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TPS61080, TPS61081
SLVS644E – FEBRUARY 2006 – REVISED DECEMBER 2014
TPS6108x High-Voltage DC-DC Boost Converter With 0.5-A,1.3-A Integrated Switch
1 Features
3 Description
•
•
•
The TPS6108x is a 1.2 MHz/600 kHz fixed-frequency
boost regulator designed for high integration, which
integrates a power switch, an I/O isolation switch, and
a power diode. When a short-circuit condition is
detected, the isolation switch opens up to disconnect
the output from the input. As a result, the IC protects
itself and the input source from any pin, except VIN,
from being shorted to ground. The isolation switch
also disconnects the output from input during
shutdown to prevent any leakage current. Other
provisions for protection include 0.5 A/1.3 A peak-topeak overcurrent protection, programmable soft start
(SS), over voltage protection (OVP), thermal
shutdown, and under voltage lockout (UVLO).
1
•
•
•
•
•
•
•
•
•
2.5-V to 6-V Input Voltage Range
Up to 27-V Output Voltage
0.5-A Integrated Switch (TPS61080)
1.3-A Integrated Switch (TPS61081)
12-V/400-mA and 24-V/170-mA From 5-V Input
(Typical)
Integrated Power Diode
1.2-MHz/600-kHz Selectable Fixed Switching
Frequency
Input-to-Output Isolation
Short-Circuit Protection
Programmable Soft Start
Overvoltage Protection
Up to 87% Efficiency
10-Pin 3-mm × 3-mm QFN Package
The IC operates from input supplies including single
Li-ion battery, triple NiMH, and regulated 5 V, such as
USB output. The output can be boosted up to 27 V.
TPS6108x can provide the supply voltages of OLED,
TFT-LCD bias, 12-V and 24-V power rails. The output
of TPS6108x can also be configured as a current
source to power up to seven WLEDs in flash light
applications.
2 Applications
•
•
•
•
•
•
3.3-V to 12-V, 5-V to 12-V, and 24-V Boost
Converter
White LED Backlight for Media Form Factor
Display
OLED Power Supply
xDSL Applications
TFT-LCD Bias Supply
White LED Flash Light
Device Information(1)
PART NUMBER
TPS61080
TPS61081
PACKAGE
VSON (10)
BODY SIZE (NOM)
3.00 mm × 3.00 mm
(1) For all available packages, see the orderable addendum at
the end of the datasheet.
4 5-V To 12-V, 250-mA Step-Up DC-DC Converter
Vin 5V
TPS61081
VIN L
EN
C1
4.7 mF
L1 4.7 µH
SW
OUT
R3
100 Ω
FSW
Cs
47 nF
SS
GND
VO 12 V/250 mA
FB
PGND
L1: TDK VLCF5020T-4R7N1R7-1
C1: Murata GRM188R60J105K
C2: Murata GRM219R61C475K
R1
437 kW
C3
33 pF
4.7 µF
R2
49.9 kW
C3: Feed forward capacitor for stability
R3: Noise decoupling resistor
Cs: Soft start programming capacitor
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.
TPS61080, TPS61081
SLVS644E – FEBRUARY 2006 – REVISED DECEMBER 2014
www.ti.com
Table of Contents
1
2
3
4
5
6
7
8
9
Features ..................................................................
Applications ...........................................................
Description .............................................................
5-V To 12-V, 250-mA Step-Up DC-DC Converter.
Revision History.....................................................
Device Comparison Table.....................................
Pin Configuration and Functions .........................
Specifications.........................................................
1
1
1
1
2
3
3
4
8.1
8.2
8.3
8.4
8.5
8.6
4
4
4
4
5
6
Absolute Maximum Ratings ......................................
ESD Ratings..............................................................
Recommended Operating Conditions.......................
Thermal Information .................................................
Electrical Characteristics..........................................
Typical Characteristics ..............................................
