Automotive Infotainment Power

Automotive Infotainment Power
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Agenda
Infotainment Overview
Regulation Options
ON Semiconductor Solutions
Example Applications
System Power Architecture Design Examples
•
•
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Automotive Infotainment System
Tuner
5.0 V
8.0 V
Keyboard
HS Loads
Power
Antenna
LS Loads
High Side
Driver
Smart High
Side Driver
Smart Low
Side Driver
Voltage
Regulation
(Linear,
Switched)
Audio
Amp
7.0 V
1.8 V
3.3 V
5.0 V
5.0 V SB
7.0 V
8.0 V
8.5 V
64 V
2.0 – 10 V
AUX
Input
Supervisory
Audio
Amp
MCU
5.0 V SB
5.0 V SB
LCD
Backlighting
Display
VFD
Driver
Subwoofer
Amp
Vehicle
Networking
5.0 V SB
DSP
5.0 V
3.3 V
1.8 V
Multiplexer
Local
Networking
Audio
Amp
Video
2.0 – 10 V
5.0 V
64 V
Audio
Amp
Line
Driver
I/O Protection
L
Rear
Seat
DVD
2.5 V
5.0 V
3.3 V
3
Single / 6-CD
8.0 V
3.3 V
8.0 V
5.0 V
Line
Driver
R
Key Infotainment Features
• Many output voltages
• Low power stand-by, “always on” supplies
– Low Iq LDOs (NCV861X)
• Higher power supplies during full operation
– Switched-Mode Power Supplies (SMPS)
• Drive towards less power dissipation, higher efficiency
– Necessitates more SMPS, upstream vs. downstream converters
• Drive towards more integration
– System-basis devices (NCV885X)
• EMC of high importance
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Infotainment Power Requirements
• Low current
– Microcontrollers: 5.0 V, 3.3 V; 10’s to 100’s of milliamps of current
– Sensors / transducers: tracking output; 10’s of milliamps of current
• Low voltage, higher current
– DSPs: 3.3 V, 1.8 V, 1.2 V; amps of current
• Medium voltage, medium-higher current
– DVD, CD, Tuner: 8.0 V; 100’s of milliamps to amps of current
– Fans, blowers, motors: tracking output; amps of current
• Pre-regulation boosting, high current
– “Start/stop”: 18.0 V; many amps of current
• High voltage
– VFD: 64 V
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Upstream vs. Downstream Converters
1. High power SMPS
1. Inexpensive SMPS
2. Low power stand-by LDOs
2. Higher current LDOs, too
3. Wide range, high input voltage
3. Narrow range, low input voltage
– Battery
– Load dump: Vin >= 45 V
– Cold crank: Vin as low as 3-4 V
4. Expensive automotive-grade
– NCV devices on PS5, I2T/I3T
5. Low-frequency SMPS
– In design: NCV8901, 2 MHz
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– Upstream converter
– Typically: tight, regulated input
4. Inexpensive “consumer”-grade
– NCP conversions
5. High-frequency SMPS available
– 2+ MHz, multiple outputs
Agenda
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•
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Infotainment Overview
Regulation Options
ON Semiconductor Solutions
Example Applications
System Power Architecture Design Examples
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Regulation
• Purpose: maintain constant output
– Keep constant over input and load operating points (dc)
– Minimize variation during transient perturbations (ac)
• Most applications: voltage is regulated
– Other applications: current is regulated, such as LED driving
• Output is fixed or tracking
– Fixed: output fed back, compared to internal, fixed reference
– Tracking: output fed back, compared to external/variable reference
• Remote output buffering, control via digital/analog converter (DAC)
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Linear Regulation
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Concept: Burn off excess voltage to regulate output voltage to value
lower than input voltage
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Resistive divider, dropping VIN – VOUT over RPASS
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RPASS must be adjusted for changes in VIN and load (RL)
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Regulation: Automatically adjust RPASS based on feedback
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LDO Realization
(Voltage-mode)
• Output voltage is fed back,
compared to reference
– Internally fixed or externally
adjustable output
– Tracking regulator: reference
voltage is also adjustable
• Error amplifier adjusts pass
transistor control signal
– Pass transistor operates in
linear/triode region
• Power dissipation:
(VIN-VOUT)*IOUT
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What’s the Problem with LDOs?
