Tiny DCDC Converter Reference Design

Application Report
SLVA332A – October 2009 – Revised June 2010
3.6-V to 6-V Input, 3.3-V Output, Tiny, and High-Efficiency
DC/DC Converter
................................................................................................... PMP - DC/DC Low-Power Converters
ABSTRACT
This reference design is presented to help application designers and others who are trying to use the
MSP430 in a system with an input voltage in the range of 3.6 V to 6 V with the primary design objective to
minimize solution size as well as to maintain high efficiency and long battery life.
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Contents
Features ......................................................................................................................
Introduction ..................................................................................................................
Requirements ................................................................................................................
List of Materials .............................................................................................................
Test Results .................................................................................................................
5.1
Test Results ........................................................................................................
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2
3
5
6
6
List of Figures
8
.......................................................................................................................
Startup .......................................................................................................................
Startup .......................................................................................................................
Startup .......................................................................................................................
Output Ripple Voltage .....................................................................................................
Load Transient ..............................................................................................................
Switching Node Waveform ................................................................................................
Switching Node Waveform ................................................................................................
1
CC43 Family Power Requirements ....................................................................................... 3
2
MSP430x1xx Family Power Requirements
3
3
MSP430x2xx Family Power Requirements
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1
2
3
4
5
6
7
Startup
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7
List of Tables
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5
6
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MSP430x4xx Family Power Requirements .............................................................................
MSP430x5xx Family Power Requirements .............................................................................
PMP4775 List of Materials .................................................................................................
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NanoStar is a trademark of Texas Instruments.
All other trademarks are the property of their respective owners.
SLVA332A – October 2009 – Revised June 2010
3.6-V to 6-V Input, 3.3-V Output, Tiny, and High-Efficiency DC/DC Converter
Copyright © 2009–2010, Texas Instruments Incorporated
1
Features
1
Features
•
•
•
•
•
•
2
www.ti.com
3.6-V to 6-V input voltage range
Capable of driving up to 500 mA (TPS62300)
High efficiency (over 92%)
3-MHz operation allows for small passive components
Low quiescent current (20 mA)
Tiny 8-pin NanoStar™ (chip scale) and QFN-10 packages
Introduction
This reference design is for the MSP430 family of microcontroller devices and accounts for the voltage
and current requirements as described herein. The MSP430 devices require only a single 3.3-V input; no
sequencing is required. The operating input voltage for this reference design is between 3.6 V to 6 V. This
design is optimized for a small solution size with a low component count and high efficiency.
For more information and other reference designs, please visit www.ti.com/processorpower.
2
3.6-V to 6-V Input, 3.3-V Output, Tiny, and High-Efficiency DC/DC Converter
SLVA332A – October 2009 – Revised June 2010
Copyright © 2009–2010, Texas Instruments Incorporated
Requirements
www.ti.com
3
Requirements
The power requirements for each MSP430 family are listed below. The power given is based on the
amount of current the core consumes per megahertz (MHz). The Analog IMAX column indicates the amount
of current added if the additional functional blocks are used.
For more information and other reference designs, please visit www.ti.com/processorpower.
Table 1. CC43 Family Power Requirements
(1)
(2)
DEVICE
FAMILY
PIN
NAME
F613x,
F513x
AVCC,
DVCC (1)
VOLTAGE (V)
MIN
MAX
CPU IMAX
(mA/MHz)
ANALOG
IMAX (mA)
SEQUENCIN
G ORDER
TIMING
DELAY
COMMENTS
1.8
3.6
250 (2)
IREF = 140
n/a
n/a
+Maximum
CPU speed of
20 MHz
It is recommended to power AVCC and DVCC from the same source. A maximum difference of 0.3 V between AVCC and DVCC can
be tolerated during power-up.
Maximum value for CPU clocked at 20 MHz at 3 V shown. Actual value depends on supply voltage and MCLK/internal regulator
settings. Does not include peripheral module supply current or GPIO source/sink currents, which must be added separately.
Table 2. MSP430x1xx Family Power Requirements (1)
DEVICE
FAMILY
VOLTAGE (V)
PIN NAME
MIN
MAX
CPU IMAX
(mA/MHz) (2)
ANALOG
IMAX (mA)
x11x1A
VCC
1.8
3.6
350
Comp_A = 60
F12x
VCC
1.8
3.6
350
Comp_A+ = 60
F11x2, 12x2
VCC
1.8
3.6
350
ADC10 = 1200, IREF = 400
COMMENTS
C11x1: 300 mA/MHz max
F13x, 14x[1]
AVCC, DVCC
(3)
1.8
3.6
560
Comp_A = 60,
ADC12 = 1600,
IREF = 800
F13x, 14x: Comp_A, ADC12
F14x1: Comp_A
F15x, 16x,
161x
AVCC, DVCC
(3)
1.8
3.6
600
Comp_A = 60,
ADC12 = 1600,
IREF = 800, DAC12 = 1500
DAC outputs not loaded; DAC12
currents for a single DAC, max of
two DAC12s in device)
(1)
(2)
(3)
Additional 7-mA maximum required when writing/erasing Flash In-system.
