NCV891130 Step-Down Regulator Automotive, Low-Iq, Dual-Mode 1.2 A, 2 MHz www.onsemi.com The NCV891130 is a Dual Mode regulator intended for Automotive, battery-connected applications that must operate with up to a 45 V input supply. Depending on the output load, it operates either as a PWM Buck Converter or as a Low Drop-Out Linear Regulator, and is suitable for systems with low noise and Low Quiescent Current requirements often encountered in automotive driver information systems. A reset pin (with fixed delay) simplifies interfacing with a microcontroller. The NCV891130 also provides several protection features expected in automotive power supply systems such as current limit, short circuit protection, and thermal shutdown. In addition, the high switching frequency produces low output voltage ripple even when using small inductor values and an all-ceramic output filter capacitor - forming a space-efficient switching regulator solution. 8 1 SOIC-8 EXPOSED PAD CASE 751AC MARKING DIAGRAM 8 891130XX ALYW G Features * * * * * * * * * * * 30 mA Iq in Light Load Condition 1.2 A Maximum Output Current in PWM Mode Internal N-channel Power Switch VIN Operating Range 3.7 V to 36 V Withstands Load Dump to 45 V Logic Level Enable Pin can be Tied to Battery Fixed Output Voltage of 5.0 V, 4.0 V or 3.3 V 2 MHz Free-running Switching Frequency 2 % Output Voltage Accuracy NCV Prefix for Automotive Requiring Site and Control Changes These Devices are Pb-Free and are RoHS Compliant Typical Applications * * * * Audio Infotainment Instrumentation Safety-Vision Systems NCV891130 VIN CIN RESET VIN DRV RSTB GND CDRV SW 1 With XX = 33 for 3.3 V Output = 40 for 4.0 V Output = 50 for 5.0 V Output A = Assembly Location L = Wafer Lot Y = Year W = Work Week G = Pb-Free Device PIN CONNECTIONS VIN 1 8 SW DRV 2 7 BST RSTB 3 6 VOUT GND 4 5 EN (Top View) DBST L1 CBST VOUT DFW BST COUT ORDERING INFORMATION See detailed ordering and shipping information on page 13 of this data sheet. VOUT EN EN Figure 1. Typical Application (c) Semiconductor Components Industries, LLC, 2016 August, 2019 - Rev. 1 1 Publication Order Number: NCV891130/D NCV891130 CDRV DBST VIN VIN CIN SW 3.3 V Reg VOUT Enable comp Soft-Start RESET EN EN + Switcher Supply ON MODE SELECTION LINEAR REGULATOR ON OVLD GND + - RESET VOLTAGES MONITORS 1.2 A detector + - + - + +S TSD COUT BST Low PWM LOGIC ON OFF Oscillator RSTB DFW CBST DRV VOUT L1 + Logic NCV891130 Figure 2. Simplified Block Diagram Table 1. PIN FUNCTION DESCRIPTION Pin No. Pin Name 1 VIN Input voltage from battery. Place an input filter capacitor in close proximity to this pin. 2 DRV Output voltage to provide a regulated voltage to the Power Switch gate driver. 3 RSTB Reset function. Open drain output, pulling down to ground when the output voltage is out of regulation. 4 GND Battery return, and output voltage ground reference. 5 EN This TTL compatible Enable input allows the direct connection of Battery as the enable signal. Grounding this input stops switching and reduces quiescent current draw to a minimum. 6 VOUT Output voltage feedback and LDO output. Feedback of output voltage used for regulation, as well as LDO output in LDO mode. 7 BST Bootstrap input provides drive voltage higher than VIN to the N-channel Power Switch for minimum switch Rdson and highest efficiency. 