Page 2 - PIN ASSIGNMENT
MB3773 2 ■ ■ ■ ■ PIN ASSIGNMENT C T RESET CK GND RESET V S V REF V CC 1 2 3 4 8 7 6 5 C T RESET CK GND RESET V S V REF V CC 1 2 3 4 8 7 6 5 (TOP VIEW) (SIP-8P-M03) (DIP-8P-M01) (FPT-8P-M01) (FRONT VIEW)
Page 3 - BLOCK DIAGRAM; GND; RESET; Inhibit; CK
MB3773 3 ■ ■ ■ ■ BLOCK DIAGRAM C T + _ + _ 8 2 7 3 1 4 5 GND RESET V S V CC R S Q := 1.24 V := 40 k Ω := 1.24 V := 10 µ A := 1.2 µ A := 100 k Ω WatchDogTimer P.G + _ Reference Voltage Generator + _ Reference AMP. V REF 6 COMP.O RESET := 10 µ A Inhibit CK COMP.S
Page 4 - FUNCTIONAL DESCRIPTIONS
MB3773 4 ■ ■ ■ ■ FUNCTIONAL DESCRIPTIONS Comp.S is comparator including hysteresis. it compare the reference voltage and the voltage of Vs, so that whenthe voltage of Vs terminal falls below approximately 1.23 V, reset signal outputs. Instantaneous breaks or drops in the power can be detected as abn...
Page 6 - OPERATION SEQUENCE
MB3773 6 ■ ■ ■ ■ OPERATION SEQUENCE (1) When Vcc rises to about 0.8 V, RESET goes “Low” and RESET goes “High”. The pull-up current of approximately 1 µ A (Vcc = 0.8 V) is output from RESET. (2) When Vcc rises to V SH ( := 4.3V) , the charge with C T star ts. At this time, the output is being reset. ...
Page 8 - ELECTORICAL CHARACTERISTICS
MB3773 8 ■ ■ ■ ■ ELECTORICAL CHARACTERISTICS (1) DC Characteristics ( V CC = 5 V, Ta = + 25 ° C) Parameter Symbol Condition Value Unit Min Typ Max Supply current I CC Watch dog timer operating 600 900 µ A Detection voltage V SL V CC 4.10 4.20 4.30 V Ta = − 40 ° C to + 85 ° C 4.05 4.20 4.35 V SH V ...
Page 10 - TYPICAL CHARACTERISTIC CURVES; terminal; Supply voltage V; Output sink current I; Supply current I; Output voltage; Detection voltage; Output voltage; Output saturation voltage
MB3773 10 ■ ■ ■ ■ TYPICAL CHARACTERISTIC CURVES (Continued) 6.0 5.0 4.0 3.0 2.0 1.0 0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 Ta = + 85 ° C Ta = + 25 ° C Ta = − 40 ° C 4.50 4.44 4.30 4.20 4.10 4.00 − 40 − 20 0 20 40 60 80 100 V SH V SL 400 300 200 0 2.0 10.0 12.0 14.0 16.0 4.0 6.0 8.0 18.0 100 Ta = − 40 ° C Ta ...
Page 11 - Reference current I; High level output current I
MB3773 11 (Continued) Ta = + 25 ° C Ta = + 85 ° C Ta = − 40 ° C C T = 0.1 µ F 5.0 4.5 4.0 0 − 5 − 10 − 15 5.0 4.5 4.0 0 − 5 − 10 − 15 C T = 0.1 µ F Ta = + 25 ° C Ta = + 85 ° C Ta = − 40 ° C 1.246 1.244 1.242 1.240 1.238 1.236 1.234 0 3.0 5.0 7.0 9.0 13.0 11.0 17.0 19.0 21.0 15.0 Ta = − 40 ° C Ta = +...
Page 12 - erminal capacitance C
MB3773 12 (Continued) 3 2 1 0 − 40 − 20 20 0 40 60 80 100 C T = 0.1 µ F V CC = 5 V − 40 − 20 20 0 40 60 80 100 16 14 12 10 8 6 4 0 C T = 0.1 µ F V CC = 5 V 10 6 10 5 10 4 10 3 10 2 10 1 10 0 10 − 1 10 − 2 10 − 3 10 − 3 10 − 2 10 − 1 10 0 10 1 10 2 Ta = − 40 ° C Ta = + 25 ° C + 85 ° C 10 − 3 10 − 2 1...
