FUJITSU SEMICONDUCTOR DATA SHEET DS04-27502-3E ASSP For Power Supply Applications Bi-CMOS Battery Backup IC MB3790 ■ DESCRIPTION The MB3790 is designed to control power supplies to SRAM, logic IC, or other circuit devices and protects them against momentary power failures by using backup batteries. In addition to its function to supply the power to these devices, it has a function to switch the source of power to the primary or secondary backup battery when the power supply voltage drops below a predetermined level. Also, it outputs a reset signal when the power supply turns on or off or when a fault occurs in the power supply. Ideally designed as a single-chip IC for power supply control, the MB3790 consumes only a minimal current and comes in a thin-type package. Therefore, it is best suited for power supply control in memory cards and similar other devices. ■ FEATURES • • • • • • Input circuit current consumption when non-loaded: 50 µA [typ] Output drive current: 200 mA [max] Resistance between input and output: 0.5 ohms [typ] Input power-down detection level: 4.2 V ± 2.5 % On-chip power-on reset circuit Primary battery voltage-down detection levels: 2.65 V, 2.37 V (Continued) ■ PACKAGES Plastic SOP, 16 pin Plastic SSOP*, 20 pin (FPT-16P-M06) (FPT-20P-M04) * : Since the SSOP is an extremely thin package, use a partial heating method when mounting the device. MB3790 (Continued) • On-chip secondary battery recharging function • Output current during battery backup: VBAT1: 500 µA [max], VBAT2: 50 µA [max] • Leakage current: 0.5 µA [max] ■ PIN ASSIGNMENTS (TOP VIEW) (TOP VIEW) N.C. 1 16 CONTROL N.C. 1 20 CONTROL V BAT1 2 15 N.C. V BAT1 2 19 N.C. V OUT 3 14 V IN V OUT 3 18 V IN V OUT 4 13 V IN V OUT 4 17 V IN V BAT2 5 12 V SENSE V BAT2 5 16 V SENSE ALARM1 6 11 CT N.C. 6 15 N.C. ALARM2 7 10 RESET N.C. 7 14 N.C. GND 8 9 RESET ALARM1 8 13 CT ALARM2 9 12 RESET 10 11 RESET (FPT-16P-M06) GND (FPT-20P-M04) 2 MB3790 ■ BLOCK DIAGRAM R ON =0.5Ω V IN V OUT 100Ω CONTROL SBD 590KΩ 2.65V Reference voltage power 1.24V supply circuit - ALARM1 - 500Ω V IN + V SENSE V IN + S Q 3 µA 2.37V + ALARM2 R V OUT RESET Vth:3V 240KΩ V OUT RESET Vth:1.5V GND CT V BAT2 V BAT1 3 MB3790 ■ PIN DESCRIPTION Pin number 4 Symbol I/O 1 N.C. — 2 2 VBATI I This pin connects to the primary battery. 3, 4 3, 4 VOUT O These pins supply the output voltage. (Range of output current value IOUT ≤ 200 mA) 5 5 VBAT2 I/O This pin connects to the secondary battery. When the power supply voltage is greater than or equal to the detection level (i.e., VINH), the secondary battery is recharged using the constant-voltage method of charging. — 6, 7 N.C. — Non connection 6 8 ALARM1 O This is an open-collector output pin for a primary battery alarm signal. When the power supply voltage is greater than or equal to VINH, it monitors the primary battery voltage. If the power supply voltage is less than VINL, it does not monitor the primary battery voltage. If VBAT1 is less than or equal to 2.65 V, its output voltage is forced to a Low level. 7 9 ALARM2 O This is an open-collector output pin for a primary battery alarm signal. When the power supply voltage is greater than or equal to VINH, it monitors the primary battery voltage. If the power supply voltage is less than VINL, it does not monitor the primary battery voltage. If VBAT1 is less than or equal to 2.37 V, its output voltage is forced to a Low level. 8 10 GND — This pin connects to the ground (0 V). 9 11 RESET O This pin outputs a reset signal. When the power supply voltage is less than or equal to VINL, it outputs a High level. If the power supply voltage of SRAM is less than the designated range, it directly controls the CE or CS of SRAM to disable writes and thereby protect the data in memory. 10 12 RESET O This pin outputs an inverted signal of RESET. 