operating the watchdog timer. the watchdog timer monitor reset time t wr is set with the following equation: t wr (ms) d x c tp ( m f) the value of d is 55 with v cc = 3.3 v and about 50 with v cc = 3.0 v. the mb3793 repeats operations (4) and (5) as long as the ck1/ck2 pin inputs clock pulses. if no clock pulse is input, the mb3793 repeats operations (6) and (7). (8) if v cc is lowered to the fall-time detected voltage (v sl ) or less, the ctp pin voltage decreases and the mb3793 outputs a reset signal (setting the reset pin to l level from h level). the value of v sl is 2.7 v (9) when v cc reaches or exceeds v sh again, the mb3793 starts charging the c tp . (10) when the ctp pin voltage reaches or exceeds v th , the mb3793 cancels the reset and restarts operating the watchdog timer. it repeats operations (4) and (5) as long as the ck1/ck2 pin inputs clock pulses. (11) making the inhibit pin active (setting the inh pin to h from l) forces the watchdog timer to stop operation. this stops only the watchdog timer, leaving the mb3793 monitoring v cc (operations (8) to (10)). the watchdog timer remains inactive unless the inhibit input is canceled. (12) canceling the inhibit input (setting the inh pin to l from h) restarts the watchdog timer. (13) the reset signal is output when the power supply is turned off to set v cc to v sl or less. . . = . . = . . =
13 mb3793 -27a n typical characteristics note: without writing the value clearly, vcc = 3.3 (v), ctp = 0.1 ( m f), ctw = 0.01 ( m f). (continued) 40 35 30 25 20 15 10 watchdog timer monitoring f = 1 khz duty = 10 % v l = 0 v v h = v cc MB3793-27A c tw c tp v inh v cc 0.01 m f 0.1 m f 0 1.0 2.0 3.0 4.0 power supply voltage v cc (v) power supply current i cc ( m a) power supply current vs. power supply voltage (v inh = 0 v) ta = - 40 c to + 85 c v sh (ta = + 25 c) max v sl (ta = + 25 c) ( ta = - 40 c to + 85 c ) typ min max typ min v sh v sl 2.5 - 20 - 40 0 20406080100 2.6 2.7 2.8 2.9 3.0 ambient temperature ta ( c) detection voltage v sh , v sl (v) detection voltage vs. ambient temperature 3.3 2.3 + 85 c + 25 c - 40 c 3.2 3.1 3.0 2.9 2.8 2.7 2.6 2.5 2.4 - 1 - 2 - 3 - 4 - 5 0 reset output voltage vs. reset output current reset output voltage v reset (v) reset output current i reset (ma) (p-mos side) 1.0 0 0 + 85 c + 25 c - 40 c 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 1 2 3 4 5 reset output voltage vs. reset output current (n-mos side) reset output voltage v reset (v) reset output current i reset (ma)
14 mb3793 -27a (continued) (continued) 7 6 5 4 3 2 1 0 01234 pull-up resistance 100 k w ta = + 85 c ta = + 25 c ta = - 40 c power supply voltage v cc (v) reset output voltage v reset (v) reset output voltage vs. power supply voltage - 40 - 20 0 20 40 60 80 100 0 20 40 60 80 100 120 140 160 180 200 ta = - 40 c to + 85 c ta = + 25 c max typ min ambient temperature ta ( c) power-on reset hold time t pr (ms) power-on reset hold time vs.ambient temperature (when vcc rising) - 40 - 20 0 20 40 60 80 100 0 2 4 6 8 10 12 14 16 18 20 22 24 26 ta = - 40 c to + 85 c ta = + 25 c max typ min ambient temperature ta ( c) watchdog timer reset time t wr (ms) watchdog timer reset time vs.ambient temperature (when monitoring) - 40 - 20 0 20 40 60 80 100 0 2 4 6 8 10 12 14 16 18 20 22 24 26 ta = - 40 c to + 85 c ta = + 25 c max typ min ambient temperature ta ( c) watchdog timer monitoring time t wd (ms) watchdog timer monitoring time vs. ambient temperature
