Sample &
Buy
Product
Folder
Support &
Community
Tools &
Software
Technical
Documents
TPS61169
SNVSA40A – OCTOBER 2014 – REVISED MARCH 2016
TPS61169 38-V High Current-Boost WLED Driver
With PWM Control
1 Features
3 Description
•
•
•
•
•
•
•
•
•
•
•
•
•
With a 40-V rated integrated switch FET, the
TPS61169 is a boost converter that drives LEDs in
series. The boost converter has a 40-V, 1.8-A internal
MOSFET with minimum 1.2-A current limit; thus it can
drive single or parallel LED strings for small- to largesize panel backlighting. The default white LED current
is set with the external sensor resistor, RSET, and the
feedback voltage is regulated to 204 mV, as shown in
the Simplified Schematic. During the operation, the
LED current can be controlled by using a pulse width
modulation (PWM) signal applied to the CTRL pin,
through which the duty cycle determines the feedback
reference voltage. The TPS61169 does not burst the
LED current; therefore, it does not generate audible
noises on the output capacitor. For maximum
protection, the device features integrated open LED
protection that disables the TPS61169 to prevent the
output voltage from exceeding the absolute maximum
voltage ratings of the device during open LED
conditions.
1
2.7-V to 5.5-V Input Voltage
Integrated 40-V, 1.8-A MOSFET
Drives LED String up to 38 V
1.2-A Minimum Switch Current Limit
1.2-MHz Switching Frequency
204-mV Reference Voltage
Internal Compensation
PWM Brightness Control
Open LED Protection
Undervoltage Protection
Built-in Soft-Start
Thermal Shutdown
Up to 90% Efficiency
2 Applications
•
•
•
•
•
•
•
•
•
•
•
Smartphone Backlighting
Tablet Backlighting
PDAs, Handheld Computers, GPS Receivers
Portable Media Players, Portable TVs
White LED Backlighting for Small and Media
Form-Factor Displays
Handheld Data Terminals (EPOS)
Handheld Medical Equipment
Thermostat Display
Blood Glucose Meters
Flashlights
Refrigerators and Ovens
The TPS61169 is available in a space-saving 5-pin
SC70 package.
Device Information(1)
PART NUMBER
TPS61169
PACKAGE
SOT (5)
BODY SIZE (NOM)
2.00 mm × 1.25 mm
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
4 Simplified Schematic
L
D
VBAT
CIN
TPS61169
COUT
VIN
SW
CTRL
PWM DIMMING
CONTROL
FB
GND
RSET
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.
TPS61169
SNVSA40A – OCTOBER 2014 – REVISED MARCH 2016
www.ti.com
Table of Contents
1
2
3
4
5
6
7
8
Features ..................................................................
Applications ...........................................................
Description .............................................................
Simplified Schematic.............................................
Revision History.....................................................
Pin Configuration and Functions .........................
Specifications.........................................................
1
1
1
1
2
3
4
7.1
7.2
7.3
7.4
7.5
7.6
4
4
4
4
5
6
Absolute Maximum Ratings ......................................
ESD Ratings..............................................................
Recommended Operating Conditions.......................
Thermal Information ..................................................
Electrical Characteristics...........................................
Typical Characteristics ..............................................
Detailed Description .............................................. 7
8.1 Overview ................................................................... 7
8.2 Functional Block Diagram ......................................... 8
8.3 Feature Description .................................................. 8
8.4 Device Functional Modes........................................ 10
9
Application and Implementation ........................ 11
9.1 Application Information............................................ 11
9.2 Typical Application .................................................. 11
9.3 Application Curves .................................................. 13
10 Power Supply Recommendations ..................... 16
11 Layout................................................................... 16
11.1 Layout Guidelines ................................................. 16
11.2 Layout Example .................................................... 16
12 Device and Documentation Support ................. 17
12.1
12.2
12.3
12.4
12.5
Device Support......................................................
Community Resources..........................................
Trademarks ...........................................................
Electrostatic Discharge Caution ............................
Glossary ................................................................
17
17
17
17
17
13 Mechanical, Packaging, and Orderable
Information ........................................................... 17
5 Revision History
NOTE: Page numbers for previous revisions may differ from page numbers in the current version.
Changes from Original (October 2014) to Revision A
Page
•
Added new items to "Applications" on page 1 ....................................................................................................................... 1
•
Changed Handling Ratings to ESD Ratings table; move storage temperature range from Handling Ratings to Abs
Max table ............................................................................................................................................................................... 4
2
Submit Documentation Feedback
Copyright © 2014–2016, Texas Instruments Incorporated
Product Folder Links: TPS61169
TPS61169
www.ti.com
SNVSA40A – OCTOBER 2014 – REVISED MARCH 2016
6 Pin Configuration and Functions
DCK Package
5-Pin SC70
(Top View)
SW
1
GND
2
FB
3
5
VIN
4
CTRL
Pin Functions
PIN
NUMBER
NAME
I/O
DESCRIPTION
1
SW
I
Drain connection of the internal power FET.