11 13 CT — This pin is used to set the reset pulse width. Insert a capacitor between this pin and GND to set the pulse width. — 14, 15 N.C. — Non connection 12 16 VSENSE I This pin accepts comparator input for detecting the power supply voltage level. For details, refer to APPLICATION in this data sheet. 13, 14 17, 18 VIN I These pins accept the input voltage for the device. 15 19 N.C. — 16 20 CONTROL I 16P 20P 1 Name and function Non connection Non connection This pin is used for output control. For details, refer to APPLICATION in this data sheet. MB3790 ■ FUNCTIONAL DESCRIPTION 1. Battery Backup Function • When the power supply voltage exceeds the voltage detection level (i.e., VINH), the device outputs a current of up to 200 mA from the VIN power supply to the load circuit via the VOUT pin. • When the power supply voltage is less than or equal to VINL, the device switches the source of power for VOUT from VIN to the primary or secondary battery for backup purposes. 2. Power Supply Voltage Level Detect Function When the power supply voltage drops below VINL, the voltage level detection comparator is actuated to perform the following (note that the detection voltage level has the hysteresis characteristics listed in ELECTRICAL CHARACTERISTICS in this data sheet): • The comparator first outputs the RESET signal (High level). • It switches the source of power for the load circuit to the primary or secondary battery. The power supply voltage detection level can be adjusted by fitting an external resistor to the VSENSE pin. When adjusting the detection level, be sure to set it to 4.0 V or higher by considering the power supply voltage for the internal circuit operation. In addition, the detection set time can be extended by connecting a capacitator. For this method of adjustment, refer to APPLICATION in this data sheet. 3. Reference Voltage Circuit This is a temperature-compensated reference voltage circuit of a band gap type so that it outputs a trimmingadjusted exact reference voltage. The reference voltage power supply is used to set the reference voltage/constant current values of the detection circuit, as well as the secondary battery recharging voltage. 4. Power-on Reset Function By charging the capacitator connected to the CT pin with constant current (approx. 3 µA), this function determines the reset pulse width. The calculation formula for this is given below: Reset pulse width tPO (sec) ≅ CT (F) × 106 (When CT = 1000 pF, tPO ≅ 1 ms [typ]) 5. Primary Battery Voltage Detection Function If the primary battery voltage drops below the detection level when the power supply voltage is greater than or equal to VINL, the device outputs an alarm signal (Low level) from the CMOS output pin, ALARM1 or ALARM2. Note that the voltage level detection comparator has the hysteresis characteristics listed in ELECTRICAL CHARACTERISTICS in this data sheet. • When the primary battery voltage is 2.65 V [typ] or less: The ALARM1 output pin is forced to a Low level to issue an alarm indicating that it’s time to replace the primary battery. • When the primary battery voltage is 2.37 V [typ] or less: The ALARM2 output pin is forced to a low level to issue an alarm indicating that the primary battery voltage is less than the voltage necessary to retain the SRAM data (approx. 2.0 V) 6. Secondary Battery Recharging Function When the power supply voltage is greater than or equal to VINL, the device recharges the secondary battery using the constant-voltage method of charging. Note that the typical value of the device's internal recharging resistor is 500 ohms. 5 MB3790 ■ DESCRIPTION OF OPERATION 1. Operation When the Input Voltage Goes On or Off DV IN V IN V INH V INL (1) (2) (3) (4) (2) (3) (4) V IN-DV1 V OUT V BAT1-DVB1 t PO t PO V IN-DV1 RESET V BAT1-DVB1 High level Low level High level Low level High level RESET V IN-DV1 Low level High level Low level High level