M62055FP MITSUBISHI | Alldatasheet

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( / 6 ) M62055FP 3V POWER SUPPLY with WATCHDOG TIMER MITSUBISHI<Dig./Ana.INTERFACE> M62055FP RESET VOC GND CLM Vcc VDDTC WD GENERAL DESCRIPTION M62055FP is a 3V power supply featuring a watchdog timer function for a microcontroller system. It can be a power source of 3V ± 5% by utilizing the reference voltage and amplifier. It can also generate a reset pulse for the applied systems during power-on, moreover it includes the watchdog timer for a self diagnostics of the system, which can prevent system erroneous functions.

FEATURES

  • Power-on reset
  • Watchdock timer
  • High accuracy voltage source of 3V ±5% (max)
  • Overcurrent protection circuit
  • The voltage detection accuracy of ±5% (max)
  • Output power (Vo) cutoff function at erroneous conditions
  • Backward voltage protection circuits for inputs and outputs PIN CONFIGURATION(TOP VIEW) Outline 8P2S APPLICATION Handy information terminal equipment, CD-ROM, Portable audio equipment. BLOCK DIAGRAM TCWDGND CLMVcc VD VO Q R S Q Vcc R Q QS Q R S Q Vcc Q R S Q Q R S Q Vcc Vref =1.25v RESET VOLTAGE DETECTOR (CURRENT LIMITER) START CIRCUIT RISE DELAY (300µsec) Vcc Vref =0.9v Vref =1.5v Vref =1.5v Vref =1.25v 56K 40K Set priority Reset priority Reset priority Reset priority The input and output reversal conservation circuit Set priority Note ; It indicates Vo, unless otherwise noted

( / 6 ) M62055FP 3V POWER SUPPLY with WATCHDOG TIMER MITSUBISHI<Dig./Ana.INTERFACE> Ta ≥ 25°C - 20 ~ + 75 - 55 ~ + 150 V mW/°C °CTstg Topr Vcc Ko 4.0 VRM IRM VWDM V mA V pin number symbol Functional description Pin Functional description Vcc8 Power supply voltage CLM7 Current limiting VD6 VO5 Feedback to a power supply for a MCU. RESET4 Reset signal output TC3 Setting up reset timer and watchdock timer. WD2 Input for watchdock timer. GND1 Ground symbol Parameter conditions Ratings Unit supply voltage Reset pin Output voltage Output current Watchdock pin input voltage ABSOLUTE MAXIMUM RATINGS (Ta=25°C, Unless otherwise noted) Thermal derating Operating temperature Storage temperature Controlling the stability of an output voltage with a PNP transistor connected externally.

( / 6 ) M62055FP 3V POWER SUPPLY with WATCHDOG TIMER MITSUBISHI<Dig./Ana.INTERFACE> IBmax VO Reg-in ΔVo/ΔT IWD VTH(WD ) Itco VTH2(H) VOL(RST ) VIN=3V VIN=0.8V V mA %/V mV %/T V µA VCC ICC I BSC Reg-lo Vcc=3.5V~13V Io=10mA~100mA VTH2(L) Ileak VTH1(H) VTH1(L) ΔVTH1 3.5 13 2.85 3.0 3.15 1.5 0.02 0.02 1.5 2.28 2.4 2.52 0.95 1.0 1.05 0.2 0.4 650 2.82 2.72 0.1 950 Itc1 Itc2 µA mA 2.68 2.58 2.96 2.86 2.0 mA mA V VIN=2.4V 8.0 VTHCLM 200 mV Isink=4mA VCCMIN *1 2.0 V mStWD tRST(1) tRST(2) C=0.1µF,R1=10KΩ CO=10µF, R1=10KΩ , IL=0 0.5 1.2 1.7 0.1 0.7 2.0 symbol Parameter Test conditions UnitMin Typ Max Limits ELECTRICAL CHARACTERISTICS (Vcc=5.0V,Ta=25°C, Unless otherwise noted) (1) DC CHARACTERISTICS Battery• back up• regulator supply voltage Circuitry current Output voltage Bias current Listing short-circuit bias current Input voltage regulation Loading voltage regulation Output voltage thermal coefficient CLM threshold voltage Reset, watch dock timer Vo detection voltage Output voltage Output leakage current Reset pin Watchdock timer threshold voltage WD input current WD input threshold voltage TC output current TC input current Vcc min operating voltage In the output cutoff transmission mode Note *1; The Vcc minimum operating voltage at which the RESET output is Low symbol Parameter Test conditions UnitMin Typ Max Limits (2) AC CHARACTERISTICS (Vcc=5.0V,Ta=25°C, Unless otherwise noted) Watch dock timer Reset timer (1) Reset timer (2) 0.25 180 220 µA V V V V V V µA C=0.1µF,R1=10KΩ mS mS

