TB9000F

TB9000F TOSHIBA BiCMOS Integrated Circuit Silicon Monolithic TB9000F 5 V Voltage Regulator with Watchdog Timer The TB9000F is an IC specially designed for microcomputer systems in automobile. It features low standby current and various system reset functions. With external pass Tr., TB9000F can supply high output current. As a protective function, current limiter function is incorporated. The system reset includes low voltage reset/power on reset/watchdog timer. Weight: 0.14 g (typ.) Features • • • • • • Accurate output: 5.0 V ± 0.15 V Low current consumption: 120 µA (VIN = 12V ,Ta = 25°C) at 5 V Output + Reset timer Reset functions: Low voltage reset/Power on reset/Watchdog timer Current limiter: Adjustable with external resistor Operating temperature : −40 to 125°C Small SMD package: SSOP-16pin 1 2003-10-16 TB9000F Block Diagram & Pin Layout NC 16 NC 15 WS 14 CK 13 NC 12 TC 11 NC 10 RESET 9 Watchdog timer Power on reset Vref Comp Current limiter 0.3 V 5 V Reg Amp 70 kΩ 1 VIN 2 NC 3 VS 4 OUT 5 COMP 6 Vcc 7 NC 8 GND Note: Some of the functional blocks, circuits, or constants in the block diagram are omitted or simplified to clarify the descriptions of the relevant features. 100 kΩ 2 2003-10-16 TB9000F Pin Description Pin No. 1 Symbol VIN Description Power supply input pin. It contains current limiter and startup circuit. Detection pin for the VCC current limiter. A voltage drop occurring in the external resistor RS between pins VIN and VS is monitored. The current limiter is actuated when the voltage drop exceeds 0.3 V. Ex.) When the current limiter need to be actuated at a load current of 600 mA RS = 0.3 V/600 mA = 0.5 Ω This pin is used to connect the base of an external PNP transistor. The output voltage is controlled by an internal op-amp to maintain it stably at 5 V. Since the recommended current of IOUT is 8 mA, an output current of 600 mA can be flowed if HFE of the external transistor is 80 or more. Phase compensating pin for VCC. Connect a phase compensating capacitor between pin VCC and this pin. Voltage detection pin for the 5 V constant-voltage power supply, VCC. It also supplies power to the reset timer circuit. Grounded Reset output pin for power on reset and watchdog timer. ● Generates a reset signal which is determined by CT at the TC pin. ● If no clock is fed to the CK input, this pin generates a reset pulse intermittently. This is an N-MOS drain output with a 100 kΩ pull-up resistor to VCC. Time setup pin for the reset and watchdog timers. Connect capacitor CT to GND. The time is set up by internal constant current. Clock input pin for the watchdog timer. This pin detects rising edge of the input signal and does not require external coupling capacitor. Watchdog timer function ON/OFF control pin. Set to "Low" for active mode and "High" for inactive mode. Not connected. (Electrically, this pin is completely open.) 3 VS 4 OUT 5 6 8 COMP VCC GND 9 RESET 11 TC 13 CK 14 2, 7, 10, 12, 15, 16 WS NC 3 2003-10-16 TB9000F Functional Description The TB9000F incorporates a constant-voltage 5 V power supply function to feed stable power to the CPU and the system reset and CPU monitor functions to ensure stable operation of the CPU, etc. These functions are explained below. (1) Constant-voltage 5V power supply function This constant-voltage function has the reference voltage Vref 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 5 V 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. An overcurrent protection function is incorporated as a protective measure in case a fault such as shorting to GND occurs in the 5 V output. A current detecting resistor is inserted between the VIN and the VS pins, and a voltage drop across this resistor is detected by a comparator, thereby suppressing the operation of the OP amp to ensure that the voltage drop will not exceed 0.3 V. In this way, a current limiter function is actuated to prevent no more current from flowing. (2) System reset function (See Timing Chart) ● Voltage monitoring function When powered on, the power-on reset timer