8 SW Switching node of the Regulator. Connect the output inductor and cathode of the freewheeling diode to this pin. EPAD Description Connect to Pin 4 (electrical ground) and to a low thermal resistance path to the ambient temperature environment. www.onsemi.com 2 NCV891130 Table 2. ABSOLUTE MAXIMUM RATINGS Rating Symbol Min/Max Voltage VIN Value Unit -0.3 to 45 V 45 V -0.7 to 40 V Max Voltage VIN to SW Min/Max Voltage SW Min Voltage SW - 20 ns -3.0 V Min/Max Voltage EN -0.3 to 40 V Min/Max Voltage VIN to EN -1.5 to 45 V Min/Max Voltage BST -0.3 to 43 V Min/Max Voltage BST to SW -0.3 to 3.6 V -0.3 to 6 V Min/Max Voltage VOUT -0.3 to 18 V Min/Max Voltage DRV -0.3 to 3.6 V 30 C/W -55 to +150 C TJ -40 to +150 C VESD 2.0 kV MSL Level 2 Min/Max Voltage on RSTB Thermal Resistance, SOIC8-EP Junction-to-Ambient (Note 1) RJA Storage Temperature range Operating Junction Temperature Range ESD withstand Voltage (Note 2) Human Body Model Moisture Sensitivity Peak Reflow Soldering Temperature (Note 3) 260 C Stresses exceeding those listed in the Maximum Ratings table may damage the device. If any of these limits are exceeded, device functionality should not be assumed, damage may occur and reliability may be affected. 1. Value based on 4 layers of 645 mm2 (or 1 in2) of 1 oz copper thickness on FR4 PCB substrate. 2. This device series incorporates ESD protection and is tested by the following methods: ESD Human Body Model tested per AEC-Q100-002 (EIA/JESD22-A114) Latchup Current Maximum Rating: v150 mA per JEDEC standard: JESD78 3. For information, please refer to our Soldering and Mounting Techniques Reference Manual, SOLDERRM/D Table 3. ELECTRICAL CHARACTERISTICS VIN = 4.5 to 28 V, VEN = 5 V, VBST = VSW + 3 V, CDRV = 0.1 mF, for typical values TJ = 25C, Min/Max values are valid for the temperature range -40C v TJ v 150C unless noted otherwise, and are guaranteed by test, design or statistical correlation (Notes 4, 5) Parameter Test Conditions Symbol Min Typ Max Unit Iq 30 39 mA IqSD 9 12 mA QUIESCENT CURRENT Quiescent Current, enabled VIN = 13.2 V, IOUT = 100 mA, 25C Quiescent Current, shutdown VIN = 13.2 V, VEN = 0 V, 25C UNDERVOLTAGE LOCKOUT - VIN (UVLO) UVLO Start Threshold VIN rising UVLO Stop Threshold VIN falling UVLO Hysteresis VUVLSTT 4.1 4.5 V VUVLSTP 3.1 3.7 V VUVLOHY 0.4 1.4 V tSS 0.8 1.4 2.0 ms 4.9 3.92 3.234 5.0 4.0 3.3 5.1 4.08 3.366 SOFT-START (SS) Soft-Start Completion Time OUTPUT VOLTAGE Output Voltage during regulation 100 mA < IOUT < 1.2 A 5.0 V option 4.0 V option 3.3 V option VOUTreg V 4. Refer to ABSOLUTE MAXIMUM RATINGS and APPLICATION INFORMATION for Safe Operating Area. 5. Performance guaranteed over the indicated operating temperature range by design and/or characterization tested at TJ = TA = 25C. Low duty cycle pulse techniques are used during testing to maintain the junction temperature as close to ambient as possible. www.onsemi.com 3 NCV891130 Table 3. ELECTRICAL CHARACTERISTICS VIN = 4.5 to 28 V, VEN = 5 V, VBST = VSW + 3 V, CDRV = 0.1 mF, for typical values TJ = 25C, Min/Max values are valid for the