NJU7287 Battery Backup Switching IC GENERAL DESCRIPTION The NJU7287 is a battery backup system IC with three regulators, two voltage detectors, a battery switching system and their control circuit. It switches the regulator output from main power supply source to the backup battery when it detects main power supply drop and also has two voltage detection outputs. The NJU7287 employs an exclusive sequence on the battery switching system which reduces the battery operation. Combining the special sequence and its low operating current, it is well-suited for battery backup systems of DSC, DVC and other portable devices. The NJU7287 is available in small and thin packages of 8-lead MSOP (TVSP) and 12-lead PCSP12-C3. PACKAGE OUTLINE NJU7287xRB1 (MSOP8 (TVSP8)) FEATURES z Low Quiescent Current :13µA max. / Normal operation :2.1µA max. / Backup z Low Dropout Voltage :0.06V max. (IRO =3mA) / REG1 :0.3V max. (IOUT =23mA) / REG2 :0.06Vmax. (ICH=3mA) / REG3 z 3ch(REG1, REG2, REG3) Output Voltage :±2.0% ——————— : ± 2.0% z 2ch(CS, RESET ) Detection Voltage z Exclusive Sequence z Small Package NJU7287xRB1 : MSOP8 (TVSP8)* *MEET JEDEC MO-187-DA / THIN TYPE PIN CONFIGURATION 1 2 3 4 8 7 6 5 1.VSS 2.VCH 3.VBAT 4.CS ——————— 5. RESET 6.VOUT 7.VIN 8.VRO NJU7287xRB1 Ver.2012-07-18 -1- NJU7287 SELECTION GUIDE Device Name NJU7287A Output Voltage (V) ——————— CS Voltage (V) Switch Voltage (V) RESET Voltage (V) VRO VOUT VCH -VDET1 +VDET1 -VDET2 +VDET2 VSW1 3.000 3.000 3.100 4.000 4.129 2.000 2.096 +VDET1×0.85 ——————— Caution: CS voltage should be set up so that switch voltage (VSW1) may become more than RESET voltage (-VDET2). Note: The selection range is as follows. VRO, VOUT, VCH : 2.3 to 5.4V (0.1V Step) -VDET1 :2.4 to 5.3V (0.1V Step) -VDET2 :1.7 to 3.4V (0.1V Step) VSW1 :+VDET1X0.85 ABSOLUTE MAXIMAM RATINGS PARAMETER (Ta=25˚C) SYMBOL RATINGS UNIT Main Power Supply Input Voltage VIN +10 V Backup Power Supply Input Voltage VBAT +10 V Output Voltage of Voltage Regulator VRO, VOUT, VCH VSS-0.3 to VIN+0.3 V Output Voltage CS Output Voltage ——————— RESET Output Voltage Power Dissipation VCS VRESET VSS-0.3 to +10 V V PD 320 mW Operating Temperature Topr - 40 to +85 ˚C Storage Temperature Tstg - 40 to +125 ˚C -2- Ver.2012-07-18 NJU7287 ELECTRICAL CHARACTERISTICS NJU7287A (CIN=0.1µF, CO(VOUT)=10µF, CO(VRO)=10µF, CO(VCH)=10µF, Ta=25˚C) PARAMETER SYMBOL TEST CONDITION MIN. TYP. MAX. UNIT Total Quiescent Current Backup Power Supply Input Voltage ISS1 VIN =3.6V, No-Load - 5.5 13 µA IBAT1 VIN =3.6V, VBAT=3.0V, No-Load - - 0.1 µA IBAT2 VIN=OPEN,VBAT=3.0V, No-Load - 1.0 2.1 µA 2.0 - 4.0 V 2.94 3.00 3.06 V IRO=3mA - 30 60 mV VBAT Voltage Regulator 1 Output Voltage 1 VRO Dropout Voltage 1 ∆VI-O1 VIN=7.2V, IRO=3mA Load Regulation 1A ∆VROA/∆IRO VIN=7.2V, IRO=0.1 to 30mA - 0.06 0.15 %/mA Load Regulation 1B ∆VROB/∆IRO VIN=3.6V, IRO=0.1 to 30mA - 0.06 0.15 %/mA Line Regulation 1 ∆VRO/∆VIN VIN=4 to 9V, IRO=3mA - - 0.2 %/V Average Temperature Coefficient of Output Voltage 1 ∆VRO/∆T Ta=0 to +85°C - ±100 - ppm/°C 2.94 3.00 3.06 V Voltage