starts counting the moment the voltage VCC applied to the CPU exceeds 4.7 V. When powered off, this voltage monitoring function outputs a reset signal immediately when VCC drops below 4.7 V. A reset signal also is output immediately when VCC drops for some reason during normal operation. Then, when VCC is restored to the normal voltage and exceeds 4.7 V, the power-on reset timer starts counting. The reset signal is output from the RESET pin. ● Power-on reset timer function To allow the 5 V constant voltage to stabilize at power-on, as well as provide a sufficient time for the clock oscillation in the CPU to stabilize, 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 capacitor connected to the TC pin. The system starts charging the capacitor when the VCC voltage exceeds 4.7 V. When this charge voltage exceeds 4 V, the capacitor is discharged by the IC’s internal transistor. When the capacitor is discharged down to 2 V, the reset signal is inverted to deactivate the reset. ● Watchdog timer function Program your system to output a clock each time one program routine is finished in the CPU system software, and input this clock to the CK pin of the IC. The IC’s TC pin is repeatedly charged and discharged between 2 V and 4 V. However, when a clock is input, it switches over and starts discharging in the middle of charging and then starts charging from 2 V again. Since the clock is generated at predetermined intervals when the CPU system is operating normally, the TC pin switches over and starts discharging before the charge voltage reaches 4 V. However, if no clock is input while being charged from 2 V to 4 V, the clock is assumed to have stopped, i.e., the CPU system has gone wild, so that a reset signal is output to reset the CPU system. ● Watchdog timer stop function The watchdog timer can be switched ON or OFF by WS pin. If WS pin is fixed to low, the watchdog timer will be active. (TIMING CHART 1) If WS pin is fixed to high, the watchdog timer will be inactive. (TIMING CHART 2) When the WS pin is fixed to high, no reset signal is output, in which case only the power-on reset timer is useful. Note: The overcurrent protection feature is only intended to protect the IC from a temporary short circuit. A short circuit over an extended period of time may place excessive stress on the IC, possibly causing it to be damaged. The system must be configured so that any overcurrent condition will be eliminated as soon as possible. 4 2003-10-16 TB9000F Timing Chart 1 WS = Low 5V VCC 0V VTH TC 0V CK 0V RESET 0V TPOR TWD TRST TPOR Timing Chart 2 WS = High 5V VCC 0V VTH VTH TC 0V RESET 0V TPOR TPOR Note: Timing charts may be simplified to clarify the descriptions of features and operations. 5 2003-10-16 TB9000F Maximum Rating (Ta = 25°C) Characteristics Symbol VIN Input voltage COMP,Vcc, -----------------RESET,CK, WS,TC IOUT Topr Tstg Tsol Rating 45 (1 s) 6.0 10 Unit V V mA °C °C °C Output current Operating temperature Storage temperature Lead temperature-time −40 to 125 −55 to 150 240 (10 s) SSOP16-P-225 Thermal Resistance Data (Ta = 25°C) Characteristics Rθj-a PD1 PD2 Rating 200 0.6 0.78 Unit °C/W W W Test Condition Without radiation board Without radiation board 50 × 50 × 1.6 mm 30% Cu board mounted Note: The absolute maximum ratings of a semiconductor device are a set of specified parameter values which must not be exceeded during operation, even for an instant. If any of these levels is exceeded during operation, the device's electrical characteristics may be irreparably altered and the reliability and lifetime of the device can no longer be guaranteed, possibly causing damage to any other equipment with which it is used. Applications using the device should be designed such that the maximum ratings will never be exceeded in any operating conditions. Ensuring that the parameter values remain within these specified ranges during device operation will help to ensure that the integrity of the device is not compromised. 