8-MHz maximum CPU clock speed (ex. Imax_x11x1 = 8 MHz × 350 mA = 2.8 mA). VCC = DVCC = AVCC = 3 V. Actual value
depends on supply voltage. Does not include peripheral module supply current or GPIO source/sink currents, which must be
added separately.
It is recommended to power AVCC and DVCC from the same source. A maximum difference of 0.3 V between AVCC and DVCC can
be tolerated.
Table 3. MSP430x2xx Family Power Requirements (1)
DEVICE
FAMILY
PIN NAME
VOLTAGE (V)
MIN
MAX
CPU IMAX (2)
(mA/MHz)
ANALOG
IMAX (mA)
F20xx
VCC
1.8
3.6
370
Comp_A+ = 60
ADC10 = 1200,
ADC10_IREF = 400
SD16_A + IREF = 1700
RefBuffer = 600
F21x1
VCC
1.8
3.6
410
Comp_A+ = 60
F21x2
AVCC, DVCC
1.8
3.6
350
Comp_A+ = 60
ADC10 = 1200,
IREF = 400
F22xx
AVCC, DVCC
(3)
1.8
3.6
550
ADC12 = 1200,
IREF = 400
OA = 290
F23x0
AVCC, DVCC
(3)
1.8
3.6
550
Comp_A + = 60
(1)
(2)
(3)
COMMENTS
20x1: Comp_A+
20x2: ADC10
20x3: SD16_A
22x2: ADC10
22x4: ADC10, 2 OAs OA
currents for a single amplifier
Additional 7-mA maximum required when writing/erasing Flash In-system.
16 MHz maximum CPU clock speed (ex. Imax_20xx = 16 MHz × 370 mA = 5.90 mA). VCC = DVCC = AVCC = 3 V. Actual value
depends on supply voltage. Does not include peripheral module supply current or GPIO source/sink currents, which must be
added separately.
It is recommended to power AVCC and DVCC from the same source. A maximum difference of 0.3 V between AVCC and DVCC can
be tolerated during power-up.
SLVA332A – October 2009 – Revised June 2010
3.6-V to 6-V Input, 3.3-V Output, Tiny, and High-Efficiency DC/DC Converter
Copyright © 2009–2010, Texas Instruments Incorporated
3
Requirements
www.ti.com
Table 3. MSP430x2xx Family Power Requirements (1) (continued)
DEVICE
FAMILY
F23x, 24x[1],
2410
F241x, 261x
VOLTAGE (V)
PIN NAME
AVCC, DVCC
AVCC, DVCC
(3)
(3)
MIN
MAX
CPU IMAX (2)
(mA/MHz)
1.8
3.6
445
Comp_A + = 60,
ADC12 = 1000,
IREF = 700
224x1: Comp_A+
23x, 24x, 2410: Comp_A+,
ADC12
560
Comp_A + = 60,
ADC12 = 1000,
IREF = 700
DAC12 = 1500
241x: Comp_A+, ADC12
261x: Comp_A+, ADC12, two
DAC12s DAC12 outputs not
loaded; DAC12 currents for a
single DAC
1.8
3.6
ANALOG
IMAX (mA)
COMMENTS
Table 4. MSP430x4xx Family Power Requirements (1)
DEVICE
FAMILY
x41x
(2)
AVCC, DVCC
VOLTAGE (V)
MIN
MAX
CPU IMAX
(mA/MHz) (3)
ANALOG
IMAX (mA)
1.8
3.6
350
Comp_A = 60
COMMENTS
C41x: 300 mA/MHz max
FW42x
AVCC, DVCC
1.8
3.6
350
Comp_A = 60
Scan IF = 650
F42x
AVCC, DVCC
1.8
3.6
500
SD16 + IREF = 1550
Ref Buffer = 600
SD16 current is for a single A/D
(three on device)
FE42x[a], 42x2
AVCC, DVCC
1.8
3.6
500
ESP430CE1 = 4900
Ref Buffer = 600
ESP430 current for 4-MHz
operation
F43x[1], F44x
AVCC, DVCC
1.8
3.6
560
Comp_A = 60,
ADC12 = 1600,
IREF = 800
F42x0
AVCC, DVCC
1.8
3.6
520
SD16_A + IREF=1800
Ref Buffer = 600
DAC12=1500
DAC12 output not loaded
560
SD16_A + IREF=1800
Ref Buffer = 600
DAC12 = 1500,
OA = 290
DAC12 output not loaded; OA
current for a single amplifier (two
OAs in device)
570
Comp_A = 60,
ADC12 = 1600,
IREF = 800,
DAC12 = 1500,
OA = 490
DAC12 outputs not loaded; OA
and DAC12 currents for a single
amplifier/DAC (three OAs, two
DACs in device)
DAC12 outputs no loaded; OA
and DAC12 currents for a single
amplifier/DAC (three OAs, two
DACs in device)
16 MHz max CUP frequency;
SD16 current is for a single A/D
(four on device)
FG42x0
FG43x
AVCC, DVCC
AVCC, DVCC
1.8
1.8
3.6
3.6
FG46xx
AVCC, DVCC
1.8
3.6
740
Comp_A = 60,
ADC12 = 1600,
VREF = 800,
DAC12 = 1500,
OA = 490
F47xx
AVCC, DVCC
1.8
3.6
560
Comp_A = 60,
SD16_A + IREF = 1700
Ref Buffer = 600
(1)
(2)
(3)
4
PIN NAME
Additional 7-mA maximum required when writing/erasing Flash In-system.