Regulator 2 Output Voltage 2 VOUT VIN=7.2V, IOUT=23mA Dropout Voltage 2 ∆VI-O2 IOUT=23mA - 150 300 mV Load Regulation 2A ∆VOUTA/∆IOUT VIN=7.2V, IOUT=0.1 to 60mA - 0.04 0.10 %/mA Load Regulation 2B ∆VOUTB/∆OUT VIN=3.6V, IOUT=0.1 to 60mA - 0.04 0.10 %/mA Line Regulation 2 ∆VOUT/∆VIN VIN=4 to 9V, IOUT=23mA - - 0.2 %/V Average Temperature Coefficient of Output Voltage 2 ∆VOUT/∆T Ta=0 to +85°C - ±100 - ppm/°C 3.038 3.100 3.162 V Voltage Regulator 3 Output Voltage 3 VOUT VIN=7.2V, IOUT=3mA Dropout Voltage 3 ∆VI-O3 IOUT=3mA - 30 60 mV Load Regulation 3A ∆VOUTA/∆IOUT VIN=7.2V, IOUT=0.1 to 30mA - 0.06 0.15 %/mA Load Regulation 3B ∆VOUTB/∆OUT VIN=3.6V, IOUT=0.1 to 30mA - 0.06 0.15 %/mA Line Regulation 3 ∆VOUT/∆VIN VIN=4 to 9V, IOUT=3mA - - 0.2 %/V Average Temperature Coefficient of Output Voltage 3 ∆VOUT/∆T Ta=0 to +85°C - ±100 - ppm/°C 3.920 4.000 4.080 V 4.030 4.129 4.228 V - ±100 - ppm/°C CS Voltage Detector Detection Voltage 1 -VDET1 Release Voltage 1 +VDET1 Average Temperature Coefficient of Detection Voltage 1 ∆VDET1/∆T VIN Voltage Detection Ta=0 to +85°C Output Current 1 ISINK1 VDS=0.5V, VIN=VBAT=2.0V 1.50 2.30 - mA Leak Current 1 ILEAK1 VDS=9V, VIN=9V - - 0.1 µA Operation Voltage 1 VOPR1 VIN or VBAT 1.7 - 9.0 V Ver.2012-07-18 -3- NJU7287 PARAMETER SYMBOL TEST CONDITION MIN. TYP. MAX. UNIT 1.960 2.000 2.040 V ——————— RESET Voltage Detector Detection Voltage 2 -VDET2 Release Voltage 2 +VDET2 2.046 2.096 2.146 V Release Delay Time TDELAY 200 500 - µs - ±100 - ppm/°C 1.50 2.30 - mA Average Temperature Coefficient of Detection Voltage 2 ∆VDET2/∆T VOUT Voltage Detection Ta=0 to +85°C Output Current 2 ISINK2 VDS=0.5V, VIN=VBAT=2.0V Leak Current 2 ILEAK2 VDS=9V, VIN=9V - - 0.1 µA Operation Voltage 2 VOPR2 VIN or VBAT 1.7 - 9.0 V +VDET1 x 0.83 VOUT x 0.93 +VDET1 x 0.85 VOUT x 0.95 +VDET1 x 0.87 VOUT x 0.97 - - 0.1 µA VIN=OPEN, VBAT=3.0V - 30 60 Ω Switch Control VBAT=2.8V, VIN Voltage Detection VBAT=3.0V, VOUT Voltage Detection VIN=3.6V, VBAT=0V V Switch Voltage VSW1 CS Output Inhibit Voltage VSW2 VBAT Switch Leak Current ILEAK VBAT Switch Resistance RSW Average Temperature Coefficient of Switch Voltage ∆VSW1/∆T Ta=0 to +85°C - ±100 - ppm/°C Average Temperature Coefficient of CS Output Inhibit Voltage ∆VSW2/∆T Ta=0 to +85°C - ±100 - ppm/°C V CAUTION ON USE z Make a power supply line thick and short to reduce impedance. Particularly, VIN line that flows output current needs to cautions. z IRO or IOUT should be set 10µA or more to prevent the output voltage rises and a load regulation becomes unstable. z Pay attention to overshoot of regulator to prevent exceed rating of IC and/or capacitors connected to the NJU7287. z The output capacitors should surely connect between each output terminal, VIN, VOUT, VRO and VSS. Particularly, the output capacitor connected to the VOUT terminal should use 10µF or more to avoid drop the output voltage when switch the VOUT output from REG2 to VBAT. z External parts should connect as closer as possible to the NJU7287. ——————— z The output capacitor should connect to the