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Document overview

  • Manufacturer or author: Provided By ALLDATASHEET.COM(FREE DATASHEET DOWNLOAD SITE)
  • PDF pages: 9

Technical content

Features

  • Constant current LED driver:
  • 20mA to 2A programmable
  • Step-up or step-down operation
  • >90 efficiency
  • 2.5V to 450V
  • Up to 2MHz switching frequency

Applications

  • DC/DC LED Drivers
  • AC/DC LED Drivers
  • RGB Backlighting
  • Flat Panel Backlighting
  • Signs and Decorative LED Lighting

Description

The PA5910 is a high efficiency LED driver control Integrated Circuit. It is a universal control LED driver that can be configured to operate as a step-up or step-down LED driver. The input and output voltage can be extended beyond 450V. The PA5910 uses a fixed off time and 2MHz switching frequency can be achieved. The minimum off time can be set by an external capacitor and resistor. R OFF and COFF The LED current is programmable from 20mA to 2.0A and is set by an external resistor. Pin Designation Description Symbol Description Symbol 1：Ground VSS 8：Power supply (2V-6.5V) VDD 2：Chip Enable EN 7：Off time selection TOFF 3：No connection NC 6：LED Current sensing CS 4：Voltage feedback GND 5：Driver DRV Absolute Maximum Ratings Type Symbol Maximum voltage on VDD pins V Voltage VMIN-MAX Voltage range on EN, CS and FB pins -0.3-VDD+0.3 V TMIN-MAX Operation temperature range -20-85 oC Thermal TSTORAGE Storage temperature range -40-165 oC ESD VESD ESD voltage for human body model 2000 V 95220

561 E. Elliot Road #175 Chandler, AZ 85225 Tel: (480) 539-2900. Fax: (480) 632-1715 www.protekanalog.com PA5910 Switching Type LED Driver. 95220 Rev.0. 04/09 NOT FOR USE IN LIFE SUPPORT SYSTEMS Block Diagram Fig.1 Electrical Characteristics. Parameter Symbol Test Condition Min Typ Max Unit Power supply VDD 2.5 6.5 V CS pin feedback voltage VCS 240 250 260 mV Operation current IDD 0.5 1 mA Off time (without ROFF and COFF) TOFF 620 nS Standby current IDDQ 1 μA EN pin high level voltage VENH 2.0 V EN pin low level voltage VENL 0.8 V DRV Rising Time TRISE 500pF cap on DRV pin 50 nS DRV Falling Time TFALL 500pF cap on DRV pin 50 nS BANDGAP S Q R OFF TIME VDD TOFF EN GND DRV CS 250mV PA5910 VIN Zener Diode 2.5V – 5.5V R CS RTC L (Optional)

561 E. Elliot Road #175 Chandler, AZ 85225 Tel: (480) 539-2900. Fax: (480) 632-1715 www.protekanalog.com PA5910 Switching Type LED Driver. 95220 Rev.0. 04/09 NOT FOR USE IN LIFE SUPPORT SYSTEMS Typical Applications Step-Up LED Driver without Schottky Diode Fig.2 Step-Up LED Driver with Schottky Diode Fig.3 BANDGAP S Q R OFF TIME VDD TOFF EN GND DRV CS 250mV PA5910 VIN RCS L L BANDGAP S Q R OFF TIME VDD TOFF EN GND DRV CS 250mV PA5910 VIN RCS Zener Diode 2.5V – 5.5V

561 E. Elliot Road #175 Chandler, AZ 85225 Tel: (480) 539-2900. Fax: (480) 632-1715 www.protekanalog.com PA5910 Switching Type LED Driver. 95220 Rev.0. 04/09 NOT FOR USE IN LIFE SUPPORT SYSTEMS 220VACIN Drive 45series 6 parallel white LED’s ILED = 120mA Fig.4 220vAC In BD1 300V 0.5A C1 22μF 400V 4.7μF 510K 10mH SF36 LED+ LED- 5N60 12V 1N5819 5.1V 4.7μF 330Ω 470pF 100K 2.5Ω AP2306 1 V SS 2 EN 3 NC

4 GND DRV 5

AC~ AC~

561 E. Elliot Road #175 Chandler, AZ 85225 Tel: (480) 539-2900. Fax: (480) 632-1715 www.protekanalog.com PA5910 Switching Type LED Driver. 95220 Rev.0. 04/09 NOT FOR USE IN LIFE SUPPORT SYSTEMS 220VACIN Drive 12 series connected 1WATT white LED’s Fig.5. 220vAC In BD1 300V 0.5A C1 22μF 400V 4.7μF 510K 10mH SF36 LED1 1Watt 5N60 12V 1N5819 5.1V 4.7μF 330Ω 470pF 100K 2.5Ω AP2306 1 V SS 2 EN 3 NC AC~ AC~ LED2 1Watt LED3 1Watt LED4 1Watt LED11 1Watt LED12 1Watt

