NCV8614MNR2G

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The ASO circuit selects between three different input voltage sources to reduce power dissipation and to maintain the output voltage level across varying battery line voltages associated with an automotive environment. The NCV8614 is specifically designed to address automotive radio systems and instrument cluster power supply requirements. The NCV8614 can be used in combination with the 4−Output Controller/Regulator IC, NCV885x, to form a complete automotive radio or instrument cluster power solution. The NCV8614 is intended to supply power to various “always on” loads such as the CAN transceivers and microcontrollers (core, memory and IO). The NCV8614 has three output voltages, a reset / delay circuit, and a host of control features suitable for the automotive radio and instrument cluster systems. http://onsemi.com MARKING DIAGRAM 20 NCV8614 AWLYYWWG G 1 DFN20 MN SUFFIX CASE 505AB A WL YY WW G = Assembly Location = Wafer Lot = Year = Work Week = Pb−Free Package (Note: Microdot may be in either location) Features • • • • • • • • • • • • • Operating Range 7.0 V to 18.0 V (45 V Load Dump Tolerant) Output Voltage Tolerance, All Rails, $2% < 50 mA Quiescent Current Independent Input for LDO3 Linear Regulator High Voltage Ignition Buffer Automatic Switchover Input Voltage Selector Independent Input Voltage Monitor with a High Input Voltage and Low Input Voltage (Brown−out) Indicators Thermal Warning Indicator with Thermal Shutdown Single Reset with Externally Adjustable Delay for the 3.3 V Rail Push−Pull Outputs for Logic Level Control Signals All Ceramic Solution for Reduced Leakage Current at the Output NCV Prefix for Automotive and Other Applications Requiring Site and Control Changes This is a Pb−Free Device Applications July, 2010 − Rev. 1 ASO_RAIL VIN_S3 VIN−B VOUT3 VIN−H VOUT2 VIN−A VOUT1 VBATT_MON VOUT3FB HV_DET RST BO_DET DLY NC GND GND IGNOUT IGNIN HOT_FLG ORDERING INFORMATION Device NCV8614MNR2G • Automotive Radio • Instrument Cluster © Semiconductor Components Industries, LLC, 2010 PIN CONNECTIONS Package Shipping† DFN20 2500 / Tape & Reel (Pb−Free) †For information on tape and reel specifications, including part orientation and tape sizes, please refer to our Tape and Reel Packaging Specification Brochure, BRD8011/D. 1 Publication Order Number: NCV8614/D NCV8614 NC 8 D2 8V ASO_RAIL 1 1 uF 20 19 VINT VIN-B 2 VIN_S3 VOUT3 Adj Voltage ILIMIT VBG VBATT D1 VTH1 VTH2 1 uF VRFB3 VREF VOUT3 FB VREF VPP VIN-H VOUT2 3 1000 uF Clamp VIN-A 5 ILIMIT VREF Switchover Control Circuit 4 VBATT_MON 3.3 V 18 VIN_MON VPP HV_DET RST2 OVS VRFB2 VRTH VOUT1 5V 17 VTH1 6 VPP ILIMIT VIN_MON Fault Logic VTH2 BO_DET 7 VREF VPP VRFB1 VRFB3 16 VOUT3 FB TSD VPP HOT_FLG 10 TSD 15 IGNIN 11 D3 IGNOUT RST HV_DET 14 12 10 kΩ 9 13 GND + 5V GND Components Value Manufacturer D1 MBRS2H100T3G ON Semiconductor D2 MBR0502T1 ON Semiconductor D3 MMDL914T1 ON Semiconductor Figure 1. Typical Circuit with the Internal Schematic http://onsemi.com 2 DLY NCV8614 PIN FUNCTION DESCRIPTIONS Pin No. Symbol 1 ASO_RAIL Description Output/Input of the automatic switchover (ASO) circuitry. Place a 1 uF ceramic capacitor on this pin to provide local bypassing to the LDO linear regulator pass devices. 2 VIN−B Primary power supply input. Connect battery to this pin through a blocking diode. 3 VIN−H Holdup power supply rail. Connect a storage capacitor to this pin to provide a temporary backup rail during loss of battery supply. A bleed resistor (typically 1 kW) is needed from VIN− B to this pin in order to trickle charge this capacitor. 