MITSUBISHI<Dig.Ana.INTERFACE> M62021L,P,FP SYSTEM RESET IC WITH SWITCH FOR MEMORY BACK-UP DESCRIPTION PIN CONFIGURATION (TOP VIEW) The M62021 is a system IC that controls the memory backup function of SRAM and microcomputer (internal RAM). The IC outputs reset signals(RES/RES) to a microcomputer at power-down and power failure.It also shifts the power supply to RAM from main to backup,outputs a signal (CS) that invokes standby mode,and alters RAM to backup circuit mode. The M62021 contains,in a single chip,power supply monitor and RAM backup functions needed for a microcomputer system,so that the IC makes it possible to construct a system easily and with fewer components compared with a conventional case that uses individual ICs and discrete components. 8 CS 7 RES 6 GND 5 RES 4 Ct(DELAY CAPACITANCE) 3 VIN 2 VBAT VOUT 1 FEATURES •Built-in switch for selection between main power supply and backup power supply to RAM. •Small difference between input and output voltage (IOUT=80mA,VIN=5V)0.2V typ •Detection voltage (power supply monitor voltage)4.40V±0.2V •Chip select signal output(CS) Two channels of reset outputs(RES/RES) •Power on reset circuit built-in •Delay time variable by an external capacitance connected to Ct pin •Facilitates to form backup function with a few number of components Outline 8P5(L) VOUT VBAT 1 8 CS 2 7 RES VIN 3 6 GND 4 5 RES Ct(DELAY CAPACITANCE) Outline 8P4(P) 8P2S-A(FP) APPLICATION Power supply control systems for memory backup of microcomputer system and SRAM boards with built-in backup function that require switching between external power supply and battery. BLOCK DIAGRAM SW VIN 3 VOUT 2 VBAT 8 CS 4 Ct D1 R1 R2 1 + Com RESET CIRCUIT 1.24V RES 7 RES 5 DELAY CIRCUIT 6 GND MITSUBISHI ELECTRIC ( 1 / 9 ) MITSUBISHI<Dig.Ana.INTERFACE> M62021L,P,FP SYSTEM RESET IC WITH SWITCH FOR MEMORY BACK-UP ABSOLUTE MAXIMUM RATINGS(Ta=25°C, unless otherwise noted) Symbol VIN IOUT Pd K Topr Tstg Power dissipation Thermal derating Operating temperature Storage temperature Ratings 7 Conditions Parameter Input voltage Output current 100 800(SIP)/625(DIP)/440(FP) 8(SIP)/6.25(DIP)/4.4(FP) -20 ~ +75 (Ta≥25°C) Unit V mA mW mW/°C -40 ~ +125 °C °C ELECTRICAL CHARACTERISTICS(Ta=25°C, unless otherwise noted) Symbol Vs ∆Vs Vs/∆T ICC VDROP Test conditions Parameter Detection voltage Hysteresis voltage VIN(At the change from H L) ∆Vs=VSH-VSL Min. 4.2 50 Temperature coefficient of detection voltage Circuit current VIN=4V VIN=5V IOUT=50mA IOUT=80mA IOUT=0mA Difference between input and output voltage VIN=5V VOH(Ct) Ct output voltage (high level) VOL(Ct) Ct output voltage (low level) VOH(RES) RES output voltage (high level) VIN=5V(Note1) VIN=4V(Note1) VIN=4V(Note1) VOL(RES) RES output voltage (low level) VIN=5V VOH(RES) RES output voltage (high level) VIN=5V(Note1) VOL(RES) RES output voltage (low