15 mb3793 -27a (continued) 10 4 10 3 10 2 10 1 1 10 - 1 10 - 4 10 - 3 10 - 2 10 - 1 110 1 10 2 ta = - 40 c ta = + 25 c ta = + 85 c power-on reset time setting capacitance c tp ( m f) power-on reset time vs. c tp capacitance power-on reset time t pr (ms) 10 3 10 2 10 1 1 10 - 1 10 - 4 10 - 3 10 - 2 10 - 1 110 1 10 2 10 - 2 ta = - 40 c ta = + 25 c ta = + 85 c power-on reset time setting capacitance c tp ( m f) reset time t wr (ms) reset time vs. c tp capacitance 10 3 10 2 10 1 1 10 - 1 10 - 4 10 - 3 10 - 2 10 - 1 110 1 10 - 5 ta = - 40 c ta = + 25 c ta = + 85 c watchdog timer monitoring time setting capacitance c tw ( m f) watchdog timer monitoring time vs. c tw capacitance watchdog timer monitoring time t wd (ms)
16 mb3793 -27a n application example 1. supply voltage monitor and watchdog timer (1-clock monitor) 2. supply voltage monitor and watchdog timer stop 5 2 3 6 4 7 8 1 reset microprocessor v cc reset ck gnd gnd gnd c tw * c tp * v cc v cc ctw ctp ck1 ck2 inh mb3793 * : use a capacitor with less leakage current. the mb3793 monitors the clock (ck1,2) at every other input pulse. gnd c tw * c tp * v cc reset v cc ck gnd reset microprocessor 1 microprocessor 2 v cc ck gnd halt halt 5 6 2 3 4 7 8 1 reset gnd v cc inh ctw ck1 ck2 ctp mb3793 * : use a capacitor with less leakage current.
17 mb3793 -27a n typical application 2 3 6 1 8 7 4 5 v cc c tw *c tp * gnd inh gnd v cc ctp ctw reset ck1 ck2 reset microprocessor 1 microprocessor 2 ck gnd v cc reset ck gnd v cc mb3793 1. equation of time-setting capacitances (c tp and c tw ) and set time t pr [ms] a c tp [ m f] t wd [ms] b c tw [ m f] t wr [ms] d c tp [ m f] values of a, b, c, and d 2. example (when c tp = 0.1 m f and c tw = 0.01 m f ) abcdremark 750 1600 0 55 v cc = 3.3 v 700 1600 0 50 v cc = 3.0 v time (msec) symbol v cc = 3.3 v v cc = 3.0 v t pr 75 70 t wd 16 16 t wr 5.5 5 = . . = . . = . . = . . = . . = . . = . . = . . = . . * : use a capacitor with less leakage current.
18 mb3793 -27a n ordering information part number package marking remarks MB3793-27Ap 8-pin plastic dip (dip-8p-m01) 3793-y MB3793-27Apf 8-pin plastic sop (fpt-8p-m01) 3793-y MB3793-27Apnf 8-pin plastic sol (fpt-8p-m02) 3793-y MB3793-27Apfv 8-pin plastic ssop (fpt-8p-m03) 93-y
19 mb3793 -27a n package dimensions (continued) 8-pin plastic sop (fpt-8p-m01) c 1994 fujitsu limited f08002s-4c-4 0.10(.004) 0.13(.005) m "a" 0.68(.027)max 0.18(.007)max 0.20(.008) 0.50(.020) details of "a" part 0.45?.10 0.05(.002)min 7.80?.40 5.30?.30 0.50?.20 (.020?008) (stand off) (.018?004) (.209?012) (.307?016) .250 ?008 +.010 ?.20 +0.25 6.35 .006 ?001 +.002 ?.02 +0.05 0.15 .268 ?008 +.016 ?.20 +0.40 6.80 index typ 1.27(.050) 3.81(.150)ref 2.25(.089)max (mounting height) dimensions in mm (inches)
20 mb3793 -27a (continued) (continued) 8-pin plastic sol (fpt-8p-m02) c 1994 fujitsu limited f08004s-2c-4 1.27(.050)typ 0.42?.10 0.20?.05 0.15?.10 3.90?.30 6.00?.40 0.50?020 5.00?.30 0.40(.016) 3.81(.150)ref .199 ?008 +.010 ?.20 +0.25 5.05 0.10(.004) 0.13(.005) m (.017?004) (.008?002) (.154?012) (.236?016) (.197?012) (.006?004) "a" 0.65(.026)max 0.18(.007)max 0.40(.016) 0.20(.008) details of "a" part (.020?008) (stand off) 45 1.55?.20(.061?008) (mounting height) dimensions in mm (inches)
21 mb3793 -27a (continued) (continued) 8-pin plastic ssop (fpt-8p-m03) c 1994 fujitsu limited f08005s-1c-2 3.50?.10 0.35?.10 2.40(.094)ref 4.20?.10 5.20(.205) 6.20?.20 (.138?004) (.014?004) nom (.244?008) (.165?004) 0.10(.004) m .049 ?004 +.008 ?.10 +0.20 1.25 .006 ?001 +.002 ?.02 +0.05 0.15 0.10(.004) "a" index * typ 0.80(.0315) 0.50?.20 (.020?008) 0.10?.10(.004?004) (stand off) 0 10 details of "a" part (mounting height) dimensions in mm (inches) *: these dimensions do not include resin protrusion.
