What is Digital Power? - Portal Texas Instruments - Brasil

Texas Instruments
Brazil Tech Day
Digital Power
Adrian Harris
Product Marketing Engineer
High Performance Analog

Overview
What is Digital Power?
UCD911x + UCD7230 Solution
UCD92xx + Power Train Solution
Application Examples
Cost Analysis
Phase Management
Summary
2

Vin in
Controller
(Compensator)
What is Digital Power?
Generic Power System Block Diagram
Rectifier
PWM
Switches
(FETs)
LC
Network
Vout out
The controller block is what differentiates between a digital
power system and a conventional analog power system
3

Vout out
Vout out
Error
Amplifier
R 1
R 4
C 3
R 3
What is Digital Power?
Analog Controller (s-domain)
Vref ref
R 2
-
+
C 1
Analog
Controller
C 2
(s-domain)
(s domain)
R 5
R 6
-
+
Analog
PWM
V c
PWM
4

Vout out
ADC
(Hi-speed) (Hi speed)
ADC
What is Digital Power?
Digital Controller (z-domain)
Digital
Controller
(z-domain)
(z domain)
Data Bus
Digital
PWM
CPU
PMBus
GPIO
Flash watchdog
PWM
5

ANALOG
DIGITAL
Analog vs. Digital Solution Tradeoffs
Continuous operation (infinite sample rate)
Low power consumption
Single chip solutions available
(integrated driver)
Strengths Weaknesses
GUI, programmable parameters
Adaptive and nonlinear compensation
Flexibility, easier board development
Features integration
Multiphase reliability
Phase shedding
N+1 redundancy
Easier PWM synchronization
Fault logging
Up to 32 devices on single PMBus
Hardwired design
Separate “signal” lines for every
converter
No communication with controllers
Need separate system manager
Higher quiescent current
Dual chip solution (controller + driver)
6

What does a digital solution provide?
High levels of integration
Multiple outputs and phases with one controller
Integrated sequencing, margining, management
General purpose microcontroller for housekeeping
Advanced functionality
Real time power system diagnostics – data logging and failure prediction
Adaptive control for varying operation modes and load characteristics
Calibration in manufacturing
System optimization
Dead band control for improved efficiency
Enhanced phase management
7

Digital Power Ready End Equipment
Computer
Servers
Storage
UPS
Communications
Rectifiers
Base stations
Routers
Industrial, Test and Measurement
Semiconductor Test Equipment
Lighting
Medical equipment
8

Outputs
TI’s UCD 9k Digital Power Controller Family
UCD91xx
UCD92xx
UCD9112
UCD9111
Performance
1 output, 2 phase
32 pin
1 output, 1 phase
32 pin
UCD9240
UCD9230
UCD9220
FUTURE
4 ind outputs
64 & 80 pin
3 ind outputs
48 pin
2 ind outputs
40 pin
9

Digital Power Conversion
UCD91K
Family Products
10

UCD911x – Single Loop Controller
Single and dual phase synchronous buck
controllers
High speed Fusion Power Peripheral (FPP)
175ps PWM resolution to support wide Vin to Vout ratio’s
Switching frequency up to 1 MHz
Feature rich solutions:
Soft start, soft stop, margining, tracking, sequencing, fan control
Dual phase solution supports phase shedding for improved light load
efficiency
Reconfigurable via PMBus
32pin QFN package
11

Differential
Sense Inputs
PWM Outputs
UCD9112 Dual Phase Synch Buck Controller
Fusion Power Peripheral
Feedback Analog
Conditioning
Digital Error
Converter
Digital
Compensator
2 x 175ps
DPWM’s
Compensator
Configuration 1
Compensator
Configuration 2
0.5% 800mV
Reference
32MHz
Oscillator
Internal Data Bus
6 User Configurable
Channels for Monitoring
• Voltage
• Current
• Temperature
CPU Core
Data
Flash
PMBus TM
Watchdog
12