It is recommended to power AVCC and DVCC from the same source. A maximum difference of 0.3 V between AVCC and DVCC can
be tolerated.
8 MHz maximum CPU clock speed (ex. Imax_x41x = 8 MHz × 350 mA = 2.8 mA). (F47xx max CPU clock = 16 MHz) VCC = DVCC
= AVCC = 3 V. Actual value depends on supply voltage. Does not include peripheral module supply current or GPIO source/sink
currents, which must be added separately. LCD current not included.
3.6-V to 6-V Input, 3.3-V Output, Tiny, and High-Efficiency DC/DC Converter
SLVA332A – October 2009 – Revised June 2010
Copyright © 2009–2010, Texas Instruments Incorporated
List of Materials
www.ti.com
Table 5. MSP430x5xx Family Power Requirements
DEVICE
FAMILY
F54xx
(1)
AVCC, DVCC
(3)
MIN
MAX
CPU IMAX
(mA/MHz) (2)
2.2
3.6
348
ANALOG
IMAX (mA)
ADC12_A = 220,
IREF = 190
COMMENTS
18 MHz maximum CPU clock
speed
Additional 5-mA maximum required when writing/erasing Flash In-system.
16 MHz maximum at 3-V CPU clock speed. Actual value depends on supply voltage and MCLK/internal regulator settings. Does
not include peripheral module supply current or GPIO source/sink currents, which must be added separately.
It is recommended to power AVCC and DVCC from the same source. A maximum difference of 0.3 V between AVCC and DVCC can
be tolerated during power-up.
(2)
(3)
4
VOLTAGE (V)
PIN NAME
(1)
List of Materials
Table 6 shows the bill of materials (BOM) for this design.
Table 6. PMP4775 List of Materials
REF
DES
QTY
VALUE
DESCRIPTION
SIZE
PART NUMBER
MFR
C1, C2
2
10 mF
Capacitor, ceramic, 6.3 V, X5R, 10%
0603
C1608X5R0J106KT
TDK
L1
1
2.2 mH
Inductor, SMT, 1.5A, 110 mΩ
0.102" x 0.110"
VLF3010AT-2R2M1R0
TDK
R1
1
453 kΩ
Resistor, chip, 1/16W, 1%
0603
Std
Std
R2
1
100 kΩ
Resistor, chip, 1/16-W, 1%
0603
Std
Std
U1
1
3-MHz synchronous step-down
converter, 500-mA, adjustable
QFN-10
TPS62300DRC
TI
SLVA332A – October 2009 – Revised June 2010
3.6-V to 6-V Input, 3.3-V Output, Tiny, and High-Efficiency DC/DC Converter
Copyright © 2009–2010, Texas Instruments Incorporated
5
Test Results
5
www.ti.com
Test Results
The input and output startup waveforms are shown in Figure 1 through Figure 4. The output ripple voltage
is shown in Figure 5. Figure 6 shows the transient response. The switching node waveform is shown in
Figure 7.
5.1
6
Test Results
Figure 1. Startup
Figure 2. Startup
Figure 3. Startup
Figure 4. Startup
3.6-V to 6-V Input, 3.3-V Output, Tiny, and High-Efficiency DC/DC Converter
SLVA332A – October 2009 – Revised June 2010
Copyright © 2009–2010, Texas Instruments Incorporated
Test Results
www.ti.com
VIN = 3.3 V
Load Step 250 mA to 500 mA
VOUT
(50 mV/div)
IOUT
(200 mA/div)
t – Time – 5 ms/div
Figure 5. Output Ripple Voltage
Figure 6. Load Transient
Figure 7. Switching Node Waveform
Figure 8. Switching Node Waveform
SLVA332A – October 2009 – Revised June 2010
3.6-V to 6-V Input, 3.3-V Output, Tiny, and High-Efficiency DC/DC Converter
Copyright © 2009–2010, Texas Instruments Incorporated
7
Test Results
www.ti.com
EFFICIENCY
vs
OUTPUT CURRENT
94
VOUT = 3.3 V
VIN = 5 V
93
h – Efficiency – %
92
91
90
89
88
87
86
85
0
0.1
0.2
0.3
0.4
0.5
IOUT – Output Current – A
Figure . Figure 9.
8
3.6-V to 6-V Input, 3.3-V Output, Tiny, and High-Efficiency DC/DC Converter
SLVA332A – October 2009 – Revised June 2010
Copyright © 2009–2010, Texas Instruments Incorporated
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