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2929 South Fair Lane, Tempe Tel: (602) 431-8101. Fax: (602) 431-2288 1 www.protekdevices.com PA5711 High Voltage LED Driver Rev.0. 03/12 NOT FOR USE IN LIFE SUPPORT SYSTEMS
FEATURES
11V to 480V Input Voltage Range. Over 95% Efficiency. Drives from 1 to hundreds of LED’s in Serial and Parallel combinations. Constant LED Drive current. Linear or PWM luminance dimming control. Light sense and Motion detection inputs to control the LED’s. Resistor Programmable Oscillator Frequency. QFN-16 RoHs Compliant Package.
APPLICATIONS
General Illumination Displays Industrial and Decorative LED Lighting. Automotive applications. DC/DC or AC/DC LED driver applications. Constant current source. SMPS switching controller. LED back lighting. Security, Street and Parking garage lighting. GENERAL DESCRIPTION The PA5711 is a High -Efficiency LED driver with multiple dimming options that include Pulse Width Modulation (PWM), Linear dimming (LD), Motion Detection (MD) and Light sense (LS) inputs. PA5711 features a direct gate driver control through an active high enable pin. It has an internal oscillator whose frequency can be set externally through a resistor. The PA5711 in fly -back mode can b e used as a current controlled LED driver (Isolated), driving an LED load at fixed current from a few mA to over 1.4A. The PA5711 allows the users to introduce the lead ing edge blanking upon their desired delay requirements, also this can be used to control the Duty cycle of the driver. The LD pin allows the users to set the threshold beneath the pre-set 280mV, for smaller duty cycle and reduced dissipation across the CS resistors. The PA5711 has a PWM dimming option that through an externally programmed control signal, with duty ratio 0 -100% and a frequency of a few Kilo -hertz, can control the LED brightness. PA5711 BLOCK DIAGRAM
ORDERING INFORMATION
Temperature Range Package Part Number -40 to 85 °C QFN-16 PA5711-T7 VIN VDD REXT CS LD Voltage Regulator 280mV PWM MD LS EN PWM Controller Oscillator ROSC Gate GND Gate Driver Figure 1. Block diagram
2929 South Fair Lane, Tempe Tel: (602) 431-8101. Fax: (602) 431-2288 2 www.protekdevices.com PA5711 High Voltage LED Driver Rev.0. 03/12 NOT FOR USE IN LIFE SUPPORT SYSTEMS 1. SPECIFICATIONS
1.1 Absolute Maximum Rating
1.2 Pin Description
PIN # NAME FUNCTION
1 NC No Connect
2 NC No Connect
3 NC No Connect
4 VIN Supply voltage 11V- 480V
5 REXT Pin for current limiting resistor between VIN and REXT. 6 ROSC Resistor to ground sets the oscillator Frequency.
7 MD Motion detection signal input; Connect to VDD when
unused. 8 LS Light sense signal input; Connect to GND when unused. 9 EN Gate driver enable. Connect to VDD to enable the Gate driver output. 10 PWM PWM input to control the Gate output. Connect to VDD when unused
11 VDD
5V regulated supply voltage output . Requ ires a storage capacitor to ground. External Voltage source can be connected to power the chip 12 LD Linear Dimming. Used to reduce the threshold voltage lower than the internal 280mV. Connect to VDD when unused 13 CS LED Current sense input.
14 GND Chip Ground
15 Gate Gate driver Output
16 VDD 5V regulated supply voltage output
Input Voltage VIN -0.5 to 500 V Input and Output voltage to GND CS, LD, PWM, MD, EN, Gate -0.3 to VDD+0.3 V VDD, externally applied VDD-EXT 8 V Power Dissipation PD 3.45 W Maximum Junction Temperature TJMAX 168 °C Operating Temperature TA -40 to +85 °C Junction temperature (operating) TJ -40 to+150 °C Thermal Resistance Junction to Ambient ja 12 °C/W Storage Temperature TSTG -55 to +150 °C VIN
1.3 Pin Configuration
Note: Continuous operation at or beyond these conditions may permanently damage the device. Top view of the PA5711
2929 South Fair Lane, Tempe Tel: (602) 431-8101. Fax: (602) 431-2288 3 www.protekdevices.com PA5711 High Voltage LED Driver Rev.0. 03/12 NOT FOR USE IN LIFE SUPPORT SYSTEMS
1.4 Electrical Specifications