6 2003-10-16 TB9000F Electrical Characteristics (VIN = 6 to 16 V, ILOAD = 10 mA, Ta = −40 to 125°C) Characteristics Output voltage Line regulation Load regulation Temperature coefficient Output voltage Output leakage current Input current Input current Input current Input voltage Symbol VREG VLINE VLOAD Pin VCC VCC VCC VCC RESET Test Circuit Test Condition Ta = −40 to 105°C Ta = −40 to 125°C VIN = 6 to 40 V ILOAD = 1 to 300 mA Min 4.85 4.82 Typ. 5.0 5.0 0.1 0.2 0.01 Max 5.15 5.15 0.5 1.0 Unit V % % %/°C V               VOL ILEAK IIN IIN IIN VIH VIL VIH VIL VLIMIT ICC VTH  0.3 5 IOL = 2 mA VIN( RESET ) = VCC VIN(TC) = GND VIN(CK) = 0 to VCC VIN(WS) = 0 to VCC    −5 −5 0.8 VCC   −10       0.3 120 120 4.7 0.30 400 × CT RESET µA µA µA µA V TC CK WS CK  5 5  0.2 VCC  0.8 VCC Input voltage Current limiter detection Current consumption WS VCC   Ta = 25°C, VIN = 12 V  0.2 VCC 0.375 170 190 4.9 0.35 520 × CT  0.225 V V   4.5   Ta = −40 to 125°C VIN = 12 V µA Reset detection voltage Power on reset W atchdog timer ∆VTH TPOR TWD VCC RESET      VCC − VTH 0.25 280 × CT V RESET RESET CK 140 × CT 4.0 × CT 3 200 × CT 8.0 × CT 260 × CT 12.0 × CT ms Reset timer Clock pulse width TRST Tw   µs Note1: CT is measured in unit of µF. Note2: The specification values of power-on reset, watchdog timer and reset timer above are intended to guarantee the IC itself. Note that the fluctuations of CT value should be taken into consideration for practical use of the IC. Note3:The specification of "Current consumption" is specified that ILOAD=0mA. Recommended Conditions Part Name CT Min 0.01 Typ. 0.25 Max 10 Unit µF 7 2003-10-16 TB9000F Reference Characteristics Input – Output characteristics RESET output characteristics 6 6 (V) (V) VRESET 4 4 VCC 2 2 0 0 2 4 6 0 0 2 4 6 VIN (V) VCC (V) Current Limiter Characteristics 7 6 5 (V) VCC 4 3 2 1 0 0 0.1 0.2 0.3 0.4 VLIMIT (V) 8 2003-10-16 TB9000F Example of Application Circuit VB RS 5.0 V VDD 470 pF C1 C3 VIN VS OUT COMP VCC 5 V monitor CPU Current limiter Constant voltage TB9000F RESET TC Reset timer CK WS RESET Po1 Caution for Wiring Note 1: C1 and C2 are for absorbing disturbances, noise, etc. C3 is for phase compensation. Note 2: Connect each capacitor as close to the IC as possible. Note 3: Ensure that the IC is mounted correctly. Failing to do so may result in the IC or target equipment being damaged. Note 4: The application circuit shown above is not intended to guarantee mass production. A thorough evaluation is required when designing an application circuit for mass production. CT C2 9 2003-10-16 TB9000F Package Dimensions W eight: 0.14 g (typ.) 10 2003-10-16 TB9000F RESTRICTIONS ON PRODUCT USE • The information contained herein is subject to change without notice. 030619EBA • The information contained herein is presented only as a guide for the applications of our products. No responsibility is assumed by TOSHIBA for any infringements of patents or other rights of the third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of TOSHIBA or others. • 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 TOSHIBA products listed in this document are intended for usage in general electronics applications (computer, personal equipment, office equipment, measuring equipment, industrial robotics, domestic appliances, etc.). These TOSHIBA products are neither intended nor warranted for usage in equipment that requires extraordinarily high quality and/or reliability or a malfunction or failure of which may cause loss of human life or bodily injury (“Unintended Usage”). Unintended Usage include atomic energy control instruments, airplane or spaceship instruments, transportation instruments, traffic signal instruments, combustion control instruments, medical instruments, all types of safety devices, etc.. Unintended Usage of TOSHIBA products listed in this document shall be made at the customer’s own risk. • The products described in this document are subject to the foreign exchange and foreign trade laws. • TOSHIBA products should not be embedded to the downstream products which are prohibited to be produced and sold, under any law and regulations. 11 2003-10-16