Detailed Description .............................................. 9
9.1 Overview ................................................................... 9
9.2 Functional Block Diagram ......................................... 9
9.3 Feature Description................................................. 10
9.4 Device Functional Modes........................................ 11
10 Application and Implementation........................ 13
10.1 Application Information.......................................... 13
10.2 Typical Application ............................................... 15
10.3 System Examples ................................................. 18
11 Power Supply Recommendations ..................... 20
12 Layout................................................................... 20
12.1 Layout Guidelines ................................................. 20
12.2 Layout Example .................................................... 20
13 Device and Documentation Support ................. 21
13.1
13.2
13.3
13.4
13.5
Device Support......................................................
Related Links ........................................................
Trademarks ...........................................................
Electrostatic Discharge Caution ............................
Glossary ................................................................
21
21
21
21
21
14 Mechanical, Packaging, and Orderable
Information ........................................................... 21
5 Revision History
Changes from Revision D (April 2013) to Revision E
•
Page
Added Device Information and ESD Ratings tables, Feature Description section, Device Functional Modes,
Application and Implementation section, Power Supply Recommendations section, Layout section, Device and
Documentation Support section, and Mechanical, Packaging, and Orderable Information section ..................................... 1
Changes from Revision C (July 2011) to Revision D
Page
•
Changed Note 2 of the Electrical Characteristics table .......................................................................................................... 5
•
Changed the first paragraph of the START UP section ....................................................................................................... 10
Changes from Revision B (January 2007) to Revision C
Page
•
Added a Max value of 30µF to COUT in the Recommended Operating Conditions Table ...................................................... 4
•
Added sentence "The output capacitor value must be...." to the Input and Output Capacitor Selection section................. 16
Changes from Revision A (February 2006) to Revision B
•
Page
Changed from a 1 page Product Preview to the full data sheet............................................................................................. 1
Changes from Original (February 2006) to Revision A
•
2
Page
Changed the Typical Application circuit.................................................................................................................................. 1
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Copyright © 2006–2014, Texas Instruments Incorporated
Product Folder Links: TPS61080 TPS61081
TPS61080, TPS61081
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SLVS644E – FEBRUARY 2006 – REVISED DECEMBER 2014
6 Device Comparison Table
(1)
OVERCURRENT
LIMIT
PART NUMBER (1)
0.5-A (min)
TPS61080
1.3-A (min)
TPS61081
For complete orderable information see Mechanical, Packaging, and Orderable Information at the end of this data sheet.
7 Pin Configuration and Functions
10-Pin VSON
(DRC) Package with Thermal Pad
Top View
SW
L
VIN
SS
OUT
Thermal
Pad
PGND
FSW
GND
FB
EN
Pin Functions
PIN
NAME
NO.
I/O
DESCRIPTION
EN
6
I
Enable pin. When the voltage of this pin falls below enable threshold for more than 74 ms, the IC turns off
and consumes less than 2 μA current.
FB
5
I
Voltage feedback pin for the output regulation. It is regulated to an internal reference voltage. An external
voltage divider from the output to GND with the center tap connected to this pin programs the regulated
voltage. This pin can also be connected to a low side current sense resistor to program current regulation.
FSW
7
I
Switching frequency selection pin. Logic high on the pin selects 1.2 MHz, while logic low reduces the
frequency to 600 kHz for better light load efficiency.
GND
4
L
1
I
The inductor is connected between this pin and the SW pin. This pin connects to the source of the isolation
FET as well. Minimize trace area at this pin to reduce EMI.
OUT
9
O
Output of the boost regulator. When the output voltage exceeds the 27-V overvoltage protection (OVP)
threshold, the PWM switch turns off until Vout drops 0.7V below the overvoltage threshold.
PGND
8
Signal ground of the IC
Power ground of the IC. It is connected to the source of the PWM switch. This pin should be made very
close to the output capacitor in layout.
SS
3
I
Soft start programming pin. A capacitor between the SS pin and GND pin programs soft start timing.
SW
10
I
Switching node of the IC. Connect the inductor between this pin and the L pin.
VIN
2
I
Input pin to the IC. It is the input to the boost regulator, and also powers the IC circuit. It is connected to
the drain of the isolation FET as well.