Page 13 - APPLICATION CIRCUIT; EXAMPLE 1: Monitoring 5V Supply Voltage and Watchdog Timer
MB3773 13 ■ ■ ■ ■ APPLICATION CIRCUIT EXAMPLE 1: Monitoring 5V Supply Voltage and Watchdog Timer VCC (5V) MB3773 RESET RESET CK GND Logic circuit Notes : • Supply voltage is monitored using V S . • Detection voltage are V SH and V SL . C T 1 2 3 4 8 7 6 5 EXAMPLE 2: 5V Supply Voltage Monitoring (ext...
Page 16 - Logic circuit
MB3773 16 EXAMPLE 5: Monitoring Two Supply Voltages (with hysteresis and reset output) V CC 1 (5 V) 1 2 3 4 8 7 6 5 MB3773 RESET RESET CK GND Comp. 2 Example : Comp. 1, Comp. 2 : MB4204, MB47393 20 k Ω R 6 + _ + _ V CC2 (12 V) 180 k Ω R 4 30 k Ω R 3 5.1 k Ω R 2 1.2 k Ω R 1 4.7 k Ω R 5 Comp. 1 Notes ...
Page 18 - EXAMPLE 7: Monitoring Supply Voltage Using Delayed Trigger
MB3773 18 EXAMPLE 7: Monitoring Supply Voltage Using Delayed Trigger V CC 1 2 3 4 8 7 6 5 MB3773 RESET RESET CK GND Logic circuit Note : Adding voltage such as shown in the figure to V CC increases the minimum input pulse width by 50 µ s (C 1 = 1000 pF). C 1 V CC 5V 4V C T
Page 21 - EXAMPLE 9: Reducing Reset Hold Time; reduction circuit
MB3773 21 EXAMPLE 9: Reducing Reset Hold Time V CC ( = 5 V) 1 2 3 4 8 7 6 5 C T MB3773 RESET RESET CK GND Logic circuit (a) T PR reduction method V CC ( = 5 V) 1 2 3 4 8 7 6 5 C T MB3773 RESET RESET CK GND Logic circuit Notes : • RESET is the only output that can be used. • Standard T PR , T WD and ...
Page 22 - EXAMPLE 10: Circuit for Monitoring Multiple Microprocessor
MB3773 22 EXAMPLE 10: Circuit for Monitoring Multiple Microprocessor V CC ( = 5 V) 12 3 4 87 6 5 C T MB3773 RESET RESET CK GND Notes : • connects from FF1 and FF2 outputs Q 1 and Q 2 to the NOR input. • Depending on timing, these connections may not be necessary. • Example : R 1 = R 2 = 2.2 k Ω C T ...
Page 24 - EXAMPLE 11: Circuit for Limiting Upper Clock Input Frequency
MB3773 24 C R T 1 0.01 µ F 10 k Ω 30 µ s 0.1 µ F 10 k Ω 300 µ s EXAMPLE 11: Circuit for Limiting Upper Clock Input Frequency Notes : • This is an example application to limit upper frequency f H of clock pulses sent from the microprocessor.If the CK cycle sent from the microprocessor exceeds f H , t...
Page 25 - NOTES ON USE; • Take measures against static electricity.; ORDERING INFORMATION; Part number
MB3773 25 ■ ■ ■ ■ NOTES ON USE • Take account of common impedance when designing the ear th line on a printed wiring board. • Take measures against static electricity. - For semiconductors, use antistatic or conductive containers.- When storing or carrying a printed circuit board after chip mounting...
Page 26 - PACKAGE DIMENSIONS
MB3773 26 ■ ■ ■ ■ PACKAGE DIMENSIONS (Continued) 8-pin plastic DIP (DIP-8P-M01) Dimensions in mm (inches) .Note : The values in parentheses are reference values. C 1994 FUJITSU LIMITED D08006S-2C-3 0.89 +0.35–0.30 –0.30 +0.40 9.40 –0 0.99 1.52 +0.30–0 +.014–.012 .035 .370 –.012 +.016 .060 –0 +.012 +...
Page 29 - FUJITSU LIMITED; FUJITSU LIMITED Printed in Japan
MB3773 FUJITSU LIMITED All Rights Reserved. The contents of this document are subject to change without notice. Customers are advised to consult with FUJITSU salesrepresentatives before ordering.The information, such as descriptions of function and applicationcircuit examples, in this document are p...