TI TPS61085TDGKR

TPS61085T
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SLVSA41A – NOVEMBER 2009 – REVISED DECEMBER 2009
650-kHz/1.2-MHz 18.5-V STEP-UP DC-DC CONVERTER
Check for Samples: TPS61085T
FEATURES
APPLICATIONS
•
•
•
•
•
•
•
•
•
1
•
•
•
•
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2.3-V to 6-V Input Voltage Range
18.5-V Boost Converter With 2.0-A Switch
Current
650-kHz/1.2-MHz Selectable Switching
Frequency
Adjustable Soft-Start
Thermal Shutdown
Undervoltage Lockout
8-Pin MSOP Package
Handheld Devices
GPS Receiver
Digital Still Camera
Portable Applications
DSL Modem
PCMCIA Card
TFT LCD Bias Supply
DESCRIPTION
The TPS61085 is a high-frequency high-efficiency dc-to-dc converter with an integrated 2.0-A 0.13-Ω power
switch capable of providing an output voltage up to 18.5 V. The selectable frequency of 650 kHz and 1.2 MHz
allows the use of small external inductors and capacitors and provides fast transient response. The external
compensation allows optimizing the application for specific conditions. A capacitor connected to the soft-start pin
minimizes inrush current at startup.
L
3.3 mH
VIN
2.3 V to 6 V
6
CIN
Cby
1 mF
16 V
5
IN
3
10 mF
16 V
D
PMEG2010AEH
VS
12 V/300 mA
SW
EN
2
R1
156 kW
Cout
1
R2
18 kW
2* 10 mF
25 V
FB
7
COMP
FREQ
4
Rcomp
51 kW
8
GND
SS
TPS61085
Css
100 nF
Ccomp
1.6 nF
1
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas
Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2009, Texas Instruments Incorporated
TPS61085T
SLVSA41A – NOVEMBER 2009 – REVISED DECEMBER 2009
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This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with
appropriate precautions. Failure to observe proper handling and installation procedures can cause damage.
ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be more
susceptible to damage because very small parametric changes could cause the device not to meet its published specifications.
ORDERING INFORMATION (1)
PACKAGE (2)
TA
–40°C to 105°C
(1)
(2)
ORDERABLE PART NUMBER
TOP-SIDE MARKING
MSOP-8 – DGK
Reel of 2500
TPS61085TDGKR
PTQI
TSSOP-8 – PW
Reel of 2000
TPS61085TPWR
61085T
For the most current package and ordering information, see the Package Option Addendum at the end of this document, or see the TI
web site at www.ti.com.
Package drawings, thermal data, and symbolization are available at www.ti.com/packaging.
ABSOLUTE MAXIMUM RATINGS
over operating free-air temperature range (unless otherwise noted) (1)
VALUE
UNIT
Input voltage range IN (2)
–0.3 to 7
V
Voltage range on pins EN, FB, SS, FREQ, COMP
–0.3 to 7
V
Voltage on pin SW
20
V
ESD rating HBM
2
kV
ESD rating MM
200
V
ESD rating CDM
500
V
Continuous power dissipation
See Dissipation Rating Table
Operating junction temperature range
–40 to 150
°C
Storage temperature range
–65 to 150
°C
260
°C
Lead temperature (soldering, 10 sec)
(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.
