NCV8141 5.0 V, 500 mA Linear Regulator with ENABLE, RESET, and Watchdog The NCV8141 is a linear regulator suited for microprocessor applications in automotive environments. This ON Semiconductor part provides the power for the microprocessors along with many of the control functions needed in today’s computer based systems. Incorporating all of these features saves both cost, and board space. The NCV8141 provides a low sleep mode current as compared to the CS8141. Consult your local sales representative for a low sleep mode current version of the CS8140. http://onsemi.com MARKING DIAGRAM Features • • • • • • • • • • • 5.0 V ± 4.0%, 500 mA Output Voltage Lower Quiescent Current Improved Filtering for /RESET Functionality mP Compatible Control Functions ♦ Watchdog ♦ RESET ♦ ENABLE Low Dropout Voltage (1.25 V @ 500 mA) Low Quiescent Current (7.0 mA @ 500 mA) Low Noise, Low Drift Low Current SLEEP Mode 50 mA (max) Fault Protection ♦ Thermal Shutdown ♦ Short Circuit ♦ 60 V Peak Transient Voltage Pb−Free Package is Available NCV Prefix for Automotive and Other Applications Requiring Site and Control Changes NC V8141 AWLYWWG D2PAK−7 DPS SUFFIX CASE 936AB 1 1 A WL Y WW G = Assembly Location = Wafer Lot = Year = Work Week = Pb−Free Package PIN CONNECTIONS Tab = GND Pin 1. VIN 2. ENABLE 3. RESET 4. GND 5. Delay 6. WDI 7. VOUT 1 ORDERING INFORMATION Package Shipping† D2PAK 50 Units/Rail NCV8141D2TG D2PAK (Pb−Free) 50 Units/Rail NCV8141D2TR4 D2PAK 750/Tape & Reel D2PAK (Pb−Free) 750/Tape & Reel Device NCV8141D2T NCV8141D2TR4G †For information on tape and reel specifications, including part orientation and tape sizes, please refer to our Tape and Reel Packaging Specifications Brochure, BRD8011/D. © Semiconductor Components Industries, LLC, 2006 December, 2006 − Rev. 10 1 Publication Order Number: NCV8141/D NCV8141 VIN Reference & Bias Overvoltage Overtemperature Regulation ENABLE Control Logic ENABLE RESET Delay WDI VOUT Short Circuit Undervoltage Sense GND Watchdog RESET Delay Figure 1. Block Diagram PIN FUNCTION DESCRIPTION Pin Symbol Function 1 VIN 2 ENABLE 3 RESET 4 GND Ground Connection. 5 Delay Timing capacitor for Watchdog and RESET functions. 6 WDI CMOS compatible input lead. The Watchdog function monitors the falling edge of the incoming digital pulse train. The signal is usually generated by the system microprocessor. 7 VOUT Regulated output voltage, 5.0 V (typ). Supply voltage to IC, usually direct from the battery. CMOS compatible logical input. VOUT is disabled when ENABLE is LOW and WDI is invalid. CMOS compatible output lead. RESET goes low whenever VOUT drops 4.5% below its typical value for more than 2.0 ms or WDI signal falls below the watchdog threshold frequency. http://onsemi.com 2 NCV8141 MAXIMUM RATINGS Rating Value Unit −0.5 to 26 V Peak Transient Voltage (46 V Load Dump @ 14 V VBAT) 60 V Electrostatic Discharge (Human Body Model) 4.0 kV −0.3 to 7.0 V Internally Limited − Junction Temperature Range (TJ) −40 to +150 °C Storage Temperature Range −65 to +150 °C ENABLE −0.3 to VIN V 1.5 10−50† °C/W °C/W 225 peak (Note 2) °C Input Operating Range WDI Input Signal Range Internal Power Dissipation Package Thermal Resistance, D2PAK 7−Pin Junction−to−Case, RqJC Junction−to−Ambient, RqJA Lead Temperature Soldering: Reflow (SMD styles only) (Note 1) Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the Recommended Operating Conditions is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect device reliability. †Depending on thermal properties of substrate RqJA = RqJC + RqCA. 1. 