Low level (1) Power-on While the power supply voltage is less than VINH (4.3 V typ), the protected devices such as SRAM or a microprocessor are in the standby mode with the power supplied by the battery. When the power supply voltage rises to a level greater than or equal to VINH, the PMOS transistor between the input/ output pins turns on and the power for such devices is supplied from the VIN pin. At the same time, the primary battery voltage detection and the secondary battery recharging operations are actuated. (2) Standby mode When the power supply voltage rises to a level greater than or equal to VINH, the RESET pin outputs a High level for the set duration of time and the devices such as SRAM or a microprocessor are held in the standby mode. Note that the set duration of time can be adjusted by changing the capacitance of the CT pin. The RESET pin outputs an inverted signal of the RESET pin. (3) Active mode The reset signal is cleared and the devices such as SRAM or a microprocessor are placed in the operating mode. 6 MB3790 (4) Momentary power failure or voltage dip When the power supply voltage drops less than or equal to VINL. (4.2 V typ) as the power supply goes down or its voltage dips momentarily, the RESET pin outputs a High level and the RESET pin outputs a low level. The devices such as SRAM or a microprocessor are thereby placed in the standby mode and powered from the battery. When in this mode, the primary battery voltage detection and the secondary battery recharging operations are stopped. Note: To guarantee backup operation in case of momentary power failure, make sure the 5 V-to-0 V fall time on VIN is 50 µs or more by using, for example, a capacitator. 2. Alarm Operation DV BAT2 DV BAT1 V BATH1 V BATL1 V BAT1 V BATH2 V BATL2 ALARM1 (1) (1) ALARM2 (2) (2) If the primary battery voltage decreases while the power supply voltage (VIN) is greater than or equal to VINH (4.3 V typ), alarm signals are output as described below. At this time, if the VBAT1 pin is released open, the output from the alarm pin becomes indeterminate. (1) Primary battery replacement alarm (alarm-1 output) If the primary battery voltage drops to VBAT1 (2.65 V typ), the ALARM1 pin is forced to a Low level to issue an alarm indicating that it’s time to replace the primary battery. (2) Primary battery minimum voltage alarm (alarm-2 output) If the primary battery voltage further drops to VBAT2 (2.37 V typ), the ALARM2 pin is forced to a Low level to issue an alarm indicating that the primary battery power has dropped below the voltage necessary to retain the SRAM data (approx. 2.0 V). 7 MB3790 ■ ABSOLUTE MAXIMUM RATINGS (Ta = +25°C) Parameter Symbol Conditions Rating Unit Input voltage VIN –0.3 to 6 V Battery voltage VBAT –0.3 to 6 V Reset output Voltage VRESET – 0.3 to VOUT + 0.3 (≤ 6) V Alarm output Voltage VALARM – 0.3 to VIN + 0.3 (≤ 6) V Output current IOUT 250 mA Output high current IOH Source current 6 mA Output low current IOL Sink current 6 mA SSOP PD 450* mW Power dissipation SOP 540* mW –55 to +125 °C Storage temperature Tstg — Ta ≤ +25°C — * : When mounted on a 4 cm-square double-side epoxy board. WARNING: Permanent device damage may occur if the above ABSOLUTE MAXIMUM RATINGS are exceeded. Functional operation should be restricted to the conditions as detailed in the operational sections of this data sheet. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ■ RECOMMENDED OPERATING CONDITIONS Parameter Input voltage VIN Battery voltage VBAT Output current IOUT Output current during battery backup Operating temperature 8 Symbol Conditions — Value Typ. Max. — 5.0 5.5 V — 3.0 3.3 V 0 — 200 mA IO(BAT1) Supply from the primary battery — — 500 IO(BAT2) Supply from the secondary battery — — 50 — –30 — +70 Top Unit Min. µA °C MB3790 ■ ELECTRICAL CHARACTERISTICS • DC characteristics (Recommended operating conditions unless otherwise noted.) (VIN = +5 V, Ta = +25°C) Parameter Symbol Conditions Value Min. Typ. Max. Unit All sections Input current IIN1 IOUT = 0 mA — 50 100 µA Backup Power Supply Section Input/output voltage difference DV1 IOUT = 1 mA — 0.5 10 mV DV2 IOUT = 200 mA — 100 300 mV Output delay time tro CO = 0.01 µF, CT = 0 — 2.0 10 µs VIN 4.10 4.20 4.30 V Ta = – 30°C to + 70°C 4.05 4.20 4.35 V VIN 4.20 4.30 4.40 V Ta = – 30°C to + 70°C 4.15 4.30 4.45 V VINH – VINL 50 100 150 mV VOHR IOHR = 1 mA 4.5 4.8 — V VOLR IOLR = 5 mA — 0.2 0.4 V IOHR = 0.2 mA 2.2 2.6 — V IOLR = 3 mA — 0.2 0.4 V 0.5 1.0 2.0 ms 5.0 — — µs VINL Input low voltage detection VINH Input low voltage hysteresis DVIN width Power Supply Monitoring Section Reset output voltage Reset output voltage VOHR during backup V IN = 0 V VBAT1 = 3 V VOLR Reset pulse width tPO Input pulse width tPI Reset output rise time trR Reset output fall time Reset output delay time CT = 1000 pF — 2.0 3.0 µs tfR CT = 1000 pF CL = 100 pF — 0.2 1.0 µs tpdR VIN slew rate < 0.1 V/µs — 2.0 10 µs (Continued) 9 MB3790 (Continued) (VIN = +5 V, Ta = +25°C) Parameter Symbol VBATL1 Low voltage detection 1 VBATH1 Low voltage detection-1 hysteresis width DVBAT1 VBATL2 Low voltage detection 2 VBATH2 Battery-1 Monitoring Section Unit Min. Typ. Max. VBAT 2.55 2.65 2.75 V Ta = – 30°C to +70°C 2.52 2.65 2.78 V VBAT 2.59 2.69 2.79 V Ta = – 30°C to +70°C 2.56 2.69 2.82 V 20 40 60 mV VBAT 2.27 2.37 2.47 V Ta = – 30°C to +70°C 2.24 2.37 2.50 V VBAT 2.31 2.41 2.51 V Ta = – 30°C to +70°C 2.28 2.41 2.54 V VBATH1 – VBATL1 DVBAT2 VBATH2 – VBATL2 20 40 60 mV Low voltage detection difference DVBAT VBATL1 – VBATL2 0.26 0.28 0.30 V IBATA VBAT = 3 V, VIN = 0 V –100 — 500 nA IBATB VBAT = 3 V, VIN = 5 V –100 — 500 nA IBAT1 = 100 µA — 0.30 0.35 V IBAT1 = 10 µA — 0.10 0.15 V VOHA IOHA = 4 mA 4.5 4.8 — V VOLA IOLA = 5 mA — 0.2 0.4 V — 2.0 3.0 µs — 0.2 1.0 µs — 2.0 10 µs Battery-1 output voltage difference during backup, CTL = GND Alarm output voltage 10 Value Low voltage detection-2 hysteresis width Battery-1 input current Battery-2 Monitoring Section Conditions DVB1 Alarm output rise time trA Alarm output fall time tfA Alarm output delay time tpdA 50 mV overdrive Battery-2 recharging voltage VCHG ICHG = –10 µA 2.80 3.00 3.20 V Battery-2 recharging current ICHG VCHG = 2.0 V 1.0 2.0 — mA Battery-2 output voltage difference during backup IBAT2 = 10 µA — 0.10 0.15 V DVB2 CL = 100 pF MB3790 ■ TIMING CHART 1. Rise/Fall Times on Reset and Alarm Pins: tr/tf 90% RESET 90% RESET ALARM1 ALARM2 10% 10% tr tf 2. Reset Pulse Width: tPO; Input Pulse Width: tPI; Reset Output Delay Time: tpdR t PI 5V V IN V INH V INL 4V t PO t pdR t pdR V IH-DV1 RESET V BAT1-DVB2 11 MB3790 3. Alarm Output delay time: tpdA 50mV V BATL1, V BATL2 V BAT1 50mV t pdA ALARM1 ALARM2 4. VOUT Output Delay Time: tro 5V V IN 98% V OUT t ro 12 MB3790 ■ TYPICAL CHARACTERISTIC CURVES 1. VOH characteristics of RESET pin 2. VOL characteristics of RESET pin 0.5 V IN = OPEN V BAT1 =+3V 2.8 Output voltage VOL (V) Output voltage VOH (V) 3.0 2.6 2.4 2.2 2.0 0.0 -0.2 -0.4 -0.6 -0.8 0.3 0.2 0.1 0 0.0 -1.0 V IN =+5V V BAT1 =+3V 0.4 1.0 Current I (mA) Output voltage VOL (V) Output voltage VOH (V) 5.0 0.5 4.8 4.6 4.4 V IN =+5V V BAT1 =+3V 4.2 -0.4 -0.8 -1.2 -1.6 0.3 0.2 0.1 0 0.0 -2.0 V IN = OPEN V BAT1 =+3V 0.4 1.0 Current I (mA) 2.0 3.0 4.0 5.0 Current I (mA) 5. VOH characteristics of ALM pin 6. VOL characteristics of ALM pin 5.0 0.5 Output voltage VOL (V) Output voltage VOH (V) 4.0 4. VOL characteristics of RESET pin 5.0 4.8 4.6 4.4 V IN =+5V V BAT1 =+3V 4.2 4.0 0.0 3.0 Current I (mA) 3. VOH characteristics of RESET pin 4.0 0.0 2.0 -1.0 -2.0 -3.0 Current I (mA) -4.0 -5.0 V IN =+5V V BAT1 =+2V 0.4 0.3 0.2 0.1 0 0.0 1.0 2.0 3.0 4.0 5.0 Current I (mA) (Continued) 13 MB3790 (Continued) 7. Temperature characteristics of input current 8. Temperature