DISSIPATION RATINGS (1)
(1)
(2)
(2)
PACKAGE
RθJA
TA ≤ 25°C
POWER RATING
TA = 70°C
POWER RATING
TA = 105°C
POWER RATING
MSOP
181°C/W
552 mW
303 mW
110 mW
TSSOP
160°C/W
625 mW
343 mW
125 mW
PD = (TJ – TA) / RθJA
RθJA given for High-K PCB board
RECOMMENDED OPERATING CONDITIONS
MIN
VIN
Input voltage range
VS
Boost output voltage range
TA
TJ
2
TYP
MAX
UNIT
2.3
6
V
VIN +
0.5
18.5
V
Operating free-air temperature
–40
105
°C
Operating junction temperature
–40
125
°C
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ELECTRICAL CHARACTERISTICS
VIN = 3.3 V, EN = IN, VS = 12 V, TA = –40°C to 105°C, typical values are at TA = 25°C (unless otherwise noted)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
6
V
70
100
μA
SUPPLY
VIN
Input voltage range
IQ
Operating quiescent current into IN
Device not switching, VFB = 1.3 V
ISDVIN
Shutdown current into IN
EN = GND
1
μA
UVLO
Undervoltage lockout threshold
VIN falling
2.2
V
VIN rising
2.3
V
TSD
Thermal shutdown
TSD(HYS)
Thermal shutdown hysteresis
2.3
Temperature rising
150
°C
14
°C
LOGIC SIGNALS EN, FREQ
VIH
High level input voltage
VIN = 2.3 V to 6 V
VIL
Low level input voltage
VIN = 2.3 V to 6 V
2
0.5
V
V
Ilkg
Input leakage current
EN = FREQ = GND
0.1
μA
18.5
V
1.246
V
BOOST CONVERTER
VS
Boost output voltage
VIN +
0.5
VFB
Feedback regulation voltage
1.230
gm
Transconductance error amplifier
IFB
Feedback input bias current
VFB = 1.238 V
RDS(on)
N-channel MOSFET on-resistance
VIN = VGS = 5 V, ISW = current limit
VIN = VGS = 3.3V, ISW = current limit
1.238
μA/V
107
0.1
μA
0.13
0.20
Ω
0.15
0.24
2.0
2.6
3.2
A
7
10
13
μA
MHz
Ilkg
SW leakage current
ILIM
N-Channel MOSFET current limit
EN = GND, VSW = 6V
ISS
Soft-start current
VSS = 1.238 V
fosc
Oscillator frequency
FREQ = high
0.9
1.2
1.5
FREQ = low
480
650
820
Line regulation
VIN = 2.3 V to 6 V, IOUT = 10 mA
Load regulation
VIN = 3.3 V, IOUT = 1 mA to 400 mA
10
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kHz
0.0002
%/V
0.11
%/A
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µA
3
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SLVSA41A – NOVEMBER 2009 – REVISED DECEMBER 2009
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PIN ASSIGNMENT
DGK, PW PACKAGES
(TOP VIEW)
COMP
1
8
SS
FB
2
7
FREQ
EN
3
6
IN
PGND
4
5
SW
8-PIN 4.9mm x 3mm x 1.1mm MSOP (DGK)
8-PIN 6.4mm x 3mm x 1.2mm TSSOP (PW)
TERMINAL FUNCTIONS
TERMINAL
NAME
NO.
I/O
DESCRIPTION
COMP
1
I/O
FB
2
I
Feedback pin
EN
3
I
Shutdown control input. Connect this pin to logic high level to enable the device
PGND
4
Power ground
SW
5
Switch pin
IN
6
Input supply pin
FREQ
7
SS
8
4
I
Compensation pin
Frequency select pin. The power switch operates at 650 kHz if FREQ is connected to GND and at 1.2 MHz if
FREQ is connected to IN
Soft-start control pin. Connect a capacitor to this pin if soft-start needed. Open = no soft-start
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SLVSA41A – NOVEMBER 2009 – REVISED DECEMBER 2009
TYPICAL CHARACTERISTICS
TABLE OF GRAPHS
FIGURE
η
Efficiency
vs Load current, VS = 12 V, VIN = 3.3V
Figure 1
η
Efficiency
vs Load current, VS = 9 V, VIN = 3.3 V
Figure 2
PWM switching - discontinuous conduction
Figure 3
PWM switching - continuous conduction
Figure 4
Load transient response
at High frequency
Figure 5
Load transient response
at Low frequency
Figure 6
Soft-start
Figure 7
Supply current
vs Supply voltage
Figure 8
Frequency
vs Load current
Figure 9
Frequency
vs Supply voltage
Figure 10
EFFICIENCY
vs
LOAD CURRENT
100
EFFICIENCY
vs
LOAD CURRENT
100
f = 650 kHz
L = 6.8 mH
90
80
80
f = 1.2 Mhz
L = 3.3 mH
f = 1.2 Mhz
L = 3.3 mH
70
Efficiency = %
70
Efficiency = %
f = 650 kHz
L = 6.8 mH
90
60
50
40
60
50
40
30
30
20
20
VIN = 3.3 V
VS = 12 V
10
0
VIN = 3.3 V
VS = 9 V
10
0
0
0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50
0
0.10
IO - Load current - A
0.20
0.30
0.40
0.50
0.60
0.70 0.80
IO - Load current - A
Figure 1.