( / 6 ) M62055FP 3V POWER SUPPLY with WATCHDOG TIMER MITSUBISHI<Dig./Ana.INTERFACE> TRST(1) TWD TRST(2) Vo Vcc TC RESET VTH1(H) VTH1(L) WD VO +VCE(sat) =0.9V =0.9V VTH2(H) VTH2(L) 1 3 6 7 9 10 11 12 13 14 FUNCTIONAL DESCRIPTION Tick deactivation output cutoff output cutoff 1 : When Vo rises to 0.5 V, RESET becomes low. Then, charging to a capacitor C connected to TC will be started at the Vo of 2.82V(VTH1(H)). 2 : When VCC rises to 3V+VCE (sat), Vo becomes stable. 3 4 : When TC voltage rises to 1V(VTH2(L)) , RESET becomes high. When it rises to 2.4V (VTH2(H)) further, the capacitor C is switched to discharge and RESET becomes low. 5 : At the same time of a change-over to the discharge from the capacitor C, Vo is intercepted. Then,TC will be discharged completely at Vo of 2.72V(VTH1 (L)). 6 : Vo returns to 3V right after it has fallen down to 0.9 V. RESET repeats above operation till a normal clock signal is input to WD pin. 7 8 : In the case of a sudden power interruption, Vo 9 falls down according to a decrease of VCC . When it falls down to 2.72V, the capacitor C is discharged and RESET will be low. In the case of a reversion from the power interruption, Vo rises according to a increase of VCC . When it rises to 2.82V, the charging to the capacitor C is started and RESET will be high right after TC voltage reaches 1V. 10 11 : In the case a clock signal for discharging the capacitor C is applied to pin WD before TC voltage reaches to 2.4V, a reset signal to RESET is canceled. 12 13 : In the case an abnormal clock signal is input, TC repeats charging / discharging alternately between 1 V and 2.4 V, so that RESET also repeats high / low till a normal clock signal is input. 14 : When Vo falls down to 2.72 V, RESET becomes Low. .. ..

( / 6 ) M62055FP 3V POWER SUPPLY with WATCHDOG TIMER MITSUBISHI<Dig./Ana.INTERFACE> tWD = 1.2 • C • R1 C VO = 3.0V Al C t1 t2 tWDIN XV VTH2(H ) = 2.4v VTH2(L) = 1.0v Pin 3 Pin 2 1.2 • C • R1 < f 1. Pin 3 (TC pin) Charging and discharging time . When an error is occurred in WD input, TC waveform is as shown below. (Charging time) The following formula can be obtained because tRST(2) is equal to the duration of Vo cutoff. 2. Pin 2 (WD pin) Input frequency, input pulse width, charge/discharge time . Conditions of an input to pin 2 (WD pin) (1) Input period should be tWD or less. ( Pin discharge is completed before the arrival of VTH2(H) = 2.4 V ) (2) Input pulse width tWDIN should be t2 or less. cutoff Tr output cutoff Vo TC VTH1(H) VTH1(L) =0.9V VTH2(H) VTH2(L) tRST(1) tWD tRST(2) Inside delay time tRST(1) = 0.406 • C • R1 + 300µs *1 : Inside delay time (Typical values) DESCRIPTION of TERMS tRST(1) tWD tRST(2) Time from when TC is VTH2(L) until it reaches to VTH2(H). Time from when TC begins to charge until it reaches to VTH2(L). *2 : Inside delay time (Typical values) Time from when TC is VTH2(H) until TC starts charging. *3 : R = Internal resistance t1 = C • R1 • ln2 3-X t2 = 1000 • C • R1 • ln 1000 R 1 - 2 X ( + 1) - 3 1000 R 1 tRST(2) = C • R • ln ( 3 0.9 ) = 40 • C+ 300µs + 300µs When input of 2 WD is normal, TC waveform 3 is as shown below.

( / 6 ) M62055FP 3V POWER SUPPLY with WATCHDOG TIMER MITSUBISHI<Dig./Ana.INTERFACE> 3. Relationship between the input pulse width and the low pass filter RESET is output in the case of t 4> t WD . APPLICATION VCC 10µF C IN VCC CLM VD VO GND RESETWD TC M62055FP R RST C TC R TC 10µF C O MCU/MPU GND VDD RESETCLOCK Note : hFE of the external PNP transistor, 100 to 300 is recommended. (External Element) filter R C 3.0V 0.0V 1.5V VIN WD 1.5v 2.4v2.4v 1.0v tWD VIN WD TC RESET t t t t 3.0v t 3 = -C • R • lnVIN 1.5v Addition of a low pass filter makes input waveform dull. An input pulse width and CR of a low pass filter is determined referring to the right figure. If t3 is too long, the TC waveform changes as shown in the diagram above. t3 is set as follows; tWDIN (3 µs) or more and t 2 (charging time) or less. (t2 is a discharge time while an input is normal)