VOUT terminal to prevent RESET voltage detector becomes active and sequence will switch to special sequence causing undershoot. ——————— z If VIN falls down to 0V, application circuit should design to falling time of VIN is 10ms or more to prevent RESET output becomes "L". zPower dissipation should not exceeded. -4- Ver.2012-07-18 NJU7287 BLOCK DIAGRAM Short Circuit Protection VCH REG3 Short Circuit Protection VRO REG1 VIN Short Circuit Protection CS Voltage Detector REG2 VSW1 Voltage Detector VOUT RESET Voltage Detector RESET VSW2 Voltage Detector CS Switch Control Short Circuit Protection VSS VBAT Ver.2012-07-18 -5- NJU7287 FUNCTIONAL EXPLANATION OF BLOCK 1. Voltage regulator(REG1,REG2,REG3) ▪ Each output voltage can select in 0.1V steps. 2. CS Voltage Detector ▪ Monitors the VIN (main power supply) terminal voltage, and detects a drop in the main power supply. ▪ Detection result outputs to CS terminal (At the time of CS output inhibit voltage signal outputs) Detection voltage(-VDET1) ≥ VIN : “L" Output Release voltage(+VDET1) ≤ VIN : "H" Output ▪ Power is supplied from both VIN and VBAT. ——————— 3. RESET Voltage Detector ▪ Monitors the VOUT terminal voltage. ——————— ▪ Detection result is outputted to RESET terminal. Detection voltage(-VDET2) ≥ VOUT : “L" Output Release voltage(+VDET2) ≤ VOUT : "H" Output ▪ Power is supplied from the VOUT terminal. (If the VOUT ≥ 1.0 V, normal logic is output.) 4. VSW1 Voltage Detector ▪ Monitors the VIN voltage. ▪ The detection voltage (VSW1) is determined by 85% of the CS detection voltage. 5. VSW2 Voltage Detector ▪ Monitors the VOUT voltage. ▪ The CS output inhibit voltage (VSW2) is determined by 95% of the REG2 output voltage. ▪ The status of CS terminal : CS output inhibit voltage (VSW2) ≥ VOUT : fixed at “L" and CS release permission signal is stopped. CS output inhibit voltage (VSW2) ≤ VOUT : Outputs the CS detection result. ▪ Provided that the VIN terminal voltage is at least the CS detection voltage, the CS output is maintained at “H”, even if the VOUT terminal voltage is less than the VSW2 voltage. 6. Sequence explanation Special sequence ▪ Period from when the VIN voltage rises——————— from 0V until the CS output becomes “H”. ▪ When the VOUT voltage falls, and the RESET output becomes “L” level. ▪ During the period of a special sequence, the VOUT output is fixed at REG2. Normal sequence ▪ The period from when the VIN voltage rises and the CS output becomes “H” level, and then the VOUT voltage ——————— falls, and the RESET output becomes “L” level. ▪ During the period of the normal sequence, the detection result from the VSW1 detection circuit which monitors the VIN voltage causes the VOUT output to switch over to REG2 or VBAT. Terminal voltage REG2 operation state VOUT output State of operation 0V to VIN < ”+VDET1” ON REG2 Special sequence VIN > ”VSW1” ON REG2 Normal sequence VIN ≤ ”VSW1” OFF VBAT - ∆VT1 Normal sequence VOUT > ”-VDET2” ON REG2 Special sequence ∆VT1 indicates VDS of the switch transistor between VBAT and VOUT. Note : It takes a