60 seconds max above 183°C. 2. −5.0°C/+0°C allowable conditions. ELECTRICAL CHARACTERISTICS (7.0 ≤ VIN ≤ 26 V, 5.0 mA ≤ IOUT ≤ 500 mA, −40°C ≤ TJ ≤ 150°C, −40°C ≤ TA ≤ 125°C, unless otherwise noted.) (Note 3) Test Conditions Min Typ Max Unit 7.0 V ≤ VIN ≤ 26 V, 5.0 mA < IOUT < 500 mA 4.8 5.0 5.2 V IOUT = 500 mA − 1.25 1.50 V Line Regulation IOUT = 50 mA, 7.0 V ≤ VIN ≤ 26 V, − 5.0 25 mV Load Regulation VIN = 14 V, 50 mA ≤ IOUT ≤ 500 mA − 5.0 80 mV 500 mA DC and 10 mA AC, 100 Hz ≤ f ≤ 10 kHz − 200 − mW 0 ≤ IOUT ≤ 500 mA, 7.0 V ≤ VIN ≤ 26 V IOUT = 0 mA, VIN = 13 V, ENABLE = 0 V − − 7.0 25 15 50 mA mA 7.0 V ≤ VIN ≤ 17 V, IOUT = 250 mA, f = 120 Hz 60 75 − dB VIN = 7.0 V, VOUT = 4.5 V 600 1200 2000 mA Guaranteed by Design 150 180 − °C VOUT < 1.0 V 30 34 38 V VOUT ≥ 0.5 V, (VOUT(ON)) VOUT < 0.5 V, (VOUT(OFF)) − 3.5 4.05 3.95 4.50 − V V ENABLE = 5.0 V ENABLE = 0 V − −1.0 35 0 75 1.0 mA mA (HIGH − LOW) − 80 − mV Characteristic Output Stage (VOUT) Output Voltage, VOUT Dropout Voltage (VIN − VOUT) Output Impedance, ROUT Quiescent Current, (IQ) Active Mode Sleep Mode Ripple Rejection Current Limit Thermal Shutdown Overvoltage Shutdown ENABLE Threshold HIGH LOW Input Current HIGH LOW Threshold Hysteresis 3. To observe safe operating junction temperatures, low duty cycle pulse testing is used in tests where applicable. http://onsemi.com 3 NCV8141 ELECTRICAL CHARACTERISTICS (continued) (7.0 ≤ VIN ≤ 26 V, 5.0 mA ≤ IOUT ≤ 500 mA, −40°C ≤ TJ ≤ 150°C, −40°C ≤ TA ≤ 125°C, unless otherwise noted.) (Note 4) Characteristic Test Conditions Min Typ Max Unit Threshold HIGH VR(HI) VOUT Increasing 4.65 4.90 VOUT − 0.05 V Threshold LOW VR(LOW) VOUT Decreasing 4.50 4.70 4.90 V Threshold Hysteresis (VRH) (HIGH − LOW) 150 200 250 mV RESET Output Leakage RESET = HIGH VOUT ≥ VR(HI) − − 25 mA Output Voltage Low (VL(LOW)) 1.0 V ≤ VOUT ≤ VR(LOW), RP = 2.7 kW (Note 5) − 0.1 0.4 V Output Voltage Low (VRpeak) VOUT, Power up, Power down − 0.6 1.0 V Delay Time tPOR CDELAY = 0.1 mF 30 47.5 65 ms Delay Time tWDI(RESET) CDELAY = 0.1 mF 0.5 1.0 1.5 ms Input Voltage High − 2.0 − − V Input Voltage Low − − − 0.8 V WDI ≤ VOUT − 0 10 mA CDELAY = 0.1 mF 64 77 96 Hz RESET Watchdog Input Current Threshold Frequency fWDI 4. To observe safe operating junction temperatures, low duty cycle pulse testing is used in tests where applicable. 5. RP is connected to RESET and VOUT. http://onsemi.com 4 NCV8141 TYPICAL PERFORMANCE CHARACTERISTICS 1.4 1.2 Iout = 500 mA 1.0 −40°C 0.8 +25°C 0.6 1.1 DROPOUT VOLTAGE (V) DROPOUT VOLTAGE (V) 1.2 +125°C 0.4 0.9 0.8 Iout = 10 mA 0.6 0 50 0.5 −40 100 150 200 250 300 350 400 450 500 OUTPUT CURRENT (mA) Figure 2. Dropout Voltage vs. Output Current over Temperature 1000 125°C Unstable Region 25°C −20 0 20 40 60 80 TEMPERATURE (°C) 100 120 Figure 3. Dropout Voltage vs. Temperature 1000 Unstable Region −40°C 10 mF 0.1 mF 100 10 10 ESR (W) 100 Stable Region 1 Stable Region 1 T = 25°C 0.1 Cvout = 1 mF to 10 mF 0.1 NOTE: At 125°C an additional area of instability occurs (0.1 mF only) for loads less than 5 mA and low ESR. 0.01 0.01 0 10 20 30 40 50 OUTPUT CURRENT (mA) 60 0 70 Figure 4. Output Stability 10 50 20 30 40 OUTPUT CURRENT (mA) 54 Cdelay = 0.1 mF 53 52 51 50 49 48 47 −40 −20 60 70 Figure 5. Output Stability with Capacitor Change 55 TIME (ms) ESR (W) Iout = 100 mA 0.7 0.2 0 Iout = 350 mA 1.0 0 20 40 60 80 100 120 140 160 TEMPERATURE (°C) Figure 6. Delay Time http://onsemi.com 5 NCV8141 DEFINITION OF TERMS Dropout Voltage: The input−output voltage differential at which the circuit ceases to regulate against further reduction in input voltage. Measured when the output voltage has dropped 100 mV from the nominal value obtained at 14 V input, dropout voltage is dependent upon load current and junction temperature. Input Voltage: The DC voltage applied to the input terminals with respect to ground. Line Regulation: The change in output voltage for a change in the input voltage. The measurement is made under conditions of low dissipation or by using pulse techniques such that the average chip temperature is not significantly affected. Load Regulation: The change in output voltage for a change in load current at constant chip temperature. Quiescent Current: The part of the positive input current that does not