Figure 2.
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PWM SWITCHING
DISCONTINUOUS CONDUCTION MODE
PWM SWITCHING
CONTINUOUS CONDUCTION MODE
VSW
5 V/div
VSW
5 V/div
VS_AC
50 mV/div
VS_AC
50 mV/div
VIN = 3.3 V
VS = 12 V/1 mA
IL
1 A/div
VIN = 3.3 V
VS = 12 V/300 mA
IL
200 mA/div
200 ns/div
200 ns/div
Figure 3.
Figure 4.
LOAD TRANSIENT RESPONSE
HIGH FREQUENCY (1.2 MHz)
LOAD TRANSIENT RESPONSE
LOW FREQUENCY (650 kHz)
Cout = 20 mF
VIN = 3.3 V
VS = 12 V
VS_AC
200 mV/div
Cout = 20 mF
VIN = 3.3 V
VS = 12 V
L = 3.3 mH
Rcomp = 51 kW
Ccomp = 1.6 nF
L = 6.8 mH
Rcomp = 24 kW
Ccomp = 3.3 nF
VS_AC
200 mV/div
IOUT = 50 mA - 200 mA
IOUT = 50 mA - 200 mA
IOUT
100 mA/div
IOUT
100 mA/div
200µs/div
200 ms/div
200 ms/div
Figure 5.
6
Figure 6.
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SLVSA41A – NOVEMBER 2009 – REVISED DECEMBER 2009
SUPPLY CURRENT
vs
SUPPLY VOLTAGE
SOFT-START
2
1.8
EN
5 V/div
Switching
f = 1.2 Mhz
L = 3.3 mH
ICC - Supply Current - mA
1.6
VIN = 3.3 V
VS = 12 V/300 mA
VS
5 V/div
CSS = 100 nF
IL
1 A/div
1.4
1.2
1
0.8
Switching
f = 650 kHz
L = 6.8 mH
0.6
0.4
Not Switching
0.2
2 ms/div
0
2
2.5
3
3.5
4
4.5
5
VCC - Supply Current - V
Figure 7.
Figure 8.
FREQUENCY
vs
LOAD CURRENT
FREQUENCY
vs
SUPPLY VOLTAGE
1600
FREQ = VIN
VIN = 3.3 V
VS = 12 V
1200
FREQ = VIN
L = 3.3 mH
L = 3.3 mH
1000
f - Frequency - kHz
f - Frequency - kHz
1200
1000
FREQ = GND
L = 6.8 mH
600
800
FREQ = GND
L = 6.8 mH
600
400
400
200
200
0
0
6
1400
1400
800
5.5
VS = 12 V / 200 mA
0
0.1
0.3
0.2
0.4
IO - Load current - mA
0.5
0.6
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
VCC - Supply Voltage - V
Figure 9.
Figure 10.
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DETAILED DESCRIPTION
VIN
VS
EN
SS
IN
SW
FREQ
Current limit
and
Soft Start
Toff Generator
Bias Vref = 1.24 V
UVLO
Thermal Shutdown
Ton
PWM
Generator
Gate Driver of
Power
Transistor
COMP
GM Amplifier
FB
Vref
PGND
Figure 11. Block Diagram
The boost converter is designed for output voltages up to 18.5 V with a switch peak current limit of 2.0 A
minimum. The device, which operates in a current mode scheme with quasi-constant frequency, is externally
compensated for maximum flexibility and stability. The switching frequency is selectable between 650 kHz and
1.2 MHz and the minimum input voltage is 2.3 V. To control the inrush current at start-up a soft-start pin is
available.
During the on-time, the voltage across the inductor causes the current in it to rise. When the current reaches a
threshold value set by the internal GM amplifier, the power transistor is turned off, the energy stored into the
inductor is then released and the current flows through the Schottky diode towards the output of the boost
converter. The off-time is fixed for a certain VIN and VS, and therefore maintains the same frequency when
varying these parameters.
