ta8002s/as 2002-03-12 1 toshiba bipolar linear integrated circuit silicon monolithic ta8002s,TA8002AS 5v voltage regulator with reset timer the ta8002s is an ic specially designed for automotive microcomputer systems. it produces an output voltage of 50.5v without need for adjustment from its accurate reference voltage and amplifier circuit. at power-on, it outputs a reset signal to reset the system. it will also output a reset signal when the 5v output voltage drops below 92% because of external disturbance or other problem. since it is also designed to have a small bias current, power consumption on the system can be reduced. the TA8002AS produces an output voltage of 50.25v. features accurate output : 5 0.5v (TA8002AS : 5 0.25v) standby output : 3.5v low bias current : 150a (typ.) power-on reset timer operating temperature range : from ? 40 to 85c wide operating voltage range : 40v (max.) small sip-7 pin block diagram and pin layout weight: 0.7 g (typ.)
ta8002s/as 2002-03-12 2 pin description pin no. symbol description 1 bias power supply starting pin. the starting current is supplied through a resistor to which the input voltage is applied. the output current from this starting current is as follows : i out (out pin) h fe (v in ? 0.7) / (200+r 1 ) (ma) where r 1 is the external resistance attached to bias pin (k ? ) . when v cc rises above 2.7v, the starting current is absorbed in the internal circuit ; instead, the output current out is supplied via v cc . 2 out connected to the base of an external pnp transistor so that the output voltage is stabilized. 3 v cc power supply pin for internal circuit. the output voltage can also be detected at this pin. 4 gnd grounded the output voltage can be adjusted by inserting a resistor between adj and gnd or between adj and v cc . mode adj pin output voltage v reg standby open 3.5v normal gnd 5.0v 5 adj 6 tc time setting pin for reset timer. use external r t and c t to set the time. 7 reset npn transistor open-collector output. this pin supplies a reset signal when the output drops below 92% of the specified level. after the output voltage increases above 92% of the specified level, the reset signal will be output for a period of time set at the tc pin.
ta8002s/as 2002-03-12 3 functional description the ta8002s / as incorporates a constant-voltage 5v power supply function to feed the 5v logic circuits and a reset function to ensure stable operation of the system. these functions are explained below. (1) constant-voltage 5v power supply function this constant-voltage function has the reference voltage v ref in the ic that is insusceptible to temperature changes and input voltage fluctuations. the power supply circuit is designed in such a way that this voltage is stepped up to 5v by using an op amp and a voltage-dividing resistor. these op amp and dividing resistor and an output transistor connected to the op amp output together configure a closed loop. the output voltage of 5v is obtained by shorting the adj pin to gnd. the output voltage is reduced to 3.5v by leaving this pin open, allowing for a further reduction in the amount of current consumed by the entire system during standby. (2) system reset function ( see timing chart ) voltage monitoring function when powered on, the power-on reset timer starts counting the moment the voltage v cc applied to the cpu exceeds 4.6v. when powered off, this voltage monitoring function outputs a reset signal immediately when v cc drops below 4.6v. a reset signal also is output immediately when v cc drops for some reason during normal operation. then, when v cc is restored to the normal voltage and exceeds 4.6v, the power-on reset timer starts counting. power-on reset timer function to allow the 5v constant voltage to stabilize at power-on, as well as prevent the circuit system from operating erratically at power-on, the device remains reset for a predetermined time before being released from the reset state. the duration of this time can be set as desired by choosing appropriate values for the external resistor and capacitor connected to the tc pin. the system starts charging the capacitor when the vcc voltage exceeds 4.6v. when this charging voltage exceeds 1.7v, the reset signal is inverted to deactivate the reset. timing chart note: t reset : reset timer time
ta8002s/as 2002-03-12 4 maximum ratings (ta = 25c) characteristic symbol rating unit input voltage v in 40 v i out1 0.5 ma output current i out2 1 ma v out1 40 v output voltage v out2 16 v power dissipation p d 500 mw operating temperature t opr ? 40~85 c storage temperature t stg ? 55~150 c lead temperature time t sol 260 (10s) c note: v in : bias input i out1 , v out1 : out output i out2 , v out2 : reset output electrical characteristics (v in = 7 to 17v, ta = ? 40 to 85c, i load = 5ma) characteristic symbol pin test cir- cuit test condition min typ. max unit 1 ta8002s 4.5 5.0 5.5 output voltage v reg v cc 1 TA8002AS 4.75 5.0 5.25 v line regulation v cc D v in = 7~40v D 0.1 0.5 % load regulation v cc D i load = 2~10ma D 0.1 0.5 % temperature coefficient v cc D D 0.01 D % / c output voltage v ol reset 2 i ol = 300a D D 0.4 v output leakage current i leak reset 3 v out = 10v D D 5 a input current i in tc 4 v in = 0~v reg ? 2 D 2 a threshold voltage v th tc 5 tc : low to high D 1.7 D v reset detect voltage v cc 5 v reg = 5v D 4.6 D v standby voltage v s v cc 6 3.1 3.5 3.9 v standby current i s v cc 7 v in = 14v D 150 300 a reset timer t reset reset 5 D 0.4 c t r t D ms note: the unit for c t is f, the unit for r t is k ? .
ta8002s/as 2002-03-12 5 typical characteristics 1. input-output characteristic ( r l = 500 ? , external transistor 2sa817a ) 2. reset characteristic
ta8002s/as 2002-03-12 6 test circuit 1. v reg 5. v reset ,v th ,t reset 2. v ol( reset ) 3. i leak( reset ) 6. v s 4.i in(tc) 7.i s
ta8002s/as 2002-03-12 7 example of application circuit i load = 10ma max. v batt = 6~17v (load dump 120vpeak, 200ms) 1. 5v standard circuit 2. application circuit using darlington transistor *: select a c 2 value according to the working condition - typically above 2000pf. 3. backup circuit *: use an output capacitor c 1 which has a low temperature dependence (such as a tantalum capacitor) . connect it as close to the ic as possible.
ta8002s/as 2002-03-12 8 package dimensions weight: 0.7g (typ.)
ta8002s/as 2002-03-12 9 toshiba is continually working to improve the quality and reliability of its products. nevertheless, semiconductor devices in general can malfunction or fail due to their inherent electrical sensitivity and vulnerability to physical stress. it is the responsibility of the buyer, when utilizing toshiba products, to comply with the standards of safety in making a safe design for the entire system, and to avoid situations in which a malfunction or failure of such toshiba products could cause loss of human life, bodily injury or damage to property. in developing your designs, please ensure that toshiba products are used within specified operating ranges as set forth in the most recent toshiba products specifications. also, please keep in mind the precautions and conditions set forth in the ?handling guide for semiconductor devices,? or ?toshiba semiconductor reliability handbook? etc.. the information contained herein is presented only as a guide for the applications of our products. no responsibility is assumed by toshiba corporation for any infringements of intellectual property or other rights of the third parties which may result from its use. no license is granted by implication or otherwise under any intellectual property or other rights of toshiba corporation or others. the information contained herein is subject to change without notice. 000707 eaa_s restrictions on product use
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