Thermal Pad
–
The thermal pad should be soldered to the analog ground. If possible, use thermal via to connect to ground
plane for ideal power dissipation.
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Product Folder Links: TPS61080 TPS61081
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SLVS644E – FEBRUARY 2006 – REVISED DECEMBER 2014
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8 Specifications
8.1 Absolute Maximum Ratings
over operating free-air temperature range (unless otherwise noted) (1)
Supply Voltages on pin VIN (2)
Voltages on pins EN, FB, SS, L and FSW
(2)
MIN
MAX
UNIT
–0.3
7
V
7
V
Voltage on pin OUT (2)
–0.3
30V
V
Voltage on pin SW (2)
30V
V
Continuous Power Dissipation
See Thermal Information
Operating Junction Temperature Range
–40
150
°C
Storage temperature range
–65
150
°C
(1)
(2)
Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings
only, and functional operation of the device at these or any other conditions beyond those indicated under Recommended Operating
Conditions is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
All voltage values are with respect to network ground terminal.
8.2 ESD Ratings
VALUE
Human-body model (HBM), per ANSI/ESDA/JEDEC JS-001
V(ESD)
(1)
(2)
Electrostatic discharge
(1)
UNIT
±2000
Charged-device model (CDM), per JEDEC specification JESD22C101 (2)
V
±750
JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.
JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process.
8.3 Recommended Operating Conditions
over operating free-air temperature range (unless otherwise noted)
MIN
NOM
MAX
UNIT
VIN
Input voltage range
2.5
6.0
VOUT
Output voltage range
VIN
27
V
L
Inductor (1)
4.7
10
μH
CIN
Input capacitor (1)
μF
1
(1)
V
COUT
Output capacitor
4.7
30
μF
TA
Operating ambient temperature
–40
85
°C
TJ
Operating junction temperature
–40
125
°C
(1)
Refer to Application and Implementation for further information
8.4 Thermal Information
TPS6108x
THERMAL METRIC
(1)
DRC
UNIT
10 PINS
RθJA
Junction-to-ambient thermal resistance
45.3
RθJC(top)
Junction-to-case (top) thermal resistance
52.2
RθJB
Junction-to-board thermal resistance
20.9
ψJT
Junction-to-top characterization parameter
0.9
ψJB
Junction-to-board characterization parameter
20.7
RθJC(bot)
Junction-to-case (bottom) thermal resistance
5.3
(1)
4
°C/W
For more information about traditional and new thermal metrics, see the IC Package Thermal Metrics application report, SPRA953.
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8.5
SLVS644E – FEBRUARY 2006 – REVISED DECEMBER 2014
Electrical Characteristics
VIN = 3.6 V, EN = VIN, TA = –40°C to 85°C, typical values are at TA = 25°C (unless otherwise noted)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
SUPPLY CURRENT
VIN
Input voltage range
IQ
Operating quiescent current into VIN
Device switching no load
2.5
6.0
6
mA
ISD
Shutdown current
EN = GND
1
μA
VUVLO
Undervoltage lockout threshold
VIN falling
Vhys
Undervoltage lockout hysterisis
1.65
V
1.8
50
V
mV
ENABLE
VEN
Enable level voltage
VIN = 2.5 V to 6 V
Disable level voltage
VIN = 2.5 V to 6 V
Ren
Enable pulldown resistor
toff
EN pulse width to disable
1.2
400
EN high to low
V
0.4
800
1600
74
kΩ
ms
SOFT START
Iss
Soft start bias current
Vclp
SS pin to FB pin accuracy
TA = 25°C