2
GND
O
Ground
3
FB
I
Feedback pin for current. Connect the sense resistor from FB to GND.
4
CTRL
I
PWM dimming signal input
5
VIN
I
Supply input pin
Submit Documentation Feedback
Copyright © 2014–2016, Texas Instruments Incorporated
Product Folder Links: TPS61169
3
TPS61169
SNVSA40A – OCTOBER 2014 – REVISED MARCH 2016
www.ti.com
7 Specifications
7.1 Absolute Maximum Ratings
over operating free-air temperature range (unless otherwise noted) (1)
Voltage (2)
MIN
MAX
VIN, CTRL, PWM, FB
–0.3
7
SW
–0.3
40
UNIT
V
PD
Continuous power dissipation
TJ
Operating junction temperature
–40
150
°C
Tstg
Storage temperature
–65
150
°C
(1)
(2)
See Thermal Information
Table
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.
All voltage values are with respect to network ground terminal.
7.2 ESD Ratings
VALUE
V(ESD)
(1)
(2)
Electrostatic discharge
Human-body model (HBM), per ANSI/ESDA/JEDEC JS-001 (1)
±2000
Charged-device model (CDM), per JEDEC specification JESD22-C101 (2)
±500
UNIT
V
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.
7.3 Recommended Operating Conditions
MIN
NOM
MAX
UNIT
VIN
Input voltage
2.7
5.5
V
VOUT
Output voltage
VIN
38
V
L
Inductor
4.7
10
µH
CI
Input capacitor
1
CO
Output capacitor
1
FPWM
PWM dimming signal frequency
DPWM
PWM dimming signal duty cycle
TJ
Operating junction temperature
–40
125
µF
10
µF
5
100
kHz
1%
100%
°C
7.4 Thermal Information
TPS61169
THERMAL METRIC
(1)
DCK (SC70)
UNIT
5 PINS
RθJA
Junction-to-ambient thermal resistance (2)
263.8
°C/W
RθJC(top)
Junction-to-case (top) thermal resistance (3)
76.1
°C/W
(4)
RθJB
Junction-to-board thermal resistance
51.4
°C/W
ψJT
Junction-to-top characterization parameter (5)
1.1
°C/W
ψJB
Junction-to-board characterization parameter (6)
50.7
°C/W
(1)
(2)
(3)
(4)
(5)
(6)
4
For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application
report, SPRA953.
The junction-to-ambient thermal resistance under natural convection is obtained in a simulation on a JEDEC-standard, high-K board, as
specified in JESD51-7, in an environment described in JESD51-2a.
The junction-to-case (top) thermal resistance is obtained by simulating a cold plate test on the package top. No specific JEDECstandard test exists, but a close description can be found in the ANSI SEMI standard G30-88.
The junction-to-board thermal resistance is obtained by simulating in an environment with a ring cold plate fixture to control the PCB
temperature, as described in JESD51-8.
The junction-to-top characterization parameter, ψJT, estimates the junction temperature of a device in a real system and is extracted
from the simulation data for obtaining R θJA, using a procedure described in JESD51-2a (sections 6 and 7).
The junction-to-board characterization parameter, ψJB, estimates the junction temperature of a device in a real system and is extracted
from the simulation data for obtaining RθJA , using a procedure described in JESD51-2a (sections 6 and 7).
Submit Documentation Feedback
Copyright © 2014–2016, Texas Instruments Incorporated
Product Folder Links: TPS61169
TPS61169
www.ti.com
SNVSA40A – OCTOBER 2014 – REVISED MARCH 2016
7.5 Electrical Characteristics
Over operating free-air temperature range, VIN = 3.6 V, CTRL = VIN (unless otherwise specified).
