3
2
4
5
DDC, DBV PACKAGE
(Top View)
1
SW
GND
FB
VIN
EN
GND SW
VIN NC
EN FB
3
2
1
4
5
6
DRV PACKAGE
(Top View)
70
72
74
76
78
80
82
84
86
88
90
0.1 1 10 100
VI = 5 V
VI = 3.6 V
VI = 2.4 V
EFFICIENCY
vs
OUTPUT CURRENT
IO − Output Current − mA
Efficiency − %
VIN SW
FB
EN GND
L1
10 µHD1
R1
R2
CFF
CO
1 µF
VOUT
VIN to 28 V
VIN
1.8 V to 6 V
CIN
4.7 µF
5
42
3
1
VO = 18 V
TPS61040
TPS61041
www.ti.com
SLVS413F –OCTOBER 2002–REVISED DECEMBER 2010
LOW-POWER DC/DC BOOST CONVERTER IN SOT-23 AND SON PACKAGES
Check for Samples: TPS61040,TPS61041
1FEATURES DESCRIPTION
• 1.8-V to 6-V Input Voltage Range The TPS61040/41 is a high-frequency boost
converter dedicated for small to medium LCD bias
• Adjustable Output Voltage Range up to 28 V supply and white LED backlight supplies. The device
• 400-mA (TPS61040) and 250-mA (TPS61041) is ideal to generate output voltages up to 28 V from a
Internal Switch Current dual cell NiMH/NiCd or a single cell Li-Ion battery.
• Up to 1-MHz Switching Frequency The part can also be used to generate standard
3.3-V/5-V to 12-V power conversions.
• 28-mA Typical No-Load Quiescent Current
• 1-mA Typical Shutdown Current The TPS61040/41 operates with a switching
frequency up to 1 MHz. This allows the use of small
• Internal Soft Start external components using ceramic as well as
• Available in SOT23-5, TSOT23-5, tantalum output capacitors. Together with the thin
and 2 × 2 × 0.8-mm SON Packages SON package, the TPS61040/41 gives a very small
overall solution size. The TPS61040 has an internal
APPLICATIONS 400 mA switch current limit, while the TPS61041 has
• LCD Bias Supply a 250-mA switch current limit, offering lower output
voltage ripple and allows the use of a smaller form
• White-LED Supply for LCD Backlights factor inductor for lower power applications. The low
• Digital Still Camera quiescent current (typically 28 mA) together with an
• PDAs, Organizers, and Handheld PCs optimized control scheme, allows device operation at
• Cellular Phones very high efficiencies over the entire load current
range.
• Internet Audio Player
• Standard 3.3-V/5-V to 12-V Conversion
TYPICAL APPLICATION
1Please 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. Copyright © 2002–2010, Texas Instruments Incorporated
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
+
+
-
RS Latch
Logic
S
R
Gate
Driver
_
Current Limit
Power MOSFET
N-Channel
RSENSE
Soft
Start
6 µs Max
On Time
VREF = 1.233 V
Error Comparator
400 ns Min
Off Time
Under Voltage
Lockout
Bias Supply
VIN
FB
EN
GND
SW
TPS61040
TPS61041
SLVS413F –OCTOBER 2002–REVISED DECEMBER 2010
www.ti.com
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.
Table 1. ORDERING INFORMATION (1)
SWITCH CURRENT PACKAGE
TAPART NUMBER(2) PACKAGE
LIMIT, mA MARKING
TPS61040DBV 400 SOT23-5 PHOI
TPS61040DDC 400 TSOT23-5 QXK
–40°C to TPS61041DBV 250 SOT23-5 PHPI
85°C TPS61040DRV 400 SON-6 2×2 CCL
TPS61041DRV 250 SON-6 2×2 CAW
(1) For the most current package and ordering information, see the Package Option Addendum at the end
of this document, or see the TI website at www.ti.com.
(2) The devices are available in tape and reel and in tubes. Add R suffix to the part number (e.g.,
TPS61040DRVR) to order quantities of 3000 parts in tape and reel or add suffix T (e.g.,
TPS61040DRVT) to order a tube with 250 pieces..
FUNCTIONAL BLOCK DIAGRAM
2Submit Documentation Feedback Copyright © 2002–2010, Texas Instruments Incorporated
Product Folder Link(s): TPS61040 TPS61041
Ipeak(typ) +ILIM )VIN
L 100 ns
Ipeak(typ) +400 mA )VIN
L 100 ns for the TPS61040
Ipeak(typ) +250 mA )VIN
L 100 ns for the TPS61041
TPS61040
TPS61041
www.ti.com
SLVS413F –OCTOBER 2002–REVISED DECEMBER 2010
Table 2. Terminal Functions
TERMINAL I/O DESCRIPTION
DDC,
NAME DRV NO.
DBV NO.
This is the enable pin of the device. Pulling this pin to ground forces the device into shutdown
EN 4 3 I mode reducing the supply current to less than 1 mA. This pin should not be left floating and needs
to be terminated.
This is the feedback pin of the device. Connect this pin to the external voltage divider to program
FB 3 4 I the desired output voltage.
GND 2 1 – Ground
NC – 5 – No connection
Connect the inductor and the Schottky diode to this pin. This is the switch pin and is connected to
SW 1 6 I the drain of the internal power MOSFET.