contribute to the positive load current. The regulator ground lead current. Ripple Rejection: The ratio of the peak−to−peak input ripple voltage to the peak−to−peak output ripple voltage. Current Limit: Peak current that can be delivered to the output. CIRCUIT DESCRIPTION VOLTAGE REFERENCE AND OUTPUT CIRCUITRY The NCV8141 is a 5.0 V Watchdog Regulator with protection circuitry and three logic control functions that allow a microprocessor to control its own power supply. The NCV8141 is designed for use in automotive, switch mode power supply post regulator, and battery powered systems. Basic regulator performance characteristics include a low noise, low drift, 5.0 V ±4.0% precision output voltage with low dropout voltage (1.25 V @ IOUT = 500 mA) and low quiescent current (7.0 mA @ IOUT = 500 mA). On board short circuit, thermal, and overvoltage protection make it possible to use this regulator in particularly harsh operating environments. The Watchdog logic function monitors an input signal (WDI) from the microprocessor or other signal source. When the signal frequency goes below the externally programmable limit, a RESET signal is generated (RESET). Proper operation has been verified at a frequency up to 100 kHz. No abnormal RESET signals will occur with frequencies lower than 100 kHz and the maximum Threshold Frequency (96 Hz). An external capacitor (CDELAY) programs the watchdog frequency limit as well as the power on reset (POR) and RESET delay. The RESET function is activated by any of three conditions: the watchdog signal moves outside of its preset limits; the output voltage drops out of regulation by more than 4.5%; or the IC is in its power up sequence. The RESET signal is independent of VIN and reliable down to VOUT = 1.0 V. In conjunction with the Watchdog, the ENABLE function controls the regulator’s power consumption. The NCV8141’s output stage and its attendant circuitry are enabled by setting the ENABLE lead high. The regulator goes into sleep mode when the ENABLE lead goes low and the watchdog signal moves outside its preset limit. This unique combination of control functions in the NCV8141 gives the microprocessor control over its own power down sequence: i.e. it gives the microprocessor the flexibility to perform housekeeping functions before it powers down. Precision Voltage Reference The regulated output voltage depends on the precision band gap voltage reference in the IC. By adding an error amplifier into the feedback loop, the output voltage is maintained within ±4.0% over temperature and supply variation. Output Stage The composite PNP−NPN output structure (Figure 7) provides 500 mA (min) of output current while maintaining a low drop out voltage (1.25 V) and drawing little quiescent current (7.0 mA). VIN VOUT Figure 7. Composite Output Stage of the NCV8141 The NPN pass device prevents deep saturation of the output stage which in turn improves the IC’s efficiency by preventing excess current from being used and dissipated by the IC. Output Stage Protection The output stage is protected against overvoltage, short circuit and thermal runaway conditions (Figure 8). If the input voltage rises above 30 V (e.g. load dump), the output shuts down. This response protects the internal circuitry and enables the IC to survive unexpected voltage transients. http://onsemi.com 6 NCV8141 ENABLE circuitry in the IC remains powered up, drawing a quiescent current of less than 50 mA. The Watchdog monitors the frequency of an incoming WDI signal. If the signal falls below the WDI limit, a frequency programmable pulse train is generated at the RESET lead (Figure 9) until the correct Watchdog input signal reappears at the lead (ENABLE = HIGH). The threshold limit of the watchdog function is set by the value of CDELAY. The limit is determined according to the following equation for the NCV8141: Using an emitter sense scheme, the