4 VIN−A Voltage monitor which determines whether the 8 V supply is able to power the outputs. If the 8 V supply is present, the FET’s connected to VIN−B and VIN−H will be turned off, and the 8 V supply will be providing power to the outputs. If the 8 V supply is not present, the FET’s on VIN−B and VIN−H will be left on, and the greater of those voltages will be driving the outputs. 5 VBATT_MON VBATT monitor pin. To operate overvoltage shutdown, HV_DET and BO_DET, connect this pin to ASO_RAIL or battery. To eliminate overvoltage shutdown, HV_DET and BO_DET, tie this pin to ground. 6 HV_DET High−voltage detect output. When VBATT_MON surpasses 17 V, this pin will be driven to ground. During normal operation, this pin is held at VPP. 7 BO_DET Brown out indicator output. When VBATT_MON and VIN−A falls below 7.5 V, this pin will be driven to ground. During normal operation, this pin is held at VPP. 8 NC 9 GND 10 HOT_FLG No Connect Ground. Reference point for internal signals. Internally connected to pin 13. Ground is not connected to the exposed pad of the DFN20 package. Thermal warning indicator. This pin provides an early warning signal of an impending thermal shutdown. 11 IGNIN Ignition buffer input 12 IGOUT Ignition buffer logic output 13 GND Ground. Reference point for internal signals. Internally connected to pin 9. Ground is not connected to the exposed pad of the DFN20 package. 14 DLY Delay pin. Connect a capacitor to this pin to set the delay time. 15 RST Reset pin. Monitors VOUT2. 16 VOUT3 FB 17 VOUT1 5 V output. Voltage is internally set. 18 VOUT2 3.3 V output. Voltage is internally set. 19 VOUT3 Adjustable voltage output. This voltage is set through an external resistor divider. 20 VIN_S3 Supply rail for the standby linear regulator VOUT3. Tie this pin to ASO_RAIL or a separate supply rail. EP − Exposed Pad of DFN device. This pad serves as the main path for thermal spreading. The Exposed Pad is not connected to IC ground. Voltage Adjust Input; use an external voltage divider to set the output voltage http://onsemi.com 3 NCV8614 MAXIMUM RATINGS (Voltages are with respects to GND unless noted otherwise) Symbol Max Min Unit Maximum DC Voltage Rating VIN−B, VIN−A, ASO_RAIL, VBATT_MON, VIN_S3, EN, IGNIN 40 −0.3 V Peak Transient VIN−B, VIN−A, ASO_RAIL, VBATT_MON, VIN_S3, EN, IGNIN 45 −0.3 V Maximum DC Voltage VIN−H 24 −0.3 V Maximum DC Voltage IGNOUT, VPP, HV_DET, BO_DET, HOT_FLG, RST, DLY, VOUT1, VOUT2 7 −0.3 V Maximum DC Voltage VOUT3 10 −0.3 V 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. THERMAL INFORMATION Rating Symbol Min Unit RqJA 40 °C/W Operating Junction Temperature Range TJ −40 to 150 °C Maximum Storage Temperature Range TSTG −55 to +150 °C Moisture Sensitivity Level MSL 1 Thermal Characteristic (Note 1) 1. Values based on measurement of NCV8614 assembled on 2−layer 1−oz Cu thickness PCB with Copper Area of more than 645 mm2 with several thermal vias for improved thermal performance. Refer to CIRCUIT DESCRIPTION section for safe operating area. ATTRIBUTES Symbol Min Unit ESD Capability, Human Body Model (Note 2) Rating ESDHB 2 kV ESD Capability, Machine Model (Note 2) ESDMM 200 V ESD Capability, Charged Device Model (Note 2) ESDCDM 1 kV IGNIN ESD Capability, Human Body Model (Note 2) ESDHB_IGNIN 3 kV IGNIN ESD Capability, Machine Model (Note 2) ESDMM_IGNIN 200 V ESD_IGNIN 10 kV IGNIN ESD Capability (Note 3) 2. This device series incorporates ESD