VIN 5 2 I Supply voltage pin
DETAILED DESCRIPTION
OPERATION
The TPS61040/41 operates with an input voltage range of 1.8 V to 6 V and can generate output voltages up to
28 V. The device operates in a pulse-frequency-modulation (PFM) scheme with constant peak current control.
This control scheme maintains high efficiency over the entire load current range, and with a switching frequency
up to 1 MHz, the device enables the use of very small external components.
The converter monitors the output voltage, and as soon as the feedback voltage falls below the reference voltage
of typically 1.233 V, the internal switch turns on and the current ramps up. The switch turns off as soon as the
inductor current reaches the internally set peak current of typically 400 mA (TPS61040) or 250 mA (TPS61041).
See the Peak Current Control section for more information. The second criteria that turns off the switch is the
maximum on-time of 6 ms (typical). This is just to limit the maximum on-time of the converter to cover for extreme
conditions. As the switch is turned off the external Schottky diode is forward biased delivering the current to the
output. The switch remains off for a minimum of 400 ns (typical), or until the feedback voltage drops below the
reference voltage again. Using this PFM peak current control scheme the converter operates in discontinuous
conduction mode (DCM) where the switching frequency depends on the output current, which results in very high
efficiency over the entire load current range. This regulation scheme is inherently stable, allowing a wider
selection range for the inductor and output capacitor.
PEAK CURRENT CONTROL
The internal switch turns on until the inductor current reaches the typical dc current limit (ILIM) of 400 mA
(TPS61040) or 250 mA (TPS61041). Due to the internal propagation delay of typical 100 ns, the actual current
exceeds the dc current limit threshold by a small amount. The typical peak current limit can be calculated:
(1)
The higher the input voltage and the lower the inductor value, the greater the peak.
By selecting the TPS61040 or TPS61041, it is possible to tailor the design to the specific application current limit
requirements. A lower current limit supports applications requiring lower output power and allows the use of an
inductor with a lower current rating and a smaller form factor. A lower current limit usually has a lower output
voltage ripple as well.
Copyright © 2002–2010, Texas Instruments Incorporated Submit Documentation Feedback 3
Product Folder Link(s): TPS61040 TPS61041
ILIM
4
ILIM
2
TPS61040
TPS61041
SLVS413F –OCTOBER 2002–REVISED DECEMBER 2010
www.ti.com
SOFT START
All inductive step-up converters exhibit high inrush current during start-up if no special precaution is made. This
can cause voltage drops at the input rail during start up and may result in an unwanted or early system shut
down.
The TPS61040/41 limits this inrush current by increasing the current limit in two steps starting from for 256
cycles to for the next 256 cycles, and then full current limit (see Figure 14).
ENABLE
Pulling the enable (EN) to ground shuts down the device reducing the shutdown current to 1 mA (typical).
Because there is a conductive path from the input to the output through the inductor and Schottky diode, the
output voltage is equal to the input voltage during shutdown. The enable pin needs to be terminated and should
not be left floating. Using a small external transistor disconnects the input from the output during shutdown as
shown in Figure 18.
UNDERVOLTAGE LOCKOUT
An undervoltage lockout prevents misoperation of the device at input voltages below typical 1.5 V. When the
input voltage is below the undervoltage threshold, the main switch is turned off.
THERMAL SHUTDOWN
An internal thermal shutdown is implemented and turns off the internal MOSFETs when the typical junction
temperature of 168°C is exceeded. The thermal shutdown has a hysteresis of typically 25°C. This data is based
on statistical means and is not tested during the regular mass production of the IC.
ABSOLUTE MAXIMUM RATINGS
over operating free-air temperature (unless otherwise noted) (1)
UNIT
Supply voltages on pin VIN (2) –0.3 V to 7 V
Voltages on pins EN, FB (2) –0.3 V to VIN + 0.3 V
Switch voltage on pin SW (2) 30 V
Continuous power dissipation See Dissipation Rating Table
TJOperating junction temperature –40°C to 150°C
Tstg Storage temperature –65°C to 150°C
(1) 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.
(2) All voltage values are with respect to network ground terminal.
DISSIPATION RATING TABLE
DERATING
TA≤25°C FACTOR TA= 70°C TA= 85°C
PACKAGE RqJA POWER RATING ABOVE POWER RATING POWER RATING
TA= 25°C
DBV 250°C/W 357 mW 3.5 mW/°C 192 mW 140 mW
DDC, DRV 76°C/W 1300 mW 13 mW/°C 688 mW 500 mW
4Submit Documentation Feedback Copyright © 2002–2010, Texas Instruments Incorporated
Product Folder Link(s): TPS61040 TPS61041
TPS61040
TPS61041
www.ti.com
SLVS413F –OCTOBER 2002–REVISED DECEMBER 2010
RECOMMENDED OPERATING CONDITIONS MIN TYP MAX UNIT
VIN Input voltage range 1.8 6 V
VOUT Output voltage range 28 V
L Inductor(1) 2.2 10 mH
f Switching frequency(1) 1 MHz
CIN Input capacitor (1) 4.7 mF
COUT Output capacitor (1) 1mF
TAOperating ambient temperature –40 85 °C
TJOperating junction temperature –40 125 °C
(1) See application section for further information.
