5-V Low Drop Fixed Voltage Regulator TLE 4278 G Features • • • • • • • • • • • • Output voltage tolerance ≤ ±2% Very low current consumption Separated reset and watchdog output Low-drop voltage Watchdog Adjustable watchdog activating threshold Adjustable reset threshold Overtemperature protection Reverse polarity protection Short-circuit proof Suitable for use in automotive electronics Wide temperature range P-DSO-14-3, -8, -9, -11, 14 Functional Description The TLE 4278 is a monolithic integrated low-drop fixed output voltage regulator supplying loads up to 200 mA. The IC is available in a P-DSO-14-8 package. It is designed to supply microprocessor systems under the severe conditions of automotive applications and therefore equipped with additional protection functions against overload, short circuit and overtemperature. The TLE 4278 can also be used in other applications where a stabilized voltage is required. An input voltage VI in the range of 5.5 V ≤ VI ≤ 45 V is regulated to VQ,nom = 5 V with an accuracy of ±2%. The device operates in the wide temperature range of Tj = -40 to 150 °C. Two additional features are implemented in the TLE 4278 a load dependent watchdog function as well as a sophisticated reset function including power on reset, under voltage reset, adjustable reset delay time and adjustable reset switching threshold. The watchdog function monitors the microcontroller, including time base failures. In case of a missing rising edge within a certain pulse repetition time the watchdog output is set Type Ordering Code Package TLE 4278 G Q67007-A9291 P-DSO-14-8 Data Sheet 1 Rev. 1.3, 2005-04-29 TLE 4278 G to LOW. Programming of the max. repetition time can be done easily by an external reset delay capacitor. To prevent a reset in case of missing pulses, the watchdog output WO is separate from the reset output RO for the TLE 4278. The watchdog output can be used as an interrupt signal for the microcontroller. In any case it is possible to connect pin WO and pin RO externally. When the controller is set to sleep mode or low power mode its current consumption drops and no watchdog pulses are created. In order to avoid unnecessary wake-up signals due to missing pulses at pin WI the watchdog feature can be disabled as a function of the load current. The switch off threshold is set by an external resistor to pin WADJ. The watchdog function can also be used as a timer, which periodically wakes up the controller. Therefore the pin WADJ has to be connected to the output Q. The power on reset feature is necessary for a defined start of the microprocessor when switching on the application. The reset signal at pin RO goes high after a certain delay timed trd when the output voltage of the regulator has surpassed the reset threshold. The delay time is set by the external delay capacitor. An under voltage reset circuit supervises the output voltage. In case VQ falls below the reset threshold the reset output is set to LOW after a short reset reaction time trr. The reset LOW signal is generated down to an output voltage VQ of 1 V. In addition the reset switching threshold can be adjusted by an external voltage divider. This feature is useful with microprocessors which guarantee a safe operation down to voltages below the internally set reset threshold of 4.65 V typical. Data Sheet 2 Rev. 1.3, 2005-04-29 TLE 4278 G P-DSO-14-8 WO WADJ GND GND GND D RADJ 1 2 3 4 5 6 7 14 13 12 11 10 9 8 RO VΙ GND GND GND VQ WΙ AEP02113 Figure 1 Pin Configuration (top view) Table 1 Pin Definitions and Functions Pin Symbol Function 1 WO Watchdog Output; the open collector output is connected to the 5 V output via an integrated resistor of 30 kΩ. 2 WADJ Watchdog Adjust; an external resistor to GND determines the watchdog activating threshold. 