temperature range -40C v TJ v 150C unless noted otherwise, and are guaranteed by test, design or statistical correlation (Notes 4, 5) Parameter Test Conditions Symbol Min Typ Max Unit FSW FSW(HV) 1.8 0.9 2.0 1.0 2.2 1.1 MHz Frequency Foldback Threshold VIN rising VIN falling VFLDUP VFLDDN 18.4 18 Frequency Foldback Hysteresis VFLDHY 0.2 INtoL 3 OSCILLATOR Frequency 4.5 < VIN < 18 V 20 V <VIN < 28V VIN FREQUENCY FOLDBACK MONITOR 20 19.8 0.3 V 0.4 V 40 mA MODE TRANSITION Normal to Low-Iq mode Current Threshold 8 V < VIN < 28 V Mode Transition Duration Switcher to Linear Linear to Switcher Minimum time in Normal Mode before starting to monitor output current Linear to switcher transition at high Vin at low Vin VOUT = 3.3 V tSWtoLIN tLINtoSW 300 1 tSWblank 500 VLINtoSW(HV) VLINtoSW(LV) 19 3.6 ms 2 ms 28 4.5 V PEAK CURRENT LIMIT ILIM Current Limit Threshold 2.1 2.35 2.6 A 180 360 mW 10 mA 70 ns POWER SWITCH ON Resistance VBST = VSW + 3.0 V RDSON Leakage current VIN to SW VSW = 0, -40C v TJ v 85C ILKSW Minimum ON Time Measured at SW pin tONMIN Minimum OFF Time Measured at SW pin At FSW = 2 MHz (normal) At FSW = 500 kHz (max duty cycle) tOFFMIN 45 ns 30 30 50 70 1.45 0.65 2.0 1.0 2.8 1.3 A/ms SLOPE COMPENSATION 4.5 < VIN < 18 V 20 V <VIN < 28V Sramp Sramp(HV) Line Regulation IOUT = 5 mA, 6 V < VIN < 18 V VREG(line) 5 25 mV Load Regulation VIN = 13.2 V, 0.1 mA < IOUT < 50 mA VREG(load) 5 35 mV Power Supply Rejection VOUT(ripple) = 0.5 Vp-p, F = 100 Hz 80 mA mA Ramp Slope (With respect to switch current) LOW POWER LINEAR REGULATOR Current Limit Output clamp current PSRR 65 dB ILIN(lim) 50 VOUT = VOUTreg(typ) + 10% ICL(OUT) 0.5 1.0 1.5 VOUT = 0 V, 4.5 V < VIN < 18 V VOUT = 0 V, 20 V <VIN < 28 V FSWAF FSWAFHV FSWHIC 450 225 24 550 275 32 650 325 40 SHORT CIRCUIT DETECTOR Switching frequency in short-circuit condition Analog Foldback Analog foldback - high VIN Hiccup Mode kHz RESET IRSTBlk Leakage current into RSTB pin 1 uA 4. Refer to ABSOLUTE MAXIMUM RATINGS and APPLICATION INFORMATION for Safe Operating Area. 5. Performance guaranteed over the indicated operating temperature range by design and/or characterization tested at TJ = TA = 25C. Low duty cycle pulse techniques are used during testing to maintain the junction temperature as close to ambient as possible. www.onsemi.com 4 NCV891130 Table 3. ELECTRICAL CHARACTERISTICS VIN = 4.5 to 28 V, VEN = 5 V, VBST = VSW + 3 V, CDRV = 0.1 mF, for typical values TJ = 25C, Min/Max values are valid for the temperature range -40C v TJ v 150C unless noted otherwise, and are guaranteed by test, design or statistical correlation (Notes 4, 5) Parameter Test Conditions Symbol Min Typ Max 4.50 3.6 2.97 4.625 3.7 3.05 4.75 3.8 3.14 25 20 17 60 50 40 100 80 66 Unit RESET Output voltage threshold at which the RSTB VOUT decreasing 5.0 V option signal goes low 4.0 V option 3.3 V option VRESET Hysteresis on RSTB threshold VOUT increasing 5.0 V option 4.0 V option 3.3 V option VREShys Noise-filtering delay From VOUT<VRESET to RSTB pin going low tfilter 10 Restart Delay time From VOUT>VRESET+VREShys to high RSTB tdelay 14 Low RSTB voltage RRSTBpullup = VOUTreg/1 mA, VOUT > 1 V VRSTBlow 16 V mV 25 ms 18 ms 0.4 V GATE VOLTAGE