TPS61169 38-V circuit High Current-Boost WLED Driver

TPS61169 38-V circuit High Current Boost Driver

TPS61169 38v constant current boost converter and LED Driver with USB connector. The TPS61169 is a highly efficient and versatile LED driver that is commonly used in various lighting applications. This integrated circuit (IC) provides a constant current output, making it ideal for driving multiple LEDs in series or parallel configurations. With a wide input voltage range and high voltage capability, the TPS61169 can be used in various power supply designs. It also features a built-in boost converter that efficiently steps up the input voltage to achieve the desired LED forward voltage. This driver IC offers excellent dimming capabilities, allowing for smooth and flicker-free brightness control. Additionally, the TPS61169 incorporates various protection features to ensure reliable operation, such as overvoltage protection, overcurrent protection, and thermal shutdown. Overall, the TPS61169 is a reliable and efficient LED driver that offers great flexibility and performance in lighting applications.

Schematic TPS61169 38-V circuit High Current-Boost WLED Driver


The TPS61169 is a high-efficiency, high-output voltage boost converter in a small package size. The device integrates a 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 excellent 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.

Features TPS61169 38-V circuit High Current-Boost WLED Driver

  • 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

 Applications TPS61169 38-V circuit High Current-Boost WLED Driver

  • 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

Bom TPS61169 38-V circuit High Current-Boost WLED Driver

Name Designator Footprint Quantity
R400 R1 805 1
KF301-2P X1 Terminal block connector 1
4u7 C1 805 1
1u C2 805 1
TPS61169DCKR U1 38-V high-current Boost WLED driver 1
SS34 D1 SMA(DO-214AC) – Diode, Schottky 1
USB-Plug USB1 USB male Type A connector 1
4.7uH L1 SMD inductor – 4.4 × 4.2 1

Download files, links, and notes

Download PCB in Gerber, PDF, PNG, SVG




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About the author blog author. Electronics technician for the technical school of Brasilia - Brazil. Interested in electronics, circuits and technology in general.

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