22 mb3793 -27a (continued) 8-pin plastic dip (dip-8p-m01) c 1994 fujitsu limited d08006s-2c-3 0.89 +0.35 ?.30 ?.30 +0.40 9.40 ? 0.99 1.52 +0.30 ? +.014 ?012 .035 .370 ?012 +.016 .060 ? +.012 +.012 ? .039 4.36(.172)max 3.00(.118)min 2.54(.100) typ 0.46?.08 (.018?003) 0.25?.05 (.010?002) 0.51(.020)min 7.62(.300) typ 15?ax 1 pin index 6.20?.25 (.244?010) +0.30 dimensions in mm (inches)
23 mb3793 -27a fujitsu limited for further information please contact: japan fujitsu limited corporate global business support division electronic devices kawasaki plant, 4-1-1, kamikodanaka nakahara-ku, kawasaki-shi kanagawa 211-8588, japan tel: 81(44) 754-3763 fax: 81(44) 754-3329 http://www.fujitsu.co.jp/ north and south america fujitsu microelectronics, inc. semiconductor division 3545 north first street san jose, ca 95134-1804, usa tel: (408) 922-9000 fax: (408) 922-9179 customer response center mon. - fri.: 7 am - 5 pm (pst) tel: (800) 866-8608 fax: (408) 922-9179 http://www.fujitsumicro.com/ europe fujitsu mikroelektronik gmbh am siebenstein 6-10 d-63303 dreieich-buchschlag germany tel: (06103) 690-0 fax: (06103) 690-122 http://www.fujitsu-ede.com/ asia pacific fujitsu microelectronics asia pte ltd #05-08, 151 lorong chuan new tech park singapore 556741 tel: (65) 281-0770 fax: (65) 281-0220 http://www.fmap.com.sg/ f9905 ? fujitsu limited printed in japan all rights reserved. the contents of this document are subject to change without notice. customers are advised to consult with fujitsu sales representatives before ordering. the information and circuit diagrams in this document are presented as examples of semiconductor device applications, and are not intended to be incorporated in devices for actual use. also, fujitsu is unable to assume responsibility for infringement of any patent rights or other rights of third parties arising from the use of this information or circuit diagrams. fujitsu semiconductor devices are intended for use in standard applications (computers, office automation and other office equipment, industrial, communications, and measurement equipment, personal or household devices, etc.). caution: customers considering the use of our products in special applications where failure or abnormal operation may directly affect human lives or cause physical injury or property damage, or where extremely high levels of reliability are demanded (such as aerospace systems, atomic energy controls, sea floor repeaters, vehicle operating controls, medical devices for life support, etc.) are requested to consult with fujitsu sales representatives before such use. the company will not be responsible for damages arising from such use without prior approval. any semiconductor devices have an inherent chance of failure. you must protect against injury, damage or loss from such failures by incorporating safety design measures into your facility and equipment such as redundancy, fire protection, and prevention of over-current levels and other abnormal operating conditions. if any products described in this document represent goods or technologies subject to certain restrictions on export under the foreign exchange and foreign trade law of japan, the prior authorization by japanese government will be required for export of those products from japan.

▲Up To Search▲

Price & Availability of MB3793-27A

	To Download MB3793-27A Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .