PT4119EE89E

PT4119E 50V/1A Step-down High Brightness LED Driver GENERAL DESCRIPTION FEATURES The PT4119E is a continuous conduction mode inductive step-down converter, designed for driving single or multiple series connected LED efficiently from a voltage source higher than the total LED chain voltage. The device operates from an input supply between 6V and 50V and provides an externally adjustable output current of up to 1A. The PT4119E includes the power switch and a high-side output current sensing circuit, which uses an external resistor to set the nominal average output current, and a dedicated DIM input accepts either a DC voltage or a wide range of pulsed dimming. Applying a voltage of 0.3V or lower to the DIM pin turns the output off and switches the device into a low current standby state. The PT4119E is available in SOT89-5 package.              Simple low parts count Wide input voltage range: 6V to 50V High efficiency (up to 97%) Up to 1A output current Single pin on/off and brightness control using DC voltage or PWM Up to 1MHz switching frequency Typical 3% output current accuracy Inherent open-circuit LED protection Inherent Rcs open protection High-Side Current Sense Hysteretic Control: No need compensation Adjustable Constant LED Current Thermal shutdown APPLICATIONS        Low voltage halogen replacement LEDs Automotive lighting Low voltage industrial lighting LED back-up lighting Illuminated signs SELV lighting LCD TV backlighting ORDERING INFORMATION PACKAGE TEMPERATURE RANGE ORDERING PART NUMBER TRANSPORT MEDIA MARKING SOT89-5 -40 oC to 85 oC PT4119EE89E Tape and Reel 1000 units PT4119E xxxxxX Note: xxxxxX Assembly Factory Code Lot Number TYPICAL APPLICATION CIRCUIT RS DC6-50V VIN LED L D CIN AC12-24V VIN DIM CSN SW PT411E GND CR POWTECH (SHANGHAI) CO., LTD. PT4119E_DS_Rev EN 1.0 WWW.CRPOWTECH.COM Page 1 PT4119E 50V/1A Step-down High Brightness LED Driver PIN ASSIGNMENT PIN DESCRIPTIONS SOT89-5 PIN No. PIN NAMES 1 SW 2 GND 3 DIM 4 CSN Current sense input 5 VIN Input Supply Pin. Must be locally bypassed. Exposed DESCRIPTION Switch Output. SW is the drain of the internal N-Ch MOSFET switch. Signal and power ground. Connect directly to ground plane. Logic level dimming input. Drive DIM low to turn off the current regulator. Drive DIM high to enable the current regulator. PAD Internally connected to GND. Mount on board for lower thermal resistance. ABSOLUTE MAXIMUM RATINGS (note1) SYMBOL ITEMS VALUE UNIT VIN Supply Voltage -0.3~55 V SW Drain of the internal power switch -0.3~55 V CSN Current sense input (Respect to VIN) +0.3~(-6.0) V DIM Logic level dimming input -0.3~6 V 1 A 1.5 W ISW PDMAX Switch output current Power Dissipation (Note 2) θJA PTR Thermal Resistance, SOT89-5 TJ Operation Junction Temperature Range -40 to 150 o C Storage Temperature -55 to 150 o C TSTG ESD Susceptibility (Note 3) CR POWTECH (SHANGHAI) CO., LTD. PT4119E_DS_Rev EN 1.0 WWW.CRPOWTECH.COM 45 2 o C /W kV Page 2 PT4119E 50V/1A Step-down High Brightness LED Driver RECOMMENDED OPERATING RANGE SYMBOL ITEMS VIN VDD Supply Voltage TOPT Operating Temperature VALUE UNIT 6 ~ 50 V -40 to +85 o C Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Recommended Operating Range indicates conditions for which the device is functional, but do not guarantee specific performance limits. Electrical Characteristics state DC and AC electrical specifications under particular test conditions which guarantee specific performance limits. This assumes that the device is within the Operating Range. Specifications are not guaranteed for parameters where no limit is given, however, the typical value is a good indication of device performance. Note 2: The maximum power dissipation must be derated at elevated temperatures and is dictated by TJMAX, θJA, and the ambient temperature TA. The maximum allowable power dissipation is PDMAX = (TJMAX - TA)/ θJA or the number given in Absolute Maximum Ratings, whichever is lower. Note 3: Human body model, 100pF discharged through a 1.5kΩ resistor. CR POWTECH (SHANGHAI) CO., LTD. PT4119E_DS_Rev EN 1.0 WWW.CRPOWTECH.COM Page 3 PT4119E 50V/1A Step-down High Brightness LED Driver ELECTRICAL CHARACTERISTICS (Note 4, 5) The following specifications apply for V IN=24V, TA=25 oC, unless specified otherwise. SYMBOL VIN VUVLO VUVLO_HYS FSW ITEMS CONDITIONS Input Voltage Min. Typ. 6 Max. UNIT 50 V Under voltage lock out VIN rising 4.5 V UVLO hysterisis VIN falling 0.3 V Max. Switching Frequency 1 MHz 206 mV Current Sense Mean current sense VCSN VCSN_hys ICSN threshold voltage VIN-VCSN 194 Sense threshold