SUPPLY (DRV pin) VDRV 3.1 3.3 3.5 V DRV UVLO START Threshold VDRVSTT 2.7 2.9 3.05 V DRV UVLO STOP Threshold VDRVSTP 2.5 2.8 3.0 V DRV UVLO Hysteresis VDRVHYS 50 200 mV IDRVLIM 21 50 mA Output Voltage DRV Current Limit VDRV = 0 V VIN OVERVOLTAGE SHUTDOWN MONITOR Overvoltage Stop Threshold VIN increasing VOVSTP 36.5 37.7 39.0 V Overvoltage Start Threshold VIN decreasing VOVSTT 36.0 37.3 38.8 V VOVHY 0.25 0.40 0.50 V Logic low threshold voltage VENlow 0.8 Logic high threshold voltage VENhigh EN pin input current IENbias Overvoltage Hysteresis ENABLE (EN) V 2 V 0.2 1 mA TSD 155 190 C TSDrestart 135 185 C THYS 5 20 C THERMAL SHUTDOWN Activation Temperature Reset temperature Hysteresis 4. Refer to ABSOLUTE MAXIMUM RATINGS and APPLICATION INFORMATION for Safe Operating Area. 5. Performance guaranteed over the indicated operating temperature range by design and/or characterization tested at TJ = TA = 25C. Low duty cycle pulse techniques are used during testing to maintain the junction temperature as close to ambient as possible. Product parametric performance is indicated in the Electrical Characteristics for the listed test conditions, unless otherwise noted. Product performance may not be indicated by the Electrical Characteristics if operated under different conditions. www.onsemi.com 5 NCV891130 TYPICAL CHARACTERISTICS 1000 70 INPUT CURRENT (mA) NO LOAD INPUT CURRENT (mA) 80 60 50 40 30 20 0 5 10 15 400 200 0 20 0 200 400 600 800 1000 INPUT VOLTAGE (V) OUTPUT CURRENT (mA) Figure 3. No-load Input Current at TJ = 255C vs. Input Voltage Figure 4. Input Current at TJ = 255C vs. Output Current 13 Iq IN SHUTDOWN MODE (mA) 100 Iq IN LOW-Iq LINEAR MODE (mA) 600 10 0 80 60 40 20 0 -50 0 50 100 12 11 10 9 8 7 -50 150 0 50 100 150 TEMPERATURE (C) TEMPERATURE (C) Figure 5. Low-Iq Mode Quiescent Current vs. Junction Temperature Figure 6. Shutdown Mode Quiescent Current vs. Junction Temperature 3.36 3.3 V OUTPUT VOLTAGE (V) 1.6 Iq IN SWITCHER MODE (mA) 800 1.5 1.4 1.3 1.2 -50 0 50 100 150 3.35 3.34 3.33 3.32 3.31 3.30 3.29 3.28 3.27 3.26 3.25 3.24 -50 Switcher Mode Low-Iq Mode 0 50 100 TEMPERATURE (C) TEMPERATURE (C) Figure 7. Switching Mode Quiescent Current vs. Junction Temperature Figure 8. 3.3 V Output Voltage vs. Junction Temperature www.onsemi.com 6 150 NCV891130 TYPICAL CHARACTERISTICS 5.05 5.04 4.03 5.03 5 V OUTPUT VOLTAGE (V) 4 V OUTPUT VOLTAGE (V) 4.05 4.04 4.02 4.01 Switcher Mode 4.00 3.99 Low-Iq Mode 3.98 3.97 3.96 3.95 3.94 -50 0 50 100 150 Switcher Mode 4.99 4.98 Low-Iq Mode 4.97 4.96 0 50 100 150 TEMPERATURE (C) TEMPERATURE (C) Figure 9. 4.0 V Output Voltage vs. Junction Temperature Figure 10. 5.0 V Output Voltage vs. Junction Temperature 57 MINIMUM ON TIME (ns) SWITCHING FREQUENCY (MHz) 5.00 4.95 4.94 -50 2.2 2.1 2.0 1.9 1.8 -50 0 50 100 56 55 54 53 52 -50 150 0 50 100 TEMPERATURE (C) TEMPERATURE (C) Figure 11. Switching Frequency vs. Junction Temperature Figure 12. Minimum On Time vs. Junction Temperature PEAK CURRENT LIMIT (A) 2.4 2.3 2.2 2.1 -50 150 4.7 2.5 PEAK CURRENT LIMIT (A) 5.02 5.01 0 50 100 4.6 4.5 4.4 4.3 4.2 -50 150 0 50 100 TEMPERATURE (C) TEMPERATURE (C) Figure 13. Peak Current Limit vs. Junction Temperature Figure 14. Peak Current