ELECTRICAL CHARACTERISTICS
VIN = 2.4 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 1.8 6 V
IQOperating quiescent current IOUT = 0 mA, not switching, VFB = 1.3 V 28 50 mA
ISD Shutdown current EN = GND 0.1 1 mA
VUVLO Under-voltage lockout threshold 1.5 1.7 V
ENABLE
VIH EN high level input voltage 1.3 V
VIL EN low level input voltage 0.4 V
IIEN input leakage current EN = GND or VIN 0.1 1 mA
POWER SWITCH AND CURRENT LIMIT
Vsw Maximum switch voltage 30 V
toff Minimum off time 250 400 550 ns
ton Maximum on time 4 6 7.5 ms
RDS(on) MOSFET on-resistance VIN = 2.4 V; ISW = 200 mA; TPS61040 600 1000 mΩ
RDS(on) MOSFET on-resistance VIN = 2.4 V; ISW = 200 mA; TPS61041 750 1250 mΩ
MOSFET leakage current VSW = 28 V 1 10 mA
ILIM MOSFET current limit TPS61040 350 400 450 mA
ILIM MOSFET current limit TPS61041 215 250 285 mA
OUTPUT
VOUT Adjustable output voltage range VIN 28 V
Vref Internal voltage reference 1.233 V
IFB Feedback input bias current VFB = 1.3 V 1 mA
VFB Feedback trip point voltage 1.8 V ≤VIN ≤6 V 1.208 1.233 1.258 V
1.8 V ≤VIN ≤6 V; VOUT = 18 V; Iload = 10 mA;
Line regulation (1) 0.05 %/V
CFF = not connected
Load regulation(1) VIN = 2.4 V; VOUT = 18 V; 0 mA ≤IOUT ≤30 mA 0.15 %/mA
(1) The line and load regulation depend on the external component selection. See the application section for further information.
Copyright © 2002–2010, Texas Instruments Incorporated Submit Documentation Feedback 5
Product Folder Link(s): TPS61040 TPS61041
Efficiency − %
70
72
74
76
78
80
82
84
86
88
90
0.1 1 10 100
VI = 5 V
VI = 3.6 V
VI = 2.4 V
IO − Output Current − mA
VO = 18 V
70
72
74
76
78
80
82
84
86
88
90
0.1 1 10 100
TPS61040
TPS61041
IL − Load Current − mA
L = 10 µH
VO = 18 V
Efficiency − %
TPS61040
TPS61041
SLVS413F –OCTOBER 2002–REVISED DECEMBER 2010
www.ti.com
TYPICAL CHARACTERISTICS
Table 3. Table of Graphs
FIGURE
vs Load current 1, 2, 3
hEfficiency vs Input voltage 4
IQQuiescent current vs Input voltage and temperature 5
VFB Feedback voltage vs Temperature 6
ISW Switch current limit vs Temperature 7
vs Supply voltage, TPS61041 8
ICL Switch current limit vs Supply voltage, TPS61040 9
vs Temperature 10
RDS(on) RDS(on) vs Supply voltage 11
Line transient response 12
Load transient response 13
Start-up behavior 14
EFFICIENCY EFFICIENCY
vs vs
OUTPUT CURRENT LOAD CURRENT
Figure 1. Figure 2.
6Submit Documentation Feedback Copyright © 2002–2010, Texas Instruments Incorporated
Product Folder Link(s): TPS61040 TPS61041
70
72
74
76
78
80
82
84
86
88
90
0.1 1 10 100
L = 10 µH
L = 3.3 µH
IL − Load Current − mA
VO = 18 V
Efficiency − %
70
72
74
76
78
80
82
84
86
88
90
1 2 3 4 5 6
IO = 10 mA
IO = 5 mA
VI − Input Voltage − V
L = 10 µH
VO = 18 V
Efficiency − %
1.23
1.232
1.234
1.236
1.238
1.24
−40 −20 0 20 40 60 80 100 120
VCC = 2.4 V
TA − Temperature − °C
VFB − Feedback Voltage − V
TPS61040
TPS61041
www.ti.com
SLVS413F –OCTOBER 2002–REVISED DECEMBER 2010
EFFICIENCY EFFICIENCY
vs vs
LOAD CURRENT INPUT VOLTAGE
Figure 3. Figure 4.
TPS61040
QUIESCENT CURRENT FEEDBACK VOLTAGE
vs vs
INPUT VOLTAGE FREE-AIR TEMPERATURE
Figure 5. Figure 6.
Copyright © 2002–2010, Texas Instruments Incorporated Submit Documentation Feedback 7
Product Folder Link(s): TPS61040 TPS61041
230
250
270
290
310
330
350
370
390
410
430
−40−30−20−10 0 10 20 30 40 50 60 70 80 90
TPS61040
TPS61041
TA − Temperature − °C
I(SW) − Switch Current Limit − mA
240
242
244
246
248
250
252
254
256
258
260
1.8 2.4 3 3.6 4.2 4.8 5.4 6
VCC − Supply Voltage − V
TA = 27°C
I(CL) − Current Limit − mA
0
200
400
600
800
1000
1200
−40−30 −20 −10 0 10 20 30 40 50 60 70 80 90
TA − Temperature − °C
TPS61041
TPS61040
rDS(on) − Static Drain-Source On-State Resistance − mΩ
380
385
390
395
400
405
410
415
420
1.8 2.4 3 3.6 4.2 4.8 5.4 6
VCC − Supply Voltage − V
TA = 27°C
I(CL) − Current Limit − mA
TPS61040
TPS61041
SLVS413F –OCTOBER 2002–REVISED DECEMBER 2010
www.ti.com
TPS61040/41 TPS61041
SWITCH CURRENT LIMIT CURRENT LIMIT
vs vs
FREE-AIR TEMPERATURE SUPPLY VOLTAGE
Figure 7. Figure 8.