V Sense
G Sense
UCD911x Fusion Power Peripheral
Differential Amp
With
Programmable
Attenuator
Vref
Error ADC
10bit, 50ns
LSB=+/-2mV
LSB=+/ 2mV
Loop
Config A
PID Co- Co
processor
Loop
Config B
33MHz System
Clock
8 bit
Frequency
Generator
175ps PWM PWM
Resolution
20kHz – 2MHz
PWM A
PWM B
13

UCD7230 Digital Power Driver
50x
For digitally controlled power
supplies using UCD9K or F28x
controllers
High performance
Thermal management, power stage
reliability/safety, high efficiency
Unique features:
Low-offset differential current sense
amplifier
High side FET protection
3.3-V, 10-mA internal regulator
Significantly reduces number of
external components
4.75V to 15.5V supply voltage
14

UCD7230 Implementation
Digital
Controller
Digital
Driver
15

Digital Power Conversion
UCD92K
Family Products
16

Reference
Sequencing
& Tracking
High-Density Digital Power Controller
NV
Memory
Oscillator
uController for
Housekeeping
Margining
DC/DC1
DC/DC2
DC/DC3
DC/DC4
A
B
A
B
A
B
A
B
Fan Control
17

UCD92xx – Multiple Loop Controller
Up to four Outputs and up to eight phases
High speed Fusion Power Peripheral (FPP)
250ps PWM resolution to support wide Vin to Vout ratio’s
Switching frequency up to 2 MHz
Feature rich solutions:
Soft start, soft stop, margining, tracking, and sequencing
Multi-phase solution supports phase shedding for improved light load
efficiency
Reconfigurable via PMBus
64 and 80 pin QFN package
18

Diff Input 1
PWM1 Outputs
Diff Input 2
PWM2 Outputs
Diff Input 3
PWM3 Outputs
Diff Input 4
PWM4 Outputs
UCD9240 Controller Overview
Fusion Power Peripheral
Fusion Power Peripheral
Fusion Power Peripheral
Fusion Power Peripheral
Data
Flash
w/ECC
33MHz
ARM7 CPU
Core
Internal Data Bus
Linear
Regulator
+/- 0.5%
800mV
Reference
33MHz
Oscillator
Up to 16 x 12bit 200kHz Channels
& 4 Comparators for Monitoring
Voltage
Current
Temperature
PMBus TM
Watchdog
2 Counters
/ Timers
19

Driver
Sampling Today
Digital Configurability
• Output Voltage
• Current limit
• Frequency
Inductor
• UVLO
• Over-temp
• Monitoring of Vin, Vout, Iout, Temperature
Convenience of Modules
Digital Power Train Modules
• Designed and tested 10A and 20A PowerTrains
• PTD08A010W and PTD08A020W Current
Sense
Temp
Sense
FET
FET
20

Efficiency - %
100
95
90
85
80
75
70
65
60
55
50
45
40
PTD08A020W Efficiency
0 5 10 15 20
Iout()-Amps
Power Train Efficiency
PTD08A020W Efficiency
VO = 1.2 V VO = 3.3 V
100
95
90
85
4.75V
80
5.0V
75
8.0V
70
10.0V
65
12.0V
60
14.0V
55
50
45
40
Efficiency - %
0 5 10
Iout()-Amps
15 20
4.75V
5.0V
8.0V
10.0V
12.0V
14.0V
21

Ta - °C
90.0
80.0
70.0
60.0
50.0
40.0
30.0
Power Train – Thermal Performance
PTD08A020W Safe Operating Area
VI = 12 V, VO = 1.2 V, FS = 350kHz
20.0
0.0 5.0 10.0 15.0 20.0
400LFM
200LFM
100LFM
Nat conv
Ta - °C
90.0
80.0
70.0
60.0
50.0
40.0
30.0
PTD08A020W Safe Operating Area
VI = 12 V, VO = 3.3 V, FS = 350kHz
20.0
0.0 5.0 10.0 15.0 20.0
400LFM
200LFM
100LFM
Nat conv
22