amount of current through the NPN pass transistor is monitored. Feedback circuitry insures that the output current never exceeds a preset limit. > 30 V VIN VOUT tWDI + (1.3 Load Dump Short Circuit 105)CDELAY or The capacitor CDELAY also determines the frequency of the RESET signal and the POWER−ON−RESET (POR) delay period. IO Thermal Shutdown RESET Function Figure 8. Typical Circuit Waveforms for Output Stage Protection The RESET function is activated when the Watchdog frequency signal is below the watchdog threshold (Figure 9), when the regulator is in its power up state (Figure 10) or when VOUT drops below VOUT −4.5% for more than 2.0 ms (Figure 11) If the Watchdog signal falls outside of the preset voltage or below the frequency threshold, a frequency programmable pulse train is generated at the RESET lead (Figure 9) until the correct Watchdog input signal reappears at the lead. The duration of the RESET pulse is determined by CDELAY according to the following equation: Should the junction temperature of the power device exceed 180°C (typ), the power transistor is turned off. Thermal shutdown is an effective means to prevent die overheating since the power transistor is the principle heat source in the IC. REGULATOR CONTROL FUNCTIONS The NCV8141 differs from all other linear regulators in its unique combination of control features. tWDI(RESET) + (1.0 Watchdog and ENABLE Function VOUT is controlled by the logic functions ENABLE and Watchdog (Table 1). RESET CIRCUIT WAVEFORMS WITH DELAYS INDICATED If an undervoltage condition exists, the voltage on the RESET lead goes low and the delay capacitor, CDELAY, is discharged. RESET remains low until output is in regulation, the voltage on CDELAY exceeds the upper threshold and the Watchdog input signal is valid (Figures 10 and 11). The delay after the output is in regulation is: Table 1. VOUT as a Function of ENABLE and Watchdog VOUT (V) WDI ENABLE Slow Normal High Low H 5 5 5 5 L 0 5 0 0 104)CDELAY tPOR(typ) + (4.75 105)CDELAY The RESET delay circuit is also programmed with the external cap CDELAY. The output of the reset circuit is an open collector NPN. RESET is operational down to VOUT = 1.0 V. Both RESET and its delay are governed by comparators with hysteresis to avoid undesirable oscillations. As long as ENABLE is high or ENABLE is low and the Watchdog signal is normal, VOUT will be at 5.0 V (typ). If ENABLE is low and the frequency of the Watchdog input goes below the threshold frequency, the output transistor turns off and the IC goes into SLEEP mode. Only the http://onsemi.com 7 NCV8141 Batt VIN VOUT When Watchdog is Held High and ENABLE = HIGH Batt ENABLE WDI 0 V RESET 0 V VOUT 0 V POR Normal Operation WDI held High Batt VIN VOUT When Watchdog is Held Low and ENABLE = HIGH Batt ENABLE WDI 0 V RESET 0 V VOUT 0 V POR Normal Operation WDI held Low Batt VIN VOUT When Watchdog is too Slow and ENABLE = HIGH Batt ENABLE WDI 0 V RESET 0 V VOUT 0 V POR Normal Operation Slow WDI signal Batt Batt VIN WDI Held High After a Normal Period of Operation; ENABLE = LOW ENABLE WDI 0 V RESET 0 V VOUT 0 V POR Normal Operation WDI Sleep Mode high POR Normal Operation Batt VIN WDI Held Low or is too Slow after a Normal Period of Operation; ENABLE = LOW Batt ENABLE WDI 0 V RESET 0 V VOUT 0 V POR Normal Operation WDI low Sleep Mode POR Normal Operation Figure 9. Timing Diagrams for Watchdog and ENABLE Functions VOUT VOUT VOUT −4.5% VR(HI) VR(LO) < 6.0 ms ≥ 6.0 ms RESET RESET VR(LO) VR(PEAK) 5.0 V tPOR tPOR Figure 10. Power RESET and Power Down Figure 11. Undervoltage Triggered RESET http://onsemi.com 8 NCV8141 APPLICATION NOTES With a capacitor tolerance of ±10%: NCV8141 DESIGN EXAMPLE The NCV8141 with its unique integration of linear regulator and control features: RESET, ENABLE and WATCHDOG, provides a single IC solution for a microprocessor power supply. The reset delay, reset duration and watchdog