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
POWER SUPPLY
VIN
Input voltage range
2.7
VIN falling
VIN rising
VVIN_UVLO
Undervoltage lockout threshold
VVIN_HYS
VIN UVLO hysteresis
IQ_VIN
Operating quiescent current into
VIN
Device enable, switching 1.2 MHz
and no load,
ISD
Shutdown current
CTRL = GND
2
5.5
V
2.3
2.6
V
200
mV
0.3
0.45
mA
1
2
µA
CONTROL LOGIC AND TIMING
VH
CTRL Logic high voltage
VL
CTRL Logic Low voltage
RPD
CTRL pin internal pull-down
resistor
tSD
CTRL logic low time to shutdown
1.2
V
0.4
300
CTRL high to low
2.5
188
V
KΩ
ms
VOLTAGE AND CURRENT REGULATION
VREF
Voltage feedback regulation
voltage
Duty = 100%, TA ≥ 25°C
IFB
FB pin bias current
VFB = 204 mV
tREF
VREF filter time constant
204
220
mV
2.5
µA
1
ms
POWER SWITCH
RDS(ON)
N-channel MOSFET on-resistance
ILN_NFET
N-channel leakage current
0.35
VSW = 35 V
0.7
Ω
1
µA
SWITCHING FREQUENCY
ƒSW
Switching frequency
VIN = 3 V
0.75
1.2
1.5
MHz
1.8
2.4
A
PROTECTION AND SOFT START
ILIM
Switching MOSFET current limit
D = DMAX , TA ≤ 85°C
ILIM_Start
Switching MOSFET start-up
current limit
TA ≤ 85°C
tHalf_LIM
Time step for half current limit
VOVP_SW
Output voltage overvoltage
threshold
1.2
0.72
A
6.5
36
37.5
ms
39
V
THERMAL SHUTDOWN
Tshutdown
Thermal shutdown threshold
160
°C
Thys
Thermal shutdown hysteresis
15
°C
Submit Documentation Feedback
Copyright © 2014–2016, Texas Instruments Incorporated
Product Folder Links: TPS61169
5
TPS61169
SNVSA40A – OCTOBER 2014 – REVISED MARCH 2016
www.ti.com
7.6 Typical Characteristics
At TA = 25°C, unless otherwise noted.
250
1.8
1.6
Current Limit (A)
VFB-FB Voltage (mV)
200
150
100
1.4
1.2
1
0.8
50
0.6
0
0
10
20
30
40
50
60
70
Dimming Duty Cycle (%)
80
90
100
0.4
-60
-40
D001
Figure 1. FB Voltage vs Dimming Duty Cycle
6
Submit Documentation Feedback
-20
0
20
40
60
Temperature (°C)
80
100
120
D002
Figure 2. Current Limit vs Temperature
Copyright © 2014–2016, Texas Instruments Incorporated
Product Folder Links: TPS61169
TPS61169
www.ti.com
SNVSA40A – OCTOBER 2014 – REVISED MARCH 2016
8 Detailed Description
8.1 Overview
The TPS61169 is a high-efficiency, high-output voltage boost converter in small package size. The device
integrates 40-V/1.8-A switch FET and is designed for output voltage up to 39 V with a switch peak current limit of
1.2 A minimum. Its large driving capability can drive single or parallel LED strings for small to large size panel
backlighting.
The TPS61169 operates in a current mode scheme with quasi-constant frequency. It is internally compensated
for maximum flexibility and stability. The switching frequency is 1.2 MHz, and the minimum input voltage is 2.7 V.
During the on-time, the current rises into the inductor. When the current reaches a threshold value set by the
internal GM amplifier, the power switch MOSFET is turned off. The polarity of the inductor changes and forward
biases the schottky diode which lets the current flow towards the output of the boost converter. The off-time is
fixed for a certain VIN and VOUT, and therefore maintains the same frequency when varying these parameters.
However, for different output loads, the frequency slightly changes due to the voltage drop across the RDS(ON)
of the power switch MOSFET, this has an effect on the voltage across the inductor and thus on tON (tOFF remains
fixed). The fixed off-time maintains a quasi-fixed frequency that provides better stability for the system over a
wider range of input and output voltages than conventional boost converters. The TPS61169 topology has also
the benefits of providing very good load and line regulations, and excellent line and load transient responses.
The feedback loop regulates the FB pin to a low reference voltage (204 mV typical), reducing the power
dissipation in the current sense resistor.
Submit Documentation Feedback
Copyright © 2014–2016, Texas Instruments Incorporated
Product Folder Links: TPS61169
7
TPS61169
SNVSA40A – OCTOBER 2014 – REVISED MARCH 2016
www.ti.com
8.2 Functional Block Diagram
L
VBAT
D
VOUT
CIN
COUT
SW
VIN
UVLO
OVP
Current Limit and
Soft Start
TOFF
Generator
Ton
PWM
Generator
Gate Driver of
Power MOSFET
FB
GM Amplifier
VREF
RSET
CTRL
PWM Dimming
Reference Control
Shutdown
GND
8.3 Feature Description
8.3.1 Soft Start-Up
Soft-start circuitry is integrated into the IC to avoid high inrush current spike during start-up. After the device is
enabled, the GM amplifier output voltage ramps up very slowly, which ensures that the output voltage rises
slowly to reduce the input current. During this period, the switch current limit is set to 0.72 A. After around 6.5
ms, the switch current limit changes back to ILIM, and the FB pin voltage ramps up to the reference voltage
slowly. These features ensure the smooth start-up and minimize the inrush current. See Figure 12 for a typical
example.