However, for different output loads, the frequency may slightly change due to the voltage drop across the Rdson
of the power transistor which will have an effect on the voltage across the inductor and thus on tON (tOFF remains
fixed). Some slight frequency changes might also appear with a fixed output load due to the fact that the output
voltage VS is not sensed directly but via the SW Pin, which affects accuracy.
Because of the quasi-constant frequency behavior of the device, the TPS61085 eliminates the need for an
internal oscillator and slope compensation, which provides better stability for the system over a wide of input and
output voltages range, and more stable and accurate current limiting operation compared to boost converters
operating with a conventional PWM scheme. The TPS61085 topology has also the benefits of providing very
good load and line regulations, and excellent load transient response.
8
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Design Procedure
The first step in the design procedure is to verify that the maximum possible output current of the boost converter
supports the specific application requirements. A simple approach is to estimate the converter efficiency, by
taking the efficiency numbers from the provided efficiency curves or to use a worst case assumption for the
expected efficiency, e.g. 90%.
D = 1-
1. Duty Cycle:
VIN ´h
VS
DI ö
æ
Iout = ç I swpeak - L ÷ ´ (1 - D )
2 ø
è
2. Maximum output current:
3. Peak switch current:
DI L =
with
I swpeak =
I
DI L
+ out
2 1- D
VIN ´ D
fs ´ L
and
Iswpeak = converter switch current (minimum switch current limit = 2.0 A)
fs = Converter switching frequency (typically 1.2 MHz)
L = Selected inductor value
η = Estimated converter efficiency (please use the number from the efficiency plots or 90% as an estimation)
ΔIL = Inductor peak-to-peak ripple current
The peak switch current is the steady state peak switch current that the integrated switch, inductor and external
Schottky diode has to be able to handle. The calculation must be done for the minimum input voltage where the
peak switch current is the highest.
Soft-start
The boost converter has an adjustable soft-start to prevent high inrush current during start-up. To minimize the
inrush current during start-up an external capacitor connected to the soft-start pin SS is used to slowly ramp up
the internal current limit of the boost converter when charged with a constant current. When the EN pin is pulled
high, the soft-start capacitor CSS) is immediately charged to 0.3 V. The capacitor is then charged at a constant
current of 10 μA typically until the output of the boost converter VS has reached its Power Good threshold (90%
of VS nominal value). During this time, the SS voltage directly controls the peak inductor current, starting with 0 A
at VSS = 0.3 V up to the full current limit at VSS ≈ 800 mV. The maximum load current is available after the
soft-start is completed. The larger the capacitor the slower the ramp of the current limit and the longer the
soft-start time. A 100 nF capacitor is usually sufficient for most of the applications. When the EN pin is pulled
low, the soft-start capacitor is discharged to ground.
Inductor Selection
The TPS61085 is designed to work with a wide range of inductors. The main parameter for the inductor selection
is the saturation current of the inductor which should be higher than the peak switch current as calculated in the
Design Procedure section with additional margin to cover for heavy load transients. An alternative, more
conservative, is to choose an inductor with a saturation current at least as high as the maximum switch current
limit of 3.2 A. The other important parameter is the inductor dc resistance. Usually, the lower the dc resistance
the higher the efficiency. It is important to note that the inductor dc resistance is not the only parameter
determining the efficiency. Especially for a boost converter where the inductor is the energy storage element, the
type and core material of the inductor influences the efficiency as well. At high switching frequencies of 1.2 MHz
inductor core losses, proximity effects and skin effects become more important. Usually, an inductor with a larger
form factor gives higher efficiency. The efficiency difference between different inductors can vary between 2% to
10%. For the TPS61085, inductor values between 3 μH and 6 μH are a good choice with a switching frequency
of 1.2 MHz, typically 3.3 μH. At 650 kHz we recommend inductors between 6 μH and 13 μH, typically 6.8 μH.
Possible inductors are shown in Table 1.