Parameter Symbol Min Typical* Max Units Conditions Input DC Voltage Range VINDC 11 480 V DC input Voltage into the VIN pin Shut-Down Mode Supply Current IINsd 1.3 1.87 mA EN to GND VDD=5 ROSC = 1M Internal DC Voltage Regulator VDD 5 V VIN=15~450V, IDD(ext)=0, Gate output open Maximum Voltage to VDD Pin VDDmax 7 V External voltage applied to VDD pin VDD Current Available for External Circuitry IDD(ext) 1.0 mA Limited by package power dissipation PWM Pull-Down Resistance REN 55 70 72 kΩ VPWM = 5V Current Sense Threshold Voltage VCS(high) 272 280 304 mV T=25 C GATE High Output Voltage VGATE(high) VDD-0.2 VDD V IOUT=10mA VIN =20V GATE Low Output Voltage VGATE(low) 0 0.2 V IOUT=-10mA VIN =20V Oscillator Frequency fOSC 196 200 204 kHz ROSC = 150 kΩ 32 34 35 kHz ROSC = 1 MΩ Oscillator PWM Duty Cycle D 0 100 % External voltage provided to PWM Linear Dimming Voltage Range VLD 0 250 mV External voltage provided to the LD pin. Delay from CS Trip to gate low tDELAY 22.9 24.8 nS GATE Output Rise Time tRISE 25 nS GATE Output Fall Time tFALL 20 nS Quiescent current IQ 1.4 1.5 1.6 mA No load, VDD=5 Pin LS input low VLS(lo) 635 mV VDD=5 Pin LS input high VLS(hi) 630 mV VDD=5 Pin EN input low VEN(lo) 2.28 mV VDD=5 Pin EN input high VEN(hi) 2.85 mV VDD=5 Pin MD input low VMD(lo) 2.38 mV VDD=5 Pin MD input high VMD(hi) 2.55 mV VDD=5 Pin PWM input low VPWM(lo) 2.24 mV VDD=5 Pin PWM input high VPWM(hi) 2.66 mV VDD=5 *Typical values should not be used for specification limits. TA=25°C unless otherwise specified
2.1 Overview
signage and RGB back lighting. The PA5711 in the buck topology (as shown above in Fig.2) is a common choice to use the controller in non isolated LED lighting. with minimal external components. The LED’s can be dimmed using voltage 0-250mV on the LD pin or by a low frequency on the PWM. resistor at CS controls the peak current thru the LED string. Figure 2. A typical Application Circuit
2.2 LED DRIVER - THEORY OF OPERATION
next positive edge of the clock cycle.
2.2.1 Voltage Regulator
where an auxiliary supply can power to the PA5711.
2.2.2 Current Sense Resistor
inductor ripple current and the internal threshold voltage. the power rating that is calculated.
2.2.3 Current Sense Blanking
The PA5711 has no internal current sense blanking circuit.
2.2.4 Enable / Disable
operation the Enable pin must be connected high. Figure 3. PA5711 Waveforms
2.2.5 Linear Dimming
one of the four different ways the LED can be controlled. linear dimming is not required. overrides the Linear Dimming Function. greater control over the calculate current drive.
2.2.6 PWM dimming
input is driven low the LED’s are turned off.
2.2.7 Light sense
must be connected to ground if not used.
2.2.8 Motion Detection
motion detector can drive this pin to turn the LED’s on/off. This pin needs to be connected to VDD when not used.
2.2.9 Gate Driver
2.2.10 Oscillator
switching frequency and inductor size. Figure 4. Soft-Start RC arrangement Figure 5. Frequency variation across ROSC
2929 South Fair Lane, Tempe Tel: (602) 431-8101. Fax: (602) 431-2288 7 www.protekdevices.com PA5711 High Voltage LED Driver Rev.0. 03/12 NOT FOR USE IN LIFE SUPPORT SYSTEMS
2.2.11 Inductor design
The LED ripple current along with fact ors such as Maximum T ON, Minimum input voltage and total forward voltage drop across the LED’s (VF) at the desired average LED current decide the value of the inductor. The minimum voltage is dependent on the specific application and the Maximum TON is determined by the duty cycle and the switching frequency. The maximum duty cycle - Dmax is given by : The maximum duty cycle must be maintained below 50% to maintain open loop stability and sub harmonic oscillations. The Maximum ON-time can be calculated as follows: The size of the inductor can be calculated using the equation : The peak inductor current is given by : γ ILmax = ILED * [1+ ] VLEDstring Vin Dmax = Where VLEDstring is the desired forward voltage drop across LED string at the designed LED current Vin is the minimum input voltage Dmax fs tONmax = Where fs is the switching frequency tONmax * (Vin – VLEDstring) ILED * γ Lmin = Where γ is the inductor ripple
2929 South Fair Lane, Tempe Tel: (602) 431-8101. Fax: (602) 431-2288 8 www.protekdevices.com PA5711 High Voltage LED Driver Rev.0. 03/12 NOT FOR USE IN LIFE SUPPORT SYSTEMS QFN-16 Pad Layout Min Typical Max mm in mm in mm in f 0.65 0.026 Tape and Reel Specifications Reel Dia A0 B0 K0 D E F W P0 P2 P t-max QFN-16 Dimensions Min Typical Max mm in mm in mm in F 0.65 0.026 0.000 H 0.20 0.008 0.000 P2 D P E F W Pin 1 indicated by Dot Top cover tape t
10 Pitches Cumulative
Tolerance on Tape± 0.2 711 711 711 A C H J B D E F G a b c d e f 3. QFN-16 PACKAGE DIMENSIONS AND LAYOUT