MM1075XF

MITSUMI System Reset (with built-in watchdog timer) MM1075 System Reset (with built-in watchdog timer) Monolithic IC MM1075 Outline This IC functions in a variety of CPU systems and other logic systems to generate a reset signal and reset the system accurately during momentary interruption or lowering of power supply voltage. It also has a built-in watchdog timer for operation diagnosis. This prevents the system from running wild by generating an intermittent reset pulse during system mis-operation. Features 1. 2. 3. 4. 5. 6. 7. Built-in watchdog timer Low minimum operating voltage VCC=0.8V typ. Both positive and negative logic reset output can be extracted Accurate detection of drop in power supply voltage Detection voltage has hysteresis Few external parts 1 capacitor Timer monitoring time can be varied by using an external resistor Package DIP-8A (MM1075XD) SOP-8A (MM1075XF) Applications Microcomputer system monitoring, etc. Absolute Maximum Ratings Item Storage temperature Operating temperature Power supply voltage (Ta=25°C) Symbol TSTG TOPR VCC max. VVS &VCK VOH Pd Rating -40~+125 -20~+70 -0.3~+10 -0.3~+10 -0.3~+10 400 Units °C °C V V V mW Voltage applied to VS & CK pins Voltage applied to RESET, RESET pin Allowable loss ------------------------------------------------------------- MITSUMI System Reset (with built-in watchdog timer) MM1075 Electrical Characteristics (DC) Item Consumption current Detection voltage Detection voltage temperature coefficient Hysteresis voltage CK input threshold CK input current Symbol ICC VSL VSH VS/ T VHYS VTH IIH IIL VOH1 VOH2 VOL1 Output voltage (Low) VOL2 VOL3 VOL4 Output sink current IOL1 IOL2 ICT1 CT charge current 1 (Except where noted otherwise, Ta=25°C, VCC=5V) Measurement circuit 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Measurement conditions During watchdog timer operation VS=OPEN, VCC VS=OPEN, VCC Min. Typ. Max. Units 0.7 4.05 4.15 4.20 4.30 ±0.01 1.0 4.35 4.45 mA V %/°C 150 2 1 -3 mV V µA V 0.4 0.5 0.4 0.5 mA -2.4 -2.4 1.0 1.0 µA µA V V V VSH-VSL, VCC VCK=5V VCK=0V I RESET =-5µA, VS=OPEN I RESET =-5µA, VS=0V I RESET =3mA, VS=0V I RESET =10mA, VS=0V IRESET=0.5mA, VS=OPEN IRESET=1mA, VS=OPEN V RESET =1.0V, VS=0V VRESET=1.0V, VS=OPEN VTC=1.0V, RCT=OPEN during watchdog timer operation VTV=1.0V during power ON reset operation V RESET =0.4V I RESET =0.2mA ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- 50 0.8 -20 4.5 4.5 100 1.2 0 -10 4.8 4.8 0.2 0.3 0.2 0.3 Output voltage (High) 10 1 -0.8 -0.8 16 2 -1.2 -1.2 0.8 0.8 * ICT2 Minimum operating power supply voltage to ensure RESET --------------------------------------------------------------------------- VCCL1 VCCL2 Minimum operating power supply voltage to ensure RESET VRESET=VCC-0.1V RL2 (between Pin 2 and GND) MITSUMI System Reset (with built-in watchdog timer) MM1075 Electrical Characteristics (AC) Item VCC input pulse width CK input pulse width CK input cycle Watchdog timer monitoring time 2 Reset time for watchdog timer 3 Reset hold time for power supply rise 4 Symbol TP1 TCKW TCK TWD TWR TPR TPD1 TPD2 tR1 tR2 tF1 tF2 (Except where noted otherwise, Ta=25°C, VCC=5V) Measurement circuit 2 2 2 2 2 2 2 2 2 2 2 2 VCC CK Measurement conditions 