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Typically, it is recommended that the inductor current ripple is below 20% of the average inductor current. The
following equation can therefore be used to calculate the inductor value:
2
æ VS-VIN ö æ h ö
æ VIN ö
L= ç
×ç
÷×ç
÷
÷
è VS ø
è Iout_max×f ø è 0.35 ø
(1)
Table 1. Inductor Selection
L
(μH)
SUPPLIER
COMPONENT
CODE
SIZE
(L×W×H mm)
DCR TYP
(mΩ)
Isat (A)
3.3
Sumida
CDH38D09
4.7
4x4x1
240
1.25
Sumida
CDPH36D13
5 × 5 × 1.5
155
3.3
1.36
Sumida
CDPH4D19F
5.2 x 5.2 x 2
33
1.5
1.2 MHz
3.3
Sumida
CDRH6D12
6.7 x 6.7 x 1.5
62
2.2
4.7
Würth Elektronik
7447785004
5.9 × 6.2 × 3.3
60
2.5
5
Coilcraft
MSS7341
7.3 × 7.3 × 4.1
24
2.9
6.8
Sumida
CDP14D19
5.2 x 5.2 x 2
50
1
10
Coilcraft
LPS4414
4.3 × 4.3 × 1.4
380
1.2
6.8
Sumida
CDRH6D12/LD
6.7 x 6.7 x 1.5
95
1.25
10
Sumida
CDR6D23
5 × 5 × 2.4
133
1.75
10
Würth Elektronik
744778910
7.3 × 7.3 × 3.2
51
2.2
6.8
Sumida
CDRH6D26HP
7 x 7 x 2.8
52
2.9
650 kHz
Rectifier Diode Selection
To achieve high efficiency, a Schottky type should be used for the rectifier diode. The reverse voltage rating
should be higher than the maximum output voltage of the converter. The averaged rectified forward current Iavg,
the Schottky diode needs to be rated for, is equal to the output current Iout:
I avg = I out
(2)
Usually a Schottky diode with 2 A maximum average rectified forward current rating is sufficient for most
applications. The Schottky rectifier can be selected with lower forward current capability depending on the output
current Iout but has to be able to dissipate the power. The dissipated power is the average rectified forward
current times the diode forward voltage.
PD = Iavg × Vforward
Typically the diode should be able to dissipate around 500mW depending on the load current and forward
voltage.
Table 2. Rectifier Diode Selection
10
CURRENT
RATING Iavg
Vr
Vforward / Iavg
SUPPLIER
COMPONENT
CODE
PACKAGE
TYPE
750 mA
20 V
0.425 V /
750 mA
Fairchild Semiconductor
FYV0704S
SOT 23
1A
20 V
0.39 V / 1 A
NXP
PMEG2010AEH
SOD 123
1A
20 V
0.52 V / 1 A
Vishay Semiconductor
B120
SMA
1A
20 V
0.5 V / 1 A
Vishay Semiconductor
SS12
SMA
1A
20 V
0.44 V / 1 A
Vishay Semiconductor
MSS1P2L
μ-SMP (Low
Profile)
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Setting the Output Voltage
The output voltage is set by an external resistor divider. Typically, a minimum current of 50 μA flowing through
the feedback divider gives good accuracy and noise covering. A standard low side resistor of 18 kΩ is typically
selected. The resistors are then calculated as:
R2 =
Vref
» 18k W
70 m A
æ VS
ö
R1 = R 2 ´ ç
- 1÷
è Vref
ø
(3)
Compensation (COMP)
The regulator loop can be compensated by adjusting the external components connected to the COMP pin. The
COMP pin is the output of the internal transconductance error amplifier. Standard values of RCOMP = 13 kΩ and
CCOMP = 3.3 nF will work for the majority of the applications.
Please refer to Table 3 for dedicated compensation networks giving an improved load transient response. The
following equations can be used to calculate RCOMP and CCOMP:
125 × V IN × V S × Cout
L × Iout_max
R COMP =
C COMP =
V S × Cout
5 × Iout_max × R COMP
(4)
Table 3. Recommended Compensation Network Values at High/Low Frequency
FREQUENCY
L
VS
15 V
High (1.2 MHz)
3.3 µH
12 V
9V
15 V
Low (650 kHz)
6.8 µH
12 V
9V
VIN ± 20%
RCOMP
CCOMP
5V
82 kΩ
1.1 nF
3.3 V
75 kΩ
1.6 nF
5V
51 kΩ
1.1 nF
3.3 V
47 kΩ
1.6 nF
5V
30 kΩ
1.1 nF
3.3 V
27 kΩ
1.6 nF
5V
43 kΩ
2.2 nF
3.3 V
39 kΩ
3.3 nF
5V
27 kΩ
2.2 nF
3.3 V
24 kΩ
3.3 nF
5V
15 kΩ
2.2 nF
3.3 V
13 kΩ
3.3 nF
Table 3 gives conservatives Rcomp and Comp values for certain inductors, input and output voltages providing a
very stable system. For a faster response time, a higher Rcomp value can be used to enlarge the bandwidth, as
well as a slightly lower value of Ccomp to keep enough phase margin. These adjustments should be performed
in parallel with the load transient response monitoring of TPS61085.