8.3.2 Open LED Protection
Open LED protection circuitry prevents IC damage as the result of white LED disconnection. The TPS61169
monitors the voltage at the SW pin and FB pin during each switching cycle. The circuitry turns off the switch FET
and shuts down the IC when both of the following conditions persist for 3 switching cycles: (1) the SW voltage
exceeds the VOVP threshold, and (2) the FB voltage is less than 30 mV. As the result, the output voltage falls to
the level of the input supply. The device remains in shutdown mode until it is enabled by toggling the CTRL pin.
8
Submit Documentation Feedback
Copyright © 2014–2016, Texas Instruments Incorporated
Product Folder Links: TPS61169
TPS61169
www.ti.com
SNVSA40A – OCTOBER 2014 – REVISED MARCH 2016
Feature Description (continued)
8.3.3 Shutdown
The TPS61169 enters shutdown mode when the CTRL voltage is logic low for more than 2.5 ms. During
shutdown, the input supply current for the device is less than 2 μA (max). Although the internal switch FET does
not switch in shutdown, there is still a DC current path between the input and the LEDs through the inductor and
Schottky diode. The minimum forward voltage of the LED array must exceed the maximum input voltage to
ensure that the LEDs remain off in shutdown.
8.3.4 Current Program
The FB voltage is regulated by a low 204-mV reference voltage. The LED current is programmed externally using
a current-sense resistor in series with the LED string(s). The value of the RSET is calculated using:
VFB
ILED
RSET
where
•
•
•
ILED = total output current of LED string(s)
VFB = regulated voltage of FB pin
RSET = current sense resistor
(1)
The output current tolerance depends on the FB accuracy and the current sensor resistor accuracy.
8.3.5 LED Brightness Dimming
The TPS61169 receives PWM dimming signal at CTRL pin to control the total output current. When the CTRL
pin is constantly high, the FB voltage is regulated to 204 mV typically. When the duty cycle of the input PWM
signal is low, the regulation voltage at FB pin is reduced, and the total output current is reduced; therefore, it
achieves LED brightness dimming. The relationship between the duty cycle and FB regulation voltage is given
by:
VFB Duty u 204 mV
where
•
•
Duty = Duty cycle of the PWM signal
204 mV = internal reference voltage
(2)
Thus, the user can easily control the WLED brightness by controlling the duty cycle of the PWM signal.
As shown in Figure 3, the IC chops up the internal 204-mV reference voltage at the duty cycle of the PWM
signal. The pulse signal is then filtered by an internal low-pass filter. The output of the filter is connected to the
GM amplifier as the reference voltage for the FB pin regulation. Therefore, although a PWM signal is used for
brightness dimming, only the WLED DC current is modulated, which is often referred as analog dimming. This
eliminates the audible noise which often occurs when the LED current is pulsed in replica of the frequency and
duty cycle of PWM control. Unlike other methods which filter the PWM signal for analog dimming, TPS61169
regulation voltage is independent of the PWM logic voltage level which often has large variations.
For optimum performance, use the PWM dimming frequency in the range of 5 kHz to 100 kHz. If the PWM
frequency is lower than 5 kHz, it is out of the low pass filter's filter range, the FB regulation voltage ripple
becomes large, causing large output ripple and may generate audible noise.
Submit Documentation Feedback
Copyright © 2014–2016, Texas Instruments Incorporated
Product Folder Links: TPS61169
9
TPS61169
SNVSA40A – OCTOBER 2014 – REVISED MARCH 2016
www.ti.com
Feature Description (continued)
VBG
204 mV
CTRL
VREF
GM
Amplifier
EA Output
FB
Figure 3. Programmable FB Voltage Using PWM Signal
8.3.6 Undervoltage Lockout
An undervoltage lockout prevents operation of the device at input voltages below typical 2 V. When the input
voltage is below the undervoltage threshold, the device is shut down, and the internal switch FET is turned off. If
the input voltage rises by undervoltage lockout hysteresis, the IC restarts.
8.3.7 Thermal Foldback and Thermal Shutdown
When TPS61169 drives heavy load for large size panel applications, the power dissipation increases a lot and
the device junction temperature may reach a very high value, affecting the device function and reliability. In order
to lower the thermal stress, the TPS61169 features a thermal foldback function. When the junction temperature is
higher than 100°C, the switch current limit ILIM is reduced automatically as Figure 2 shows. This thermal foldback
mechanism controls the power dissipation and keeps the junction temperature from rising to a very high value. If
the typical junction temperature of 160°C is exceeded, an internal thermal shutdown turns off the device. The
device is released from shutdown automatically when the junction temperature decreases by 15°C.