level) 4.5 3.5 4.5 VOL(CS) CS output voltage (low level) IR Backup Di leak current VF tpd td Backup Di forward direction voltage Delay time Response time VOPL(RES) RES limit voltage of operation VIN=0V,VBAT=3V (Note2) (Note1) VIN=5V ISINK=1mA VIN=5V VBAT=3V VIN=0V IF=10µA 5V,Ct=4.7µF VIN=0V VIN=5V 4V (Note 3) Max. 4.6 200 4.0 12.0 0.25 0.4 Unit V mV %/°C mA V V V 0.1 4.0 0.02 0.05 V V 0.2 5.0 V 0.02 (Note1) ISINK=1mA VIN=4V (Note2) VOH(CS) CS output voltage (high level) 100 0.005 2.0 7.5 0.125 0.2 5.0 0.02 (Note1) ISINK=1mA VIN=4V Limits Typ. 4.4 0.05 3.50 2.40 10 V 0.2 3.57 2.47 0.08 0.1 0.54 27 5.0 V 0.3 ±0.5 ±0.5 0.6 55 25.0 V µA V ms µs 0.65 V Note 1.Regarding conditions to measure VOH and VOL,voltage values are to be generated by internal resistance only and no external resistor is used. 2.These values are produced inserting an external resistor,RCS=1MΩ,between the CS pin and GND. 3.With no external resistor (10kΩ internal resistance only) MITSUBISHI ELECTRIC ( 2 / 9 ) MITSUBISHI<Dig.Ana.INTERFACE> M62021L,P,FP SYSTEM RESET IC WITH SWITCH FOR MEMORY BACK-UP TEST CIRCUIT V Vm2 M62021 VIN SW2 A Vm1 V 1 SW1 2 3 Im1 1 R1 + - RES RES 2 VBAT Com 5 V 2 Vm4 6 CRT 6 7 instrument ON OFF 1 OFF 1 2 3 ON OFF 1 OFF 4 5 6 1 Im1 1 (Note5) Vm4 CRT Vm1 A 8 CS 7 SW4 2 Im2 DELAY CIRCUIT SW7 1 4 SW5 1 RESET CIRCUIT 1.24V SW6 3 D1 R2 V1 1 2 VOUT 3 IF2 Vm3 IF1 V V2 4 Ct 5 6 GND SW3 4.7µ SWITCH MATRIX Symbol Icc Vs (VSL) VDROP V1 Parameter Detection voltage IF1 VOUT CS Ct RES RES Difference between input and output voltage 1 1 Decrease from 5V 1 -50mA -80mA 5V VOH(Ct) Ct output voltage(high level) VOL(Ct) Ct output voltage(low level) VOH(RES) RES output voltage(high level) 5V 4V 4V VOL(RES) RES output voltage(low level) 1mA VOH(RES) RES output voltage(high level) 5V 5V VOL(RES) RES output voltage(low level) 4V 1mA VOH(CS) CS output voltage(high level)(Note 4) 4V 0V VOL(CS) CS output voltage(low level) 5V IR Backup Di leak current 5V 0V VF Backup Di forward direction voltage 0V tpd Delay time Response time td IF2 4V 5V Circuit current (VIN negative-going) V2 S 3 4 W 5 Measuring 1 ON OFF 1 OFF 2 2 Vm2 1 ON OFF 1 1 Vm4 1 ON OFF 1 OFF 5 1 3V 2 OFF 4 ON OFF 1 OFF 6 2 1 2 1 Vm4 Vm4 1 ON OFF 1 OFF 3 1 ON OFF 2 OFF 1 1 Im2 1 ON OFF 3 1 1 Vm3 2 ON 2 1 OFF 3 5 6 1 CRT Vm4 2 1mA 3V VOUT CS RES RES 1 10µA (Note6) ON (Note7) ON Notes 4.To measure VOH(CS),insert a 1MΩ resistor between the CS pin and GND. 5. While monitoring each output by Vm4 or CRT,measure the input voltage Vm1 when the output goes from H to L and L to H.Regarding VSH,raise VIN from 4V and measure the input voltage Vm1 when the output goes from H to L and L to H.