TPS61040 TPS61040/41
CURRENT LIMIT STATIC DRAIN-SOURCE ON-STATE RESISTANCE
vs vs
SUPPLY VOLTAGE FREE-AIR TEMPERATURE
Figure 9. Figure 10.
8Submit Documentation Feedback Copyright © 2002–2010, Texas Instruments Incorporated
Product Folder Link(s): TPS61040 TPS61041
VI
2.4 V to 3.4 V
VO
100 mV/div
200 µS/div
VO = 18 V
0
100
200
300
400
500
600
700
800
900
1000
1.8 2.4 3 3.6 4.2 4.8 5.4 6
VCC − Supply Voltage − V
TPS61041
TPS61040
rDS(on) − Static Drain-Source On-State Resistance − mΩ
VO
5 V/div
EN
1 V/div
II
50 mA/div
VO = 18 V
VO
1 mA to 10 mA
200 µS/div
VO
100 mA/div
VO = 18 V
TPS61040
TPS61041
www.ti.com
SLVS413F –OCTOBER 2002–REVISED DECEMBER 2010
TPS61040/41
STATIC DRAIN-SOURCE ON-STATE RESISTANCE
vs
SUPPLY VOLTAGE
Figure 11. Figure 12. Line Transient Response
Figure 13. Load Transient Response Figure 14. Start-Up Behavior
Copyright © 2002–2010, Texas Instruments Incorporated Submit Documentation Feedback 9
Product Folder Link(s): TPS61040 TPS61041
fSmax +
VIN(min) (VOUT *VIN)
IP L VOUT
fSǒIloadǓ+2 Iload (VOUT *VIN )Vd)
I2
P L
Iload max +h
I2
P L fSmax
2 (VOUT *VIN)
TPS61040
TPS61041
SLVS413F –OCTOBER 2002–REVISED DECEMBER 2010
www.ti.com
APPLICATION INFORMATION
INDUCTOR SELECTION, MAXIMUM LOAD CURRENT
Because the PFM peak current control scheme is inherently stable, the inductor value does not affect the stability
of the regulator. The selection of the inductor together with the nominal load current, input and output voltage of
the application determines the switching frequency of the converter. Depending on the application, inductor
values between 2.2 mH and 47 mH are recommended. The maximum inductor value is determined by the
maximum on time of the switch, typically 6 ms. The peak current limit of 400 mA/250 mA (typically) should be
reached within this 6-ms period for proper operation.
The inductor value determines the maximum switching frequency of the converter. Therefore, select the inductor
value that ensures the maximum switching frequency at the converter maximum load current is not exceeded.
The maximum switching frequency is calculated by the following formula:
Where:
IP= Peak current as described in the Peak Current Control section
L = Selected inductor value
VIN(min) = The highest switching frequency occurs at the minimum input voltage (2)
If the selected inductor value does not exceed the maximum switching frequency of the converter, the next step
is to calculate the switching frequency at the nominal load current using the following formula:
Where:
IP= Peak current as described in the Peak Current Control section
L = Selected inductor value
Iload = Nominal load current
Vd = Rectifier diode forward voltage (typically 0.3V) (3)
A smaller inductor value gives a higher converter switching frequency, but lowers the efficiency.
The inductor value has less effect on the maximum available load current and is only of secondary order. The
best way to calculate the maximum available load current under certain operating conditions is to estimate the
expected converter efficiency at the maximum load current. This number can be taken out of the efficiency
graphs shown in Figure 1 through Figure 4. The maximum load current can then be estimated as follows:
Where:
IP= Peak current as described in the Peak Current Control section
L = Selected inductor value
fSmax = Maximum switching frequency as calculated previously
h= Expected converter efficiency. Typically 70% to 85% (4)
10 Submit Documentation Feedback Copyright © 2002–2010, Texas Instruments Incorporated
Product Folder Link(s): TPS61040 TPS61041
VOUT +1.233 V ǒ1)R1
R2Ǔ
CFF +1
2 p fS
20 R1
TPS61040
TPS61041
www.ti.com
SLVS413F –OCTOBER 2002–REVISED DECEMBER 2010
The maximum load current of the converter is the current at the operation point where the converter starts to
enter the continuous conduction mode. Usually the converter should always operate in discontinuous conduction
mode.
Last, the selected inductor should have a saturation current that meets the maximum peak current of the
converter (as calculated in the Peak Current Control section). Use the maximum value for ILIM for this calculation.
Another important inductor parameter is the dc resistance. The lower the dc resistance, the higher the efficiency
of the converter. See Table 4 and the typical applications for the inductor selection.
Table 4. Recommended Inductor for Typical LCD Bias Supply (see Figure 15)
DEVICE INDUCTOR VALUE COMPONENT SUPPLIER COMMENTS
10 mH Sumida CR32-100 High efficiency
10 mH Sumida CDRH3D16-100 High efficiency
TPS61040 10 mH Murata LQH4C100K04 High efficiency
4.7 mH Sumida CDRH3D16-4R7 Small solution size
4.7 mH Murata LQH3C4R7M24 Small solution size
High efficiency
TPS61041 10 mH Murata LQH3C100K24 Small solution size
SETTING THE OUTPUT VOLTAGE
The output voltage is calculated as:
(5)
For battery-powered applications, a high-impedance voltage divider should be used with a typical value for R2 of
≤200 kΩand a maximum value for R1 of 2.2 MΩ. Smaller values might be used to reduce the noise sensitivity of
the feedback pin.