Input Capacitor Selection
For good input voltage filtering low ESR ceramic capacitors are recommended. TPS61085 has an analog input
IN. Therefore, a 1 μF bypass is highly recommended as close as possible to the IC from IN to GND.
One 10 μF ceramic input capacitors are sufficient for most of the applications. For better input voltage filtering
this value can be increased. Refer to Table 4 and typical applications for input capacitor recommendations.
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Output Capacitor Selection
For best output voltage filtering a low ESR output capacitor like ceramic capcaitor is recommended. Two 10 μF
ceramic output capacitors (or one 22 μF) work for most of the applications. Higher capacitor values can be used
to improve the load transient response. Refer to Table 4 for the selection of the output capacitor.
Table 4. Rectifier Input and Output Capacitor Selection
CAPACITOR
VOLTAGE RATING
SUPPLIER
COMPONENT CODE
CIN
10 μF/1206
16 V
Taiyo Yuden
EMK212 BJ 106KG
IN bypass
1 μF/0603
16 V
Taiyo Yuden
EMK107 BJ 105KA
COUT
10 μF/1206
25 V
Taiyo Yuden
TMK316 BJ 106KL
Frequency Select Pin (FREQ)
The frequency select pin FREQ allows to set the switching frequency of the device to 650 kHz (FREQ = low) or
1.2 MHz (FREQ = high). Higher switching frequency improves load transient response but reduces slightly the
efficiency. The other benefits of higher switching frequency are a lower output ripple voltage. Usually, it is
recommended to use 1.2 MHz switching frequency unless light load efficiency is a major concern.
Undervoltage Lockout (UVLO)
To avoid mis-operation of the device at low input voltages an undervoltage lockout is included that disables the
device, if the input voltage falls below 2.2 V.
Thermal Shutdown
A thermal shutdown is implemented to prevent damages due to excessive heat and power dissipation. Typically
the thermal shutdown threshold is 150°C. When the thermal shutdown is triggered the device stops switching
until the temperature falls below typically 136°C. Then the device starts switching again.
12
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Copyright © 2009, Texas Instruments Incorporated
Product Folder Link(s): TPS61085T
TPS61085T
www.ti.com
SLVSA41A – NOVEMBER 2009 – REVISED DECEMBER 2009
APPLICATION INFORMATION
L
3.3 mH
VIN
3.3 V ±20%
6
Cin
10 mF
16 V
Cby
1 mF
16 V
5
IN
3
VS
12 V/600 mA max
SW
EN
2
R1
156 kW
Cout
1
R2
18 kW
2* 10 mF
25 V
FB
7
FREQ
4
D
PMEG2010AEH
COMP
Rcomp
51kW
8
GND
SS
Css
TPS61085
Ccomp
1.6 nF
100 nF
Figure 12. Typical Application, 3.3 V to 12 V (fsw = 1.2 MHz)
L
6.8 mH
VIN
3.3 V ±20%
6
Cin
10 mF
16 V
Cby
1 mF
16 V
SW
IN
3
EN
5
D
PMEG2010AEH
VS
12 V/600 mA max
2
R1
156 kW
Cout
1
R2
18 kW
2* 10 mF
25 V
FB
7
FREQ
COMP
4
Rcomp
24 kW
8
GND
SS
TPS61085
Css
Ccomp
3.3 nF
100 nF
Figure 13. Typical Application, 3.3 V to 12 V (fsw = 650 kHz)
Submit Documentation Feedback