characteristics of battery power detection voltage 70 2.9 60 2.8 50 2.7 V BATH1 2.6 V BATL1 Battery voltage V BAT (V) Input current I IN (µA) V IN =+5V 40 30 20 10 V BATL2 2.2 -40 -20 0 20 40 60 80 Ambient temperature Ta (°C) 7. Temperature characteristics of power-down detection voltage 4.6 4.5 Power-down detection voltage V IN (V) V BATH2 2.4 2.3 0 4.4 V INH 4.3 V INL 4.2 4.1 4.0 3.9 -40 -20 0 20 40 60 80 Ambient temperature Ta (°C) 14 2.5 -40 -20 0 20 40 60 80 Ambient temperature Ta (°C) MB3790 ■ APPLICATION 1. Method of Using the CONTROL Pin It is possible to control the operation of analog switch 1 by entering a High or Low level to the CONTROL pin while being powered by the battery. The Table below shows how the analog switch operates when its operation is controlled from the CONTROL pin. When using the primary and the secondary batteries in combination as in the case of memory cards, be sure to set the CONTROL pin High to prevent the primary battery from being recharged by the secondary battery current flowing from analog switch 1. • Control Conditions of CONTROL Pin Operating state Control conditions ON/OFF State of analog switch*2 Input voltage (VIN) CONTROL pin*1 Analog switch 1 Analog switch 2 VIN > VINL High/Low OFF OFF VINL > VIN High (= VOUT) OFF ON VINL > VIN Low (= GND) ON ON Standby/active state Backup state *1: If the CONTROL pin is released open, the logic state of the CMOS circuit may become instable letting current flow into the circuit. Therefore, the CONTROL pin must always have a High or Low level input. *2: The ON-resistance of the analog switch is approximately 10 K ohms. Analog Switch connection Diagram V OUT SBD Analog Switch 2 Analog Switch 1 V BAT1 Connection to the primary battery V BAT2 Connection to the secondary battery 15 MB3790 3. Outputting Reset Signal Forcibly The reset signal can be output forcibly by bringing the VSENSE pin of the MB3790 to a Low level (< 1.24). The reset signal is held on until the capacitator CT is charged up after the VSENSE pin is released open. Forced Reset Method 1 V IN V IN CT 47KΩ VSENSE CT SW GND SW: Turned on (VRESET = High) Forced Reset Method 2 V IN V IN CT 47KΩ VSENSE Control signal input pin CT 10KΩ Q1 GND 10KΩ When the voltage enough to turn on Q1 (≥ approx. 1.2 V) gives to the Control signal input pin, VRESET is equal to High level. [Reset Pulse Width Calculation Formula] Reset Pulse Width tPO (sec) = CT (F) ×106 (where CT = capacitance) Example: When CT = 1000 pF, tPO = 1 ms (Typ) 16 MB3790 4. Adjusting the Supply Voltage Detection Level Set time The MB3790 outputs a reset signal when the power supply momentarily goes down or its voltage sags for 5 µs or more. The set time before this reset signal is output can be extended by connecting a capacitor to the VSENSE pin. Adjusting the Supply Voltage Detection Level Set Time V IN V IN 5V VSENSE 4V t PI C GND 5. Compatibility with JEIDA Memory Card Guideline Ver. 4 The MB3790 has its ALM1 and ALM2 pin specifications matched to the BVD2 and BVD1 pin specifications of the JEIDA Memory Card Guideline Ver. 4. Therefore, the ALM1 and ALM2 pins can be connected directly to the BVD2 and BVD1 pins. • Alarm Pin Detection Voltage Levels Pin Name VBAT1 ≤ 2.37 V 2.37 V < VBAT1 ≤ 2.65V 2.65 V ≤ VBAT1 Connected Pin ALM1 Low level Low level High level BVD2 ALM2 Low level High level High level BVD1 VBAT1: Primary battery voltage 17 MB3790 ■ STANDARD DEVICE CONFIGURATION V IN *2 *1 C1 V BAT1 CONTROL V OUT V OUT V IN V IN *2 V BAT2 *1 Primary battery ALARM2 Secondary battery ALARM1 ALARM1 CT ALARM2 RESET GND RESET C2 L O G I C CT GND *1 For C1 and C2, use capacitors of 0.022 µF or more. *2 For VIN and VOUT, connect these two pins to the mating pins, respectively. ■ ORDERING INFORMATION Part number MB3790PF MB3790PFT 18 Package 16 pin, Plastic SOP (FPT-16P-M06) 20 pin, Plastic SSOP (FPT-20P-M04) Remarks