protection and is tested by the following methods: ESD Human Body Model (HBM) tested per AEC−Q100−002 (EIA/JESD22−A114) ESD Machine Model (MM) tested per AEC−Q100−003 (EIA/JESD22−A115) ESD Charged Device Model (CDM) tested per EIA/JES D22/C101, Field Induced Charge Model 3. Device tested with external 10 kW series resistance and 1 nF storage capacitor. http://onsemi.com 4 NCV8614 SUPPLY VOLTAGES AND SYSTEM SPECIFICATION ELECTRICAL CHARACTERISTICS (7 V < ASO_RAIL < 18 V, VIN−H = VIN−B w ASO_RAIL, VPP = 3.3 V, VIN_S3 tied to ASO_RAIL, VBATT_MON = 0 V, IGNIN = 0 V, ISYS = 3 mA (Note 6)) Minimum/Maximum values are valid for the temperature range −40°C v TJ v 150°C unless noted otherwise. Min/Max values are guaranteed by test, design or statistical correlation. Parameter Symbol Conditions Min Typ Max Unit 34 50 mA SUPPLY RAILS Quiescent Current (Notes 4 and 6) iq TJ = 25°C, ISYS = 70 mA, VIN−A = VIN_S3 = 0 V, VIN−B = 13.2 V Minimum Operating Voltage (VIN−H, VIN−B) 4.5 V THERMAL MONITORING Thermal Warning (HOT_FLG) Temperature TWARN 140 TWARN Hysteresis 10 Thermal Shutdown 160 Thermal Shutdown Hysteresis 10 Delta Junction Temperature (TSD − TWARN) 10 HOT_FLG Voltage Low TJ < TWARN, 10 kW Pullup to 3.3 V HOT_FLG Voltage High TJ > TWARN, 10 kW Pulldown to GND 150 170 20 160 °C 20 °C 180 °C 20 °C 30 °C 0.4 V VOUT2 − 0.5 V AUTO SWITCHOVER VIN−A Quiescent Current 24 mA VIN−A to VIN−B Risetime TJ = 25°C, CASO_RAIL = 1 mF, ISYS = 400 mA 200 msec VIN−B to VIN−A Falltime TJ = 25 °C, CASO_RAIL = 1 mF, ISYS = 400 mA 100 msec VIN−A Operating Threshold VIN−A Rising 7.2 7.5 7.75 V VIN−A Operating Hysteresis VIN−A Falling 100 175 250 mV Max VIN−B to VASO_RAIL Voltage Drop ISYS = 400 mA, VIN−B = 7 V 1.5 V Max VIN−H to VASO_RAIL Voltage Drop ISYS = 400 mA, VIN−H = 7.5 V 2.0 V 96 % 2.5 % RESET (RST Pin) RESET Threshold % of VOUT2 Hysteresis % of VOUT2 90 Reset Voltage High 10 kW Pulldown to GND Reset Voltage Low 10 kW Pullup to 3.3 V 93 VOUT2 − 0.5 V 0.4 V 7 mA DELAY (DLY Pin) Charge Current 2.4 Delay Trip Point Voltage 5 2.0 V IGNITION BUFFER Schmitt Trigger Rising Threshold 2.75 3.25 3.75 V Schmitt Trigger Falling Threshold 0.8 1.0 1.2 V 0.4 V 0.1 0.5 mA 3 5 mA IGNOUT Voltage Low IGNIN = 5 V, 10 kW Pullup to 5 V IGNOUT Leakage Current TJ = 25°C, IGNOUT = 5 V VBATT MONITOR VBATT_MON Quiescent Current TJ = 25°C, VBATT_MON = 13.2 V http://onsemi.com 5 NCV8614 SUPPLY VOLTAGES AND SYSTEM SPECIFICATION ELECTRICAL CHARACTERISTICS (7 V < ASO_RAIL < 18 V, VIN−H = VIN−B w ASO_RAIL, VPP = 3.3 V, VIN_S3 tied to ASO_RAIL, VBATT_MON = 0 V, IGNIN = 0 V, ISYS = 3 mA (Note 6)) Minimum/Maximum values are valid for the temperature range −40°C v TJ v 150°C unless noted otherwise. Min/Max values are guaranteed by test, design or statistical correlation. Parameter Symbol Conditions Min Typ Max Unit 1.0 2.0 2.5 V VBATT MONITOR VBATT_MON Minimum Operating Voltage Threshold where BO_DET and HV_DET signals become valid VBATT_MON Hysteresis 0.25 HV_DET Voltage High 10 kW Pulldown to GND VBATT_MON Tied to ASO_RAIL HV_DET Voltage Low 10 kW Pullup to 3.3 V VBATT_MON Tied to ASO_RAIL HV_DET Threshold VBATT_MON Rising 16.2 HV_DET Hysteresis VBATT_MON Falling 0.2 BO_DET Voltage High 10 kW Pulldown to GND VBATT_MON Tied to ASO_RAIL BO_DET Voltage Low 10 kW Pullup to 3.3 V VBATT_MON Tied to ASO_RAIL BO_DET Threshold VBATT_MON Falling 7 BO_DET Hysteresis VBATT_MON Rising 0.2 4. 5. 