8.4 Device Functional Modes
8.4.1 Operation With CTRL
The enable rising edge threshold voltage is 1.2 V. When the CTRL pin is held below that voltage the device is
disabled and switching is inhibited. The IC quiescent current is reduced in this state. When input voltage is above
the UVLO threshold, and the CTRL pin voltage is increased above the rising edge threshold, the device becomes
active. Switching enables, and the soft-start sequence initiates.
10
Submit Documentation Feedback
Copyright © 2014–2016, Texas Instruments Incorporated
Product Folder Links: TPS61169
TPS61169
www.ti.com
SNVSA40A – OCTOBER 2014 – REVISED MARCH 2016
9 Application and Implementation
NOTE
Information in the following applications sections is not part of the TI component
specification, and TI does not warrant its accuracy or completeness. TI’s customers are
responsible for determining suitability of components for their purposes. Customers should
validate and test their design implementation to confirm system functionality.
9.1 Application Information
The TPS61169 device is a step-up DC-DC converter which can drive single or parallel LED strings for small- to
large-size panel backlighting. This section includes a design procedure (Detailed Design Procedure) to select
component values for the TPS61169 typical application (Figure 4).
9.2 Typical Application
L
4.7 µH
2.7 V to 5.5 V
D
10s1p
VBAT
CIN
4.7 µF
COUT
1 µF
TPS61169
VIN
SW
PWM DIMMING
CONTROL
CTRL
FB
GND
RSET
10.2
Figure 4. TPS61169 2.7-V to 5.5-V Input, 10 LEDs in Series Output Converter
9.2.1 Design Requirements
For this design example, use the parameters listed in Table 1 as the input parameters.
Table 1. Design Parameters
DESIGN PARAMETER
EXAMPLE VALUE
Input voltage range
2.7 V to 5.5 V
Output, LED number in a string
10
Output, LED string number
1
Output, LED current per string
20 mA
9.2.2 Detailed Design Procedure
9.2.2.1 Inductor Selection
The selection of the inductor affects power efficiency, steady state operation as well as transient behavior and
loop stability. These factors make it the most important component in power regulator design. There are three
important inductor specifications, inductor value, DC resistance and saturation current. Considering inductor
value alone is not enough. The inductor value determines the inductor ripple current. Choose an inductor that
can handle the necessary peak current without saturating. Follow Equation 3 to Equation 4 to calculate the peak
current of the inductor. To calculate the current in the worst case, use the minimum input voltage, maximum
output voltage and maximum load current of application. In a boost regulator, the input DC current can be
calculated as Equation 3.
Submit Documentation Feedback
Copyright © 2014–2016, Texas Instruments Incorporated
Product Folder Links: TPS61169
11
TPS61169
SNVSA40A – OCTOBER 2014 – REVISED MARCH 2016
IL(DC)
www.ti.com
VOUT u IOUT
VIN u K
where
•
•
•
•
VOUT = boost output voltage
IOUT = boost output current
VIN = boost input voltage
η = power conversion efficiency
(3)
The inductor current peak to peak ripple can be calculated as Equation 4.
1
'IL(P P)
1
1
Lu(
) u FS
VOUT VIN VIN
where
•
•
•
•
•
ΔIL(PP) = inductor peak-to-peak ripple
L = inductor value
FS = boost switching frequency
VOUT = boost output voltage
VIN = boost input voltage
(4)
Therefore, the peak current IL(P) seen by the inductor is calculated with Equation 5.
'IL(P P)
IL(P) IL(DC)
2
(5)
Inductor values can have ±20% tolerance with no current bias. When the inductor current approaches saturation
level, its inductance can decrease 20% to 35% from the 0-A value depending on how the inductor vendor defines
saturation current. Using an inductor with a smaller inductance value forces discontinuous PWM when the
inductor current ramps down to zero before the end of each switching cycle. This reduces the boost converter’s
maximum output current, causes large input voltage ripple and reduces efficiency. Large inductance value
provides much more output current and higher conversion efficiency. For these reasons, a 4.7-μH to 10-μH
inductor value range is recommended, and 4.7-μH inductor is recommended for higher than 5-V input voltage by
considering inductor peak current and loop stability. Table 2 lists the recommended inductor for the TPS61169.
