System Reset (with battery back-up) MM1027, 1081 MITSUMI System Reset (with battery back-up) Monolithic IC MM1027, 1081 Outline These ICs were developed for STATIC-RAM (S-RAM) battery back-up, and have built-in switching circuit for main power supply and battery, back-up timing circuit and battery checker. Power ON/OFF and momentary power interruptions can damage S-RAM data on equipment that contains an S-RAM. These ICs switch the S-RAM to back-up mode (CS signal makes S-RAM CE pin low and CE pin high) when power supply voltage goes below a set voltage (detection voltage 4.2V typ., variable), preventing damage to data. Further, when power supply voltage drops, these ICs switch from main power supply to battery back-up (switching voltage 3.3V typ.). Then, when power supply voltage rises, they first switch the SRAM from battery back-up state to main power supply (switching voltage 3.3V typ.), and from back-up mode to normal mode (CS signal makes S-RAM CE pin high and CE pin low). These signal processes provide reliable protection against data damage. The CS signal also can absorb power supply chattering and roughness through the external capacitor. There is a built-in battery checker to monitor the back-up battery voltage, and this circuit is turned ON/OFF by the control pin. -------------------------- ------------------------- Features 1. Battery back-up 1. Low IC current consumption (loss current) 2. Drop voltage inside IC (input/output voltage difference) 3. Reverse current (reverse leak current) 2. Normal operation MM1027 Drop voltage inside IC (input/output voltage difference) Output voltage VCC=5V Current consumption D.CONT OPEN External transistor drive current MM1081 Drop voltage inside IC (input/output voltage difference) Output voltage VCC=5V Current consumption External transistor drive current (for output current increase) TC source current 3. Battery-Vcc switching voltage 4. Detection voltage (CS, CS) variable 5. Battery checker 1 X type N type 6. Battery checker 2 X type N type ------------------------ Package TSOP-20A (MM1027XV, MM1027NV, MM1081XV) SOP-16A (MM1027XF, MM1027NF) DIP-16A (MM1027XD) IO=10µA 0.3µA typ. 0.2V typ. 0.1µA max. IO=70mA IO=10mA 0.2V typ. 4.8V typ. 3.0mA max. 25mA typ. IO=120mA IO=120mA 0.25V typ. 4.75V typ. 350µA max. 25mA typ. 3.0µA typ. 3.3V typ. 4.2V typ. 2.70V typ. 2.50V typ. 2.55V typ. 2.35V typ. System Reset (with battery back-up) MM1027, 1081 MITSUMI Applications 1. 2. 3. 4. IC memory cards (RAM cards) PCs, word processors Fax machines, photocopiers, other office equipment Other equipment with S-RAMs (equipment requiring back-up) Pin Assignment 16 15 14 13 12 11 10 9 20 19 18 17 16 15 14 13 12 11 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 9 10 SOP-16A/DIP-16A TSOP-20A Pin no. Function TSOP-20A SOP-16A DIP-16A 1 GND GND GND 2 ADJ. NC NC 3 NC ADJ. ADJ. 4 TC TC TC 5 NC CS CS 6 CS NC NC -------------------------- -------------------------- 7 NC CS CS -------------------------- 8 CS DET.CONT DET.CONT 9 NC Bat.DET1 Bat.DET1 10 DET.CONT NC NC 11 Bat.DET1 Bat.DET2 Bat.DET2 12 NC Battery Battery 13 Bat.DET2 VOUT VOUT 14 NC External drive External drive 15 Battery NC NC 16 NC VCC VCC 17 VOUT 18 NC 19 External drive 20 VCC System Reset (with battery back-up) MM1027, 1081 MITSUMI Block Diagram Absolute Maximum Ratings (Ta=25°C) Item Symbol Rating Units Storage temperature TSTG -40~+125 °C Operating temperature TOPR -20~+70 °C Power supply voltage VCC max. 7 V Operating voltage VCCOP 7 V Allowable loss Pd 300 mW MM1027 IO1 90 mA MM1081 IO1 120 mA IO2 200 µA