6. iq is equal to IVIN−B + IVIN−H − ISYS ISHDN is equal to IVIN−B + IVIN−H ISYS is equal to IOUT1 + IOUT2 + IOUT3 http://onsemi.com 6 V VOUT2 − 0.5 V 0.35 0.4 V 17.8 V 0.5 V VOUT2 − 0.5 V 0.4 V 7.5 8 V 0.35 0.5 V NCV8614 ELECTRICAL CHARACTERISTICS (7 V < ASO_RAIL < 18 V, VIN−H = VIN−B w ASO_RAIL, VPP = 3.3 V, VIN_S3 tied to ASO_RAIL, VBATT_MON = 0 V, IGNIN = 0 V, ISYS = 3 mA (Note 6)) Min/Max values are valid for the temperature range −40°C vTJ v 150 °C unless noted otherwise. Min/Max values are guaranteed by test, design or statistical correlation. Parameter Symbol Conditions Min Typ Max Unit 4.9 5 5.1 V 500 mV LOW DROP−OUT LINEAR REGULATOR 1 (LDO1) SPECIFICATION Output Voltage Dropout (ASO_RAIL − VOUT1) IOUT1 = 0 mA to 100 mA, 7 V < ASO_RAIL < 18 V VDR1 IOUT1 = 100 mA (Note 7) Load Regulation IOUT1 = 0 mA to 100 mA, VIN_B = 13.2 V 0 75 mV/mA Line Regulation IOUT1 = 1 mA, 7 V < ASO_RAIL < 18 V 0 2 mV/V Output Current Limit Output Load Capacitance Range Output Load Capacitance ESR Range (Notes 8 and 9) 200 Co ESRCo mA Output Capacitance for Stability 1.0 100 mF Cap ESR for Stability 0.01 13 W DVOUT1 (ASO Low to High Transient) TJ = 25 °C , IOUT1 = 100 mA, ISYS = 400 mA, CASO_RAIL = 1 mF, ESRCo = 0.01 W, Co = 10 mF, VIN−A falling 70 100 $mV DVOUT1 (ASO high to Low Transient) TJ = 25 °C , IOUT1 = 100 mA, ISYS = 400 mA, CASO_RAIL = 1 mF, ESRCo = 0.01 W, Co = 10 mF, VIN−A rising 70 100 $mV VIN_B = 13.2 V, 0.5 VPP, 100 Hz 60 Power Supply Ripple Rejection (Note 8) PSRR Startup Overshoot IOUT1 = 0 mA to 100 mA dB 3 % 3.366 V 1.5 V LOW DROP−OUT LINEAR REGULATOR 2 (LDO2) SPECIFICATION Output Voltage Dropout (ASO_RAIL − VOUT2) IOUT2 = 0 mA to 300 mA, 7 V < ASO_RAIL < 18 V VDR2 3.234 3.3 IOUT2 = 300 mA (Note 7) Load Regulation IOUT2 = 0 mA to 300 mA, VIN_B = 13.2 V 0 66 mV/mA Line Regulation IOUT2 = 1 mA, 7 V < ASO_RAIL < 18 V 0 1.2 mV/V Output Current Limit Output Load Capacitance Range Output Load Capacitance ESR Range (Notes 8 and 9) 400 mA Co Output Capacitance for Stability 1.0 100 mF ESRCo Maximum Cap ESR for stability 0.01 10 W DVOUT2 (ASO Low to High Transient) TJ = 25 °C , IOUT2 = 300 mA, ISYS = 400 mA, CASO_RAIL = 1 mF, ESRCo = 0.01 W, Co = 22 mF, VIN−A falling 30 66 $mV DVOUT2 (ASO high to Low Transient) TJ = 25 °C , IOUT2 = 300 mA, ISYS = 400 mA, CASO_RAIL = 1 mF, ESRCo = 0.01 W, Co = 22 mF, VIN−A rising 30 66 $mV VIN_B = 13.2 V, 0.5 VPP, 100 Hz 60 Power Supply Ripple Rejection (Note 8) PSRR Startup Overshoot IOUT2 = 0 mA to 300 mA dB 3 % +2% V 2.5 V LOW DROP−OUT LINEAR REGULATOR 3 (LDO3) SPECIFICATION Output Voltage VOUT3 IOUT3 = 0 mA to 400 mA, VOUT3 + VDR3 v VIN_S3 v 18 V Dropout (VIN_S3 − VOUT3) VDR3 IOUT3 = 400 mA , VOUT3 = 5 V (Notes 7 and 10) Output Current Limit −2% − 500 mA Load Regulation IOUT3 = 0 mA to 400 mA, VIN_B = 13.2 V 0 75 mV/mA Line Regulation IOUT3 = 1 mA, VREF v VIN_S3 v 18 V 0 654 mV /V http://onsemi.com 7 NCV8614 ELECTRICAL CHARACTERISTICS (7 V < ASO_RAIL < 18 V, VIN−H = VIN−B w ASO_RAIL, VPP = 3.3 V, VIN_S3 tied to ASO_RAIL, VBATT_MON = 0 V, IGNIN = 0 V, ISYS = 3 mA (Note 6)) Min/Max values are valid for the temperature range −40°C vTJ v 150 °C unless noted otherwise. Min/Max values are guaranteed by test, design or statistical correlation. Parameter Symbol Conditions Min Typ Max Unit LOW DROP−OUT LINEAR REGULATOR 3 (LDO3) SPECIFICATION Output Load Capacitance Range Output Load Capacitance ESR Range (Notes 8 and 9) Co ESRCo Output Capacitance for Stability 1.0 100 mF Maximum Capacitance ESR for stability 0.01 12 W DVOUT3 (ASO Low to High Transient) TJ = 25 °C , IOUT3 = 400 mA, ISYS = 400 mA, CASO_RAIL = 1 mF, ESRCo = 0.01 W, Co = 47 mF, VIN−A falling 15 36 $mV DVOUT3 (ASO high to Low Transient) TJ = 25 °C , IOUT3 = 400 mA, ISYS = 400 mA, CASO_RAIL = 1 mF, ESRCo = 0.01 W, Co = 47 mF, VIN−A rising 15 36 $mV VIN_B = 13.2 V, 0.5 VPP, 100 Hz 60 Power Supply Ripple Rejection (Note 8) Startup Overshoot PSRR IOUT3 = 0 mA to 400 mA dB 3 % 7. Dropout voltage is measured when the output voltage has dropped 100 mV relative to the nominal value obtained with ASO_RAIL = VIN_S3 = 13.2 V. 8. Not tested in production. Limits are guaranteed by design. 