Table 2. Recommended Inductors for TPS61169
PART NUMBER
L (µH)
DCR MAX (mΩ)
SATURATION
CURRENT (A)
SIZE (L x W x H
mm)
VENDOR
LPS4018-472ML
4.7
125
1.9
4 × 4 × 1.8
Coilcraft
LPS4018-103ML
10
200
1.3
4 × 4 × 1.8
Coilcraft
PCMB051H-4R7M
4.7
85
4
5.4 × 5.2 × 1.8
Cyntec
PCMB051H-100M
10
155
3
5.4 × 5.2 × 1.8
Cyntec
9.2.2.2 Schottky Diode Selection
The TPS61169 demands a low forward voltage, high-speed and low capacitance Schottky diode for optimum
efficiency. Ensure that the diode average and peak current rating exceeds the average output current and peak
inductor current. In addition, the diode reverse breakdown voltage must exceed the open LED protection voltage.
ONSemi NSR0240 is recommended for the TPS61169.
9.2.2.3 Output Capacitor Selection
The output capacitor is mainly selected to meet the requirement for the output ripple and loop stability. This ripple
voltage is related to capacitor capacitance and its equivalent series resistance (ESR). Assuming a capacitor with
zero ESR, the minimum capacitance needed for a given ripple can be calculated with Equation 6:
(VOUT VIN ) u IOUT
COUT
VOUT u FS u Vripple
12
Submit Documentation Feedback
Copyright © 2014–2016, Texas Instruments Incorporated
Product Folder Links: TPS61169
TPS61169
www.ti.com
SNVSA40A – OCTOBER 2014 – REVISED MARCH 2016
where
•
Vripple = peak-to-peak output ripple
(6)
The additional part of the ripple caused by ESR is calculated using: Vripple_ESR = IOUT × RESR
Due to its low ESR, Vripple_ESR could be neglected for ceramic capacitors, a 1-µF to 4.7-µF capacitor is
recommended for typical application.
9.2.2.4 LED Current Set Resistor
The LED current set resistor can be calculated by Equation 1.
9.2.2.5 Thermal Considerations
The allowable IC junction temperature must be considered under normal operating conditions. This restriction
limits the power dissipation of the TPS61169. The allowable power dissipation for the device can be determined
by Equation 7:
TJ - TA
PD
RTJA
where
•
•
•
TJ is allowable junction temperature given in recommended operating conditions
TA is the ambient temperature for the application
RθJA is the thermal resistance junction-to-ambient given in Power Dissipation Table
(7)
The TPS61169 device also features a thermal foldback function to reduce the thermal stress automatically.
9.3 Application Curves
Typical application condition is as in Figure 4, VIN = 3.6 V, RSET = 10.2 Ω, L = 4.7 µH, COUT = 1 µF, 10 LEDs in series (unless
otherwise specified).
100
100
10 LEDs in series
6 LEDs in series
90
Efficiency (%)
Efficiency (%)
90
80
70
60
80
70
Vin = 3.0 V
Vin = 3.6 V
Vin = 4.2 V
Vin = 5.0 V
60
50
50
0
10
20
30
40
50
60
70
Dimming Duty Cycle (%)
80
90
100
0
10
D003
20
30
40
50
60
70
Dimming Duty Cycle (%)
80
90
100
D004
10 LEDs in series
Figure 5. Efficiency vs Dimming Duty Cycle
Figure 6. Efficiency vs Dimming Duty Cycle
Submit Documentation Feedback
Copyright © 2014–2016, Texas Instruments Incorporated
Product Folder Links: TPS61169
13
TPS61169
SNVSA40A – OCTOBER 2014 – REVISED MARCH 2016
www.ti.com
Application Curves (continued)
100
100
90
90
Efficiency (%)
Efficiency (%)
Typical application condition is as in Figure 4, VIN = 3.6 V, RSET = 10.2 Ω, L = 4.7 µH, COUT = 1 µF, 10 LEDs in series (unless
otherwise specified).
80
70
Vin = 3.0 V
Vin = 3.6 V
Vin = 4.2 V
Vin = 5.0 V
60
80
70
Vin = 3.0 V
Vin = 3.6 V
Vin = 4.2 V
Vin = 5.0 V
60
50
50
0
10
20
30
40
50
60
70
Dimming Duty Cycle (%)
80
90
100
0
10
20
D005
8 LEDs in series
30
40
50
60
70
Dimming Duty Cycle (%)
80
90
100
D006
6 LEDs in series
Figure 7. Efficiency vs Dimming Duty Cycle
Figure 8. Efficiency vs Dimming Duty Cycle
SW (20 V/DIV)
SW (20 V/DIV)
VOUT (100 mV/DIV, AC coupled)
VOUT (100 mV/DIV, AC coupled)
IInductor (500 mA/DIV)
IInductor (500 mA/DIV)
ILED (9 mA/DIV)
ILED (9 mA/DIV)
Time = 1 µs/DIV
Time = 1 µs/DIV
Figure 9. Switching-Dimming Duty = 100%
Figure 10. Switching-Dimming Duty = 50%
SW (20 V/DIV)
PWM
(2 V/DIV)
VOUT (100 mV/DIV, AC coupled)
IInductor
(300 mA/DIV)
IInductor (500 mA/DIV)
VOUT (20 V/DIV)
ILED (5 mA/DIV)
ILED (9 mA/DIV)
Time = 2 µs/DIV
Time = 2 ms/DIV
Figure 11. Switching-Dimming Duty = 10%
14
Figure 12. Start-Up Dimming Duty = 100%
Submit Documentation Feedback
Copyright © 2014–2016, Texas Instruments Incorporated
Product Folder Links: TPS61169
TPS61169
www.ti.com
SNVSA40A – OCTOBER 2014 – REVISED MARCH 2016
Application Curves (continued)
Typical application condition is as in Figure 4, VIN = 3.6 V, RSET = 10.2 Ω, L = 4.7 µH, COUT = 1 µF, 10 LEDs in series (unless
otherwise specified).