3, 4, 5, GND 10, 11, 12 Ground 6 D Reset Delay; connect a capacitor to ground for delay time adjustment. 7 RADJ Reset Switching Threshold Adjust; for setting the switching threshold, connect a voltage divider from output to ground. If this input is connected to ground, the reset is triggered at the internal threshold. 8 WI Watchdog Input; rising edge-triggered input for monitoring a microcontroller. 9 Q 5 V Output Voltage; block to ground with min. 10 µF capacitor, ESR ≤ 5 Ω. 13 I Input Voltage; block to ground directly on the IC with ceramic capacitor. 14 RO Reset Output; the open collector output is connected to the 5 V output via an integrated resistor of 30 kΩ. Data Sheet 3 Rev. 1.3, 2005-04-29 TLE 4278 G VΙ 13 9 Temperature Sensor Protection Circuit 14 VQ RO Reset Generator + - Control Amplifier 7 1 Bandgap Reference Watchdog 2 3-5, 10-12 WADJ GND Figure 2 Data Sheet 6 RADJ WO D 8 WΙ AEB02114 Block Diagram 4 Rev. 1.3, 2005-04-29 TLE 4278 G Table 2 Absolute Maximum Ratings Tj = -40 to 150 °C Parameter Symbol Limit Values Unit Notes Min. Max. VI II -42 45 V – – – mA Internally limited VQ IQ -1 25 V – – – mA Internally limited VRO IRO -0.3 25 V – -5 5 mA – VD ID -0.3 7 V – -2 2 mA – Input Voltage I Voltage Current Output Voltage Q Voltage Current Reset Output RO Voltage Current Reset Delay D Voltage Current Reset Switching Threshold Adjust RADJ Voltage Current VRADJ IRADJ -0.3 7 V – – – mA Internally limited VWI IWI -0.3 7 V – – – mA Internally limited VWO IWO -0.3 25 V – -5 5 mA – VWADJ IWADJ -0.3 7 V – – – mA Internally limited IGND -100 50 mA – Watchdog Input WI Voltage Current Watchdog Output WO Voltage Current Watchdog Adjust WADJ Voltage Current Ground GND Current Data Sheet 5 Rev. 1.3, 2005-04-29 TLE 4278 G Table 2 Absolute Maximum Ratings (cont’d) Tj = -40 to 150 °C Parameter Symbol Limit Values Unit Notes Min. Max. -50 150 °C – -50 150 °C – Temperatures Junction temperature Storage temperature Tj Tstg Note: ESD protection according to MIL Std. 883: ±2 kV. Maximum ratings are absolute ratings; exceeding any one of these values may cause irreversible damage to the integrated circuit. Table 3 Operating Range Parameter Input voltage Junction temperature Symbol Limit Values Unit Notes Min. Max. VI Tj 5.5 45 V – -40 150 °C – Rthj-a Rthj-pin – 80 K/W 1) – 30 K/W Thermal Resistance Junction ambient Junction pin Measured to pin 4 1) Package mounted on PCB 80 × 80 × 1.5 mm ; 35µ Cu; 5µ Sn; Heat Sink Area 6 cm ; zero airflow. 