TPS6104x Low-Power DC-DC Boost Converter in SOT-23 and WSON Packages
1Features3Description
1
•1.8-V to 6-V Input Voltage Range
•Adjustable Output Voltage Range up to 28 V
•400-mA (TPS61040) and 250-mA (TPS61041)
Internal Switch Current
•Up to 1-MHz Switching Frequency
•28-μA Typical No-Load Quiescent Current
•1-μA Typical Shutdown Current
•Internal Soft Start
•Available in SOT23-5, TSOT23-5,
and 2-mm × 2-mm × 0.8-mm WSON Packages
2Applications
•LCD Bias Supply
•White-LED Supply for LCD Backlights
•Digital Still Camera
•PDAs, Organizers, and Handheld PCs
•Cellular Phones
•Internet Audio Players
•Standard 3.3-V or 5-V to 12-V Conversion
The TPS6104x is a high-frequency boost converter
dedicated for small to medium LCD bias supply and
white LED backlight supplies. The device is ideal to
generate output voltages up to 28 V from a dual-cell
NiMH/NiCd or a single-cell Li-Ion battery. The part
can also be used to generate standard 3.3-V or 5-V
to 12-V power conversions.
The TPS6104x operates with a switching frequency
up to 1 MHz. This frequency allows the use of small
external components using ceramic as well as
tantalum output capacitors. Together with the thin
WSON package, the TPS6104x gives a very small
overall solution size. The TPS61040 device has an
internal 400-mAswitch current limit, while the
TPS61041 device has a 250-mA switch current limit,
offering lower output voltage ripple and allows the
use of a smaller form factor inductor for lower power
applications. The low quiescent current (typically 28
μA) together with an optimized control scheme,
allows device operation at very high efficiencies over
the entire load current range.
Device Information
PART NUMBERPACKAGEBODY SIZE (NOM)
TPS61040SOT (5)2.90 mm ×1.60 mm
TPS61041
(1) For all available packages, see the orderable addendum at
the end of the datasheet.
TPS61040,TPS61041
(1)
SOT-23 (5)2.90 mm × 1.60 mm
WSON (6)2.00 mm × 2.00 mm
SOT-23 (5)2.90 mm ×1.60 mm
WSON (6)2.00 mm × 2.00 mm
4Typical Application Schematic
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.
Changes from Revision G (December 2014) to Revision HPage
•Added 500 µs/div label to X-axis of Figure 15. ................................................................................................................... 15
Changes from Revision F (December 2010) to Revision GPage
•Added ESD Ratings table, 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
over operating free-air temperature range (unless otherwise noted)
Supply voltages on pin V
Voltages on pins EN, FB
Switch voltage on pin SW
Operating junction temperature, T
Storage temperature, T
(1) Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings
only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under Recommended
Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
(2) All voltage values are with respect to network ground terminal.
(2)
IN
(2)
(2)
J
stg
7.2 ESD Ratings
Human body model (HBM), per ANSI/ESDA/JEDEC JS-001
V
(ESD)
(1) JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process. Manufacturing with
(2) JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process. Manufacturing with
Electrostatic dischargeV
Charged-device model (CDM), per JEDEC specification JESD22-±750
(2)
C101
less than 500-V HBM is possible with the necessary precautions. Pins listed as ±XXX V may actually have higher performance.
less than 250-V CDM is possible with the necessary precautions. Pins listed as ±YYY V may actually have higher performance.
The TPS6104x is a high-frequency boost converter dedicated for small to medium LCD bias supply and white
LED backlight supplies. The device is ideal to generate output voltages up to 28 V from a dual-cell NiMH/NiCd or
a single cell device Li-Ion battery.
8.2 Functional Block Diagram
8.3 Feature Description
8.3.1 Peak Current Control
The internal switch turns on until the inductor current reaches the typical dc current limit (I
(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:
The higher the input voltage and the lower the inductor value, the greater the peak.
By selecting the TPS6104x, 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.
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 TPS6104x limits this inrush current by increasing the current limit in two steps starting fromfor 256
cycles tofor the next 256 cycles, and then full current limit (see Figure 15).
8.3.3 Enable
Pulling the enable (EN) to ground shuts down the device reducing the shutdown current to 1 μA (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 17.
8.3.4 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.
8.3.5 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.
8.4 Device Functional Modes
8.4.1 Operation
The TPS6104x 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 Peak Current Control for more information. The second criteria that turns off the switch is the maximum ontime of 6 μs (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.