NCV8613 Ultra-Low Iq Automotive System Power Supply IC Power Saving Triple-Output Linear Regulator
The NCV8613 is a multiple output linear regulator IC’s with an Automatic Switchover (ASO) input voltage selector. 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 NCV8613 is specifically designed to address automotive radio systems and instrument cluster power supply requirements. The NCV8613 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 NCV8613 is intended to supply power to various “always on” loads such as the CAN transceivers and microcontrollers (core, memory and IO). The NCV8613 has three output voltages, a reset / delay circuit, and a host of control features suitable for the automotive radio and instrument cluster systems.
Features
http://onsemi.com MARKING DIAGRAM
NCV8613 AWLYYWWG G
20 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)
• • • • • • • • • • • • •
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
PIN CONNECTIONS
ASO_RAIL VIN−B VIN−H VIN−A VBATT_MON HV_DET BO_DET NC GND HOT_FLG VIN_S3 VOUT3 VOUT2 VOUT1 VPP RST DLY GND IGNOUT IGNIN
ORDERING INFORMATION
Device NCV8613MNR2G Package Shipping†
Applications
• Automotive Radio • Instrument Cluster
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.
© Semiconductor Components Industries, LLC, 2008
December, 2008 − Rev. 0
1
Publication Order Number: NCV8613/D
NCV8613
NC 8 8V D2 ASO_RAIL 1 uF VIN-B VBATT D1 1 uF VTH1 VTH2 1 VINT VBG VREF VREF VOUT2 VPP 20 ILIMIT 19 VOUT3 VIN_S3 3.3 V
2
VRFB3
VIN-H 1000 uF
3 OVS ILIMIT VREF RST2 VRFB2 VRTH
18
3.3 V
VIN-A VBATT_MON
4 5
Switchover Control Circuit
VIN_MON VPP VTH1 VIN_MON
OVS
HV_DET 6 VPP BO_DET 7
17 ILIMIT
Fault Logic
VOUT1
5V
VTH2 VPP TSD TSD
VREF
VRFB1
HOT_FLG IGNIN D3 IGNOUT 10 kΩ + 5V
10 11 12
16 15
VPP
RST DLY
HV_DET 14 9 GND 13 GND
Components D1 D2 D3
Value MBRS2H100T3G MBR0502T1 MMDL914T1
Manufacturer ON Semiconductor ON Semiconductor ON Semiconductor
Figure 1. Typical Circuit with the Internal Schematic
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NCV8613
PIN FUNCTION DESCRIPTIONS
Pin No. 1 2 3 Symbol ASO_RAIL VIN−B VIN−H 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. Primary power supply input. Connect battery to this pin through a blocking diode. 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. 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. 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. 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. 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. 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. Ignition buffer input Ignition buffer logic output Ground. Reference point for internal signals. Internally connected to pin 9. Ground is not connected to the exposed pad of the DFN20 package. Delay pin. Connect a capacitor to this pin to set the delay time. Reset pin. Monitors VOUT1. Supply rail for the push−pull outputs of the control signals HOT_FLG, RST, HV_DET & BO_DET 5 V output. Voltage is internally set. 3.3 V output. Voltage is internally set. 3.3 V output. Voltage is internally set. Supply rail for the standby linear regulator VOUT3. Tie this pin to ASO_RAIL or a separate supply rail. Exposed Pad of DFN device. This pad serves as the main path for thermal spreading. The Exposed Pad is not connected to IC ground.
4
VIN−A
5
VBATT_MON
6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 EP
HV_DET BO_DET NC GND HOT_FLG IGNIN IGOUT GND DLY RST VPP VOUT1 VOUT2 VOUT3 VIN_S3 −
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NCV8613
MAXIMUM RATINGS (Voltages are with respects to GND unless noted otherwise)
Rating Maximum DC Voltage Peak Transient Maximum DC Voltage Maximum DC Voltage Symbol VIN−B, VIN−A, ASO_RAIL, VBATT_MON, VIN_S3, EN, IGNIN VIN−B, VIN−A, ASO_RAIL, VBATT_MON, VIN_S3, EN, IGNIN VIN−H IGNOUT, VPP, HV_DET, BO_DET, HOT_FLG, RST, DLY, VOUT1, VOUT2, VOUT3 Max 40 45 24 7 Min −0.3 −0.3 −0.3 −0.3 Unit V V V 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 Thermal Characteristic (Note 1) Operating Junction Temperature Range Maximum Storage Temperature Range Moisture Sensitivity Level Symbol RqJA TJ TSTG MSL Min 40 −40 to 150 −55 to +150 1 Unit °C/W °C °C
1. Values based on measurement of NCV8613 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
Rating ESD Capability, Human Body Model (Note 2) ESD Capability, Machine Model (Note 2) ESD Capability, Charged Device Model (Note 2) IGNIN ESD Capability, Human Body Model (Note 2) IGNIN ESD Capability, Machine Model (Note 2) IGNIN ESD Capability (Note 3) Symbol ESDHB ESDMM ESDCDM ESDHB_IGNIN ESDMM_IGNIN ESD_IGNIN Min 2 200 1 3 200 10 Unit kV V kV kV V kV
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.
