PT4121EE23F

PT4121E 60V Step-down High Brightness LED Controller GENERAL DESCRIPTION FEATURES The PT4121E is a high efficiency step-down  Simple low parts count controller. It is designed to operate in continuous  Wide input voltage range: 6V to 60V conduction mode and drive single or multiple  High efficiency (up to 97%) series connected LED efficiently from a voltage  Single pin on/off and brightness control using source higher than the total LED chain voltage. It DC Voltage or PWM operates with a wide input voltage from 6V to 60V  Up to 1MHz switching frequency and provides an externally adjustable output  Adjustable Constant LED Current current.  Typical 3% output current accuracy The PT4121E includes a high-side output  High-Side Current Sense current sense circuit, which uses an external  Hysteretic Control: No need compensation resistor to set the nominal average output current,  Inherent RCS open protection and a dedicated DIM input accepts either a DC  Inherent open-circuit LED protection voltage or PWM dimming.  Inherent short-circuit LED protection  Over Temperature Protection The PT4121E is available in SOT23-6 or SOP-8 packages. APPLICATIONS  Low voltage halogen replacement LEDs  Automotive/Decorative lighting  Low voltage industrial lighting  LED back-up lighting  Signs/Emergency lighting  SELV lighting  LCD TV backlighting ORDERING INFORMATION PACKAGE TEMPERATURE ORDERING PART TRANSPORT RANGE NUMBER MEDIA Tape and Reel 3000 units o o SOT23-6 -40 C to 125 C PT4121EE23F SOP-8 -40℃ to 125℃ PT4121EESOH Tape and Reel 4000 units MARKING 4121E PT4121E xxxxxX TYPICAL APPLICATION CIRCUIT D1 VIN 6.0V~50V CIN Rcs VIN VCC CSN PT4121E DIM DRV L1 GND CR POWTECH (SHANGHAI) CO., LTD. PT4121E_DS_Rev EN 1.1 WWW.CRPOWTECH.COM Page 1 PT4121E 60V Step-down High Brightness LED Controller PIN ASSIGNMENT CSN 2 DIM 3 6 VCC 5 DRV 4 GND NC 1 VCC 2 DRV 3 GND 4 SOT23-6 PT4121E 1 4121E VIN 8 NC 7 CSN 6 VIN 5 DIM SOP-8 PIN DESCRIPTIONS PIN No. SOP-8 PIN No. SOT23-6 1 PIN NAMES NC 2 6 VCC 3 5 DRV 4 4 GND 5 3 DIM 6 1 VIN 7 2 CSN 8 NC DESCRIPTION Not connected. Internal Regulator Output. Connect a 1µF decoupling cap from this pin to ground. Gate-Driver Output. Connect this pin to the gate of the external MOSFET. 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. Input Supply Pin. Connect a decoupling capacitor from VIN pin to GND. LED Current Sense Input. Connect a current-sense resistor that programs LED average current to the VIN pin. Not connected. ABSOLUTE MAXIMUM RATINGS SYMBOL VIN (note1) PARAMETER Supply Voltage CSN Current sense input (Respect to VIN) VI/O Other I/O PIN Input Voltage θJA TJ TOP TSTG VALUE UNIT -0.3~60 V +0.3~(-6.0) V -0.3~6 V 220 o SOP-8 Thermal Resistance 145 o Junction Temperature 150 o -40~125 o -55 to 150 o SOT23-6 Thermal Resistance Operating Temperature Range Storage Temperature Range ESD Susceptibility (Note 2) 2 C /W C /W C C C kV Note 1: Exceeding these Absolute Maximum Ratings may damage the device. Recommended Operating Range indicates conditions for which the device is functional. 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: Human body model, 100pF discharged through a 1.5kΩ resistor. CR POWTECH (SHANGHAI) CO., LTD. PT4121E_DS_Rev EN 1.1 WWW.CRPOWTECH.COM Page 2 PT4121E 60V Step-down High Brightness LED Controller ELECTRICAL CHARACTERISTICS (Note 3) o The following specifications apply for VIN=24V, TA=25 C, unless specified otherwise. SYMBOL ITEMS VIN CONDITIONS Input Voltage VCC UVLO hysterisis FSW Typ. 6 Internal Regulated Voltage VUVLO_HYS Min. 4.5 VCC falling Max. Switching Frequency 5.0 Max. UNIT 60 V 5.5 V 0.3 V 1 MHz Current Sense VCSN Current sense threshold voltage VCSN_HYS VIN-VCSN Nominal 194 Sense threshold hysteresis ICSN CSN Pin input current VIN-VCSN=50mV 200 206 mV ±15 % 8 µA Operating Current ISD Shutdown supply current Quiescent supply current with IOFF 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 VDIM_L DIM