S R A M MB3790 ■ PACKAGE DIMENSIONS 16-pin, Plastic SOP (FPT-16P-M06) 2.25(.089)MAX 10.15 +0.25 –0.20 .400 +.010 –.008 0.05(.002)MIN (STAND OFF) INDEX 5.30±0.30 (.209±.012) +0.40 6.80 –0.20 +.016 .268 –.008 7.80±0.40 (.307±.016) "B" 1.27(.050) TYP 0.45±0.10 (.018±.004) +0.05 Ø0.13(.005) 0.15 –0.02 +.002 .006 –.001 M Details of "A" part Details of "B" part 0.40(.016) 0.15(.006) 0.20(.008) "A" 0.10(.004) 8.89(.350)REF C 0.50±0.20 (.020±.008) 1994 FUJITSU LIMITED F16015S-2C-4 0.20(.008) 0.18(.007)MAX 0.18(.007)MAX 0.68(.027)MAX 0.68(.027)MAX Dimensions in mm (inches) (Continued) 19 MB3790 (Continued) 20-pin, Plastic SSOP (CASE No.: FPT-20P-M04) * 6.50±0.10 1.10±0.10 (.043±.004) (.256±.004) 0.10(.004) * 4.40±0.10 6.40±0.20 (.173±.004) (.252±.008) INDEX 5.40(.213)NOM "A" 0.22 .009 0.65±0.12 (.0256±.0047) +0.10 –0.05 +.004 –.002 +0.05 0.15 –0.02 +.002 .006 –.001 Details of "A" part 0.10±0.10 (STAND OFF) (.004±.004) 0.50±0.20 (.020±.008) 5.85(.230)REF 0°~10° C 1994 FUJITSU LIMITED F20014S-1C-4 Dimensions in mm (inches) Since the SSOP (FPT-20P-M04) is built in an extremely thin structure, use a partial heating method when mounting the device. 20 FUJITSU LIMITED For further information please contact: Japan FUJITSU LIMITED Corporate Global Business Support Division Electronic Devices KAWASAKI PLANT, 4-1-1, Kamikodanaka Nakahara-ku, Kawasaki-shi Kanagawa 211-88, Japan Tel: (044) 754-3763 Fax: (044) 754-3329 North and South America FUJITSU MICROELECTRONICS, INC. Semiconductor Division 3545 North First Street San Jose, CA 95134-1804, U.S.A. Tel: (408) 922-9000 Fax: (408) 432-9044/9045 Europe FUJITSU MIKROELEKTRONIK GmbH Am Siebenstein 6-10 63303 Dreieich-Buchschlag Germany Tel: (06103) 690-0 Fax: (06103) 690-122 Asia Pacific FUJITSU MICROELECTRONICS ASIA PTE. LIMITED #05-08, 151 Lorong Chuan New Tech Park Singapore 556741 Tel: (65) 281-0770 Fax: (65) 281-0220 All Rights Reserved. The contents of this document are subject to change without notice. Customers are advised to consult with FUJITSU sales representatives before ordering. The information and circuit diagrams in this document presented as examples of semiconductor device applications, and are not intended to be incorporated in devices for actual use. Also, FUJITSU is unable to assume responsibility for infringement of any patent rights or other rights of third parties arising from the use of this information or circuit diagrams. FUJITSU semiconductor devices are intended for use in standard applications (computers, office automation and other office equipment, industrial, communications, and measurement equipment, personal or household devices, etc.). CAUTION: Customers considering the use of our products in special applications where failure or abnormal operation may directly affect human lives or cause physical injury or property damage, or where extremely high levels of reliability are demanded (such as aerospace systems, atomic energy controls, sea floor repeaters, vehicle operating controls, medical devices for life support, etc.) are requested to consult with FUJITSU sales representatives before such use. The company will not be responsible for damages arising from such use without prior approval. Any semiconductor devices have inherently a certain rate of failure. You must protect against injury, damage or loss from such failures by incorporating safety design measures into your facility and equipment such as redundancy, fire protection, and prevention of over-current levels and other abnormal operating conditions. If any products described in this document represent goods or technologies subject to certain restrictions on export under the Foreign Exchange and Foreign Trade Control Law of Japan, the prior authorization by Japanese government should be required for export of those products from Japan. F9703 FUJITSU LIMITED Printed in Japan 24