PWM (2 V/DIV)
PWM (2 V/DIV)
IInductor (300 mA/DIV)
IInductor
(300 mA/DIV)
VOUT (20 V/DIV)
ILED (9 mA/DIV)
VOUT (20 V/DIV)
ILED (9 mA/DIV)
Time = 2 ms/DIV
Time = 2 ms/DIV
Figure 13. Start-Up Dimming Duty = 50%
PWM (2 V/DIV)
Figure 14. Shutdown Dimming Duty = 100%
PWM (2 V/DIV)
VOUT (5 V/DIV, AC coupled)
IInductor (300 mA/DIV)
IInductor (300 mA/DIV)
VOUT (20 V/DIV)
ILED (9 mA/DIV)
ILED (9 mA/DIV)
Time = 2 ms/DIV
Duty = 50%
Time = 5 ms/DIV
Duty = 1%-100%-1%
Figure 15. Shutdown Dimming
Figure 16. Dimming Transient-Dimming
VFB (200 mV/DIV)
VOUT (20 V/DIV)
IInductor (600 mA/DIV)
ILED (9 mA/DIV)
Time = 50 µs/DIV
Figure 17. Open LED Protection
Submit Documentation Feedback
Copyright © 2014–2016, Texas Instruments Incorporated
Product Folder Links: TPS61169
15
TPS61169
SNVSA40A – OCTOBER 2014 – REVISED MARCH 2016
www.ti.com
10 Power Supply Recommendations
The device is designed to operate from an input voltage supply range between 2.7 V and 5.5 V. This input supply
must be well regulated. If the input supply is located more than a few inches from the TPS61169 device,
additional bulk capacitance may be required in addition to the ceramic bypass capacitors.
11 Layout
11.1 Layout Guidelines
As for all switching power supplies, especially those high frequency and high current ones, layout is an important
design step. If layout is not carefully done, the regulator could suffer from instability as well as noise problems.
Therefore, use wide and short traces for high current paths. The input capacitor CIN must be close to VIN pin and
GND pin in order to reduce the input ripple seen by the device. If possible choose higher capacitance value for it.
The SW pin carries high current with fast rising and falling edge; therefore, the connection between the SW pin to
the inductor must be kept as short and wide as possible. The output capacitor COUT must be put close to VOUT
pin. It is also beneficial to have the ground of COUT close to the GND pin because there is large ground return
current flowing between them. FB resistor must be put close to FB pin. When laying out signal ground, TI
recommends using short traces separated from power ground traces, and connect them together at a single
point close to the GND pin.
11.2 Layout Example
Bottom
GND
Plane
FB
GND
VIN
SW
VIN
CTRL
GND
GND
VOUT
Figure 18. TPS61169 Board Layout
16
Submit Documentation Feedback
Copyright © 2014–2016, Texas Instruments Incorporated
Product Folder Links: TPS61169
TPS61169
www.ti.com
SNVSA40A – OCTOBER 2014 – REVISED MARCH 2016
12 Device and Documentation Support
12.1 Device Support
12.1.1 Third-Party Products Disclaimer
TI'S PUBLICATION OF INFORMATION REGARDING THIRD-PARTY PRODUCTS OR SERVICES DOES NOT
CONSTITUTE AN ENDORSEMENT REGARDING THE SUITABILITY OF SUCH PRODUCTS OR SERVICES
OR A WARRANTY, REPRESENTATION OR ENDORSEMENT OF SUCH PRODUCTS OR SERVICES, EITHER
ALONE OR IN COMBINATION WITH ANY TI PRODUCT OR SERVICE.
12.2 Community Resources
The following links connect to TI community resources. Linked contents are provided "AS IS" by the respective
contributors. They do not constitute TI specifications and do not necessarily reflect TI's views; see TI's Terms of
Use.