Limit vs. Junction Temperature www.onsemi.com 7 150 NCV891130 TYPICAL CHARACTERISTICS 4.6 4.4 UVLO THRESHOLDS (V) OVERVOLTAGE THRESHOLDS (V) 40 Start-up Threshold 4.2 4.0 3.8 3.6 UVLO Threshold 3.4 3.2 3.0 -50 0 50 100 Restart Threshold 36 35 0 50 100 150 Figure 15. UVLO Thresholds vs. Junction Temperature Figure 16. Input Overvoltage Thresholds vs. Junction Temperature 3.5 3.4 DRV VOLTAGE (V) 1.50 1.45 IDRV = 0 mA 3.3 IDRV = 21 mA 3.2 3.1 0 50 100 3.0 -50 150 0 50 100 TEMPERATURE (C) TEMPERATURE (C) Figure 17. Soft-start Duration vs. Junction Temperature Figure 18. DRV Voltage vs. Junction Temperature FREQUENCY FOLDBACK VIN THRESHOLDS (V) SOFT-START TIME (ms) 37 TEMPERATURE (C) 3.0 DRV UVLO THRESHOLDS (V) Overvoltage Threshold TEMPERATURE (C) 1.55 DRV Start-up Threshold 2.9 2.8 DRV UVLO Threshold 2.7 2.6 -50 38 34 -50 150 1.60 1.40 -50 39 0 50 100 150 TEMPERATURE (C) 19.8 19.6 19.4 VIN Rising 19.2 19.0 18.8 VIN Falling 18.6 18.4 18.2 18.0 -50 Figure 19. DRV Voltage UVLO Tresholds vs. Junction Temperature 0 50 100 TEMPERATURE (C) Figure 20. Frequency Foldback Voltage Tresholds vs. Junction Temperature www.onsemi.com 8 150 150 NCV891130 1.10 3.3 V RESET VOUT THRESHOLDS (V) SWITCHING FREQUENCY AT HIGH VIN (MHz) TYPICAL CHARACTERISTICS 1.05 1.00 0.95 0.90 -50 0 50 100 150 RSTB Toggles High (VOUT Rising) 3.1 RSTB Toggles Low (VOUT Falling) 3.0 2.9 2.8 -50 0 50 100 150 TEMPERATURE (C) Figure 21. Foldback Frequency vs. Junction Temperature Figure 22. 3.3 V Version RESET Thresholds vs. Junction Temperature 5.0 5 V RESET VOUT THRESHOLDS (V) 3.9 3.8 RSTB Toggles High (VOUT Rising) 3.7 RSTB Toggles Low (VOUT Falling) 3.6 3.5 3.4 -50 0 50 100 150 4.9 4.8 RSTB Toggles High (VOUT Rising) 4.7 4.6 RSTB Toggles Low (VOUT Falling) 4.5 4.4 4.3 -50 0 50 100 150 TEMPERATURE (C) TEMPERATURE (C) Figure 23. 4.0 V Version RESET Thresholds vs. Junction Temperature Figure 24. 5.0 V Version RESET Thresholds vs. Junction Temperature 17.0 71 16.8 69 LINEAR TO SWITCHER MODE CURRENT THRESHOLD (mA) 4 V RESET VOUT THRESHOLDS (V) 3.2 TEMPERATURE (C) 4.0 RESET DELAY (ms) 3.3 16.6 16.4 16.2 16.0 15.8 15.6 15.4 -50 0 50 100 67 65 63 61 59 57 55 -50 150 0 50 100 150 TEMPERATURE (C) TEMPERATURE (C) Figure 25. RESET Delay vs. Junction Temperature Figure 26. Low-Iq to Switcher Mode Transition vs. Junction Temperature www.onsemi.com 9 NCV891130 30 CURRENT RANGE FOR LOW-Iq TRANSITION - 5 V VERSION (mA) CURRENT RANGE FOR LOW-Iq TRANSITION - 3.3 V VERSION (mA) TYPICAL CHARACTERISTICS 20 10 0 30 20 10 0 5 10 15 18 5 10 15 18 INPUT VOLTAGE (V) INPUT VOLTAGE (V) Figure 27. Switcher to Low-Iq Mode Transition (3.3 V Version, 2.2 mH) vs. Input Voltage Figure 28. Switcher to Low-Iq Mode Transition (5.0 V Version, 2.2 mH) vs. Input Voltage www.onsemi.com 10 NCV891130 APPLICATION INFORMATION Hybrid Low-Power Mode VFLDUP, it will not transition to low-power mode even if the output current becomes lower than INtoL. At low input voltage, the NCV891130 stays in low-power mode down to VLINtoSW(LV) if it entered this mode while in normal battery range. However it may not enter low-power mode below 8 V depending on the charge of the bootstrap capacitor (see Bootstrap section for details). A high-frequency