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Efficiency is very low with high
conversion ratios
VOUT, VIN = 13.2 V, vs. Efficiency
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As current increases, power
dissipation becomes very large
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Large heat sinking is required for
many applications
From 13.2 V to 5 V, even just
500 mA is 4.1 W!
If you’re going to be
dissipating over 2 watts,
consider using a switcher!
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Output Voltage (V)
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8
6
4
2
0
100%
80%
60%
40%
Efficiency (%)
20%
0%
Switching: Who Needs It?
• High current demands
• Hot environments
• High voltage conversion ratio
• Voltage step-up or negative voltage generation
• Isolation
• Pre-regulation for down-stream LDOs (and other SMPS)
• NCV8851 can go from 40 V to 5 V at 4 A with just 2.2 W
of dissipation, spread out amongst the power stage and
IC!
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Switcher “Hand-waving” Explanation
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Concept: Conservation of power from input to output to regulate output
voltage (or current) to value lower, higher or equal to input voltage
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Switches some source fully-on/fully-off
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Source applies voltage to
current storage element
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Current storage element supplies
current into voltage storage element
Control
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Voltage storage element provides output voltage
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Regulation: Feedback from output voltage controls switch(es)
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Switcher Topologies Primer
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Buck
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– Steps voltage down
– High-side gate driver
– NCV8842/43, NCV8851, NCV8901
– Steps voltage up
– Low-side gate driver
– NCV8871/72
VO
=D
VIN
•
Buck-Boost
– Steps voltage up or down
– Inverts sign (negative output)
– Low-side gate driver
VO
D
=−
VIN
1− D
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Boost
VO
1
=
VIN 1 − D
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Buck-Boost Derived Topologies
– Non-inverting, isolation
– Flyback (turns ratio), SEPIC
– Low-side gate driver
VO
nD
=
VIN 1 − D
Synchronous vs. Non-synchronous
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Primary, active, switch, QSW1:
– Typically: MOSFETs
• Low-side: NMOS
• High-side: PMOS, NMOS
– NMOS requires charge pump
– BJTs also popular
– IGBTs, SCRs, relays, tubes
• Fundamentally same
• Difference is in driving
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“Rectifier”, QSW2:
– Non-synchronous:
• Passive rectification
– Schottky diode
• Lower efficiency at high load
• Subject to DCM
• Less complicated, single driver
– Synchronous:
• Active rectification
– As primary switch
• Higher efficiency at higher loads
• No DCM
• More complicated, dual, drivers
– Avoid cross-conduction with
non-overlap time
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Switchers vs. LDOs for Automotive
