NTE7208 Integrated Circuit Constant Current Single Output LED Driver Description: The NTE7208 is a step-down constant current source designed for driving high power white LEDs. A standard output current of 350mA makes this driver compatible with a wide range of LEDs from many different manufacturers without the need for any external components. Despite its compact size, the NTE7208 is fully featured with very high efficiency, wide input voltage range, high ambient operating temperature and two means of LED dimming: PWM/digital control and analog voltage dim‐ ming. Both dimming controls are independent and can be combined. The driver is also designed to be as reliable as the LEDs it is driving, even at the full operating temperature of +85°C. Features: D Constant Current Output D Power LED Driver D Wide Input Voltage Range D PWM/Digital Dimming and Analog Voltage Dimming D Short Circuit Protected D 96% Efficiency Electrical Specifications: (Typical at TA = +25°C, nominal input voltage, rated output current unless otherwise specified. Input Voltage (Absolute Maximum) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36V Recommended Input Voltage Minimum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5V Typical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24V Maximum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36V Input Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Capacitor Output Voltage Range (Vin = 36V) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2V to 32V Output Current Range (Vin - Vout > 1.5V to 4V) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 350mA Typical Output Current Accuracy (IO = 350mA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±2% Internal Power Dissipation, (Load of 5 LEDs) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 700mW Maximum Output Current Stability (Vin = 36V, Vout =2V to 32V) . . . . . . . . . . . . . . . . . . . . . . . . . . ±1% Maximum Output Ripple and Noise, (20MHz limited, Vin = 36V, Vout = 2V to 32V) . . . . . 120mVp-p Maximum Temperature Coefficient (TA = -40° to +85°C) . . . . . . . . . . . . . . . . . . . . . . . . . ±0.015%/ °C Maximum Capacitive Load, . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100μF Operating Frequency Minimum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210kHz Typical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260kHz Maximum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300kHz Maximum Effieciency at Full Load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96% Short Circuit Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Regulated at Rated Output Current Operating Temperature Range, TA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -40° to +85°C Storage Temperature Range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -55° to +125°C Electrical Specifications (Cont'd): (Typical at TA = +25°C, nominal input voltage, rated output current unless otherwise specified. Maximum Case Tempeature, TC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +100°C Thermal Impedance (Nature Convection) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +55°C/W Case Material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Non Conductive Black Plastic Potting Material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Epoxy (UL94-V0) Maximum Wave Soldering Profile (10 seconds) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +235°C PWM Dimming and ON/OFF Control (Leave Open if Not Used): Remote ON/OFF DC/DC ON, . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Open or 0V < Vr < 0.6V DC/DC OFF (Standby) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.6 < Vr < 2.9V DC/DC OFF (Shutdown), . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.9 < Vr < 6V Maximum Remote Pin Drive Current (Vr = 5V) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1mA Maximum Quiescent Input Current in Shutdown Mode (Vin = 36V, Vr > 2.9V) . . . . . . . . . . . . 200μA Maximum PWM Frequency for Linear Operation (measured 10% to 90% Dimming) . . . . . . . 200Hz Analog Dimming Control (Leave Open if Not Used): Input Voltage Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 to 15V Control Voltage Range Limits Full On . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.13V ± 50mV Full Off . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.5V ± 50mV Maximum Analog Pin Drive Current (Vc = 5V) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.2mA Environmental: Relative Humidity (See Note) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5% to 95% RH, non-condensing Conducted Emissions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . EN55022, Class B Radiated Emissions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . EN55022, Class B ESD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . EN61000-4-2, Class A Radiated Immunity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . EN61000-4-3, Class A Fast Transient . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . EN61000-4-4, Class A Conducted Immunity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . EN61000-4-6, Class A MTBF (RCD-24-0.70, Nominal Vin, Full Load) +25°C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 605 x 103 hours Using MIL-HDBK 217F, +71°C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 516 x 103 hours Note: Requires an input filter to meet EN55022 Class B conducted emissions, see below. Class B Filter Suggestion 47μH (not dimmed) or 120μH (dimmed) 1 +Vin 2.5μF Elect. 10nF, Cer. (only if Analog Dimming is not used) 10nF, Cer. (only if Analog Dimming is used) +LED NTE7208 LED Driver 10nF Cer. -Vin 6 4 5 2 C1 or C2 -LED Analog Dimming Control and Application Circuit Examples LED Driver with 0-10V Interface +Vin NTE7208 GND 1st LED 2k4 Analog Dim 0−10VDC 3k3 Last LED On/Off (Optional) LED DIMMER for up to 7 white LEDs 24VDC NTE7208 GND 1st LED 4k7 1K Pot. Voltage Control (0-15V max) Manual Dimming Control Last LED 100% Output Current Analog Input Voltage) 0% 0.13V 1V 2V 3V 4V 15V 4.5V Digital Dimming Control PWM Digital Control Signal PWM Digital Control Signal PWM Digital Control Signal 1 1 1 0 0 Output Current Max* 0 *Max output current can also be set using Analog input 0~ 200 Output Current (LED appears dim 0 0~ 200 Output Current (LED appears dim Package Style and Pinning .492 (12.5) .870 (22.1) .335 (8.5) .161 (4.1) .024 (0.61) .300 (7.62) .689 (17.5) Pin Connections Pin # Out Comments 1 +Vin DC Suplly 2 Analog Dimming Leave open if not used 3 PWM/ON/OFF Leave open if not used 4 GND Do not connect to -Vout 5 -Vout LED Cathode Connection 6 +Vout LED Anode Connection xx.x ± 0.5mm xx.xx ± 0.25mm Pin Tolerance 0.1mm Recommended Foorprint Details 1.00ø+0.15/-0 Leave 1mm space around case pcb 3rd angle projection 4 3 2 1 5 Bottom View .100 (2.54) 6 .100 (2.54) Top View Analog Dimming Control and Application Circuit Examples LED Driver +Vin GND NTE7208 1st LED Analog Dim PWM Dim/ On/Off Last LED