4.75
5
5.25
4.6
5
5.4
VSS = 500 mV
487
500
513
mV
VFB = 1.229 V
–100
100
nA
1.229
1.254
V
0.06
0.1
Ω
VIN = VGS = 3.6 V
0.17
0.22
VIN = VGS = 2.5 V
0.2
0.32
1
2
μA
0.85
1
V
1
μA
μA
FEEDBACK FB
IFB
Feedback input bias current
VFB
Feedback regulation voltage
1.204
POWER SWITCH AND DIODE
Isolation MOSFET on-resistance
RDS(ON)
N-channel MOSFET on-resistance
ILN_NFET
N-channel leakage current
VDS = 28 V
VF
Power diode forward voltage
Id = 1 A
ILN_ISO
Isolation FET leakage current
L pin to ground
Ω
OC AND SC
TPS61080, FSW = High or FSW = Low
0.5
0.7
1.0
TPS61081, FSW = High or FSW = Low
1.3
1.6
2.0
TPS61080
1.0
2.2
TPS61081
2.0
3.5
ILIM
N-Channel MOSFET current limit (1)
ISC
Short circuit current limit
tscd
Short circuit delay time
13
μs
tscr
Short circuit release time
57
ms
VSC
OUT short detection threshold
1.4
V
(2)
VIN – VOUT
A
A
OSCILLATOR
FSW pin high
1.0
1.2
1.5
FSW pin low
0.5
0.6
0.7
90%
94%
FSW pin pulldown resistance
400
800
FSW high logic
1.6
fS
Oscillator frequency
Dmax
Maximum duty cycle
Dmin
Minimum duty cycle
Rfsw
VFSW
(1)
(2)
FB = 1.0 V
MHz
5%
FSW low logic
1600
kΩ
0.8
V
VIN = 3.6 V, VOUT = 15 V, Duty cycle = 76%. See Figure 5 to Figure 8 for other operation conditions.
OUT short circuit condition is detected if OUT stays lower than VIN – VSC for 1.7 ms after IC enables. See the Start Up section for
details.
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Electrical Characteristics (continued)
VIN = 3.6 V, EN = VIN, TA = –40°C to 85°C, typical values are at TA = 25°C (unless otherwise noted)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
28
29
UNIT
OVP
Vovp
Output overvoltage protection
VOUT rising
Output overvoltage protection hysteresis
VOUT falling
27
V
0.7
V
160
°C
15
°C
THERMAL SHUTDOWN
Tshutdown
Thermal shutdown threshold
Thysteresis
Thermal shutdown threshold hysteresis
8.6 Typical Characteristics
Table 1. Table Of Graphs
FIGURE
Efficiency
VS IOUT, VIN = 3.6 V OUT = 12 V, 15 V, 20 V, 25 V, FSW = HIGH, L = 4.7 μH
Figure 1
VS IOUT, VIN = 3.6 V OUT = 12 V, 15 V, 20 V, 25 V, FSW = LOW, L = 10 μH
Figure 2
VS IOUT, VIN = 3 V, 3.6 V, 5 V, OUT = 12 V, FSW = HIGH, L = 4.7 μH
Figure 3
VS IOUT, VIN = 3 V, 3.6 V, 5 V, OUT = 12 V, FSW = LOW, L = 10 μH
Figure 4
Overcurrent Limit
VIN = 3.0 V, 3.6 V, 5 V, FSW = High/Low
Figure 5,
Figure 6,
Figure 7, Figure 8
Line Regulation
TPS61081, VIN = 2.5 V to 6 V, OUT = 12 V, IOUT = 100 mA
Figure 9
Load Regulation
TPS61081, VIN = 3.6 V, OUT = 12 V
Figure 10
100
100
90
90
80
80
VO = 16 V
70
VO = 25 V
VO = 20 V
Efficiency - %
Efficiency - %
spacer
VO = 12 V
VO = 25 V
60
60
50
50
40
0
50
VI = 3.6 V
100
150
200
IO - Output Current - mA
250
300
VO = 20 V
70
40
0
50
VI = 3.6 V
FSW = HIGH
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100
150
200
IO - Output Current - mA
VO = 12 V
250
300
FSW = LOW
Figure 2. TPS61081 Efficiency
Figure 1. TPS61081 Efficiency
6
VO = 16 V
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100
100
90
90
80
80
VI = 3 V
VI = 5 V
VI = 3.6 V
Efficiency - %
Efficiency - %
www.ti.com
70
60
VI = 3.6 V
60
50
50
40
40
30
0
VI = 5 V
VI = 3 V
70
30
50
100
150
200
250
IO - Output Current - mA
VO = 12 V
300
0
350
50
100
150
200
250
300
350
IO - Output Current - mA
FSW = HIGH
VO = 12 V
Figure 3. TPS61081 Efficiency