TI E2E™ Online Community TI's Engineer-to-Engineer (E2E) Community. Created to foster collaboration
among engineers. At e2e.ti.com, you can ask questions, share knowledge, explore ideas and help
solve problems with fellow engineers.
Design Support TI's Design Support Quickly find helpful E2E forums along with design support tools and
contact information for technical support.
12.3 Trademarks
E2E is a trademark of Texas Instruments.
All other trademarks are the property of their respective owners.
12.4 Electrostatic Discharge Caution
These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam
during storage or handling to prevent electrostatic damage to the MOS gates.
12.5 Glossary
SLYZ022 — TI Glossary.
This glossary lists and explains terms, acronyms, and definitions.
13 Mechanical, Packaging, and Orderable Information
The following pages include mechanical, packaging, and orderable information. This information is the most
current data available for the designated devices. This data is subject to change without notice and revision of
this document. For browser-based versions of this data sheet, refer to the left-hand navigation.
Submit Documentation Feedback
Copyright © 2014–2016, Texas Instruments Incorporated
Product Folder Links: TPS61169
17
PACKAGE OPTION ADDENDUM
www.ti.com
27-Feb-2016
PACKAGING INFORMATION
Orderable Device
Status
(1)
TPS61169DCKR
ACTIVE
Package Type Package Pins Package
Drawing
Qty
SC70
DCK
5
3000
Eco Plan
Lead/Ball Finish
MSL Peak Temp
(2)
(6)
(3)
Green (RoHS
& no Sb/Br)
CU NIPDAU
Level-1-260C-UNLIM
Op Temp (°C)
Device Marking
(4/5)
-40 to 85
SZL
(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.
(4)
There may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device.
(5)
Multiple Device Markings will be inside parentheses. Only one Device Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a continuation
of the previous line and the two combined represent the entire Device Marking for that device.
(6)
Lead/Ball Finish - Orderable Devices may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead/Ball Finish values may wrap to two lines if the finish
value exceeds the maximum column width.
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
Samples
PACKAGE OPTION ADDENDUM
www.ti.com
27-Feb-2016
Addendum-Page 2
PACKAGE MATERIALS INFORMATION
www.ti.com
27-Feb-2016
TAPE AND REEL INFORMATION
*All dimensions are nominal
Device
TPS61169DCKR
Package Package Pins
Type Drawing
SC70
DCK
5
SPQ
Reel
Reel
A0
Diameter Width (mm)
(mm) W1 (mm)
3000
178.0
9.0
Pack Materials-Page 1
2.4
B0
(mm)
K0
(mm)
P1
(mm)
2.5
1.2
4.0
W
Pin1
(mm) Quadrant
8.0
Q3
PACKAGE MATERIALS INFORMATION
www.ti.com
27-Feb-2016
*All dimensions are nominal
Device
Package Type
Package Drawing
Pins
SPQ
Length (mm)
Width (mm)
Height (mm)
TPS61169DCKR
SC70
DCK
5
3000
180.0
180.0
18.0
Pack Materials-Page 2
IMPORTANT NOTICE AND DISCLAIMER
TI PROVIDES TECHNICAL AND RELIABILITY DATA (INCLUDING DATASHEETS), DESIGN RESOURCES (INCLUDING REFERENCE
DESIGNS), APPLICATION OR OTHER DESIGN ADVICE, WEB TOOLS, SAFETY INFORMATION, AND OTHER RESOURCES “AS IS”
AND WITH ALL FAULTS, AND DISCLAIMS ALL WARRANTIES, EXPRESS AND IMPLIED, INCLUDING WITHOUT LIMITATION ANY
IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT OF THIRD
PARTY INTELLECTUAL PROPERTY RIGHTS.
These resources are intended for skilled developers designing with TI products. You are solely responsible for (1) selecting the appropriate
TI products for your application, (2) designing, validating and testing your application, and (3) ensuring your application meets applicable
standards, and any other safety, security, or other requirements. These resources are subject to change without notice. TI grants you
permission to use these resources only for development of an application that uses the TI products described in the resource. Other
reproduction and display of these resources is prohibited. No license is granted to any other TI intellectual property right or to any third
party intellectual property right. TI disclaims responsibility for, and you will fully indemnify TI and its representatives against, any claims,
damages, costs, losses, and liabilities arising out of your use of these resources.
TI’s products are provided subject to TI’s Terms of Sale (www.ti.com/legal/termsofsale.html) or other applicable terms available either on
ti.com or provided in conjunction with such TI products. TI’s provision of these resources does not expand or otherwise alter TI’s applicable
warranties or warranty disclaimers for TI products.
Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265
Copyright © 2019, Texas Instruments Incorporated
工商网监
湘ICP备2023018690号