A feedforward capacitor across the upper feedback resistor R1 is required to provide sufficient overdrive for the
error comparator. Without a feedforward capacitor, or one whose value is too small, the TPS61040/41 shows
double pulses or a pulse burst instead of single pulses at the switch node (SW), causing higher output voltage
ripple. If this higher output voltage ripple is acceptable, the feedforward capacitor can be left out.
The lower the switching frequency of the converter, the larger the feedforward capacitor value required. A good
starting point is to use a 10-pF feedforward capacitor. As a first estimation, the required value for the feedforward
capacitor at the operation point can also be calculated using the following formula:
Where:
R1 = Upper resistor of voltage divider
fS = Switching frequency of the converter at the nominal load current (See the Inductor Selection, Maximum
Load Current section for calculating the switching frequency)
CFF = Choose a value that comes closest to the result of the calculation (6)
Copyright © 2002–2010, Texas Instruments Incorporated Submit Documentation Feedback 11
Product Folder Link(s): TPS61040 TPS61041
DVout +Iout
Cout ǒ1
fS(Iout)–IP L
Vout )Vd–VinǓ)IP ESR
TPS61040
TPS61041
SLVS413F –OCTOBER 2002–REVISED DECEMBER 2010
www.ti.com
The larger the feedforward capacitor the worse the line regulation of the device. Therefore, when concern for line
regulation is paramount, the selected feedforward capacitor should be as small as possible. See the following
section for more information about line and load regulation.
LINE AND LOAD REGULATION
The line regulation of the TPS61040/41 depends on the voltage ripple on the feedback pin. Usually a 50 mV
peak-to-peak voltage ripple on the feedback pin FB gives good results.
Some applications require a very tight line regulation and can only allow a small change in output voltage over a
certain input voltage range. If no feedforward capacitor CFF is used across the upper resistor of the voltage
feedback divider, the device has the best line regulation. Without the feedforward capacitor the output voltage
ripple is higher because the TPS61040/41 shows output voltage bursts instead of single pulses on the switch pin
(SW), increasing the output voltage ripple. Increasing the output capacitor value reduces the output voltage
ripple.
If a larger output capacitor value is not an option, a feedforward capacitor CFF can be used as described in the
previous section. The use of a feedforward capacitor increases the amount of voltage ripple present on the
feedback pin (FB). The greater the voltage ripple on the feedback pin (≥50 mV), the worse the line regulation.
There are two ways to improve the line regulation further:
1. Use a smaller inductor value to increase the switching frequency which will lower the output voltage ripple,
as well as the voltage ripple on the feedback pin.
2. Add a small capacitor from the feedback pin (FB) to ground to reduce the voltage ripple on the feedback pin
down to 50 mV again. As a starting point, the same capacitor value as selected for the feedforward capacitor
CFF can be used.
OUTPUT CAPACITOR SELECTION
For best output voltage filtering, a low ESR output capacitor is recommended. Ceramic capacitors have a low
ESR value but tantalum capacitors can be used as well, depending on the application.
Assuming the converter does not show double pulses or pulse bursts on the switch node (SW), the output
voltage ripple can be calculated as:
where:
IP= Peak current as described in the Peak Current Control section
L = Selected inductor value
Iout = Nominal load current
fS (Iout) = Switching frequency at the nominal load current as calculated previously
Vd = Rectifier diode forward voltage (typically 0.3 V)
Cout = Selected output capacitor
ESR = Output capacitor ESR value (7)
See Table 5 and the typical applications section for choosing the output capacitor.
Table 5. Recommended Input and Output Capacitors
DEVICE CAPACITOR VOLTAGE RATING COMPONENT SUPPLIER COMMENTS
4.7 mF/X5R/0805 6.3 V Tayo Yuden JMK212BY475MG CIN/COUT
10 mF/X5R/0805 6.3 V Tayo Yuden JMK212BJ106MG CIN/COUT
TPS61040/41 1 mF/X7R/1206 25 V Tayo Yuden TMK316BJ105KL COUT
1mF/X5R/1206 35 V Tayo Yuden GMK316BJ105KL COUT
4.7 mF/X5R/1210 25 V Tayo Yuden TMK325BJ475MG COUT
12 Submit Documentation Feedback Copyright © 2002–2010, Texas Instruments Incorporated
Product Folder Link(s): TPS61040 TPS61041
VIN SW
FB
EN GND
L1 D1
R1
R2
CFF
CO
VO
VIN
CIN
TPS61040
TPS61041
www.ti.com
SLVS413F –OCTOBER 2002–REVISED DECEMBER 2010
INPUT CAPACITOR SELECTION
For good input voltage filtering, low ESR ceramic capacitors are recommended. A 4.7 mF ceramic input capacitor
is sufficient for most of the applications. For better input voltage filtering this value can be increased. See Table 5
and typical applications for input capacitor recommendations.
DIODE SELECTION
To achieve high efficiency a Schottky diode should be used. The current rating of the diode should meet the
peak current rating of the converter as it is calculated in the Peak Current Control section. Use the maximum
value for ILIM for this calculation. See Table 6 and the typical applications for the selection of the Schottky diode.
Table 6. Recommended Schottky Diode for Typical LCD Bias Supply (see Figure 15)
DEVICE REVERSE VOLTAGE COMPONENT SUPPLIER COMMENTS
30 V ON Semiconductor MBR0530
20 V ON Semiconductor MBR0520
TPS61040/41 20 V ON Semiconductor MBRM120L High efficiency
30 V Toshiba CRS02
LAYOUT CONSIDERATIONS
Typical for all switching power supplies, the layout is an important step in the design; especially at high peak
currents and switching frequencies. If the layout is not carefully done, the regulator might show noise problems
and duty cycle jitter.