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Product Folder Link(s): TPS61085T
13
TPS61085T
SLVSA41A – NOVEMBER 2009 – REVISED DECEMBER 2009
www.ti.com
L
3.3 mH
VIN
3.3 V ±20%
6
Cin
10 mF
16 V
Cby
1 mF
16 V
SW
IN
3
EN
5
D
PMEG2010AEH
VS
9 V/800 mA max
2
R1
113 kW
Cout
1
R2
18 kW
2* 10 mF
25 V
FB
7
FREQ
COMP
4
Rcomp
28 kW
8
GND
SS
Css
TPS61085
Ccomp
1.6 nF
100 nF
Figure 14. Typical Application, 3.3 V to 9 V (fsw = 1.2 MHz)
L
6.8 mH
VIN
3.3 V ±20%
6
Cin
10 mF
16 V
Cby
1 mF
16 V
SW
IN
3
EN
5
D
PMEG2010AEH
VS
9 V/800 mA max
2
R1
113 kW
Cout
1
R2
18 kW
2* 10 mF
25 V
FB
7
FREQ
COMP
4
Rcomp
14 kW
8
GND
SS
TPS61085
Css
Ccomp
3.3 nF
100 nF
Figure 15. Typical Application, 3.3 V to 9 V (fsw = 650 kHz)
14
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Copyright © 2009, Texas Instruments Incorporated
Product Folder Link(s): TPS61085T
TPS61085T
www.ti.com
SLVSA41A – NOVEMBER 2009 – REVISED DECEMBER 2009
Riso
10 kW
L
6.8 mH
VIN
3.3 V ±20%
Cby
1 mF/16 V 6
3
Cin
10 mF
16 V
7
4
IN
SW
EN
FB
FREQ
COMP
GND
SS
D
PMEG2010AEH
5
Ciso
1 mF/ 25 V
2
VS
12 V/300 mA
BC857C
Rff1
156 kW
1
8
Css
100nF
TPS61085
Rff2
18 kW
Rcomp
24 kW
Cout
2*10 mF
25 V
Ccomp
3.3 nF
Figure 16. Typical Application with External Load Disconnect Switch
TFT LCD APPLICATION
Vgl
-7 V/ 20 mA
T1
BC857B
-Vs
C4
100nF/
50V
D2
BAT54S
C3
100 nF
50 V
C2
R8
7 kW 470 nF
25 V
C1
1µF/
35V
D3
BAT54S
D1
BZX84C7V5
D4
BAT54S
C6
470 nF
50 V
D5
BAT54S
C5
100 nF
50 V
D6
BAT54S
R10
13 kW
2.Vs
C7
470 nF
50 V
Vgh
20 V/20 mA
T2
BC850B
3.Vs
C8
1 µF
35 V
D8
BZX84C 20V
D7
BAT54S
L
3.3µH
VIN
3.3 V± 20%
6
Cin
10 µF
16 V
Cby
1 µF
16 V
5
VIN
SW
EN
FB
3
D
PMEG2010AEH
R1
113 kW
2
7
R2
18 kW
1
FREQ
COMP
SS
GND
TPS 61085
Cout
2*10 µF
25 V
Rcomp
28 kW
8
4
VS
9 V/500 mA
Css
Ccomp
1.6 nF
100 nF
Figure 17. Typical Application 3.3 V to 9 V (fsw = 1.2 MHz) for TFT LCD with External Charge Pumps
(VGH, VGL)
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Product Folder Link(s): TPS61085T
15
TPS61085T
SLVSA41A – NOVEMBER 2009 – REVISED DECEMBER 2009
www.ti.com
WHITE LED APPLICATIONS
L
6.8 mH
VIN
3.3 V ± 20%
Cin
10 mF/
16 V
Cby
1 mF/ 16 V
D
PMEG2010AEH
6
3
7
4
IN
SW
EN
FB
FREQ
COMP
PGND
SS
5
Dz
BZX84C 18 V
VS
300 mA
3S3P wLED
LW E67C
2
Cout
2* 10 mF/
25 V
1
Rcomp
24 kW
8
Css
100 nF
TPS61085
Rsense
14 W
Ccomp
3.3 nF
Figure 18. Simple Application (3.3V input - fsw = 650 kHz) for wLED Supply (3S3P) (with optional
clamping Zener diode)
L
6.8 mH
VIN
3.3 V ± 20%
Cin
10 mF/
16 V
Cby
1 mF/ 16 V
D
PMEG2010AEH
6
3
7
4
IN
SW
EN
FB
FREQ
COMP
PGND
SS
PWM
100 Hz to 500 Hz
TPS61085
5
Dz
BZX84C 18 V
2
VS
300 mA
3S3P wLED
LW E67C
Cout
2* 10 mF/
25 V
1
Rcomp
24 kW
8
Css
100 nF
Ccomp
3.3 nF
Rsense
14 W
Figure 19. Simple Application (3.3V input - fsw = 650 kHz) for wLED Supply (3S3P) with Adjustable
Brightness Control using a PWM Signal on the Enable Pin (with optional clamping Zener diode)
16
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Copyright © 2009, Texas Instruments Incorporated