frequency limit are all determined by a single capacitor. For a particular microprocessor the overriding requirement is usually the reset delay (also known as power on reset). The capacitor is chosen to meet this requirement and the reset duration and watchdog frequency follow. The reset delay is given by: tPOR(typ) + (4.75 tWDI + (1.3 105 tWDI + (1.3 0.8 0.9 CDELAY PASS CDELAY Hz ms 7 141 13 76 Figure 12. WDI Signal for CDelay = 0.82 mF using NCV8141 0.9 ENERGY CONSERVATION AND SMART FEATURES Energy conservation is another benefit of using a regulator with integrated microprocessor control features. Using the NCV8141 as indicated in Figure 13, the microprocessor can control its own power down sequence. The momentary contact switch quickly charges C1 through R1. When the voltage across C1 reaches 3.95 V ( the enable threshold), the output switches on and VOUT rises to 5.0 V. After a delay period determined by CDelay, a frequency programmable reset pulse train is generated at the reset output. The pulse train continues until the correct watchdog signal appears at the WDI lead. C1 is now left to discharge through the input impedance of the enable lead (approximately 150 kW) and the enable signal disappears. The output voltage remains at 5.0 V as long as the NCV8141 continues to receive the correct watchdog signal. The microprocessor can power itself down by terminating its watchdog signal. When the microprocessor finishes its housekeeping or power down software routine, it stops sending a watchdog signal. In response, the regulator generates a reset signal and goes into a sleep mode where VOUT drops to 0 V, shutting down the microprocessor. Closest standard value is 0.82 mF. Minimum and maximum delays using 0.82 mF are 220 ms and 586 ms. The duration of the reset pulse is given by: CDELAY This has a tolerance of ±50% due to the IC, and ±10% due to the capacitor. The duration of the reset pulse ranges from 3.69 ms to 13.5 ms. The watchdog signal can be expressed as a frequency or time. From a programmers point of view, time is more useful since they must ensure that a watchdog signal is issued consistently several times per second. The watchdog time is given by: tWDI + (1.3 105) FAIL CDELAY(min) + 0.743 mF 104) CDelay tWDI + 76 ms (min) t (min) CDELAY(min) + POR 2.69 105 TWDI(RESET)(typ) + (1.0 1.1 The software must be written so that a watchdog signal arrives at least every 76 ms. 105)CDELAY 0.63) 1.2 tWDI + 141 ms (max) Assume that the reset delay must be 200 ms minimum. From the NCV8141 data sheet the reset delay has a $37% tolerance due to the regulator. Assume the capacitor tolerance is $10%. tPOR(min) + (4.75 105) 105)CDELAY There is a tolerance of ±20% due to the NCV8141. http://onsemi.com 9 NCV8141 9.0 V VOUT VIN NCV8141 Switch R1 110 K RESET WDI ENABLE C1 0.1 mF CDELAY GND C2 0.1 mF VCC 10 mF 2.7 kW Microprocessor RESET WATCHDOG PORT Figure 13. Application Diagram for NCV8141. The NCV8141 Provides a 5.0 V Tightly Regulated Supply and Control Function to the Microprocessor. In this Application, the Microprocessor Controls its own Power Down Sequence (see text). http://onsemi.com 10 NCV8141 Battery VOUT VIN C1 * 0.1 mF (optional) Ignition C2 * 10 mF* 2.7 kW NCV8141 ENABLE RESET RESET DELAY 0.1 mF VCC WATCHDOG PORT WDI GND R*** Microprocessor *C1 is required if regulator is located far from the power source filter. **C2 is required for stability. ***R ≤ 80 kW. Figure 14. Application Diagram STABILITY CONSIDERATIONS Step 4: Maintain the worst case load conditions set in Step 3 and vary the input voltage until the oscillations increase. This point represents the worst case input voltage conditions. Step 5: If the capacitor is adequate, repeat Steps 3 and 4 with the next smaller valued capacitor. A smaller capacitor will usually cost less and occupy less board space. If the output oscillates within the range of expected operating