The input capacitor should be placed as close as possible to the input pin for good input voltage filtering. The
inductor and diode should be placed as close as possible to the switch pin to minimize the noise coupling into
other circuits. Because the feedback pin and network is a high-impedance circuit, the feedback network should
be routed away from the inductor. The feedback pin and feedback network should be shielded with a ground
plane or trace to minimize noise coupling into this circuit.
Wide traces should be used for connections in bold as shown in Figure 15. A star ground connection or ground
plane minimizes ground shifts and noise.
Figure 15. Layout Diagram
Copyright © 2002–2010, Texas Instruments Incorporated Submit Documentation Feedback 13
Product Folder Link(s): TPS61040 TPS61041
VIN SW
FB
EN GND
L1
10 µHD1
R1
2.2 MW
R2
160 kW
CFF
22 pF C2
1 µF
VOUT
18 V
VIN
1.8 V to 6 V
C1
4.7 µFL1: Sumida CR32-100
D1: Motorola MBR0530
C1: Tayo Yuden JMK212BY475MG
C2: Tayo Yuden TMK316BJ105KL
TPS61040
VIN SW
FB
EN GND
L1
10 µHD1
R1
2.2 MW
R2
160 kW
CFF
22 pF
C2
1 µF
VO
18 V
VIN
1.8 V to 6 V
C1
4.7 µFDAC or Analog Voltage
0 V = 25 V
1.233 V = 18 V
TPS61040
L1: Sumida CR32-100
D1: Motorola MBR0530
C1: Tayo Yuden JMK212BY475MG
C2: Tayo Yuden GMK316BJ105KL
VIN SW
FB
EN GND
L1
10 µHD1
R1
2.2 MW
R2
160 kW
CFF
22 pF
C2
1 µF
VOUT
18 V / 10 mA
VIN
1.8 V to 6 V
C1
4.7 µF
R3
200 kW
BC857C
C3
0.1 µF
(Optional)
L1: Sumida CR32-100
D1: Motorola MBR0530
C1: Tayo Yuden JMK212BY475MG
C2: Tayo Yuden TMK316BJ105KL
TPS61040
TPS61040
TPS61041
SLVS413F –OCTOBER 2002–REVISED DECEMBER 2010
www.ti.com
Figure 16. LCD Bias Supply
Figure 17. LCD Bias Supply With Adjustable Output Voltage
Figure 18. LCD Bias Supply With Load Disconnect
14 Submit Documentation Feedback Copyright © 2002–2010, Texas Instruments Incorporated
Product Folder Link(s): TPS61040 TPS61041
VIN SW
FB
EN GND
L1
6.8 µHD1
R1
1.5 MW
R2
210 kW
CFF
22 pF C2
1 µF
V1 = 10 V/15 mA
VIN = 2.7 V to 5 V
C1
4.7 µF
C4
4.7 µF
C3
1 µF
V2 = –10 V/15 mA
D2
D3
L1: Murata LQH4C6R8M04
D1, D2, D3: Motorola MBR0530
C1: Tayo Yuden JMK212BY475MG
C2, C3, C4: Tayo Yuden EMK316BJ105KF
TPS61040
VIN SW
FB
EN GND
L1
6.8 µHD1
R1
1.8 MW
R2
205 kW
CFF
4.7 pF C2
4.7 µF
VO = 12 V/35 mA
VIN 3.3 V
C1
10 µFL1: Murata LQH4C6R8M04
D1: Motorola MBR0530
C1: Tayo Yuden JMK212BJ106MG
C2: Tayo Yuden EMK316BJ475ML
TPS61040
VIN SW
FB
EN GND
3.3 µHD1
C2
4.7 µF
5 V/45 mA
1.8 V to 4 V
C1
4.7 µF
TPS61040
L1: Murata LQH4C3R3M04
D1: Motorola MBR0530
C1, C2: Tayo Yuden JMK212BY475MG
CFF
3.3 pF
R1
620 kW
R2
200 kW
TPS61040
TPS61041
www.ti.com
SLVS413F –OCTOBER 2002–REVISED DECEMBER 2010
Figure 19. Positive and Negative Output LCD Bias Supply
Figure 20. Standard 3.3-V to 12-V Supply
Figure 21. Dual Battery Cell to 5-V/50-mA Conversion
Efficiency Approx. Equals 84% at VIN = 2.4 V to Vo = 5 V/45 mA
Copyright © 2002–2010, Texas Instruments Incorporated Submit Documentation Feedback 15
Product Folder Link(s): TPS61040 TPS61041
VIN SW
FB
EN GND
L1
10 µHD1
C2
1 µF
C1
4.7 µF
RS
82 Ω
VCC = 2.7 V to 6 V
PWM
100 Hz to 500 Hz
D2
24 V
(Optional)
L1: Murata LQH4C100K04
D1: Motorola MBR0530
C1: Tayo Yuden JMK212BY475MG
C2: Tayo Yuden TMK316BJ105KL
VIN SW
FB
EN GND
L1
10 µH
D1
MBRM120L
C2
100 nF
(See
Note A)
C1
4.7 µF
RS
110 Ω
VCC = 2.7 V to 6 V
R1
120 kΩ
R2
160 kΩ
Analog Brightness Control
3.3 V ≅ Led Off
0 V ≅ Iled = 20 mA
D2
24 V
(Optional)
L1: Murata LQH4C3R3M04
D1: Motorola MBR0530
C1: Tayo Yuden JMK212BY475MG
C2: Standard Ceramic Capacitor
TPS61040
TPS61041
SLVS413F –OCTOBER 2002–REVISED DECEMBER 2010
www.ti.com
Figure 22. White LED Supply With Adjustable Brightness Control
Using a PWM Signal on the Enable Pin, Efficiency Approx. Equals 86% at VIN =3V,ILED = 15 mA