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NCV8613
SUPPLY VOLTAGES AND SYSTEM SPECIFICATION ELECTRICAL CHARACTERISTICS (7 V < ASO_RAIL < 18 V, VIN−H
= VIN−B w ASO_RAIL, VPP = 5 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 SUPPLY RAILS Quiescent Current (Notes 4 and 6) Minimum Operating Voltage (VIN−H, VIN−B) THERMAL MONITORING Thermal Warning (HOT_FLG) Temperature TWARN Hysteresis Thermal Shutdown Thermal Shutdown Hysteresis Delta Junction Temperature (TSD − TWARN) HOT_FLG Voltage Low HOT_FLG Voltage High AUTO SWITCHOVER VIN−A Quiescent Current VIN−A to VIN−B Risetime VIN−B to VIN−A Falltime VIN−A Operating Threshold VIN−A Operating Hysteresis Max VIN−B to VASO_RAIL Voltage Drop Max VIN−H to VASO_RAIL Voltage Drop RESET (RST Pin) RESET Threshold Hysteresis Reset Voltage High Reset Voltage Low DELAY (DLY Pin) Charge Current Delay Trip Point Voltage IGNITION BUFFER Schmitt Trigger Rising Threshold Schmitt Trigger Falling Threshold IGNOUT Voltage Low IGNOUT Leakage Current VBATT MONITOR VBATT_MON Quiescent Current VBATT_MON Minimum Operating Voltage TJ = 25°C, VBATT_MON = 13.2 V Threshold where BO_DET and HV_DET signals become valid 1.0 3 2.0 5 2.5 mA V IGNIN = 5 V, 10 kW Pullup to 5 V TJ = 25°C, IGNOUT = 5 V 0.1 2.75 0.8 3.25 1.0 3.75 1.2 0.4 0.5 V V V mA 2.4 5 2.0 7 mA V % of VOUT2 % of VOUT2 10 kW Pulldown to GND 10 kW Pullup to 3.3 V VPP−0.5 0.4 90 93 96 2.5 % % V V TJ = 25°C, CASO_RAIL = 1 mF, ISYS = 400 mA TJ = 25 °C, CASO_RAIL = 1 mF, ISYS = 400 mA VIN−A Rising VIN−A Falling ISYS = 400 mA, VIN−B = 7 V ISYS = 400 mA, VIN−H = 7.5 V 7.2 100 24 200 100 7.5 175 7.75 250 1.5 2.0 mA msec msec V mV V V TJ < TWARN, 10 kW Pullup to 3.3 V TJ > TWARN, 10 kW Pulldown to GND VPP−0.5 TWARN 140 10 160 10 10 20 170 150 160 20 180 20 30 0.4 °C °C °C °C °C V V iq TJ = 25°C, ISYS = 70 mA, VIN−A = VIN_S3 = 0 V, VIN−B = 13.2 V 4.5 34 50 mA V Symbol Conditions Min Typ Max Unit
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NCV8613
SUPPLY VOLTAGES AND SYSTEM SPECIFICATION ELECTRICAL CHARACTERISTICS (7 V < ASO_RAIL < 18 V, VIN−H
= VIN−B w ASO_RAIL, VPP = 5 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 VBATT MONITOR VBATT_MON Hysteresis HV_DET Voltage High HV_DET Voltage Low HV_DET Threshold HV_DET Hysteresis BO_DET Voltage High BO_DET Voltage Low BO_DET Threshold BO_DET Hysteresis VPP PIN VPP Voltage Range Leakage Current 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 TJ = 25°C 3 5 0.1 6 0.5 V mA 10 kW Pulldown to GND VBATT_MON Tied to ASO_RAIL 10 kW Pullup to 3.3 V VBATT_MON Tied to ASO_RAIL VBATT_MON Rising VBATT_MON Falling 10 kW Pulldown to GND VBATT_MON Tied to ASO_RAIL 10 kW Pullup to 3.3 V VBATT_MON Tied to ASO_RAIL VBATT_MON Falling VBATT_MON Rising 7 0.2 7.5 0.35 16.2 0.2 VPP−0.5 0.4 8 0.5 0.35 VPP−0.5 0.4 17.8 0.5 0.25 V V V V V V V V V Symbol Conditions Min Typ Max Unit
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NCV8613
ELECTRICAL CHARACTERISTICS (7 V < ASO_RAIL < 18 V, VIN−H = VIN−B w ASO_RAIL, VPP = 5 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 1 (LDO1) SPECIFICATION