Ta - °C
90.0
80.0
70.0
60.0
50.0
40.0
30.0
Power Train – Thermal Performance
PTD08A010WAD Safe Operating Area
VI = 12 V, VO = 3.3 V, FS = 350kHz
20.0
0.0 2.0 4.0 6.0 8.0 10.0
400LFM
200LFM
100LFM
Nat conv
Ta - °C
90.0
80.0
70.0
60.0
50.0
40.0
30.0
PTD08A010WAD Safe Operating Area
VI = 12 V, VO = 1.2 V, FS = 350kHz
20.0
0.0 2.0 4.0 6.0 8.0 10.0
400LFM
200LFM
100LFM
Nat conv
23

4.75 – 14 V I
UCD9240 + Power Train Modules – Typical System Architecture
PMBus Control Lines
Vout1 @ 10A
Vout2 @ 10A
Vout3 @ 20A
Vout4 @ 40A
24

Power Stage
Power Stage Options
Integrated Driver/FET
UCD7230 Based
Discrete
Power Train Module
25

Efficiency - %
Maximize Efficiency with Integrated Driver/FET
100
95
90
85
80
75
70
65
60
55
50
45
40
UCD9240 + Integrated Driver/FET Technology
1.1-V, 150-A Efficiency
0 20 40 60 80 100 120 140
Iout()-Amps
Plots of various input voltages with output voltage set to 1.1V
Switching frequency at 300kHz, UCD9240 six phase with Renesas DrMos (8V gate drive)
10.0V
12.0V
14.0V
26

UCD9240EVM - Four-Output EVM
Digital Control
Dynamic
configuration
Full feature
• Margining
• Soft start/stop
• Tracking
• Sequencing
• Selectable fault
response
• GUI Configurable
27

Power + Designer Graphical User Interface
28

Digital Power Conversion
UCD9xxx Applications
29

PMBus
Multi-Processor, Multi-Supply Rail Systems
1.5 V
3.3 V
1.8 V
1.2 V
1.5V
3.3V
1.8V
PLL
1. 8 V
1.2V
Media
Interface
Rapid I/O
1.2V
Multiple
DSP's
30

• A digital control “stacking” alternative to
analog solutions TPS40140 and
PTH08T250W
PMBus
Very cost competitive with an analog
control solution.
High Current Application
Stacked 10 amp
Power Trains
1.0 V @ 80 A
31

Cost Analysis
32

PMBus
UCD9240 Controller
UCD9240 Cost Effectiveness - 4-Rail Systems
+
4x UCD7230 Driver
33

Cost Analysis – UCD9240 Controller -vs- Analog
Got 4 rails? Need to sequence and monitor those rails? Need multiphase
or load sharing operation?
UCD9240RGC Digital Analog Based
Controller
Controller
# of Estimated # of Estimated
devices Cost devices Cost
Controller 1 $4.50 4 $7.20
MOSFET Driver 4 $2.20 0 $0.00
Supply Voltage
Sequencer 0 $0.00 1 $1.50
Bias Power 1 $0.40 0 $0.00
Total 6 $7.10 5 $8.70
• Estimated cost figures are based on “typical” 1k unit pricing.
• The output current requirement is estimated to be at least 8-A/rail.
• The analog based controller is assumed to have a MOSFET driver built-in.
• Analysis is based on TPS40180 analog solution.
• Power stage cost estimates are not included, and are assumed to be identical for both analog and digital.
34

Digital Power Conversion
Phase Management
35

vin
+
–
UCD7230
pwm1
Multi-Phase Buck Converter
s1p2
s2p2
UCD7230
pwm2 s1p3
Lp1
s2p3
s1p4
RLp1
Lp2
s2p4
eslp1
Cp1 RLp2
Resrp1
eslp2
Cp2
Resrp2
Rp
iou
eslo
Co
vo
Resro io
Ro
36

Phase Management
Advantages of Multi-Phase Conversion
• Smaller input and output ripple
• Less capacitance
• Fast dynamic response
• Smaller PCB board
• Better Thermal Performance
• Low cost profile
+ advantages of Digital Control Technology
• Higher efficiency at both light load and heavy load
• Ripple voltage minimization across the entire load range
• Optimized dynamic response across the entire load range
37