5V 4V or CT=0.1µF RCT=OPEN CT=0.1µF CT=0.1µF, VCC RESET pin RL1=2.2kΩ, CL1=100pF RESET pin R1, 2=10kΩ, CL2=20pF RESET pin RL1=2.2kΩ, CL1=100pF RESET pin RL2=10kΩ, CL2=20pF RESET pin RL1=2.2kΩ, CL1=100pF RESET pin RL2=10kΩ, CL2=20pF Min. Typ. Max. Units 8 3 20 50 1 50 100 2 100 2 3 1.0 1.0 0.1 0.5 150 3 150 10 µS 10 1.5 1.5 0.5 1.0 µS µS µS µS µS µS µS mS mS mS * * * Output delay time from VCC 5 * * * Output rise time 6 Output fall time 6 Notes: 1 ICT1 changes according to RCT pin (Pin 6) pull up resistance. 2 Monitoring time is the time from the last pulse (negative edge) of the timer clear clock pulse until reset pulse output. In other words, reset output is output if a clock pulse is not input during this time. Also, monitoring time can be varied by pulling up the RCT pin to VCC with a resistor (RCT). Monitoring time adjustments are shown in Graph 1. 3 Reset time means reset pulse width. However, this does not apply to power ON reset. 4 Reset hold time is the time from when VCC exceeds detection voltage (VSH) during power ON reset until reset release (RESET output high, RESET output low). 5 Output delay time is the time from when power supply voltage drops below detection voltage (VSI) until reset (RESET output low, RESET output high). 6 Voltage range when measuring output rise and fall is 10~90%. 7 Watchdog timer monitoring time (TWD), watchdog timer reset time (TWR) and reset hold time (TPR) during power supply rise can be changed by varying CT capacitance. The times are expressed by the following formulae. The recommended range for CT is 0.001~10µF. * * * * * * * ------------------------------------------------------------- ------------------------------------------------------------- ~ TPR (mS) - 1000 CT (µF) ~ TWD (mS) - 1000 CT (µF) ~ 20 CT (µF) TWR (mS) Example : When CT=0.1µF (RCT pin OPEN) ~ TPR - 100mS ~ TWD - 100mS ~ TWR - 2mS MITSUMI System Reset (with built-in watchdog timer) MM1075 (mS) 100 80 TWD 60 40 20 0 50k 100k 1M RCT ∞ (Ω) 10M 100M Graph 1 RCT & Monitoring Time Note : The above graph shows data for when CT=0.1µF. TWD is proportionate to CT. Refer to the calculation formula for TWD above. Block Diagram Note 1 : CP=0.1µF approx. ~ Note 2 : C-1000pF Note 3 : The watchdog timer can be stopped by connecting the RCT pin to GND. (Then it functions as a voltage detection circuit.) Note 4 : TPR and TWD can be varied by pulling up the RCT pin to VCC with a resistor. The recommended range for RCT is 100kΩ~RCT pin OPEN. MITSUMI System Reset (with built-in watchdog timer) MM1075 Timing Chart VCC VSH VSL CK CT TCK TPR TWD TWR RESET RESET Pin Assignment 1 2 8 7 6 5 3 4 5 1 2 3 4 6 7 8 TC RESET CK GND VCC RCT VS ----------------------------------------------------------------------------- RESET Pin Description Pin No. Pin Name 1 2 3 4 5 6 7 8 TC RESET CK GND VCC RCT VS --------------------------------------------------------------- Function TWD, TWR, TPR variable pins.