TPS92690EVM Boost Evaluation Module User's Guide Literature Number: SLVU803 December 2012
Contents A ........................... 4 .................................................................................................................. 4 Detailed Description ............................................................................................................ 5 2.1 Description ................................................................................................................... 5 2.1.1 Typical Applications ...........................................................
www.ti.com List of Figures ................................................................................................ 4-1. TPS92690EVM Schematic 5-1. Efficiency ..................................................................................................................... 9 5-2. Line Regulation .............................................................................................................. 9 5-3. Switching and LED Current ...................................................
Chapter 1 SLVU803 – December 2012 N-Channel Controller for Dimmable LED Drives with Low-Side Current Sense 1.1 Introduction The TPS92690EVM evaluation module (EVM) helps designers evaluate the operation and performance of the TPS92690 DC-DC N-channel MOSFET controller. The TPS92690 is designed to drive high-brightness light emitting diodes (LEDs) and features a wide input voltage range (4.
Chapter 2 SLVU803 – December 2012 Detailed Description 2.1 Description The TPS92690EVM provides a high-brightness LED driver based on the TPS92690 configured as a boost (step-up) regulator. It is designed to operate with an input voltage in the range of 8 V to 19 V with a 12-V nominal input voltage. This input voltage range is typical for automotive applications and common for many off the shelf AC-DC sources.
Description www.ti.com 2.1.2.1.5 SYNC This test point connects directly to the SYNC pin of the TPS92690. Applying a square wave to this test point with a low level of ground and a high level between 2.5 V and 5 V synchronizes the switching frequency of the TPS92690 with the applied square wave. The falling edge of the applied square wave triggers an on time of the power FET.
Chapter 3 SLVU803 – December 2012 Electrical Performance Specifications Table 3-1. TPS92690EVM Electrical Performance Specifications PARAMETER TEST CONDITIONS MIN TYP MAX 12 19 UNITS Input Characteristics Voltage range Maximum input current Undervoltage lockout level 8 V At IOUT = 500 mA 2.4 A Input rising 7.8 V Input falling 5.
Chapter 4 SLVU803 – December 2012 Schematic µF µF µF µF Figure 4-1.
Chapter 5 SLVU803 – December 2012 Performance Data and Typical Characteristic Curves Figure 5-1 through Figure 5-8 show typical performance curves for the TPS92690EVM. 5.1 Efficiency 100 Efficiency (%) 98 96 94 92 10 LEDs @ 500mA 90 10 12 14 Input Voltage (V) 16 18 G000 Figure 5-1. Efficiency 5.2 Line Regulation 510 Output Current (mA) 506 502 498 494 10 LEDs 490 8 10 12 14 Input Voltage (V) 16 18 G001 Figure 5-2.
Switch Node Voltage and LED Current Ripple 5.3 www.ti.com Switch Node Voltage and LED Current Ripple Switching Node LED Current Figure 5-3. Switching and LED Current 5.4 PWM Dimming PWM DIM Switching Node LED Current Figure 5-4. PWM Dimming, fPWM = 200 Hz, Duty Cycle = 50% PWM DIM Switching Node LED Current Figure 5-5.
Start-up and Shut-down Response www.ti.com PWM DIM Switching Node LED Current Figure 5-6. PWM Dimming, fPWM = 200 Hz, Duty Cycle = 95% 5.5 Start-up and Shut-down Response SS/SD Switching Node LED Current Figure 5-7. Start-up Waveform SS/SD Switching Node LED Current Figure 5-8.
Thermal Performance 5.6 www.ti.com Thermal Performance Figure 5-9 and Figure 5-10 show the steady state thermal performance of the EVM under the following conditions: • Load of 10 LEDs • ILED = 500 mA • VIN = 12 VDC Figure 5-9. Top Thermal Performance Figure 5-10.
Chapter 6 SLVU803 – December 2012 TPS92690EVM PCB layout Figure 6-1 and Figure 6-2 show the design of the TPS92690EVM printed circuit board. Figure 6-1. Top Layer and Top Overlay (Top View) Figure 6-2.
Appendix A SLVU803 – December 2012 Bill of Materials Table A-1. The TPS92690EVM Components List (According to the Schematic Shown in Figure 4-1) REFERENCE DESIGNATOR 14 QTY VALUE DESCRIPTION DC-DC Controller with Low Side FET and Low Side Current Sense SIZE MFR eTSSOP-16 TI PART NUMBER U1 1 C3 1 0.1 µF Capacitor, Ceramic, 100 V, X7R 0805 Kemet C5, C6 2 4.7 µF Capacitor, Ceramic, 50 V, X7R 2220 MuRata GRM55ER71H475MA01L C7, C8 2 4.
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