561 E. Elliot Road #175 Chandler, AZ 85225 Tel: (480) 539-2900. Fax: (480) 632-1715 www.protekanalog.com PA5910 Switching Type LED Driver. 95220 Rev.0. 04/09 NOT FOR USE IN LIFE SUPPORT SYSTEMS Detail Description LED lighting applications The PA5910 is suitable for 110 V/220VAC lighting applications as shown in Fig.5. AC 220V through bridge rectifier, will be about 310VDC. The V DD supply of 5.1V is provided through a resistor and a Zener network. When MOSFET control is high, the MOSFET conducts and the inductor L is charged until it reaches the peak current 250mV/R CS . When MOSFET control is low, the MOSFET is off, the inductor releases energy through Schottky diode circuit, thereby lighting the LED string. Circuit parameters LED average current When the circuit in Fig. 1 operates in continuous mode, the LED average current is IL ILMAX is the maximum current flowing through LED’s as shown in Fig.6 Fig.6. Programming Operation Frequency The switching duty ratio can be determined by D= V OUT / VIN TON is on time of MOSFET TOFF is the off time of the MOSFET. The TOFF can be calculated by the formula () pFCKR RKT OFF OFF OFF OFF 10100 10051.0 +×Ω+ ×Ω×= If TOFF pin is left open the typical value is nSpFKTOFF 5101010051.0 =×Ω×= T TON T OFF ∆IL ILMAX IL IL(t)

561 E. Elliot Road #175 Chandler, AZ 85225 Tel: (480) 539-2900. Fax: (480) 632-1715 www.protekanalog.com PA5910 Switching Type LED Driver. 95220 Rev.0. 04/09 NOT FOR USE IN LIFE SUPPORT SYSTEMS T OFF can be reduced by adding ROFF and increased by adding COFF Operation Frequency can be calculated by the following formula OFFT D TF −== 11 When TOFF is connected to a 1000pF capacitor, TOFF =51μS, D=0.1 the resultant frequency will be 20 KHz. Inductor Design. Inductor selection criteria are to ensure that current flow through inductor is less than the maximum value specified. Referring to the typical application in Fig.5 the value can be calculated from the desired peak-to-peak LED ripple current in the Inductor. Typically the ripple current is selected to be 30% of the nominal LED current. In this example the I LED is 350mA For example, when the string consists of 12 High Brightness LED’s and each diode has a forward drop of 3.3V at nominal current, the total LED voltage V LEDS is 39.6V Knowing the rectified input voltage V IN = 220V x 1.414 = 310V, the duty ratio can be determined as: 128.0310 6.39 === IN LED V VD Given the switching frequency (20KHz) the required on time of the MOSFET can be calculated by: µSf DTON OSC 4.6== The required value of the inductor is given by: () mHI TVVL LED ON LEDIN 163.0 =××−= BANDGAP S Q R OFF TIME VDD TOFF EN GND DRV CS 250mV PA5910 ROFF COFF

561 E. Elliot Road #175 Chandler, AZ 85225 Tel: (480) 539-2900. Fax: (480) 632-1715 www.protekanalog.com PA5910 Switching Type LED Driver. 95220 Rev.0. 04/09 NOT FOR USE IN LIFE SUPPORT SYSTEMS Setting LED Output When the buck converter topology is used, the peak current sense (CS) is a good representation of the average current of the LED. There is a certain error associated with this CS method that needs to be accounted for. The error is introduced by the difference between the the peak and average current in the inductor: LL CS II mVR Δ+= 5.0 250 e.g. If the peak-to-peak ripple current in the inductor is 10.5mA, to maintain a 350mA LED current, the sense resistor should be 0.7Ω LED Brightness. There are two methods of adjusting the brightness of the LED’s. 1. Changing the resistance of R CS the lower the resistance the higher the brightness. 2. PWM dimming. The brightness of the LED’s is controlled by varying the duty ratio of the output current. This is achieved by applying a PWM signal at the EN (pin 2).

561 E. Elliot Road #175 Chandler, AZ 85225 Tel: (480) 539-2900. Fax: (480) 632-1715 www.protekanalog.com PA5910 Switching Type LED Driver. 95220 Rev.0. 04/09 NOT FOR USE IN LIFE SUPPORT SYSTEMS 0.010” (0.25 MM) M T B S A S Package Outlines and Dimensions SO-8 PACKAGE DIMENSIONS MILLIMETERS INCHES DIM MIN MAX MIN MAX PACKAGE OUTLINE -A- 8 5 -B- P 0.010” (0.25 MM) M B M 4 PL 1 4 D G C R X 45º 0º - 10º -T - K J F 8 PL A B C D F G J K P R 4.80 3.80 1.35 0.35 0.40

1.27 BSC

0.18 0.10 5.80 0.25 5.00 4.00 1.75 0.49 1.250 0.25 0.25 6.20 0.50 0.189 0.150 0.054 0.014 0.016

0.05 BSC

0.007 0.004 0.229 0.010 0.196 0.157 0.068 0.019 0.049 0.009 0.008 0.244 0.019 MOUNTING PAD 0.050” ± 0.005” 0.030” ± 0.005” 0.045” ± 0.005” NOTES 1. - T - = Seating Plane and Datum Surface. 2. Dimensions “A” and “B” are Datum. 3. Dimensions “A” and “B” do not include mold protrusion. 4. Maximum mold protrusion is 0.015” (0.380 mm) per side. 5. Dimensioning and tolerances per ANSI Y14.5M, 1982. 6. Dimensions are exclusive of mold flash and metal burrs. TAPE & REEL/BULK ORDERING NOMENCLATURE 1. Surface mount product is taped and reeled in accordance with EIA-481. 2. Suffix-T7 = 7 Inch Reel - 1,000 pieces per 12mm tape. 3. Suffix-T13 = 13 Inch Reel - 2,500 pieces per 12mm tape. 4. No Suffix = Product Shipped in T ubes of 98 pcs per T ube. Life Support Policy PROTEK ANALOG'S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF PROTEK DEVICES.