9. Refer to CIRCUIT DESCRIPTION Section for Stability Consideration 10. For other voltage versions refer to Typical Performance Characteristics Section. ORDERING INFORMATION Device NCV8614MNR2G Conditions No Enable, LDO2 Reset monitor, Adjustable LDO3 Package Shipping 20 Lead DFN, 5x6 (Pb−Free) 2500 / Tape & Reel http://onsemi.com 8 NC Ignition Filter HOT_FLG Ignition 8 10 11 Power Amplifier BO_DET 12 HOT_FLG IGNIN IGNOUT LDO3 VOUT3 Output Filter 7 18 3.3Vs 17 5Vs 19 VOUT2 VOUT1 VOUT3 FB 16 VPP RST DLY HOT_FLG_S HV_DET BO_DET DLY 14 DVD ROM Drive 6 7 8 9 OCSET HOT_FLG BST2 BST1 VIN_SW 34 SN2 SN1 GL1 5V Misc. 5 V Logic SW_FB2 SW_FB1 LDO_EN 3.3V Misc. 3.3 V Logic HOT_FLG VBATT 23 24 27 28 5V 37 COMP1 Headunit CAN USB Connector SYNC 3 SYS_EN HS_EN LDO_EN HOT_FLG 25 GH1 COMP2 4 38 SMPS2 Power Stage 5V output, 2A ILIMIT 8V SMPS1 Power Stage 8V output, 4A ILIMIT 5 HS_EN SMPS2 VOUT2 VBATT 26 LDO_EN MAIN SMPS1 VOUT1 HS_EN SYS_EN Main uC 3.3Vs NCV8855 33 Body CAN RST 15 NCV8614 SYS_EN SDARS VPP VBATT_MON HV_DET Adj V Output Filter 6 8V Output Filter HV_DET BO_DET VOUT3 20 VOUT3 Feedback Network 5 VIN-A LDO2 VOUT2 3 VIN-H VIN_S3 VOUT3 FB LDO1 VOUT1 4 VIN-B RESET / DELAY 2 ASO_RAIL AUTO SWITCHOVER 1 MONITORING LOGIC VBATT 8V INGITOIN BUFFER Oring Diodes & Filter NCV8614 VBATT 2 39 22 ISNS1LR_G1 ISNS2- 30 31 LR_FB1 VIN 29 32 HIGH-SIDE SWITCH HS_S 21 LDO2 Power Stage 3.3V output, 1A ILIMIT 40 ISNS2+ ISNS1+ LDO2 VOUT4 8.5V 1 LDO1 VOUT3 AM/FM Tuner LDO1 Power Stage 8.5V output, 0.4A ILIMIT VBATT 3.3V Main DSP Active Antenna Fan Figure 2. Automotive Radio System Block Diagram Example NCV8614 with NCV8855 http://onsemi.com 9 NCV8614 CIRCUIT DESCRIPTION Auto Switchover Circuitry The auto switchover circuit is designed to insure continuous operation of the device, automatically switching the input voltage from the ASO_RAIL input, to the VIN−B input, to the VIN−H input depending on conditions. The primary input voltage pin is ASO_RAIL, which is driven from the 8 V supply. When this voltage is present it will drive the output voltages. Regardless of whether the 8 V supply is available, the reference and core functions of the device will be driven by the higher of VIN−B and VIN−H. The switchover control circuitry will be powered solely by the 8 V supply, via VIN−A. When the 8 V supply is not present, the gates of the 2 P−FET switches will be pulled to ground, turning the switches on. In this condition, the VIN−B and VIN−H voltages will be diode or’ed, with the higher voltage powering the chip. The VIN−H voltage will be one diode lower than the VIN−B voltage, thereby forcing the VIN−B voltage to be dominant supply. In the event that both the 8 V supply and the VIN−B supply are not present, the VIN−H supply will be powering the device. The VIN−H supply is then fed from a recommended 1000 mF cap. The duration of VIN−H supply is dependent on output current. It is intended as protection against temporary loss of battery conditions. In the event of a double battery, or prolonged high voltage condition on the battery line, a