(TWD, TWR and TPR times are determined by the external capacitor.) Reset output pin (High output) Clock input pin (inputs clock from logic system) 4.2V detection voltage Watchdog timer stop pin Operation modes : Operation Detection voltage variable pin Adjustment modes : Lower Reset output pin (Low output) OPEN, Stop connect to GND pull down pull up resistance, Raise RESET MITSUMI System Reset (with built-in watchdog timer) MM1075 Measuring Circuits Measuring Circuit 1 Measuring Circuit 2 Measuring Circuit 2-1 Item Consumption current Detection voltage CK input threshold CK input current Output voltage (High) Output voltage (Low) ICC VSL VSH VTH IIH IIL VOH1 VOL1 VOL2 VOL3 VOL4 Output sink current CT charge current 1 CT charge current 2 Minimum operating power supply --------------------------------------------------------- SW & Power Supply Table VCK 5V VCT 0V 3V 3V 1V 0V 0V 3V 3V 3V 3V 3V 3V 3V 3V 1V 1V 0V 0V I RESET -5µA 3mA 10mA ------------------------------------------------------------- Symbol SW1 SW2 SW3 SW4 SW5 SW6 SW7 VCC OFF OFF OFF ON OFF OFF ON OFF OFF ON ON ON B B B B B B B C B B C C B B B B B A B B B B B B B B B B B B C A B B B B ON 5V IRESET -5µA 0.5mA 1mA - VM, IM Notes ICC VO1, CRT1 VO1, CRT1 ICK ICK ICK VO1 VO2 VO1 VO1 VO2 VO2 I O1 I O2 ITC ITC VO1, VCC VO2, VCC VOO=1V VOO=1V ON 5V 4V 3V ON 4V 5V 3V ON ON ON ON ON ON ON ON ON ON ON OFF OFF 5V 0V 3V 5V 5V 5V 5V 5V 5V 5V 5V 5V 5V 5V 5V 5V 0V 5V 5V 5V 5V 5V 5V 5V 5V - OFF OFF OFF ON OFF OFF OFF ON OFF OFF OFF ON ON OFF ON ON ON ON ON ON ON ON ON ON ON ON ON ON ON ON ON ON ON VOH2 OFF ON OFF OFF ON OFF OFF ON OFF ON ON OFF OFF ON OFF OFF ON ON OFF ON ON IOL1 IOL2 ITC1 ITC2 VCCL1 OFF OFF OFF ON voltage to ensure RESET Minimum operating power supply voltage to ensure RESET ON 0V 2V 0V ON 0V 2V 0V VCCL2 OFF ON MITSUMI System Reset (with built-in watchdog timer) MM1075 Measuring Circuit 2-2 Item VCC input pulse width SW & Power Supply Table VCCA 5V 4V 5V 0V 5V 0V T1 VCC 5V 5V 5V 5V 5V 5V 5V 5V 5V 1.4V 0V 1.4V 0V 1.4V 0V T2 or T2 T2 T3 5V 5V 5V 0V 0V 5V 5V 5V 5V CRT1, 2, 3 CRT1, 2, 3 CRT1, 2, 3 CRT1, 2, 3 CRT1, 2, 3 CRT1, 3 CRT2, 3 CRT1 CRT2 CRT1 CRT2 T2=3µS T3=20µS VCKA T2 T3 VCK CRT CRT1, 2, 3 Notes T1=8µS Symbol SW1 SW2 TPI C A A A A B B B A A A A A A A A A CK input pulse width TCKW CK input cycle Watchdog timer monitoring time Reset time for watchdog timer Reset hold time for power supply rise Output delay time from VCC TCK TWD TWR TPR B A TPD1 TPD2 TR1 TR2 TP1 TP2 C C A A A A Output rise time Output fall time Detection Voltage Adjustment 1 (lowering detection voltage) Graph 1. Detection voltage change using MM1075 external resistor Detection voltage (Vs) (V) 5.0 VSH value 4.5 VSL value 100 200 300 400 500 600 Vs pin external resistance (R2) (kΩ) Detection voltage can be changed by connecting resistor R2 externally to MM1075 VS pin. Determine R2 according to graph 1 when changing VS. MITSUMI System Reset (with built-in watchdog timer) MM1075 Detection Voltage Adjustment 2 (raising detection voltage) Graph 2. Detection voltage change using MM1075 external resistor VSH value 4.0 Detection voltage (VS) (V) VSL value 3.5 3.0 100 200 300 400 500 600 Vs pin external resistance (R1) (kΩ) Detection voltage can be changed by connecting resistor R1 externally to MM1075 VS pin. Determine R1 according to graph 2 when changing VS. Characteristics Power supply current-Power supply voltage Power supply current ICC (mA) Output voltage-Power supply voltage (RESET pin) 7.0 PULL UP resistance 10kΩ Power supply current ICC (mA) 1.4 1.2 1.0 0.8 0.6 0.4 0.2 6.0 5.0 4.0 3.0 2.0 1.