conditions, repeat Steps 3 and 4 with the next larger standard capacitor value. Step 6: Test the load transient response by switching in various loads at several frequencies to simulate its real working environment. Vary the ESR to reduce ringing. Step 7: Increase the temperature to the highest specified operating temperature. Vary the load current as instructed in Step 5 to test for any oscillations. Once the minimum capacitor value with the maximum ESR is found, a safety factor should be added to allow for the tolerance of the capacitor and any variations in regulator performance. Most good quality aluminum electrolytic capacitors have a tolerance of ± 20% so the minimum value found should be increased by at least 50% to allow for this tolerance plus the variation which will occur at low temperatures. The ESR of the capacitor should be less than 50% of the maximum allowable ESR found in Step 3 above. The output or compensation capacitor C2 in Figure 14 helps determine three main characteristics of a linear regulator: startup delay, load transient response and loop stability. The capacitor value and type should be based on cost, availability, size and temperature constraints. An aluminum electrolytic capacitor is the least expensive solution, but, if the circuit operates at low temperatures (−25°C to −40°C), both the value and ESR of the capacitor will vary considerably. The capacitor manufacturers data sheet usually provides this information. The value for the output capacitor C2 shown in Figure 14 should work for most applications, however it is not necessarily the optimized solution. To determine an acceptable value for C2 for a particular application, start with a tantalum capacitor of the recommended value and work towards a less expensive alternative part. Step 1: Place the completed circuit with a tantalum capacitor of the recommended value in an environmental chamber at the lowest specified operating temperature and monitor the outputs with an oscilloscope. A decade box connected in series with the capacitor will simulate the higher ESR of an aluminum capacitor. Leave the decade box outside the chamber, the small resistance added by the longer leads is negligible. Step 2: With the input voltage at its maximum value, increase the load current slowly from zero to full load while observing the output for any oscillations. If no oscillations are observed, the capacitor is large enough to ensure a stable design under steady state conditions. Step 3: Increase the ESR of the capacitor from zero using the decade box and vary the load current until oscillations appear. Record the values of load current and ESR that cause the greatest oscillation. This represents the worst case load conditions for the regulator at low temperature. CALCULATING POWER DISSIPATION IN A SINGLE OUTPUT LINEAR REGULATOR The maximum power dissipation for a single output regulator (Figure 15) is: PD(max) + NJVIN(max) * VOUT(min)NjIOUT(max) ) VIN(max)IQ where: VIN(max) is the maximum input voltage, VOUT(min) is the minimum output voltage, IOUT(max) is the maximum output current for the application, and http://onsemi.com 11 (1) NCV8141 In some cases, none of the packages will be sufficient to dissipate the heat generated by the IC, and an external heatsink will be required. IQ is the quiescent current the regulator consumes at IOUT(max). IIN VIN SMART REGULATOR® IOUT HEATSINKS VOUT A heatsink effectively increases the surface area of the package to improve the flow of heat away from the IC and into the surrounding air. Each material in the heat flow path between the IC and the outside environment will have a thermal resistance. Like series electrical resistances, these resistances are summed to determine the value of RqJA. Control Features IQ RqJA + RqJC ) RqCS ) RqSA Figure 15. Single Output Regulator With Key Performance Parameters Labeled where: RqJC = the