input voltage Low VDIM_HYS RDIM V 2.5 DIM input voltage hysterisis 20 DIM pull up resistor to Internal supply voltage 50 0.3 V 80 mV 200 KΩ IDIM_H DIM input leakage high VDIM=5V 2.8 µA IDIM_L DIM input leakage low VDIM = 0 22 µA Gate driver source resistor VGS=5.0V 6 Ω 2 Ω 4.8 V Driver R_source R_sink Gate driver sink resistor VOH Gate driver output-voltage high IDRV=10mA VOL Gate driver output-voltage low IDRV=10mA 0.5 V Output Switch TON_MIN Minimum on time Guarantee by 100 nS TOFF_MIN Minimun off time Designer 100 nS 140 ℃ 150 ℃ Thermal Shutdown TREG TSD Note 3: Thermal Regulation Temperature Thermal Shutdown Temperature Datasheet min/max specification limits are guaranteed by design, test, or statistical analysis. CR POWTECH (SHANGHAI) CO., LTD. PT4121E_DS_Rev EN 1.1 WWW.CRPOWTECH.COM Page 3 PT4121E 60V Step-down High Brightness LED Controller SIMPLIFIED BLOCK DIAGRAM REGULATOR VIN VCC CS CURRENT SENSE COMPARATOR Thermal Derating REFERENCE GATE DRIVER DRV UVLO COMPARATOR GND DIM BUFFER DIM OPERATION DESCRIPTION The PT4121E in conjunction with current sense resistor. The PT4121E allows dimming sense resistor (RCS),the inductor (L1), and with a PWM signal at the DIM input. A logic level MOSFET below 0.3V at DIM forces PT4121E to turn off the forms a self oscillating continuous-mode buck converter. LED and the logic level at DIM must be at least When input voltage VIN is first applied, the 2.5V to turn on the full LED current. The initial current in L1 and RCS is zero and there is frequency of PWM dimming ranges from 100Hz no output from the current sense circuit. Under to 20 kHz. this condition, the output of CS comparator is The DIM pin can be driven by an external DC high. This turns on switch, causing current to flow voltage (VDIM) to adjust the output current to a from VIN to ground, via RCS, the LED(s),L1 and value below the nominal average value defined external MOSFET. The current rises at a rate by RCS. The DC voltage is valid from 0.5V to 2.5V. determined by VIN and L1 to produce a voltage When the DC voltage is higher than 2.5V, the ramp (VCSN) across RCS. When (VIN-VCSN) > output current keeps constant. 230mV, the output of CS comparator switches Additionally, to ensure the reliability, the low and the switch turns off. The current flowing PT4121E is built with an over temperature on the RCS decreases at another rate. When protection. If the junction temperature exceeds (VIN-VCSN) < 170mV, the switch turns on again TREG, the device will reduce output current to and the mean current on the LED is determined avoid system cause to damage. by 200mV/RCS. The high-side current-sensing scheme and on-board current-setting circuitry minimize the number of external components while delivering LED current with ±3% accuracy, using a 1% CR POWTECH (SHANGHAI) CO., LTD. PT4121E_DS_Rev EN 1.1 WWW.CRPOWTECH.COM Page 4 PT4121E 60V Step-down High Brightness LED Controller 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. PT4121E_DS_Rev EN 1.1 200µS/div WWW.CRPOWTECH.COM Page 5 PT4121E 60V Step-down High Brightness LED Controller TYPICAL PERFORMANCE CHARACTERASTICS (continued) VIN=24V,3LEDs,IOUT=1A,TA=25℃，unless otherwise noted. PWM Dimming (2KHz,50%) PWM Dimming (2KHz,1%) 400µS/div 400µS/div Short LED+ to LED- Protection Short LED+ to LED- Recovery 20µS/div 20µS/div Open LED Load Protection Open LED Load Recovery 2mS/div 40µS/div CR POWTECH (SHANGHAI) CO., LTD. PT4121E_DS_Rev EN 1.1 WWW.CRPOWTECH.COM Page 6 PT4121E 60V Step-down High Brightness LED Controller 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 cycle PWM can be applied to the DIM pin, to external resistor RCS adjust the output current to a value below the The nominal average output current in the nominal average value set by resistor RCS: LED(s) is determined by the value of the external I OUT  current sense resistor (RCS) connected between VIN and CSN and is given by: IOUT=0.2/RCS 0.2  D RCS (0≤D≤100%，2.5V