FSW = LOW
Figure 4. TPS61081 Efficiency
1
1
VI = 3.6 V
0.8
0.8
0.6
VI = 3 V
Current Limit - A
Current Limit - A
VI = 3.6 V
VI = 5 V
0.4
0.2
0
20
0.6
VI = 3 V
VI = 5 V
0.4
0.2
30
40
50
60
Duty Cycle - %
70
80
0
20
90
30
40
FSW = LOW
50
60
Duty Cycle - %
70
80
90
FSW =HIGH
Figure 5. TPS61080 Overcurrent Limit
Figure 6. TPS61080 Overcurrent Limit
2
2
VI = 5 V
1.60
VI = 3.6 V
1.20
0.80
1.20
0.80
0.40
0.40
0
20
VI = 3.6 V
VI = 3 V
Current Limit - A
Current Limit - A
1.60
VI = 3 V
VI = 5 V
30
40
50
60
Duty Cycle - %
70
80
90
0
20
30
40
50
60
70
Duty Cycle - %
80
90
FSW = HIGH
FSW =LOW
Figure 7. TPS61081 Overcurrent Limit
Figure 8. TPS61081 Overcurrent Limit
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12.30
12.32
12.29
12.30
VO - Output Voltage - V
VO - Output Voltage - V
TA = 85 °C
12.28
12.27
12.26
TA = 25 °C
12.25
12.24
TA = -40 °C
TA = 85 °C
12.28
TA = 25 °C
12.26
12.24
TA = -40 °C
12.23
12.22
IO = 150 mA
12.22
12.21
2.5
VI = 5 V
12.20
3
3.5
4
4.5
5
VI - Input Voltage - V
5.5
Figure 9. TPS61081 Line Regulation
8
VI = 3.6 V
IO = 100 mA
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6
0
0.05
0.10
0.15
0.20
0.25
0.30
IO - Output Current - A
Figure 10. TPS61081 Load Regulation
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SLVS644E – FEBRUARY 2006 – REVISED DECEMBER 2014
9 Detailed Description
9.1 Overview
TPS6108x is a highly integrated boost regulator for up to 27-V output. In addition to the on-chip 0.5-A/1.2-A
PWM switch and power diode, this IC also builds in an input side isolation switch as shown in the block diagram.
One common issue with conventional boost regulator is the conduction path from input to output even when
PWM switch is turned off. It creates three problems, inrush current during start up, output leakage voltage under
shutdown, and unlimited short circuit current. To address these issues, TPS6108x turns off the isolation switch
under shutdown mode and short circuit condition to eliminate any possible current path.
TPS6108x adopts current mode control with constant PWM (pulse width modulation) frequency. The switching
frequency can be configured to either 600 kHz or 1.2 MHz through the FSW pin. 600 kHz improves light load
efficiency, while 1.2 MHz allows using smaller external component. The PWM operation turns on the PWM
switch at the beginning of each switching cycle. The input voltage is applied across the inductor and stores the
energy as inductor current ramps up. The load current is provided by the output capacitor. When the inductor
current across the threshold set by error amplifier output, the PWM switch is turned off, and the power diode is
forward biased. The inductor transfers its stored energy to replenish the output capacitor. This operation repeats
in the next switching cycle.
The error amplifier compares the FB pin voltage with an internal reference, and its output determines the duty
cycle of the PWM switching. This close loop system requires loop compensation for stable operation. TPS6108x
has internal compensation circuitry which accommodates a wide range of input and output voltages. The
TPS6108x integrates slope compensation to the current ramp to avoid the sub-harmonic oscillation that is
intrinsic to current mode control schemes.