Output Voltage Dropout (ASO_RAIL − VOUT1) Load Regulation Line Regulation Output Current Limit Output Load Capacitance Range Output Load Capacitance ESR Range (Notes 8 and 9) DVOUT1 (ASO Low to High Transient) Co ESRCo Output Capacitance for Stability Cap ESR for Stability TJ = 25 °C , IOUT1 = 100 mA, ISYS = 400 mA, CASO_RAIL = 1 mF, ESRCo = 0.01 W, Co = 10 mF, VIN−A falling TJ = 25 °C , IOUT1 = 100 mA, ISYS = 400 mA, CASO_RAIL = 1 mF, ESRCo = 0.01 W, Co = 10 mF, VIN−A rising PSRR VIN_B = 13.2 V, 0.5 VPP, 100 Hz IOUT1 = 0 mA to 100 mA VDR1 IOUT1 = 0 mA to 100 mA, 7 V < ASO_RAIL < 18 V IOUT1 = 100 mA (Note 7) IOUT1 = 0 mA to 100 mA, VIN_B = 13.2 V IOUT1 = 1 mA, 7 V < ASO_RAIL < 18 V 200 1.0 0.01 70 100 13 100 0 0 4.9 5 5.1 500 75 2 V mV mV/mA mV/V mA mF W $mV
DVOUT1 (ASO high to Low Transient)
70
100
$mV
Power Supply Ripple Rejection (Note 8) Startup Overshoot
60 3
dB %
LOW DROP−OUT LINEAR REGULATOR 2 (LDO2) SPECIFICATION
Output Voltage Dropout (ASO_RAIL − VOUT2) Load Regulation Line Regulation Output Current Limit Output Load Capacitance Range Output Load Capacitance ESR Range (Notes 8 and 9) DVOUT2 (ASO Low to High Transient) Co ESRCo Output Capacitance for Stability Maximum Cap ESR for stability TJ = 25 °C , IOUT2 = 300 mA, ISYS = 400 mA, CASO_RAIL = 1 mF, ESRCo = 0.01 W, Co = 22 mF, VIN−A falling TJ = 25 °C , IOUT2 = 300 mA, ISYS = 400 mA, CASO_RAIL = 1 mF, ESRCo = 0.01 W, Co = 22 mF, VIN−A rising PSRR VIN_B = 13.2 V, 0.5 VPP, 100 Hz IOUT2 = 0 mA to 300 mA VDR2 IOUT2 = 0 mA to 300 mA, 7 V < ASO_RAIL < 18 V IOUT2 = 300 mA (Note 7) IOUT2 = 0 mA to 300 mA, VIN_B = 13.2 V IOUT2 = 1 mA, 7 V < ASO_RAIL < 18 V 400 1.0 0.01 30 100 10 66 0 0 3.234 3.3 3.366 1.5 66 1.2 V V mV/mA mV/V mA mF W $mV
DVOUT2 (ASO high to Low Transient)
30
66
$mV
Power Supply Ripple Rejection (Note 8) Startup Overshoot
60 3
dB %
LOW DROP−OUT LINEAR REGULATOR 3 (LDO3) SPECIFICATION
Output Voltage Dropout (VIN_S3 − VOUT3) Output Current Limit Load Regulation Line Regulation IOUT3 = 0 mA to 300 mA, VIN_B = 13.2 V IOUT3 = 1 mA, 7 V v VIN_S3 v 18 V VOUT3 VDR3 IOUT3 = 0 mA to 400 mA, 7 V v VIN_S3 v 18 V IOUT3 = 300 mA (Note 7) 400 0 0 66 1.2 3.234 3.3 3.366 1.5 V V mA mV/mA mV /V
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NCV8613
ELECTRICAL CHARACTERISTICS (7 V < ASO_RAIL < 18 V, VIN−H = VIN−B w ASO_RAIL, VPP = 5 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) DVOUT3 (ASO Low to High Transient) Co ESRCo Output Capacitance for Stability Maximum Capacitance ESR for stability TJ = 25 °C , IOUT3 = 300 mA, ISYS = 400 mA, CASO_RAIL = 1 mF, ESRCo = 0.01 W, Co = 47 mF, VIN−A falling TJ = 25 °C , IOUT3 = 300 mA, ISYS = 400 mA, CASO_RAIL = 1 mF, ESRCo = 0.01 W, Co = 47 mF, VIN−A rising PSRR VIN_B = 13.2 V, 0.5 VPP, 100 Hz IOUT3 = 0 mA to 300 mA 1.0 0.01 30 100 12 66 mF W $mV
DVOUT3 (ASO high to Low Transient)
30
66
$mV
Power Supply Ripple Rejection (Note 8) Startup Overshoot
60 3
dB %
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 ORDERING INFORMATION Device NCV8613MNR2G Conditions No Enable, LDO2 Reset monitor Package 20 Lead DFN, 5x6 (Pb−Free) Shipping 2500 / Tape & Reel
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NCV8613
1
AUTO SWITCHOVER
LDO3 VOUT3
VBATT 8V
Oring Diodes & Filter
ASO_RAIL
VIN_S3 VOUT3
20 19
8V
Output Filter
2
VIN-B
3.3Vs
SDARS
LDO2 VOUT2
Output Filter Output Filter
4 3
VIN-H VIN-A
VOUT2
18
3.3Vs
VPP
VBATT_MON
MONITORING LOGIC
5 HV_DET BO_DET NC HOT_FLG 6 7 8 10 HOT_FLG HV_DET BO_DET
LDO1 VOUT1
VOUT1
17
5Vs
Body CAN
VPP
16
VPP
HOT_FLG_S HV_DET BO_DET RST DLY
INGITOIN BUFFER
11
IGNIN
RESET / DELAY
Ignition
Ignition Filter
RST DLY
15 14
Power Amplifier
12
IGNOUT
Main C
SYS_EN HS_EN LDO_EN HOT_FLG
NCV8613
3.3Vs 5V
NCV8855
SYS_EN HS_EN VBATT 33 26 SYS_EN HS_EN LDO_EN