bleed transistor has been included on the VIN−H line. With the large hold−up cap on VIN−H, the voltage on that pin has the potential to remain in an elevated position for an extended period of time. The main result of this condition would be an Overvoltage Shutdown of the device. In order to avoid this condition, a transistor that is connected to the Overvoltage Shutdown signal is tied to the VIN−H line. This transistor will become active in a high voltage event, allowing the hold−up cap to discharge the excess voltage in a timely manner. In the Block Diagram, Figure 1, CASO_RAIL is listed as a 1 mF capacitor. It is required for proper operation of the device that CASO_RAIL is no larger than 1 mF. During a switchover event, a timer in the output stages prepares the regulator in anticipation of change in input voltage. The event results in a hitch in the output waveforms, as can be seen in Figure 3. IOUT = 100 mA COUT = 47 mF Figure 3. VOUTX Response to ASO Switchover Event VIN−B/VIN−H Minimum Operating Voltage The internal reference and core functions are powered by either the VIN−B or VIN−H supply. The higher of the two voltages will dominate and power the reference. This provides quick circuit response on start−up, as well as a stable reference voltage. Since the VIN−B voltage will come up much more quickly than the VIN−H voltage, initially, the VIN−B voltage will be running the reference. In the case of any transient drops on VIN−B, the VIN−H supply, with its large hold−up capacitor, will then be the dominant voltage, and will be powering the reference. For proper operation of the device, VIN−B or VIN−H must be at least 4.5 V. Below that voltage the reference will not operate properly, leading to incorrect functioning by the device. VIN−B or VIN−H must be greater than 4.5 V regardless of the voltage on the VIN−A pin. Internal Soft−Start The NCV8614 is equipped with an internal soft−start function. This function is included to limit inrush currents and overshoot of output voltages. The soft−start function applies to all 3 regulators. The soft−start function kicks in for start up, start up via enable, start up after thermal shutdown, and startup after an over voltage condition. LDO3 is not subject to soft−start under all conditions. The LDO3 output is not affected by overvoltage shutdown, and http://onsemi.com 10 NCV8614 therefore is not effected by the soft−start function upon the device’s return from an over voltage condition. Also, when VIN_S3 is connected to an independent supply and the supply is made available after the soft−start function, LDO3 will not have an independent soft−start. COUT1 w 47 mF, ESR v 10 W COUT2 w 47 mF, ESR v 10 W COUT3 w 47 mF, ESR v 10 W Actual limits are shown in graphs in the Typical Performance Characteristics section. LDO1 Regulator Thermal The LDO1 error amplifier compares the reference voltage to a sample of the output voltage (VOUT1) and drives the gate of an internal PFET. The reference is a bandgap design to give it a temperature−stable output. As power in the NCV8614 increases, it might become necessary to provide some thermal relief. The maximum power dissipation supported by the device is dependent upon board design and layout. Mounting pad configuration on the PCB, the board material, and the ambient temperature affect the rate of junction temperature rise for the part. When the NCV8614 has good thermal conductivity through the PCB, the junction temperature will be relatively low with high power applications. The