∆Vs is VSH-VSL. 6. To measure delay time, change VIN from 0V to 5V and compare,with respect to each pin,the positive-going edge observed on a monitor with that of VIN.To measure response time,change VIN from 5V to 4V and compare,with respect to each pin,the negative-going edge observed on a monitor with that of VIN. 7.Set the switch to OFF when measuring response time. MITSUBISHI ELECTRIC ( 3 / 9 ) MITSUBISHI<Dig.Ana.INTERFACE> M62021L,P,FP SYSTEM RESET IC WITH SWITCH FOR MEMORY BACK-UP EXPLANATION OF TERMINALS Pin No. Symbol 1 VOUT 2 VBAT 3 VIN 4 Ct 5 RES 6 GND 7 RES 8 CS Name Function VIN and VBAT are controlled by means of an internal switch and output through VOUT Power supply output The pin is capable of outputting up to 100mA.Use it as VDD of CMOS RAM and the like Backup power supply is connected to this pin Backup power supply input If a lithium battery is used,insert a resistor in series for safety purposes +5V input pin.Connect to a logic power supply. Power supply input A delay capacitor is connected to this pin.By connecting a capacitor,it is Delay capacitor connection pin possible to delay each output Connect to the positive reset input of a microcomputer.The pin is capable Positive reset output of flowing 1mA sink current Ground Reference for all signals Connect to the negative reset input of a microcomputer.The pin is capable Negative reset output of flowing 1mA sink current Connect to the chip select of RAM.The CS output is at low level in normal state thereby letting RAM be active.Under failure or backup condition,the CS Chip select output output is set to high level,then RAM enters standby state disabling read/write function.The pin is capable of flowing a 1mA sink current APPLICATION EXAMPLE +5V (MAIN POWER SUPPLY) M62021 VIN 1 3 R1 CIN R2 VDD RES RES CPU D1 + 1.24V 7 2 Com VOUT VBAT RESET CIRCUIT 8 CS DELAY CIRCUIT 5 4 VIN VDD CONT BATTERY CMOS 3V RAM Ct 6 GND *Capacitance to be connected:CIN:10µF;COUT:4.7µF;Ct:4.7µF *If connecting a zener diode,select one of VZ=2~3V MITSUBISHI ELECTRIC ( 4 / 9 ) MITSUBISHI<Dig.Ana.INTERFACE> M62021L,P,FP SYSTEM RESET IC WITH SWITCH FOR MEMORY BACK-UP CONFIGURATION <Power supply detector> The internal reference voltage Vref is compared by means of a comparator with resistor-divided voltage VR(resistor-divided voltage produced by R1 and R2 from VIN). If the input voltage is 5V,VR is set to 1.24V or higher,so the comparator output is at low level and the Ct output(Q1 collector output)is set to high level.If the input voltage drops to below 4.4V in an abnormal condition,VR becomes below 1.24V,so the comparator output goes from low to high level and the Ct output,from high to low.The input voltage at this point is called VSL.Next,when the input voltage,restored from abnormal state,has a rise,the comparator output goes from high to low level and the Ct output,from low to high. The comparator used for detection has 100mV hysteresis(∆Vs),so that malfunctioning is prevented in case that the input voltage slowly drops or