hysteresis CSN Pin Input Current VIN-VCSN=50mV 200 ±15 % 8 µA Operating Current ISD Shutdown supply current IOFF Quiescent supply current with output off 60 100 µA No Switching 0.16 0.3 mA DIM floating 4.2 DIM Input VDIM Internal supply voltage VDIM_H DIM input voltage High V 0.3 0.35 V 50 80 mV 2.5 V VDIM_HYS DIM input voltage hysterisis 20 VDIM_DC DC brightness control 0.5 FDIM_MIN Min. DIM Frequency 0.1 kHz FDIM_MAX Max. DIM Frequency 20 kHz 200 KΩ RDIM DIM pull up resistor to Internal supply voltage IDIM_H DIM input leakage high VDIM = 5.0V 2.8 µA IDIM_L DIM input leakage low VDIM = 0 22 µA SW On Resistance VIN=6V～50V 0.6 Ω Output Switch RSW ISWmean ILEAK Continuous SW Current SW Leakage Current 0.5 1 A 5 µA Thermal Shutdown TSD Thermal Shutdown 155 ℃ Shutdown 20 ℃ Threshold TSD_HYS Thermal hysteresis Note 4: Note 5: Typical parameters are measured at 25˚C and represent the parametric norm. Datasheet min/max specification limits are guaranteed by design, test, or statistical analysis. CR POWTECH (SHANGHAI) CO., LTD. PT4119E_DS_Rev EN 1.0 WWW.CRPOWTECH.COM Page 4 PT4119E 50V/1A Step-down High Brightness LED Driver SIMPLIFIED BLOCK DIAGRAM OPERATION DESCRIPTION The PT4119E in conjunction with current sense on-board current-setting circuitry minimize the resistor (RCS),the inductor (L1), and MOSFET number of external components while delivering forms a self oscillating continuous-mode buck LED current with ±3% accuracy, using a 1% sense converter. resistor. The PT4119E allows dimming with a PWM When input voltage VIN is first applied, the initial signal at the DIM input. A logic level below 0.3V at current in L1 and RCS is zero and there is no output DIM forces PT4119E to turn off the LED and the from the current sense circuit. Under this condition, logic level at DIM must be at least 2.5V to turn on the output of CS comparator is high. This turns on the full LED current. The frequency of PWM switch, causing current to flow from VIN to ground, dimming ranges from 100Hz to 20 kHz. via RCS, the LED(s),L1 and internal MOSFET. The The DIM pin can be driven by an external DC current rises at a rate determined by VIN and L1 to voltage (VDIM) to adjust the output current to a value produce a voltage ramp (VCSN) across RCS. When below the nominal average value defined by RCS. (VIN-VCSN) CS The DC voltage is valid from 0.5V to 2.5V. When comparator switches low and the switch turns off. the DC voltage is higher than 2.5V, the output The current flowing on the RCS decreases at current keeps constant. > 230mV, the output of another rate. When (VIN-VCSN) < 170mV, the Additionally, to ensure the reliability, the switch turns on again and the mean current on the PT4119E is built with a thermal shutdown (TSD) LED is determined by 200mV/RCS. protection. The TSD protests the IC from over The high-side current-sensing scheme and CR POWTECH (SHANGHAI) CO., LTD. PT4119E_DS_Rev EN 1.0 temperature (155℃). WWW.CRPOWTECH.COM Page 5 PT4119E 50V/1A Step-down High Brightness LED Driver TYPICAL PERFORMANCE CHARACTERASTICS VIN=24V,3LEDs,IOUT=1A,TA=25℃，unless otherwise noted. Efficiency Steady State 2µS/div Input Power On Input Power Off 2mS/div 100mS/div EN Power On EN Power Off 400µS/div CR POWTECH (SHANGHAI) CO., LTD. PT4119E_DS_Rev EN 1.0 200µS/div WWW.CRPOWTECH.COM Page 6 PT4119E 50V/1A Step-down High Brightness LED Driver TYPICAL PERFORMANCE CHARACTERASTICS(continued) VIN=24V,3LEDs,IOUT=1A,TA=25℃，unless otherwise noted. PWM Dimming PWM Dimming (2KHz,50%) (2KHz,1%) 400µS/div 400µS/div Short LED+ to LED- Protection Short LED+ to LED- Recovery 20µS/div Open LED Load Protection 20µS/div Open LED Load Recovery 2mS/div CR POWTECH (SHANGHAI) CO., LTD. PT4119E_DS_Rev EN 1.0 40µS/div WWW.CRPOWTECH.COM Page 7 PT4119E 50V/1A Step-down High Brightness LED Driver TYPICAL PERFORMANCE CHARACTERASTICS(continued) VIN=24V,3LEDs,IOUT=1A,TA=25℃，unless otherwise noted. Open RCS Protection 2S/div APPLICATION NOTES Setting nominal average output current with external resistor RCS Output control current adjustment by PWM The nominal average output current in the A Pulse Width Modulated (PWM) signal with LED(s) is determined by the value of the external duty cycle PWM can be applied to the DIM pin, to current sense resistor (RCS) connected between adjust the output current to a value below the VIN and CSN and is given by: nominal average value set by resistor RCS: IOUT=0.2/RCS This equation is valid when DIM pin is float or I OUT  0.2  D RCS applied with a voltage higher than 2.5V (must be less than 5V). Actually, RCS sets the maximum （0≤D≤100%，2.5V