3 2 Note: In the operating range the functions given in the circuit description are fulfilled. Data Sheet 6 Rev. 1.3, 2005-04-29 TLE 4278 G Table 4 Electrical Characteristics VI = 13.5 V; -40 °C ≤ Tj ≤ 125 °C (unless otherwise specified) Parameter Symbol Limit Values Min. Typ. Max. Unit Test Condition Output voltage VQ 4.90 5.00 5.10 V 0 mA ≤ IQ ≤ 150 mA; 6 V ≤ VI ≤ 28 V Output voltage VQ 4.8 5.0 5.2 V 1 mA ≤ IQ ≤ 50 mA; 28 V ≤ VI ≤ 45 V 200 400 – mA Output current limiting IQ Current consumption Iq = II - IQ Iq,o – 180 200 µA Current consumption Iq = II - IQ Iq,o – 210 230 µA Current consumption Iq = II - IQ Iq,150 – 5 12 mA VQ = 4.8 V Tj = 25 °C; IQ = 0 mA IQ = 0 mA; Tj = 85 °C IQ = 150 mA Drop voltage VDR = VI - VQ Vdr – 0.25 0.5 V IQ = 150 mA1) Load regulation ∆VQ.lo -30 -5 – mV Line regulation ∆VQ,li – 5 20 mV IQ = 5 to 150 mA; VI = 6 V VI = 6 to 28 V IQ = 5 mA 4.5 4.65 4.8 V RADJ connected to GND 180 350 – mV IQ = 10 mA 1.28 1.35 1.45 V – 0.20 0.40 V VQ ≥ 3.5 V Rext = 10 kΩ to VQ VQ ≥ 1 V 4.5 – – V – 20 30 45 kΩ Internal connected to VQ 2 5 8 µA VD = 1.0 V Reset Generator VQ,rt Reset headroom ∆VQ,rt = (VQ,nom VQ,rt) Reset adjust threshold VRADJ,th Reset low voltage VRO,l Reset threshold Reset high voltage Reset pull-up Charging current Data Sheet VRO,h RRO ID,c 7 Rev. 1.3, 2005-04-29 TLE 4278 G Table 4 Electrical Characteristics (cont’d) VI = 13.5 V; -40 °C ≤ Tj ≤ 125 °C (unless otherwise specified) Parameter Symbol Upper timing threshold VDU Limit Values Unit Test Condition Min. Typ. Max. 1.5 1.9 2.3 V – Lower reset timing threshold VDRL 0.2 0.3 0.4 V – Delay time trd trr 12 20 28 ms 0.4 1.0 2.0 µs CD = 47 nF CD = 47 nF 1.28 1.35 1.45 V Voltage at WADJ 650 720 800 – IQ ≤ 10 mA 5 – – V/µs From 20% up to 80% VQ – 0.2 0.4 V Rext > 10 kΩ to VQ 4.5 – – V – 20 30 45 kΩ Internal connected to VQ 2 5 8 µA 0.6 1.3 2.0 µA VD = 1.0 V VD = 1.0 V 1.5 1.9 2.3 V – 0.5 0.7 0.9 V – Reset reaction time Watchdog VWADJ,th Current ratio IQ/IWADJ Slew rate dVWI/dt Watchdog low voltage VWOL Watchdog high voltage VWOH Watchdog pull-up RWO Charge current ID,wc Discharge current ID,wd Upper timing threshold VDU Lower watchdog VDWL Activating threshold timing threshold Watchdog output pulse period TWD,p 42 60 80 ms Cd = 47 nF Watchdog output low time tWD,l 7 13 19 ms VQ > VRT 35 47 61 ms Cd = 47 nF Watchdog trigger time TWI,tr 1) Measured when the output voltage VQ has dropped 100 mV from the nominal value. Data Sheet 8 Rev. 1.3, 2005-04-29 TLE 4278 G ΙΙ C Ι1 1000 µF Ι WO VΙ WO VΙ WΙ VWADJ 9 VQ ΙQ C Ι2 470 nF Ι WADJ WADJ VWO 13 VW VD CQ 10 µF TLE 4278 G 1 2 8 3-5, 10-12 GND 6 D CD 47 nF Ι GND RO 14 7 RADJ Ι RO VQ VRO VRE AES02115 VDR = VΙ -VO Outside the control range Figure 3 Data Sheet Test Circuit 9 Rev. 1.3, 2005-04-29 TLE 4278 G Application Information Input, Output The input capacitors CI1 and CI2 are necessary for compensating line influences. Using a resistor of approx. 1 Ω in series with CI1, the LC circuit of input inductance and input capacitance can be damped. To stabilize the regulation circuit the output capacitor CQ is necessary. Stability is guaranteed at values CQ ≥ 10 µF with an ESR ≤ 5 Ω within the operating temperature range. VΙ +12 V C Ι1 CΙ2 13 9 VQ 470 nF 1 TLE 4278G 14 8 3-5, 10-12 GND 6 D WO R1 CQ 22 µF RO WΙ RADJ 7 2 WADJ µP *) Cooling Area CD 47 nF R WADJ R2 *) or short to GND for internal threshold Figure 4 Data Sheet AES02116 Application Circuit 10 Rev. 1.3, 2005-04-29 TLE 4278 G Reset Timing The power-on reset delay time is defined by the charging time of an external capacitor CD which can be calculated as follows: CD = (∆trd × ID,c)/∆V (1) Definitions: CD = delay capacitor ∆trd = delay time ID,c = charge current, typical 5 µA ∆V = VDU, typical 1.9 V