A. A smaller output capacitor value for C2 causes a larger LED ripple.
Figure 23. White LED Supply With Adjustable Brightness Control
Using an Analog Signal on the Feedback Pin
16 Submit Documentation Feedback Copyright © 2002–2010, Texas Instruments Incorporated
Product Folder Link(s): TPS61040 TPS61041
PACKAGE OPTION ADDENDUM
www.ti.com 10-Feb-2011
Addendum-Page 1
PACKAGING INFORMATION
Orderable Device Status (1) Package Type Package
Drawing Pins Package Qty Eco Plan (2) Lead/
Ball Finish MSL Peak Temp (3) Samples
(Requires Login)
TPS61040DBVR ACTIVE SOT-23 DBV 5 3000 Green (RoHS
& no Sb/Br) CU NIPDAU Level-1-260C-UNLIM
TPS61040DBVRG4 ACTIVE SOT-23 DBV 5 3000 Green (RoHS
& no Sb/Br) CU NIPDAU Level-1-260C-UNLIM
TPS61040DDCR ACTIVE SOT DDC 5 3000 Green (RoHS
& no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR
TPS61040DDCT ACTIVE SOT DDC 5 250 Green (RoHS
& no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR
TPS61040DRVR ACTIVE SON DRV 6 3000 Green (RoHS
& no Sb/Br) CU NIPDAU Level-1-260C-UNLIM
TPS61040DRVRG4 ACTIVE SON DRV 6 3000 Green (RoHS
& no Sb/Br) CU NIPDAU Level-1-260C-UNLIM
TPS61040DRVT ACTIVE SON DRV 6 250 Green (RoHS
& no Sb/Br) CU NIPDAU Level-1-260C-UNLIM
TPS61040DRVTG4 ACTIVE SON DRV 6 250 Green (RoHS
& no Sb/Br) CU NIPDAU Level-1-260C-UNLIM
TPS61041DBVR ACTIVE SOT-23 DBV 5 3000 Green (RoHS
& no Sb/Br) CU NIPDAU Level-1-260C-UNLIM
TPS61041DBVRG4 ACTIVE SOT-23 DBV 5 3000 Green (RoHS
& no Sb/Br) CU NIPDAU Level-1-260C-UNLIM
TPS61041DRVR ACTIVE SON DRV 6 3000 Green (RoHS
& no Sb/Br) CU NIPDAU Level-1-260C-UNLIM
TPS61041DRVRG4 ACTIVE SON DRV 6 3000 Green (RoHS
& no Sb/Br) CU NIPDAU Level-1-260C-UNLIM
TPS61041DRVT ACTIVE SON DRV 6 250 Green (RoHS
& no Sb/Br) CU NIPDAU Level-1-260C-UNLIM
TPS61041DRVTG4 ACTIVE SON DRV 6 250 Green (RoHS
& no Sb/Br) CU NIPDAU Level-1-260C-UNLIM
(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.
PACKAGE OPTION ADDENDUM
www.ti.com 10-Feb-2011
Addendum-Page 2
(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.
OTHER QUALIFIED VERSIONS OF TPS61040, TPS61041 :
•Automotive: TPS61040-Q1, TPS61041-Q1
NOTE: Qualified Version Definitions:
•Automotive - Q100 devices qualified for high-reliability automotive applications targeting zero defects
TAPE AND REEL INFORMATION
*All dimensions are nominal
Device Package
Type Package
Drawing Pins SPQ Reel
Diameter
(mm)
Reel
Width
W1 (mm)
A0
(mm) B0
(mm) K0
(mm) P1
(mm) W
(mm) Pin1
Quadrant
TPS61040DBVR SOT-23 DBV 5 3000 179.0 8.4 3.2 3.2 1.4 4.0 8.0 Q3
TPS61040DBVR SOT-23 DBV 5 3000 178.0 9.0 3.23 3.17 1.37 4.0 8.0 Q3
TPS61040DDCR SOT DDC 5 3000 179.0 8.4 3.2 3.2 1.4 4.0 8.0 Q3
TPS61040DDCT SOT DDC 5 250 179.0 8.4 3.2 3.2 1.4 4.0 8.0 Q3
TPS61040DRVR SON DRV 6 3000 179.0 8.4 2.2 2.2 1.2 4.0 8.0 Q2
TPS61040DRVT SON DRV 6 250 179.0 8.4 2.2 2.2 1.2 4.0 8.0 Q2
TPS61041DBVR SOT-23 DBV 5 3000 179.0 8.4 3.2 3.2 1.4 4.0 8.0 Q3
TPS61041DBVR SOT-23 DBV 5 3000 178.0 9.0 3.23 3.17 1.37 4.0 8.0 Q3
TPS61041DRVR SON DRV 6 3000 179.0 8.4 2.2 2.2 1.2 4.0 8.0 Q2
TPS61041DRVT SON DRV 6 250 179.0 8.4 2.2 2.2 1.2 4.0 8.0 Q2
PACKAGE MATERIALS INFORMATION
www.ti.com 19-Jul-2012
Pack Materials-Page 1
*All dimensions are nominal
Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm)
TPS61040DBVR SOT-23 DBV 5 3000 203.0 203.0 35.0
TPS61040DBVR SOT-23 DBV 5 3000 180.0 180.0 18.0
TPS61040DDCR SOT DDC 5 3000 195.0 200.0 45.0
TPS61040DDCT SOT DDC 5 250 195.0 200.0 45.0
TPS61040DRVR SON DRV 6 3000 203.0 203.0 35.0
TPS61040DRVT SON DRV 6 250 203.0 203.0 35.0
TPS61041DBVR SOT-23 DBV 5 3000 203.0 203.0 35.0
TPS61041DBVR SOT-23 DBV 5 3000 180.0 180.0 18.0
TPS61041DRVR SON DRV 6 3000 203.0 203.0 35.0
TPS61041DRVT SON DRV 6 250 203.0 203.0 35.0
PACKAGE MATERIALS INFORMATION
www.ti.com 19-Jul-2012
Pack Materials-Page 2
IMPORTANT NOTICE
Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, enhancements, improvements and other
changes to its semiconductor products and services per JESD46C and to discontinue any product or service per JESD48B. Buyers should
obtain the latest relevant information before placing orders and should verify that such information is current and complete. All
semiconductor products (also referred to herein as “components”) are sold subject to TI’s terms and conditions of sale supplied at the time
of order acknowledgment.