Output current Output current Note : IO1 expresses VCC output current value, and IO2 expresses VBATT output current value. Electrical Characteristics (Except where noted otherwise, Ta=25°C, VCC=5V, VBAT=3V) Item Consumption All current 1 circuits Consumption current 2 Symbol MM1027 CS, CS detection voltage 1 CS, CS hysteresis voltage 1 Detection voltage VCC=5V, VBAT=3V, IO=0mA ICC1 D.CONT pin : OPEN VCC=5V, VBAT=3V, IO=0mA MM1081 MM1027 MM1027 temperature characteristic MM1081 Measurement conditions VCC=5V, VBAT=3V, IO=0mA ICC2 D.CONT pin : GND VS1 VCC=H VS1 VS/ L, VBAT=3V, ADJ pin : OPEN VCC=L H Min. Typ. Max. Units 0.9 1.7 3.0 mA 150 210 350 µA 1.2 2.2 mA 3.5 4.05 4.20 4.35 V 0.05 0.10 0.20 V ±0.08 T ±0.06 %/°C --------------------------------- CS•CS circuit CS, CS detection voltage 2 unit CS, CS hysteresis voltage 2 VS2 VS2 VCC=H L, VBAT=3V ADJ pin : 12kΩ PULL UP (to VCC) VCC=L H CS output voltage L VCSL VCC=3V, ICS=3µA CS output voltage H VCSH VCC=5V, ICS=-3µA CS source current ICSH VCC=5V, VCS=4.6V current measured 3.25 3.50 3.75 V 0.05 0.10 0.20 V 0.05 0.10 V 4.85 4.95 8 15 V µA System Reset (with battery back-up) MM1027, 1081 MITSUMI Electrical Characteristics (Except where noted otherwise, Ta=25°C, VCC=5V, VBAT=3V) Item CS sync current --------------------------- Symbol Measurement conditions ICSL VCC=3.5, VCS=0.4V Current measured 0.5 ---------------------------------- VCC=5V, ICS=3µA - 0.10 0.25 V ------------------------- VCC=4V, VOUT-VCSH, ICS=-3µA - 0.14 0.40 V VCC=5V, VCS=0.4V Current measured 0.3 Minimum power supply voltage at which - VCSL CS output voltage L --------------------------- VCSH CS output voltage H --------------------------- -------------------------------- ICSL CS sync current Min. Typ. Max. Units 2.0 - mA 1.0 - mA 2.0 2.4 V --------------------------- CS CS circuit Operation limit voltage L unit ON delay time 1 tPLH1 VCC=L H, TC : OPEN, C1=47pF - 30 - µS OFF delay time 1 tPHL1 VCC=H L, TC : OPEN, C1=47pF - 2.0 5 µS ON delay time 2 tPLH2 VCC=L H, TC : 1nF, C1=47pF - 0.8 - mS OFF delay time 2 tPHL2 VCC=H L, TC : 1nF, C1=47pF - 2.0 10 µS • BATT MM1027X detection voltage 1 MM1081N BATT hysteresis voltage 1 BD BATT MM1027X circuit detection voltage 2 MM1081N unit BATT hysteresis voltage 2 BD output voltage L BD output sink current Leakage current I/O voltage MM1027 difference 1 MM1081 VBD1 VBD1 VBD2 VBD2 CS pin can hold low level VCS <= 0.4V VCC=5V, R1=10kΩ PULL UP VBAT=H L (to VCC) VCC=5V, R1=10kΩ PULL UP VBAT=L H(to VCC) VCC=5V, R2=10kΩ PULL UP VBAT=H L (to VCC) VCC=5V, R2=10kΩ PULL UP VBAT=L H (to VCC) 2.60 2.70 2.80 V 0.05 0.10 0.20 V 2.45 2.55 2.65 V 0.05 0.10 0.20 V VBDL VCC=5V, VBAT=0V - 0.2 0.4 V IBDSNK VCC=5V, VBAT=0V, VBD=4V 1.0 3.0 - mA IBDH VCC=5V, VBAT=3V, VBD=5V - - 0.2 µA VCC=5V, IO=70mA - 0.2 0.3 VCC=5V, IO=120mA - 0.25 0.4 VSAT1 V I/O voltage difference 2 VSAT2 VBAT=3V, IO=10µA - 0.2 0.3 V I/O voltage difference 3 VSAT3 VBAT=3V, IO=100µA - 0.3 0.4 V External transistor driving current IBUD VCC=5V, V (TB) =4.5V 16 25 - mA VBB VCC=H L, VBAT=3V 3.15 3.30 3.45 V VCC=L H, VBAT=3V 0.05 0.10 0.20 V Backup Power supply switching voltage VBB circuit Hysteresis voltage unit VOPL Switching voltage MM1027 temperature characteristic MM1081 - VBB/ T Loss current ILOS Reverse current IOREV TC source current ITCSCE - ±0.08 ±0.06 VCC=0V, VBAT=3V, IO=0µA D.CONT pin : GND VCC=0V, VBAT=3V, IO=0µA D.CONT pin : OPEN VCC=5V, VTC=0V %/°C - - 0.3 µA - - 0.1 µA 2.0 3.0 5.0 µA System Reset (with battery back-up) MM1027, 1081 MITSUMI Timing Chart VS1 VCC VS VBB VBD2 VBD1 VBATT VOUT