VDU = upper delay switching threshold at CD for reset delay time The reset reaction time trr is the time it takes the voltage regulator to set the reset out • • • • • LOW after the output voltage has dropped below the reset threshold. It is typically 1 µs for delay capacitor of 47 nF. For other values for CD the reaction time can be estimated using Equation (2): trr ≈ 20 s/F × CD (2) VΙ t < t rr VQ V Q, rt d V Ι D,c = dt CD VD t V DU V DRL VRO t rr t rd t t Power-on-Reset Figure 5 Data Sheet Thermal Shutdown Voltage Dip at Input Undervoltage Secondary Spike Overload at Output AED03010 Reset Timing (watchdog disabled) 11 Rev. 1.3, 2005-04-29 TLE 4278 G Reset Switching Threshold The present default value is 4.65 V. When using the TLE 4278 the reset threshold can be set to 3.5 V < VQ,rt < 4.6 V by connecting an external voltage divider to pin RADJ. The calculation can be easily done since the reset adjust input current can be neglected. If this feature is not needed, the pin has to be connected to GND. VQ,rt = Vref × (1 + R1/R2) (3) Definitions: • • VQ,rt = Reset threshold Vref = comparator reference voltage, typical 1.35 V (Reset adjust input current ≈ 50 nA) TLE 4278 G Ι 13 9 Q 30 kΩ 14 RO Band-GapReference Band-GapReference 1.35 V 1.35 V >1 + - R1 7 3 ... 5, RADJ 10 ... 12 GND R2 AES03071 Figure 6 The reset output pin is internally connected to the 5 V output Q via a 30 kΩ pull-up resistor. Down to an output voltage VQ of typical 1 V the reset LOW signal at pin RO is generated. For the timing of the reset feature please refer to Figure 5. Data Sheet 12 Rev. 1.3, 2005-04-29 TLE 4278 G Watchdog Activating The calculation of the external resistor which adjusts the watchdog switch off threshold can be done by Equation (4): RWADJ = VWADJ,th × (IQ/IWADJ)/IQ,act (4) Definitions: • • • VWADJ,th = switch off threshold, typical 1.35 V IQ/IWADJ = current ratio, typical 720 IQ,act = switch off load current TLE 4278 G Ι Q Band-GapReference HIGH + - WADJ Watchdog active LOW Watchdog disabled R WADJ GND AES03072 Figure 7 Data Sheet 13 Rev. 1.3, 2005-04-29 TLE 4278 G Watchdog Timing The frequency of the watchdog pulses has to be higher than the minimum pulse sequence which is set by the external reset delay capacitor CD. Calculation can be done according to the formulas given in Figure 8. The watchdog output is internally connected to the output Q via a 30 kΩ pull-up resistor. To generate a watchdog created reset signal for the microcontroller the pin WO can be connected to the reset input of the microcontroller. It is also allowed to parallel the watchdog out to the reset out. VW Ι t VΙ VQ t T WD, p VD t T WI, tr VDU VDWL VWO T WI, tr = t WD, L (VDU - VDWL ) Ι D, wd C D ; T WD, p = (VDU -VDWL ) (Ι D, wc + Ι D, wd ) Ι D, wc x Ι D, wd C D ; t WD, L = t (VDU - VDWL ) Ι D, wc t CD AED03099 Figure 8 Data Sheet Timing of the Watchdog Function 14 Rev. 1.3, 2005-04-29 TLE 4278 G Table 5 Hints for Unused Pins Symbol Function Connect to RO Reset output open D Reset delay open or to output Q RADJ Reset switching threshold adjust GND WI Watchdog input GND WO Watchdog output open WADJ Watchdog adjust 1) Data Sheet to output Q via a 270 kΩ resistor: Watchdog always active 2) to GND: Watchdog disabled 15 Rev. 1.3, 2005-04-29 TLE 4278 G Drop Voltage Vdr versus Output Current IQ Current Consumption