TI warrants performance of its components to the specifications applicable at the time of sale, in accordance with the warranty in TI’s terms
and conditions of sale of semiconductor products. Testing and other quality control techniques are used to the extent TI deems necessary
to support this warranty. Except where mandated by applicable law, testing of all parameters of each component is not necessarily
performed.
TI assumes no liability for applications assistance or the design of Buyers’ products. Buyers are responsible for their products and
applications using TI components. To minimize the risks associated with Buyers’ products and applications, Buyers should provide
adequate design and operating safeguards.
TI does not warrant or represent that any license, either express or implied, is granted under any patent right, copyright, mask work right, or
other intellectual property right relating to any combination, machine, or process in which TI components or services are used. Information
published by TI regarding third-party products or services does not constitute a license to use such products or services or a warranty or
endorsement thereof. Use of such information may require a license from a third party under the patents or other intellectual property of the
third party, or a license from TI under the patents or other intellectual property of TI.
Reproduction of significant portions of TI information in TI data books or data sheets is permissible only if reproduction is without alteration
and is accompanied by all associated warranties, conditions, limitations, and notices. TI is not responsible or liable for such altered
documentation. Information of third parties may be subject to additional restrictions.
Resale of TI components or services with statements different from or beyond the parameters stated by TI for that component or service
voids all express and any implied warranties for the associated TI component or service and is an unfair and deceptive business practice.
TI is not responsible or liable for any such statements.
Buyer acknowledges and agrees that it is solely responsible for compliance with all legal, regulatory and safety-related requirements
concerning its products, and any use of TI components in its applications, notwithstanding any applications-related information or support
that may be provided by TI. Buyer represents and agrees that it has all the necessary expertise to create and implement safeguards which
anticipate dangerous consequences of failures, monitor failures and their consequences, lessen the likelihood of failures that might cause
harm and take appropriate remedial actions. Buyer will fully indemnify TI and its representatives against any damages arising out of the use
of any TI components in safety-critical applications.
In some cases, TI components may be promoted specifically to facilitate safety-related applications. With such components, TI’s goal is to
help enable customers to design and create their own end-product solutions that meet applicable functional safety standards and
requirements. Nonetheless, such components are subject to these terms.
No TI components are authorized for use in FDA Class III (or similar life-critical medical equipment) unless authorized officers of the parties
have executed a special agreement specifically governing such use.
Only those TI components which TI has specifically designated as military grade or “enhanced plastic” are designed and intended for use in
military/aerospace applications or environments. Buyer acknowledges and agrees that any military or aerospace use of TI components
which have not been so designated is solely at the Buyer's risk, and that Buyer is solely responsible for compliance with all legal and
regulatory requirements in connection with such use.
TI has specifically designated certain components which meet ISO/TS16949 requirements, mainly for automotive use. Components which
have not been so designated are neither designed nor intended for automotive use; and TI will not be responsible for any failure of such
components to meet such requirements.
Products Applications
Audio www.ti.com/audio Automotive and Transportation www.ti.com/automotive
Amplifiers amplifier.ti.com Communications and Telecom www.ti.com/communications
Data Converters dataconverter.ti.com Computers and Peripherals www.ti.com/computers
DLP® Products www.dlp.com Consumer Electronics www.ti.com/consumer-apps
DSP dsp.ti.com Energy and Lighting www.ti.com/energy
Clocks and Timers www.ti.com/clocks Industrial www.ti.com/industrial
Interface interface.ti.com Medical www.ti.com/medical
Logic logic.ti.com Security www.ti.com/security
Power Mgmt power.ti.com Space, Avionics and Defense www.ti.com/space-avionics-defense
Microcontrollers microcontroller.ti.com Video and Imaging www.ti.com/video
RFID www.ti-rfid.com
OMAP Mobile Processors www.ti.com/omap TI E2E Community e2e.ti.com
Wireless Connectivity www.ti.com/wirelessconnectivity
Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265
Copyright © 2012, Texas Instruments Incorporated