Misc. 5 V Logic Misc. 3.3 V Logic
MAIN
38 34
LDO_EN HOT_FLG VBATT
3.3V
HOT_FLG
5
OCSET BST1 GH1
BST2 VIN_SW
25
SMPS1 Power Stage 8V output, 4A ILIMIT
7 8
SN2
SMPS1 VOUT1
DVD ROM Drive
8V
SMPS2 VOUT2
SN1
24
SMPS2 Power Stage 5V output, 2A ILIMIT
6
23
5V
Headunit CAN
9
GL1
SW_FB2 COMP2
27 28
4 3
SW_FB1 COMP1 SYNC
37
USB Connector
VBATT
LDO1 VOUT3
AM/FM Tuner
8.5V
40 2 39
LDO2 VOUT4
ISNS1LR_G1 LR_FB1
ISNS2-
30 31 32
LDO2 Power Stage 3.3V output, 1A ILIMIT
LDO1 Power Stage 8.5V output, 0.4A ILIMIT
1
ISNS1+
ISNS2+
29
3.3V
Main DSP
VBATT
22
VIN
HIGH-SIDE SWITCH
HS_S
21
Active Antenna
Fan
Figure 2. Automotive Radio System Block Diagram Example NCV8613 with NCV8855
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NCV8613
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 NCV8613 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
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NCV8613
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.
LDO1 Regulator
The maximum dissipation the NCV8613 can handle is given by: PD(max) = (TJ(max)−TA)/RthJA See Figure 18 for RthJA versus PCB Area. RthJA could be further decreased by using Multilayer PCB and/or if Air Flow is taken into account.
IGNOUT Circuitry
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.
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 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. The reset and warning circuits utilize a push−pull output stage. The high signal is provided by VPP. VPP is an externally fed signal that can be tied to an output, or tied to another regulated voltage signal, typically 5 V, but as low as 3.0 V. 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.
Reset Outputs VPP Function
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
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 20 − 25 should work for most applications; however, it is not necessarily the optimized solution. Stability is guaranteed at the following values: 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.
Thermal
As power in the NCV8613 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 NCV8613 has good thermal conductivity through the PCB, the junction temperature will be relatively low with high power applications.
The Reset Output is used as the power on indicator to the Microcontroller. The NCV8613 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 4, 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 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
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NCV8613
is not desirable as it can result in unwanted signals being coupled onto the pin.
VBATT_MON and Warning Flags
The NCV8613 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 NCV8613 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
Load Dump 17 V Vin
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. When VPP is tied to an output of the NCV8613, the signal will go low if the corresponding output shuts down due to a fault condition.
Overvoltage Shutdown
The NCV8613 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.
LDOX
Vout Reset Threshold
Delay
Reset
Power On Reset
Overload on Output
Over Voltage On Input
Overvoltage on Input Momentary Glitch on Output
Shutdown via Input
Figure 4. NCV8613 Reset Timing Diagram
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12
NCV8613
Load Dump
VIN_B
7.0 V 4.4 V
45 V > 3.25 V
IGNIN