junction−to−case thermal resistance, RqCS = the case−to−heatsink thermal resistance, and RqSA = the heatsink−to−ambient thermal resistance. RqJC appears in the package section of the data sheet. Like RqJA, it too is a function of package type. RqCS and RqSA are functions of the package type, heatsink and the interface between them. These values appear in heatsink data sheets of heatsink manufacturers. Once the value of PD(max) is known, the maximum permissible value of RqJA can be calculated: RqJA + 150°C * TA PD (3) (2) The value of RqJA can then be compared with those in the package section of the data sheet. Those packages with RqJA’s less than the calculated value in Equation 2 will keep the die temperature below 150°C. http://onsemi.com 12 NCV8141 PACKAGE DIMENSIONS D2PAK−7 (SHORT LEAD) CASE 936AB−01 ISSUE A TERMINAL 8 A K U E S B NOTES: 1. DIMENSIONS AND TOLERANCING PER ANSI Y14.5M, 1982. 2. CONTROLLING DIMENSION: INCH. DIM A B C D E G H K L M N P R S U V V M H L P D G N R C SOLDERING FOOTPRINT* 9.5 0.374 2.16 0.085 1.27 0.050 3.25 0.128 CL 10.54 0.415 CL 3.8 0.150 1 0.96 0.038 8.26 0.325 SCALE 3:1 mm Ǔ ǒinches *For additional information on our Pb−Free strategy and soldering details, please download the ON Semiconductor Soldering and Mounting Techniques Reference Manual, SOLDERRM/D. http://onsemi.com 13 INCHES MIN MAX 0.396 0.406 0.326 0.336 0.170 0.180 0.026 0.036 0.045 0.055 0.050 REF 0.539 0.579 0.055 0.066 0.000 0.010 0.100 0.110 0.017 0.023 0.058 0.078 0° 8° 0.095 0.105 0.256 REF 0.305 REF MILLIMETERS MIN MAX 10.05 10.31 8.28 8.53 4.31 4.57 0.66 0.91 1.14 1.40 1.27 REF 13.69 14.71 1.40 1.68 0.00 0.25 2.54 2.79 0.43 0.58 1.47 1.98 0° 8° 2.41 2.67 6.50 REF 7.75 REF NCV8141 SMART REGULATOR is a registered trademark of Semiconductor Components Industries, LLC (SCILLC). ON Semiconductor and are registered trademarks of Semiconductor Components Industries, LLC (SCILLC). SCILLC reserves the right to make changes without further notice to any products herein. SCILLC makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does SCILLC assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation special, consequential or incidental damages. “Typical” parameters which may be provided in SCILLC data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. All operating parameters, including “Typicals” must be validated for each customer application by customer’s technical experts. SCILLC does not convey any license under its patent rights nor the rights of others. SCILLC products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other applications intended to support or sustain life, or for any other application in which the failure of the SCILLC product could create a situation where personal injury or death may occur. Should Buyer purchase or use SCILLC products for any such unintended or unauthorized application, Buyer shall indemnify and hold SCILLC and its officers, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if such claim alleges that SCILLC was negligent regarding the design or manufacture of the part. SCILLC is an Equal Opportunity/Affirmative Action Employer. This literature is subject to all applicable copyright laws and is not for resale in any manner. PUBLICATION ORDERING INFORMATION LITERATURE FULFILLMENT: Literature Distribution Center for ON Semiconductor P.O. Box 5163, Denver, Colorado 80217 USA Phone: 303−675−2175 or 800−344−3860 Toll Free USA/Canada Fax: 303−675−2176 or 800−344−3867 Toll Free USA/Canada Email: [email protected] N. American Technical Support: 800−282−9855 Toll Free USA/Canada Europe, Middle East and Africa Technical Support: Phone: 421 33 790 2910 Japan Customer Focus Center Phone: 81−3−5773−3850 http://onsemi.com 14 ON Semiconductor Website: www.onsemi.com Order Literature: http://www.onsemi.com/orderlit For additional information, please contact your local Sales Representative NCV8141/D