maximum of several hundred µsec for REG2 to go from OFF to ON. During this period, it is possible that VOUT may become high impedance, so it is necessary to connect a capacitor of at least 10 µF to the VOUT terminal to prevent the voltage from falling. -6- Ver.2012-07-18 NJU7287 TIMING CHART +VDET1 -VDET1 VSW1 VIN (V) t VRO/VCH (V) t VSW2 +VDET2 VOUT (V) -VDET2 t VBAT (V) t CS *(V) (Monitoring VIN) t RESET *(V) (Monitoring VOUT) t T DELAY Exclusive sequence Ver.2012-07-18 T DELAY Exclusive sequence T DELAY T DELAY Exclusive sequence -7- NJU7287 TEST CIRCUIT 2. 1. VIN ISS A IBAT VOUT or VRO or VCH VRO VIN 10µF VOUT VBAT VBAT A VSS + VCH - VSS V To Measure IBAT2, apply 6V to VIN, 3V to VBAT and then leave VIN open and measure IBAT2. 4. 3. 100kΩ VOUT VIN Pulse Generator VBAT V V V VSS Oscillo scope VOUT VIN VBAT —————— Oscillo scope RESET VSS Measure the value after applying 6V to VIN. 5. 6. VOUT VIN VIN + VBAT VBAT VSS VSS A 500µA V - 10µF Leave VIN open and measure the value after applying 6V to VIN. 8. 7. 100kΩ 100kΩ VOUT VIN VOUT VIN CS CS V VBAT VBAT ——————— V RESET VSS ——————— RESET A V VSS V -8- V A V Ver.2012-07-18 NJU7287 CORRESPOND TABLE OF TEST CIRCUIT TEST PARTNER Quiescent Current Back up power supply Input Voltage Output Voltage 1 Dropout Voltage 1 Load Regulation 1A Load Regulation 1B Line Regulation 1 Average Temperature Coefficient of Output Voltage 1 Output Voltage 2 Dropout Voltage 2 Load Regulation 2A Load Regulation 2B Line Regulation 2 Average Temperature Coefficient of Output Voltage 2 Output Voltage 3 Dropout Voltage 3 Load Regulation 3A Load Regulation 3B Line Regulation 3 Average Temperature Coefficient of Output Voltage 3 Detection Voltage 1 Release Voltage 1 Average Temperature Coefficient of Detection Voltage1 Output Current 1 Leak Current 1 Operation Voltage 1 Detection Voltage 2 Release Voltage 2 Release Delay Time Average Temperature Coefficient of Detection Voltage 2 Output Current 2 Leak Current 2 Operation Voltage 2 Switch Voltage VBAT Switch Leak Current VBAT Switch Resistance Average Tempereture Coefficient of Switch Voltage Ver.2012-07-18 TEST CIRCUIT NUMBER 1 6 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 7 7 7 8 8 7 7 7 4 7 8 8 7 3 5 6 3 -9- NJU7287 TYPICAL APPLICATIONS VCH VRO + + 10µF - 10µF VCH VRO 100kΩ VIN VIN VOUT VOUT + 6V + NJU7287 - - 10µF 10µF ——————— RESET VBAT 1kΩ 3V VSS CS 0.1µF When the rechargeable battery is used as the backup battery. 100kΩ + - 10µF VRO VCH 100kΩ VIN VOUT NJU7287 6V + 10µF VCC - MPU VBAT ——————— RESET + - 10µF 3V VSS CS ——————— RESET INT 0.1µF The backup battery can be flating –recharged by using voltage regulator 3 (REG3). - 10 - Ver.2012-07-18 NJU7287 [CAUTION] The specifications on this databook are only given for information , without any guarantee as regards either mistakes or omissions. The application circuits in this databook are described only to show representative usages of the product and not intended for the guarantee or permission of any right including the industrial rights. Ver.2012-07-18 - 11 -