Product Folder Link(s): TPS61085T
TPS61085T
www.ti.com
SLVSA41A – NOVEMBER 2009 – REVISED DECEMBER 2009
L
6.8 mH
VIN
3.3 V ± 20%
Cin
10 mF/
16 V
Cby
1 mF/ 16 V
D
PMEG2010AEH
6
3
7
4
IN
SW
EN
FB
FREQ
COMP
PGND
SS
TPS61085
5
Dz
BZX84C 18 V
3S3P wLED
LW E67C
2
Cout
2* 10 mF/
25 V
R1
1
Rcomp
24 kW
8
Css
100 nF
Ccomp
3.3 nF
VS
300 mA
180 kW
R2
127 kW
Rsense
14 W
Analog Brightness Control
3.3 V ~ wLED off
0 V ~ lled = 30 mA (each string)
PWM Signal
Can be used Swinging from 0 V to 3.3 V
Figure 20. Simple Application (3.3V input - fsw = 650 kHz) for wLED Supply (3S3P) with Adjustable
Brightness Control using an Analog Signal on the Feedback Pin (with optional clamping Zener diode)
Submit Documentation Feedback
Copyright © 2009, Texas Instruments Incorporated
Product Folder Link(s): TPS61085T
17
PACKAGE OPTION ADDENDUM
www.ti.com
16-Aug-2012
PACKAGING INFORMATION
Orderable Device
Status
(1)
Package Type Package
Drawing
Pins
Package Qty
Eco Plan
(2)
Lead/
Ball Finish
MSL Peak Temp
TPS61085TDGKR
ACTIVE
VSSOP
DGK
8
2000
Green (RoHS
& no Sb/Br)
CU NIPDAU Level-1-260C-UNLIM
TPS61085TPWR
ACTIVE
TSSOP
PW
8
2000
Green (RoHS
& no Sb/Br)
CU NIPDAU Level-1-260C-UNLIM
(3)
Samples
(Requires Login)
(1)
The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2)
Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability
information and additional product content details.
TBD: The Pb-Free/Green conversion plan has not been defined.
Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that
lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes.
Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between
the die and leadframe. The component is otherwise considered Pb-Free (RoHS compatible) as defined above.
Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight
in homogeneous material)
(3)
MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature.
Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information
provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and
continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals.
TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release.
In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis.
Addendum-Page 1
PACKAGE MATERIALS INFORMATION
www.ti.com
16-Aug-2012
TAPE AND REEL INFORMATION
*All dimensions are nominal
Device
Package Package Pins
Type Drawing
SPQ
Reel
Reel
A0
Diameter Width (mm)
(mm) W1 (mm)
B0
(mm)
K0
(mm)
P1
(mm)
W
Pin1
(mm) Quadrant
TPS61085TDGKR
VSSOP
DGK
8
2000
330.0
12.4
5.3
3.4
1.4
8.0
12.0
Q1
TPS61085TPWR
TSSOP
PW
8
2000
330.0
12.4
7.0
3.6
1.6
8.0
12.0
Q1
Pack Materials-Page 1
PACKAGE MATERIALS INFORMATION
www.ti.com
16-Aug-2012
*All dimensions are nominal
Device
Package Type
Package Drawing
Pins
SPQ
Length (mm)
Width (mm)
Height (mm)
TPS61085TDGKR
VSSOP
DGK
8
2000
367.0
367.0
35.0
TPS61085TPWR
TSSOP
PW
8
2000
367.0
367.0
35.0
Pack Materials-Page 2
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