9.2 Functional Block Diagram
L1
2
1
VIN
10
L
Charge
Pump
C1
EN
EN
6
SW
Current
Sensor
OUT
SC
OVP
ShortCircuit
BandGap
SS
1.229V
3
Ramp
Generator
SC
OVP
+
9
OVP
R1
Oscillator
Thermal
Shutdown
1.2MHz
600KHz
C2
Clamp
MUX
Cs
FB
C3
PWM
Control
R2
Error
Amplifer
5
FSW
7
PGND
GND
8
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4
R3
FB
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9.3 Feature Description
9.3.1 Start Up
TPS6108x turns on the isolation FET when the EN pin is pulled high, provided that the input voltage is higher
than the undervoltage lockout threshold. The Vgs of the isolation FET is clamped to maintain high on-resistance
and limits the current to 30mA charging the output capacitor. This feature limits the in-rush current and maximum
start up current to 30mA. Once the output capacitor is charged to VIN, the IC removes the Vgs clamp to fully turn
on the isolation FET and at the same time actives soft start by charging the capacitor on the SS pin. If OUT stays
lower than VIN-Vsc following a 1.7ms delay after enable is taken high, the IC recognizes a short circuit condition.
In this case, the isolation FET turns off, and IC remains off until the EN pin toggles or VIN cycles through power
on reset (POR).
During the soft start phase, the SS pin capacitor is charged by internal bias current of the SS pin. The SS pin
capacitor programs the ramp up slope. The SS pin voltage clamps the reference voltage of the FB pin, therefore
the output capacitor rise time follows the SS pin voltage. Without the soft start, the inductor current could reach
the overcurrent limit threshold, and there is potential for output overshoot. see the Application and
Implementation section on selecting soft start capacitor values. Pulling the SS pin to ground disables the PWM
switching. However, unlike being disabled by pulling EN low, the IC continues to draw quiescent current and the
isolation FET remains on.
9.3.2 Overcurrent and Short Circuit Protection
TPS6108x has a pulse by pulse overcurrent limit feature which turns off the power switch once the inductor
current reaches the overcurrent limit. The PWM circuitry resets itself at the beginning of the next switch cycle.
The overcurrent threshold determines the available output current. However, the maximum output is also a
function of the input voltage, output voltage, switching frequency and inductor value. Larger inductor values and
1.2MHz switching frequency increase the current output capability because of the reduced current ripple. See the
APPLICATION INFORMATION section for the maximum output current calculation.
In typical boost converter topologies, if the output is grounded, turning off the power switch does not limit the
current because a current path exists from the input to output through the inductor and power diode. To eliminate
this path, TPS6108x turns off the isolation FET between the input and the inductor. This circuit is triggered when
the inductor current remains above short circuit current limit for more than 13μs, or the OUT pin voltage falls
below VIN-1.4V for more than 1.7ms. An internal catch-diode between the L pin and ground turns on to provide a
current discharge path for the inductor. If the short is caused by the output being low, then the IC shuts down
and waits for EN to be toggled or a POR. If the short protection is triggered by short circuit current limit, the IC
attempts to start up one time. After 57ms, the IC restarts in a fashion described in the above section. If the short
is cleared, the boost regulator properly starts up and reaches output regulation. However, after reaching
regulation, if another event of short circuit current limit occurs, the IC goes into shutdown mode again, and the
fault can only be cleared by toggling the EN pin or POR. Under a permanent short circuit, the IC shuts down after
a start up failure and waits for POR or the EN pin toggling.
The same circuit also protects the ICs and external components when the SW pin is shorted to ground. These
features provide much more comprehensive and reliable protection than the conventional boost regulator.
Table 2 lists the IC protection against the short of each IC pin.
10
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SLVS644E – FEBRUARY 2006 – REVISED DECEMBER 2014
Feature Description (continued)
Table 2. TPS6108x Short Circuit Protection Mode
SHORTED TO GND
FAULT DETECTION
IC OPERATION
HOW TO CLEAR THE FAULT
L, SW
INDUCTOR > ISC for 13 μs
Turn off isolation FET
IC restarts after 57ms; If it happens again,
the fault can only be cleared by toggling
EN or POR.
OUT (during start
up)
OUT
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