VR nearly equals Vref. 5 4 2 VSL =Ct X 22kΩ X 0.2614 . =5.75 X 10 3 X Ct . VSH 1 0 4.0 4.2 4.4 4.6 4.8 5.0 INPUT VOLTAGE VIN(V) <Delay Circuit> Connecting an external capacitor to the Ct pin lets RES,RES,CS,and VOUT be delayed due to RC transient phenomenon(electric charge). Delay time is determined as follows. Delay time(tpd)= Ct X (R3 + R4) X In ∆Vs 3 tpd VOH(Ct) [VOH(Ct)-VOL(Ct)] [VOH(Ct)-INV1(VTH)] INV1(Vth) VOL(Ct) *Ct is an external capacitance. DELAYED OUTPUT WAVEFORMS OF Ct Taking into consideration the time taken by the oscillator of microcomputer to be stable,connect a 4.7µF capacitor to the Ct pin. (As the response time of detection can be slowed due to internal structure depending on the rising rate of power supply,avoid connecting a too large capacitance. <Schmitt trigger circuit> Since waveforms show a gentle rise due to the RC delay circuit,INV1,INV2,R5,and R6 constitute a schmitt trigger circuit to produce hysteresis so as to prevent each output from chattering. INTERNAL CIRCUIT Ct VIN RES RES 4 3 5 7 Q4 R3 22k R4 R1 60.94k Com R2 24K Vref 1.24V 47 Q1 R7 10k R6 R5 10k R8 10k Q2 VOUT 2 VBAT 8 CS 6 GND D1 R10 800 R11 10k INV1 INV2 INV3 INV4 Q3 INV5 INV6 INV7 R9 5k R10 INV8 INV9 22k MITSUBISHI ELECTRIC 1 Q5 ( 5 / 9 ) MITSUBISHI<Dig.Ana.INTERFACE> M62021L,P,FP SYSTEM RESET IC WITH SWITCH FOR MEMORY BACK-UP TIMING CHART tpd tpd 5V VIN ∆Vs VSH VSL 0V V1 V2 V3 V4 V5 VOUT V2 V4 V5 CS VOL(CS) 5V VIN(VSL) RES VOL(RES) VOL(RES) VIN(VSL) RES V1=VIN-VDROP V2=VIN-Q4VEB(Di) V3=VIN(VSL)-VDROP Input voltage In normal operation Input voltage:5V Output pin VOUT RES RES CS With Q4 set to ON, a voltage (VIN-VDROP)is output The output level is VOL(RES) with a logic low Restoration from failure (instantaneous drop) In failure(instantaneous drop) Input voltage:5V 4V Each output varies if the input voltage drops to VSL or under Q4 is turned OFF.A voltage (VIN-Q4 VEB(Di) is output by the diode between E and B of Q4 As the state shifts from a logic low to logic high,the output level becomes approximately equal to the input voltage VOL(RES) V4=VIN(VSL)-Q4VEB(Di) V5=VBAT-VF In backup state Input voltage:0V Input voltage:4V 5V Backup voltage:3V If the input voltage goes higher than VSL by 100mV,each out-put varies after delay produced by the delay circuit Q4 is turned ON after delay and a voltage(VIN-VDROP) is output VBAT-VF A logic high is maintained,and than shifts to a logic high The output level is VOH(RES) with a logic low As the state shifts from a logic A logic low is held,and than shifts high to logic low,the output level to a logic high becomes VOL(RES) The output level is VOL(CS) with a logic low As the state shifts from a logic A logic high is maintained,and than The output is a logic high low to logic high,the output level shifts to a logic high and the output level is becomes the voltage