Losses (W)
40
35
30
25
20
15
10
5
Power Dissipation and Efficiency
Power Losses Versus Load
0
0 10 20 30 40 50 60 70 80
Iout (A)
90
One Phase Tw o Phase Three Phase Four Phase
Effi(%)
90
80
70
60
50
40
30
20
10
Effi versu Load
0
0 10 20 30 40 50 60 70 80 90
One phase Tw o phase Three phase Four phase
Iout(A)
• Using a single phase converter, power losses increase dramatically at heavy load
• Multi-phase converters have slightly higher power losses at light load
• Multi-phase converters has higher conversion efficiency at heavy load
38

Phase Shedding – Efficiency Optimization
Effi (%)
90
80
70
60
50
40
30
20
10
0
Light Load Efficiency
0 5 10 15 20 25
Load (A)
One Phase
Two Phase
Three Phase
Four Phase
Efficiency has optimum point at different phase and load conditions
30% efficiency increase at 1-A load for single phase compared with 4 phases
Phase Shedding Benefits
Selectable # of phases for a given load condition
Optimized efficiency across the entire load range for enhanced performance
39

Magnitude (dB)
Phase (deg)
80
60
40
20
0
-20
0
-45
-90
-135
-180
-225
10 2
10 3
Phase Management – Control Loop Design
Bode Diagram
Gm = 6.95 dB (at 1.57e+006 rad/sec) , Pm = 70.2 deg (at 3.09e+005 rad/sec)
10 4
• At heavy load (30A) and 4-phase,
PM = 70.2 deg at F cr = 50kHz
10 5
Frequency (rad/sec)
10 6
10 7
Magnitude (dB)
Phase (deg)
80
60
40
20
0
-20
-45
-90
-135
-180
-225
10 2
Bode Diagram
Gm = 18.9 dB (at 1.57e+006 rad/sec) , Pm = 42 deg (at 1.02e+005 rad/sec)
10 3
10 4
• At light load (1A) and 1-phase with the
same controller PM=42 deg at Fcr =13 kHz
10 5
Frequency (rad/sec)
10 6
10 7
40

Control Loop Design – Stability and Dynamic Response
• The PM decreases when shedding phases for light load operation; this may affect stability.
• The bandwidth also decreases during phase shedding. This will affect the dynamic response.
• After compensator redesign, the loop will have improved performance characteristics.
Magnitude (dB)
Phase (deg)
80
60
40
20
0
-20
-45
-90
-135
-180
-225
10 2
Bode Diagram
Gm = 6.87 dB (at 1.57e+006 rad/sec) , Pm = 67.6 deg (at 3.09e+005 rad/sec)
10 3
10 4
10 5
Frequency (rad/sec)
10 6
10 7
• At light load (1A) and 1-phase with
redesigned controller. PM=68 deg at
F cr =50KHz
41

11
10
9
1
0.5
0
1.002
1
0.998
0.996
4 Phase, I o = 40A, V o =1V
90º interval, V p-p = 4mV
1
Iph1, Iph2, Iph3, Iph4 (A)
pwm1, pwm2, pwm3, pwm4
Vout (V)
Dynamic Phase Adjustment
2
Time ( s)
3 4 5
11
10
Shedding from 4 to 3 phases without
interval adjustment, V p-p =10mV
9
1
0
1.005
1
0.995
0.990
Iph1, Iph2, Iph3 (A)
pwm1, pwm2, pwm3
Vout (V)
1 2 3
Time ( s)
4 5
42

Phase Adjustment – Ripple Voltage Reduction
Shedding from 4 to 3 phases with adjustment to 120º gives 5mV p-p
43

Digital power management capabilities
include voltage tracking, margining,
sequencing, and monitoring.
Eliminate the need
for external filters and
improve EMI performance.
Fusion Digital Power Controller – UCD9240
Reduce the number of
design components.
Bringing Intelligence to the Point-of-Load
Maximize over the entire load range
through phase management and
integrated driver/FET technology.
Configure your POL
system to cost effectively
meet any power requirement
using a single device.
Meet 3% IC Supply Voltage Tolerance
for up to 20-A load step with
minimum capacitance.
44

Product Marketing
Contacts
Broad Market - Adrian Harris (214) 567-2207 - aharris@ti.com
45