CS CS VBD1 VBD2 VBB VBD1 VBD2 System Reset (with battery back-up) MM1027, 1081 MITSUMI Application Circuits (Example : MM1027XV) System Reset (with battery back-up) MM1027, 1081 MITSUMI Characteristics (MM1027X) CS pin ON delay time VS. Capacitance ON delay time OFF delay time Vs. Capacitance 100m Delay time (S) 10m 1m ON delay time 100µ 10µ OFF delay time 1µ 1p 10p 100p 0.001µ 0.01µ 0.1µ Capacitance (F) ------------------------------ Note : CS and CS output waveforms may be disturbed if delay time is more than 10mS. Characteristics (MM1027 series) Current consumption Loss current during back-up IB (µA) I (mA) VBAT=3V, IO=0µA 2.400 5.000 0 .5000 /div CCONT GND CCONT OPEN .0000 .0000 VI 5.000 .5000/div (V) Output voltage 1 .6000 /div -3.600 .0000 VI .5000/div (V) 5.000 Shot key barrier diode reverse current VO (V) IB (µA) VBAT=3V VBAT=0 2.700 5.000 VCC 5.000 VOUT .1000 /div .5000 /div 0 .9000 /div -6.300 .0000 .0000 IO .8000/div (mA) 4.000 -80.00 .0000 VI .5000/div (V) 5.000 System Reset (with battery back-up) MM1027, 1081 MITSUMI Output voltage 2 3 VO ICS-VCS 1 ICS (V) 3.000 -20.00 .1000 /div 2.000 .0000 (mA) VCC=0V 2.000 /div IO 10.00/div (V) -100.0 .0000 .0000 VCS .5000/div (V) 5.000 CS pin Sink current VCC=4.5V VCS=Variable ICS-VCS 2 ICS ICS-VCS ICS (mA) (mA) -5.000 5.000 5.000 /div .5000 /div VCC=5V VCS=Variable .0000 .0000 VCS .3500/div (V) CS pin Sink current VCC=3.5V VCS=Variable 3.500 0000 000 5.000 VCS .5000/div (V) System Reset (with battery back-up) MM1027, 1081 MITSUMI ON delay time-Temperature CS detection voltage adjustment (ADJ pin) Tc pin (CT=1000PF±60PPM/°C) CS detection voltage Detection voltage (V) PPM Delay time 800 750 700 -770 PPM/°C -25 0 -706 PPM/°C 25 50 75 100 125 Ambient temperature (°C) max. typ. min. 4.0 3.0 2.0 10 100 Resistor R1 (kΩ) How to Adjust Detection Voltage Vs1 1. Connecting a resistor between ADJ pin and Vcc pin (effective only when lowering detection voltage) Calculated min. and max. values take into account resistance, etc. variance inside the IC. Refer to Figure 1 2. Using resistors to divide Vcc potential and connect to ADJ pin Detection voltage can be determined close to external resistance value by setting external R2 and R3 values small. Refer to Figure 2 (However, current increases when R2 and R3 are made smaller, so set at around R2+R3=6kΩ.) System Reset (with battery back-up) MM1027, 1081 MITSUMI CS detection voltage adjustment (ADJ pin) Detection voltage CS detection voltage adjustment (ADJ pin) 5 4 max. typ. min. 3 0 1 2 3 4 Resistor R2 (kΩ) CS Output 0.5mS 2V/Div 0.5mS VCC VCC CS CS *TC pin *TC pin OPEN 2V/Div 1000pF ------------------------------------------ CS Output 0.5mS 2V/Div VCC VCC CS CS *TC pin OPEN *TC pin 1000pF System Reset (with battery back-up) MM1027, 1081 MITSUMI Characteristics (MM1081 series) --------------------------- CS-CS detection voltage-Temperature Output voltage (V) Input/output voltage difference 1 (Vcc=5.0V) (V) 5.0 L H 4.30 4.5 4.25 H L 4.20 4.0 50 60 70 80 90 100 110 120 130 140 150 4.15 Output current (mA) 4.10 -25 VCC-ICC 0 25 50 75 TEMP(°C) Power supply switching voltage-Temperature ICC (µA) 300.0 VOUT-CS 47kΩ CS open 30.00/div (V) 3.45 L H 3.40 3.35 H L 3.30 3.25 .0000 0.0000 -25 .5000/div 0 25 50 75 5.000 VCC (V) Timing Chart VCC 5V 3.6V 4.3V 3.4V 3.0V VBATT 4.2V 3.5V 3.4V3.6V 4.3V 3.3V 2.50V 2.38V 4.2V3.5V 3.3V 2.53V 2.35V VOUT CS CS D1,BD2 B D.CONT:OPEN B D1 D.CONT:GNO B D2 D.CONT:GNO --------------------------- The broken lines for CS and CS indicate timing when the ADJ pin is pulled up to VCC by 12kΩ. TEMP(°C)