switch-mode regulator is not very efficient in light load conditions, making it difficult to achieve low-Iq requirements for sleep-mode operation. To remedy this, the NCV891130 includes a low-Iq linear regulator that turns on at light load, while the PWM regulator turns off, ensuring a high-efficiency low-power operation. Another advantage of the low-power mode is the tight regulation free of voltage ripple usually associated with low-Iq switchers in light load conditions. In either mode, the NCV891130 meets the 2% output voltage regulation specification. At initial start-up the NCV891130 will soft-start into PWM converter mode regardless of output current. During a 300 s period, the NCV891130 will assess the level of output current. The NCV891130 will not make the assessment if RSTB is low. If the output current is above the INtoL threshold, the NCV891130 will stay in PWM mode. Otherwise, the NCV891130 will transition to low power mode. It will stay in this low-power mode until the output current exceeds the ILIN(lim) limit: it then transitions back to PWM converter mode. This low-power mode to PWM mode transition happens within 2 s. The transient response is not affected by the mode change. Once the NCV891130 has transitioned to switcher mode, a 500 s blanking period will occur. After the blanking period, the NCV891130 will reassess the output current level. If the output current level is below the INtoL threshold, the NCV891130 will enter low-Iq mode. If the NCV891130 is in low-power mode and in normal battery range, it will transition to switcher mode when VIN increases above VLINtoSW(HV), regardless of the output current. Similarly, if the NCV891130 is in PWM mode and VIN is higher than Input Voltage An Undervoltage Lockout (UVLO) circuit monitors the input, and can inhibit switching and reset the Soft-start circuit if there is insufficient voltage for proper regulation. Depending on the output conditions (voltage option and loading), the NCV891130 may lose regulation and run in drop-out mode before reaching the UVLO threshold: refer to the Minimum Vin calculation tool for details. When the input voltage drops low enough that the part cannot regulate because it reaches its maximum duty cycle, the switching frequency is divided down by up to 4 (down to 500 kHz). This helps lowering the minimum voltage at which the regulator loses regulation. An overvoltage monitoring circuit automatically terminates switching if the input voltage exceeds VOVSTP (see Figure 29), but the NCV891130 can withstand input voltages up to 45 V. To avoid skipping switching pulses and entering an uncontrolled mode of operation, the switching frequency is reduced by a factor of 2 when the input voltage exceeds the VIN Frequency Foldback threshold (see Figure 29). Frequency reduction is automatically terminated when the input voltage drops back below the VIN Frequency Foldback threshold. This also helps to limit the power lost in switching and generating the drive voltage for the Power Switch. FSW (MHz) 2 1 III III III III III III III III III Frequency folds back if drop-out mode 3.5 18 20 36 39 45 V IN (V) Figure 29. NCV891130 Switching Frequency Profile vs. Input