maximum dissipation the NCV8614 can handle is given by: PD(max) = (TJ(max)−TA)/RthJA See Figure 20 for RthJA versus PCB Area. RthJA could be further decreased by using Multilayer PCB and/or if Air Flow is taken into account. LDO2 Regulator The LDO2 error amplifier compares the reference voltage to a sample of the output voltage (VOUT2) and drives the gate of an internal PFET. The reference is a bandgap design to give it a temperature−stable output. LDO3 Regulator The LDO3 error amplifier compares the reference voltage to a sample of the output voltage (VOUT3) and drives the gate of an internal PFET. The reference is a bandgap design to give it a temperature−stable output LDO3 is an adjustable voltage output. The adjustable voltage option requires an external resistor divider feedback network. LDO3 can be adjusted up to 10 V. The internal reference voltage is 0.996 V. To determine the proper feedback resistors, the following formula can be used: VOUT3 = VOUT3FB [(R1+R2)/R2] IGNOUT Circuitry The IGNOUT pin is an open drain output Schmitt Trigger, externally pulled up to 3.3 V via a 10 kW resistor. The IGNOUT pin can be used to monitor the ignition signal of the vehicle, and send a signal to mute an audio amplifier during engine crank. The IGNIN pin is ESD protected, and can handle peak transients up to 45 V. An external diode is recommended to protect against negative voltage spikes. The IGNOUT circuitry requires the device to be enabled for proper operation. VOUT3 R1 VOUTA FB R2 VPP Function The reset and warning circuits utilize a push−pull output stage. The high signal is provided by VPP. VPP is tied internally to LDO2. Under this setup, and any setup where LDO’s 1−3 are tied to VPP, loss of the VPP signal can occur if the pull up voltage is reduced due to over current, thermal shutdown, or overvoltage conditions. Figure 4. Feedback Network Stability Considerations The output or compensation capacitors, COUTX help determine three main characteristics of a linear regulator: startup delay, load transient response and loop stability. The capacitor values and type should be based on cost, availability, size and temperature constraints. Tantalum, aluminum electrolytic, film, or ceramic capacitors are all acceptable solutions, however, attention must be paid to ESR constraints. The 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 manufacturer’s data sheet usually provides this information. The value for each output capacitor COUTX shown in Figures 22 − 27 should work for most applications; however, it is not necessarily the optimized solution. Stability is guaranteed at the following values: Reset Outputs The Reset Output is used as the power on indicator to the Microcontroller. The NCV8614 Reset circuitry monitors the output on LDO2. This signal indicates when the output voltage is suitable for reliable operation. It pulls low when the output is not considered to be suitable. The Reset circuitry utilizes a push pull output stage, with VPP as the high signal. In the event of the part shutting down via Battery voltage or Enable, the Reset output will be pulled to ground. The input and output conditions that control the Reset Output and the relative timing are illustrated in Figure 5, Reset Timing. Output voltage regulation must be maintained for the delay time before the reset output signals a valid condition. The delay for the reset output is defined as http://onsemi.com 11 NCV8614 The NCV8614 is also equipped with a Hot Flag pin which indicates when the junction