1. Typically, poor efficiency at very
light loads, otherwise very high
efficiency
2. Minimal heat in package, less
heat in pass devices
3. 10’s of amps is fine
4. Regulate at double battery, load
dump, without much dissipation
5. Have to be careful with layout,
components, compensators
6. Expensive magnetics,
components
7. EMI a significant problem
8. Theory of operation is much
more complicated, customers
may not be use to switchers yet
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1. Low efficiency over most
conditions, but better than
switchers at very light loads
2. Lots of heat, potentially watts in
pass device
3. ½ of an amp is pushing it
4. Even running off typical battery
causes lots of dissipation
5. Drop-in product, typically “just
works”, regardless of layout, most
components
6. Cheap!
7. EMI comparatively a non-issue
8. Theory of operation comparatively
straight-forward, customers very
acclimated to LDOs
Controllers vs. Regulators
1. External pass element(s) (FET,
BJT)
2. Less compact, more expensive
3. Power dissipation limited by
pass element package
4. More heatsinking options
1. Internal pass element(s) (FET,
BJT)
2. More compact, less expensive
3. Power dissipation limited by
regulator package
5. Higher, flexible current capability
4. Less heatsinking options
6. Wide-range of external pass
elements
5. Lower, fixed current capability
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Not necessarily optimal
Application selection / tuning
process
6. Optimized for internal pass
element
Comparison of Power Devices
SMPS
Multi-Phase
Controllers
η > 95%
Current Capability
Io > 10 A
Io > 4 A
V
η = IN
VO
⎛ IQ
⎜⎜1 +
⎝ IO
⎞
⎟⎟
⎠
SMPS
Non-Synchronous
Controllers
Io > 2 A
η > 70%
SMPS
Non-Synchronous
Regulators
LDO
Controllers
SMPS
Synchronous
Regulators
Io > 1 A
Io > 500 mA
VO I O
η=
VO I O + Pcond + Psw
Io > 5 mA
Efficiency
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η > 80%
Io > 3 A
η > 20%
LDO
Regulators
SMPS
Synchronous
Controllers
Agenda
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Infotainment Overview
Regulation Options
ON Semiconductor Solutions
Example Applications
System Power Architecture Design Examples
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LDO Device Solutions
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System Power Solutions
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NCV885X
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SMPS Buck Controller
2 A SMPS Buck Converter
2 LDO Controllers
2 A High-Side Switch
170 kHz, 340 kHz options
Options with ROSC or SYNC
– 3 LDO Outputs
• Various voltage / current options
• NCV8612
– Automatic Switch-Over (ASO)
• Decrease power dissipation
– Ultra Low Iq < 50 µA
– DFN20 6x5
• Up to 600 kHz
– QFN32 6x6
NCV861X
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NCV8881
– 1.5 A SMPS Buck Converter
– 8.5 V / 40 mA, 5.0 V / 100 mA LDOs
– ROSC and SYNC
• Up to 600 kHz
– Watchdog
– SOIC-16EP
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Agenda
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•
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Infotainment Overview
Regulation Options
ON Semiconductor Solutions
Example Applications
System Power Architecture Design Examples
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Many-Output NCV885X Application
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NCV885X / NCV861X Application
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NCV8855
5-Output NCV8851/NCV8855
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4-Output NCV8851/NCV8610
BATT
INPUT
FILTER
N1
OUTPUT
FILTER
N2
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Agenda
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•
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Infotainment Overview
Regulation Options
ON Semiconductor Solutions
Example Applications
System Power Architecture Design Examples
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System Power Architecture Considerations
1. Customer voltage / current requirements
– Standby / Quiescent current
2. Cost!
3. Efficiency / power dissipation
4. Integration / size
5. EMC requirements
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Example: System Power Requirements
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Protected connection to battery
5.0 V / 1 A USB
5.0 V / 500 mA Tuner
5.0 V / 100 mA CAN SB
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Standby HS-CAN IVN (CAN SB)
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3.3 V / 1.3 A DSP
3.3 V / 70 mA µC SB
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Standby microcontroller (µC SB)
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1.8 V / 600 mA HD
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50 µA max quiescent current (Iq)
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Vbatt / 1.7 A Antenna
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8.0 V / 1.2 A CD
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Example: System Power Architecture #1
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Example: System Power Architecture #1
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Example: System Power Architecture #1
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Example: System Power Architecture #2
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Example: System Power Architecture #2
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Example: System Power Architecture #2
Batt
13.2 V
34 µA Iq
1.419 W N
7.274 W
η = 92%
863 mW
631 mA
NCP3122
SMPS1
735 mA
180 mA
170 mA
1.979 W
SMPS2
NCP1529
8.0 V / 1.2 A CD
922 mW N
ASO
VIN_S3
1.018 A
312 mW
η = 85% 445 mW D
551 mW
η = 85% 331 mW D
360 mW
η = 75%
NCV8612
170 mA
450 mA
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2.218 A
NCV8851
ηsys = 85.9%
34 µA Iq
954 mW
P
Batt / 1.7 A ANTENNA
1.700 A
3.918 A
LDO1
LDO2
LDO3
329 mW
300 mW
1.350 W
3.3 V / 1.3 A DSP
5.0 V / 1.0 A USB
1.8 V / 600 mA HD
3.3 V / 70 mA uC SB
5.0 V / 100 mA CAN SB
5.0 V / 450 mA TUNER
For More Information
•
View the extensive portfolio of power management products from ON
Semiconductor at www.onsemi.com
•
View reference designs, design notes, and other material supporting
automotive applications at www.onsemi.com/automotive
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