VINVBAT-VF Q4EB(Di). MITSUBISHI ELECTRIC ( 6 / 9 ) MITSUBISHI<Dig.Ana.INTERFACE> M62021L,P,FP SYSTEM RESET IC WITH SWITCH FOR MEMORY BACK-UP TYPICAL CHARACTERISTICS CIRCUIT CURRENT VS. INPUT VOLTAGE THERMAL DERATING (MAXIMUM RATING) 16 1000 M62021L 14 800 12 M62021P 10 600 M62021FP 8 400 6 4 200 2 0 0 25 50 75 100 0 125 0 3 4 5 6 7 8 AMBIENT TEMPERATURE Ta(°C) DETECTION VOLTAGE VS. AMBIENT TEMPERATURE INTERRUPTION OUTPUT VOLTAGE VS. SUPPLY VOLTAGE 140 4.46 130 4.44 120 4.42 110 4.40 100 4.38 90 4.36 80 4.34 70 4.32 -40 -20 0 60 -40 -20 0 20 40 60 80 100 120 CIRCUIT CURRENT VS. AMBIENT TEMPERATURE 4.0 VIN=5V 3.5 8 3.0 7 2.5 6 2.0 5 1.5 4 1.0 3 0.5 2 -40 -20 0 20 40 60 80 100 120 AMBIENT TEMPERATURE Ta(°C) AMBIENT TEMPERATURE Ta(°C) 9 2 INPUT VOLTAGE Vcc(V) 4.48 10 1 CIRCUIT CURRENT VS. AMBIENT TEMPERATURE VIN=4V 0 -40 -20 0 20 40 60 80 100 120 20 40 60 80 100 120 AMBIENT TEMPERATURE Ta(°C) AMBIENT TEMPERATURE Ta(°C) MITSUBISHI ELECTRIC ( 7 / 9 ) MITSUBISHI<Dig.Ana.INTERFACE> M62021L,P,FP SYSTEM RESET IC WITH SWITCH FOR MEMORY BACK-UP OUTPUT CURRENT VS. DIFFERENCE BETWEEN INPUT AND OUTPUT VOLTAGES DIFFERENCE BETWEEN INPUT AND OUTPUT VOLTAGES VS. AMBIENT TEMPERATURE 100 400 VIN=5V 350 80 VIN=5V 300 60 250 IOUT=100mA 40 200 IOUT=80mA 150 IOUT=50mA 100 20 50 0 0 100 50 150 200 0 -40 -20 250 DIFFERENCE BETWEEN INPUT AND OUTPUT VOLTAGES VDROP(mV) 20 40 60 80 100 120 AMBIENT TEMPERATURE Ta(°C) BACKUP Di FORWARD DIRECTION VOLTAGE VS. AMBIENT TEMPERATURE BACKUP Di FORWARD DIRECTION CURRENT VS. VOLTAGE 160 0.8 140 0.7 120 0.6 100 0.5 80 0.4 60 0.3 40 0.2 20 0.1 0 0 IF=100µA IF=10µA IF=1µA 0 -40 -20 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0 20 40 60 80 100 120 BACKUP Di FORWARD DIRECTION VOLTAGE VF(V) AMBIENT TEMPERATURE Ta(°C) RES"L"OUTPUT VOLTAGE VS. AMBIENT TEMPERATURE RES "L"OUTPUT VOLTAGE VS. AMBIENT TEMPERATURE 80 80 70 VIN=5V ISINK=1mA 70 60 60 50 50 40 40 30 30 20 20 10 10 0 -40 -20 0 VIN=4V ISINK=1mA 0 -40 -20 20 40 60 80 100 120 0 20 40 60 80 100 120 AMBIENT TEMPERATURE Ta(°C) AMBIENT TEMPERATURE Ta(°C) MITSUBISHI ELECTRIC ( 8 / 9 ) MITSUBISHI<Dig.Ana.INTERFACE> M62021L,P,FP SYSTEM RESET IC WITH SWITCH FOR MEMORY BACK-UP CS"L"OUTPUT VOLTAGE VS. AMBIENT TEMPERATURE 4.0 160 140 3.8 VIN=5V ISINK=1mA 100 3.4 80 3.2 60 3.0 40 2.8 20 2.6 0 20 40 60 80 100 120 2.4 -40 -20 DELAY TIME VS.EXTERNAL CAPACITANCE CONNECTED TO THE Ct PIN 1000 VIN=0V 0 20 40 60 80 100 120 AMBIENT TEMPERATURE Ta(°C) AMBIENT TEMPERATURE Ta(°C) 7 5 VIN=4V RCS=1MΩ 3.6 120 0 -40 -20 CS"L"OUTPUT VOLTAGE VS. AMBIENT TEMPERATURE 5V 40 35 3 2 30 100 DELAY TIME VS.AMBIENT TEMPERATURE VIN=0V 5V Ct=4.7µA 25 7 5 20 3 2 15 10 7 5 10 3 5 2 0 0.1 2 3 5 7 1 2 3 5 7 10 2 3 5 7 100 0 -40 -20 0 20 40 60 80 100 120 AMBIENT TEMPERATURE Ta(°C) EXTERNAL CAPACITANCE CONNECTED TO THE Ct PIN Ct(µF) MITSUBISHI ELECTRIC ( 9 / 9 )