temperature is approaching thermal shutdown. The Hot Flag signal will remain high as long as the junction temperature is below the Hot flag threshold, typically 140°C to 160°C. This pin is intended as a warning that the junction temperature is approaching the Thermal Shutdown threshold, which is typically 160°C to 180°C. The Hot Flag signal will remain low until the junction temperature drops below the Hot Flag threshold. The Hot_Flag circuitry does not run off the VBATT_MON Pin, and can not be disabled by grounding VBATT_MON. Each of the three warning circuits utilizes a push−pull output stage. The high signal is provided by VPP. VPP is internally tied to VOUT2. the amount of time it takes the timing capacitor on the delay pin to charge from a residual voltage of 0 V to the Delay timing threshold voltage VD of 2 V. The charging current for this is ID of 5 mA. By using typical IC parameters with a 10 nF capacitor on the Delay Pin, the following time delay is derived: tRD = CD * VDU / ID tRD = 10 nF * (2 V)/ (5 mA) = 4 ms Other time delays can be obtained by changing the CD capacitor value. The Delay Time can be reduced by decreasing the capacitance of CD. Using the formula above, delay can be reduced as desired. Leaving the Delay Pin open is not desirable as it can result in unwanted signals being coupled onto the pin. VBATT_MON and Warning Flags Overvoltage Shutdown The NCV8614 is equipped with High Voltage Detection, Brown Out Detection, and High Temperature Detection circuitry. The Overvoltage Shutdown, High Voltage, and Brown Out Detection circuitry are all run off the VBATT_MON input. If this functionality is not desired, grounding of the VBATT_MON pin will turn off the functions. The HV_DET and BO_DET signals are in a high impedance state until the VBATT_MON circuitry reaches it minimum operating voltage, typically 1.0 V to 2.5 V. At that point the BO_DET signal will be held low, while the HV_DET signal will go high. The BO_DET signal will go high once the VBATT_MON signal reaches the Brown Out Threshold, typically 7 V to 8 V. The BO_DET signal will stay high until the VBATT_MON voltage drops below the Brown Out Threshold. The HV_DET signal will stay high until the VBATT_MON voltage rises above the HV_DET threshold, typically 16.2 V to 17.8 V. The HV_DET signal will reassert high once the HV_DET signal crosses the HV_DET threshold going low. The NCV8614 is equipped with overvoltage shutdown (OVS) functionality. The OVS is designed to turn on when the VBATT_MON signal crosses 17 V. If the VBATT_MON pin is tied to ground, the OVS functionality will be disabled. When OVS is triggered, LDO1 and LDO2 will both be shut down. LDO3 is run off a separate input voltage line, VIN_S3, and will not shutdown in this condition. Once the OVS condition has passed, LDO1 and LDO2 will both turn back on. The VIN−H line is equipped with a bleed transistor to prevent a continued OVS condition on the chip once the high battery condition has subsided. This transistor is needed to discharge the high voltage from the VIN−H hold−up capacitor. This transistor will only turn on when an OVS is detected on−chip, and will turn off as soon as the OVS condition is no longer detected by the chip. http://onsemi.com 12 NCV8614 Load Dump 17 V Vin Vout Reset Threshold LDOX Delay Reset Power On Reset Overload on Output Over Voltage On Input Overvoltage on Input Momentary Glitch on Output Shutdown via Input Figure 5. NCV8614 Reset Timing Diagram Load Dump VIN_B 7.0 V 4.4 V 45 V > 3.25 V IGNIN