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 Ta=20°C, 25°C, 75°C Clock pulse input time 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 Power supply voltage VCC (V) Power supply voltage VCC (V) Output voltage-Power supply voltage (RESET pin) 7.0 PULL UP resistance 2.2kΩ Detection voltage (VSL, VSH) temperature (RESET, RESET pins) ---------------------------------------------------------------- Output voltage VRESET (V) 6.0 5.0 4.0 3.0 2.0 1.0 Ta=-25°C Ta=25°C Ta=75°C 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 Detection voltage (V) 4.50 4.40 4.30 4.20 4.10 4.00 3.90 -40-20 0 20 40 60 80 100 VSL VSH Power supply voltage VCC (V) Ambient temperature Ta (°C) MITSUMI System Reset (with built-in watchdog timer) MM1075 Output saturation voltage-Output sink current (RESET pin) ----------------------------------------------------------------------- Output saturation voltage-Output sink current (RESET pin) ---------------------------------------------------------------- Output saturation voltage VOL (mV) Output saturation voltage VOL (mV) 500 400 300 200 100 Ta=25°C Ta=75 °C 500 400 300 200 100 Ta=-25°C Ta=75°C Ta=25°C Ta= -25°C 0.2 0.4 0.6 0.8 1.0 1.4 1.6 1.8 2 4 6 8 10 12 14 16 18 Output sink current IOL (mA) Output sink current IOL (mA) High level output voltage-High level output current (RESET pin) High level output voltage VOM (V) 5.0 4.8 4.6 4.4 4.2 4.0 3.8 -2 -4 -6 -8-10 -12 -14 -16 -18 High level output voltage-High level output current (RESET pin) ---------------------------------------------------------- High level output voltage VOM (V) 5.0 4.8 4.6 4.4 4.2 4.0 3.8 -2 -4 -6 -8-10-12 -14 -16 -18 High level output current IOM (µA) High level output current IOM (µA) Reset hold time temperature during power supply rise Reset hold time temperature during power supply rise TPR (mS) 160 140 120 100 80 60 40 -40-20 0 20 40 60 80 100 VCC=5V (Cr=0.1µF) Watchdog timer monitoring time temperature Watchdog timer monitoring time temperature TWD (mS) VCC=5V (Cr=0.1µF) 160 140 120 100 80 60 40 -40 -20 0 20 40 60 80 100 Ambient temperature Ta (°C) Ambient temperature Ta (°C ) MITSUMI System Reset (with built-in watchdog timer) MM1075 Reset time temperature (for watchdog timer) VCC=5V (Cr=0.1µF) 3.5 Watchdog timer monitoring time temperature VCC=5V (Cr=0.1µF) Reset time TWR (mS) 3.0 2.5 2.0 1.5 1.0 0.5 -40 -20 0 20 40 60 80 100 -40 -20 0 20 40 60 80 100 10 6PIN 100kΩ PULL UP 100 6PIN 5MΩ PULL UP Ambient temperature Ta (°C) Ambient temperature Ta (°C) CT value for reset hold time during power supply rise 105 CT value for reset time (for watchdog timer) 103 Hold time TPR (mS) 104 103 102 101 100 10-3 10-2 10-1 100 101 Reset time TWR (mS) 102 101 100 10-1 10-2 10-3 10-2 10-1 100 101 CT capacitance (µF) CT capacitance (µF) CT value for watchdog timer monitoring time Timer monitoring time TWD (mS) Type of timer time adjustment CT value for watchdog timer monitoring time Timer monitoring time TWD (mS) 105 104 103 102 101 100 10-3 10-2 10-1 100 101 104 103 102 101 100 10-1 Connect R between Rct and VCC R= OPEN 2.2MΩ 1kΩ 470kΩ 200kΩ 10-3 10-2 10-1 100 101 CT capacitance (µF) CT capacitance (µF)