Voltage www.onsemi.com 11 NCV891130 Soft-Start compensation signal requires the inductor to be greater than a minimum value, depending on output voltage, in order to avoid sub-harmonic oscillations. The recommended inductor values are 2.2 or 3.3 mH, although higher values are possible. Upon being enabled or released from a fault condition, and after the DRV voltage is established, a soft-start circuit ramps the switching regulator error amplifier reference voltage to the final value. During soft-start, the average switching frequency is lower until the output voltage approaches regulation. Current Limiting Due to the ripple on the inductor current, the average output current of a buck converter is lower than the peak current setpoint of the regulator. Figure 30 shows - for a 2.2 mH inductor - how the variation of inductor peak current with input voltage affects the maximum DC current the NCV891130 can deliver to a load. Slope Compensation A fixed slope compensation signal is generated internally and added to the sensed current to avoid increased output voltage ripple due to bifurcation of inductor ripple current at duty cycles above 50%. The fixed amplitude of the slope Figure 30. NCV891130 Load Current Capability with a 2.2 mH Inductor Short Circuit Protection The RSTB pin is also pulled low immediately in case of VIN overvoltage, Thermal shutdown, VIN UVLO or DRV UVLO. During severe output overloads or short circuits, the NCV891130 automatically reduces its switching frequency. This creates duty cycles small enough to limit the peak current in the power components, while maintaining the ability to automatically reestablish the output voltage if the overload is removed. In more severe short-circuit conditions where the inductor current is still too high after the switching frequency has fully folded back, the regulator enters a hiccup mode that further reduces the power dissipation and protects the system. Feedback Loop All components of the feedback loop (output voltage sensing, error amplifier and compensation) are integrated inside the NCV891130, and are optimized to ensure regulation and sufficient phase and gain margin for the recommended conditions of operation. Recommended conditions and components: * Input: car battery * Output: 3.3 V, 4 V or 5 V, with output current up to 1.2 A * Output capacitor: one to three parallel ceramic 10 mF capacitors * Inductor: 2.2 mH to 3.3 mH With these operating conditions and components, the open loop transfer function has a phase margin greater than 50. RESET Function The RSTB pin is pulled low when the output voltage falls below 7.5% of the nominal regulation level, and floats when the output is properly regulated. A pull-up resistor tied to the output is needed to generate a logic high signal on this open drain pin. The pin can be left unconnected when not used. When the output voltage drops out of regulation, the pin goes low after a short noise-filtering delay (tfilter). It stays low for a 16 ms delay time after the output goes back to regulation, simplifying the connection to a micro-controller. www.onsemi.com 12 NCV891130 Bootstrap mode for input voltages below 8 V, and the 4 V version for input