Iq versus Output Current IQ TL E42 7 8_ IQ -IQ .VSD AED01544 mV I q [mA] V dr 700 V I = 13.5V T j = 25°C 10 600 500 1 400 Tj = 125 C 300 Tj = 25 C 0.1 200 100 0 0 50 100 150 200 250 0.01 0.1 mA 1 10 100 ΙQ IQ [mA] Current Consumption Iq versus Input Voltage VI Output Voltage VQ versus Input Voltage VI AED01546 12 Iq mA VQ Tj = 25 ˚C 10 10 8 8 6 AED01547 mA 6 R L= 33 Ω R L= 33 Ω 4 4 R L= 50 Ω 2 0 2 R L= 100 Ω 0 10 20 30 0 40 V 50 VI Data Sheet 0 2 4 6 8 V VΙ 16 Rev. 1.3, 2005-04-29 TLE 4278 G Charge Current ID,wc and Discharge Current ID,wd versus Temperature Tj Ι Switching Voltage VDU, VDWL and VDRL versus Temperature Tj AED03111 8 µA VD VΙ = 13.5 V VD = 1.0 V 7 V Ι = 13.5 V 2.4 6 Ι D, wc 5 2.0 4 1.6 3 1.2 2 Ι D, wd 1 0 -40 AED03055 3.2 V 2.8 0 40 80 120 V DU 0.8 V DWL 0.4 V DRL 0 -40 C 0 40 80 Tj Tj Output Voltage VQ versus Temperature Tj VQ Output Current Limit IQ versus Input Voltage VI AED03056 5.2 120 ˚C 160 AED03057 500 IQ V 5.1 Tj = 25 ˚C mA 400 VΙ = 13.5 V 5.0 300 4.9 200 4.8 100 4.7 4.6 -40 0 0 40 80 120 ˚C 160 10 20 30 40 V 50 VI Tj Data Sheet 0 17 Rev. 1.3, 2005-04-29 TLE 4278 G Package Outlines -0.01 0.2 +0.05 1.27 0.41 +0.1 -0.06 0.2 M 14 0.1 A C 14x C 8˚ MAX. 4 -0.2 1) 1.75 MAX. 0.1 MIN. (1.5) 0.33 ±0.08 x 45˚ 0.64 ±0.25 6 ±0.2 8 1 7 1) 8.75 -0.2 A Index Marking 1) Does not include plastic or metal protrusion of 0.15 max. per side GPS09033 Figure 9 P-DSO-14-8 (Plastic Dual Small Outline) Revision History Version Date Changes Rev. 1.2 2004-01-01 Final Data Sheet Rev. 1.3 2005-04-29 * Typ. Perf. Char. Graph “Iq vs. IQ”: Replaced by a logarithmic graph in order to precise at low IQ. * Order number typo corrected You can find all of our packages, sorts of packing and others in our Infineon Internet Page “Products”: http://www.infineon.com/products. Dimensions in mm SMD = Surface Mounted Device Data Sheet 18 Rev. 1.3, 2005-04-29 Edition 2005-04-29 Published by Infineon Technologies AG, St.-Martin-Strasse 53, 81669 München, Germany © Infineon Technologies AG 2005. All Rights Reserved. Attention please! The information herein is given to describe certain components and shall not be considered as a guarantee of characteristics. Terms of delivery and rights to technical change reserved. We hereby disclaim any and all warranties, including but not limited to warranties of non-infringement, regarding circuits, descriptions and charts stated herein. Information For further information on technology, delivery terms and conditions and prices please contact your nearest Infineon Technologies Office (www.infineon.com). Warnings Due to technical requirements components may contain dangerous substances. For information on the types in question please contact your nearest Infineon Technologies Office. Infineon Technologies Components may only be used in life-support devices or systems with the express written approval of Infineon Technologies, if a failure of such components can reasonably be expected to cause the failure of that life-support device or system, or to affect the safety or effectiveness of that device or system. Life support devices or systems are intended to be implanted in the human body, or to support and/or maintain and sustain and/or protect human life. If they fail, it is reasonable to assume that the health of the user or other persons may be endangered.