voltages below 6.5 V (see typical characteristics curves for details). At the DRV pin an internal regulator provides a ground- referenced voltage to an external capacitor (CDRV), to allow fast recharge of the external bootstrap capacitor (CBST) used to supply power to the power switch gate driver. If the voltage at the DRV pin goes below the DRV UVLO Threshold VDRVSTP, switching is inhibited and the Soft-start circuit is reset, until the DRV pin voltage goes back up above VDRVSTT. The NCV891130 permanently monitors the bootstrap capacitor, and always ensures it stays charged no matter what the operating conditions are. As a result, the additional charging current for the bootstrap capacitor may prevent the regulator from entering Low-Iq mode at low input voltage. Practically, the 5 V output version does not enter Low-Iq Enable The NCV891130 is designed to accept either a logic level signal or battery voltage as an Enable signal. However if voltages above 40 V are expected, EN should be tied to VIN through a 10 kW resistor in order to limit the current flowing into the overvoltage protection of the pin. EN low induces a shutdown mode which shuts off the regulator and minimizes its supply current to 9 mA typical by disabling all functions. Upon enabling, voltage is established at the DRV pin, followed by a soft-start of the switching regulator output. ORDERING INFORMATION Device Output NCV891130PD50R2G 5.0 V NCV891130PD40R2G 4.0 V NCV891130PD33R2G 3.3 V Package Shipping SOIC-8 EP 2500 / Tape & Reel 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. www.onsemi.com 13 NCV891130 PACKAGE DIMENSIONS SOIC-8 EP CASE 751AC ISSUE B 2X 0.10 C A-B D 8 E1 2X 0.10 C D EXPOSED PAD 5 EEE EEE PIN ONE LOCATION DETAIL A D A 1 5 F 8 G E h 2X 4 4 0.20 C e A 0.10 C A2 C b1 GAUGE PLANE SEATING PLANE SIDE VIEW A1 CC EE EE CC EE CC EE c H A 0.10 C A END VIEW TOP VIEW 8X DIM A A1 A2 b b1 c c1 D E E1 e L L1 F G h q 1 BOTTOM VIEW 8X b 0.25 C A-B D B NOTES: 1. DIMENSIONS AND TOLERANCING PER ASME Y14.5M, 1994. 2. DIMENSIONS IN MILLIMETERS (ANGLES IN DEGREES). 3. DIMENSION b DOES NOT INCLUDE DAMBAR PROTRUSION. ALLOWABLE DAMBAR PROTRUSION SHALL BE 0.08 MM TOTAL IN EXCESS OF THE "b" DIMENSION AT MAXIMUM MATERIAL CONDITION. 4. DATUMS A AND B TO BE DETERMINED AT DATUM PLANE H. L 0.25 (L1) DETAIL A q c1 (b) MILLIMETERS MIN MAX 1.35 1.75 0.00 0.10 1.35 1.65 0.31 0.51 0.28 0.48 0.17 0.25 0.17 0.23 4.90 BSC 6.00 BSC 3.90 BSC 1.27 BSC 0.40 1.27 1.04 REF 2.24 3.20 1.55 2.51 0.25 0.50 0_ 8_ SECTION A-A SOLDERING FOOTPRINT 2.72 0.107 1.52 0.060 7.0 0.275 Exposed Pad 4.0 0.155 2.03 0.08 0.6 0.024 1.270 0.050 SCALE 6:1 mm inches ON Semiconductor and are trademarks of Semiconductor Components Industries, LLC dba ON Semiconductor or its subsidiaries in the United States and/or other countries. ON Semiconductor owns the rights to a number of patents, trademarks, copyrights, trade secrets, and other intellectual property. A listing of ON Semiconductor's product/patent coverage may be accessed at www.onsemi.com/site/pdf/Patent-Marking.pdf. ON Semiconductor reserves the right to make changes without further notice to any products herein. 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