Data Sheet Rev. 1.40 / June 2014 ZLED7x20 Family High Current 40V LED Driver with Internal Switch Automotive ASICs and Industrial ASSPs LED Lighting ICs Multi-Functional and Robust ZLED7x20 Family High Current 40V LED Driver with Internal Switch Brief Description Benefits The ZLED7x20 continuous-mode inductive stepdown converter family is part of our line of LEDcontrol ICs. It is designed for applications requiring high brightness and high current. It can efficiently drive a single LED or multiple series-connected LEDs from a voltage input higher than the LED forward voltage: Vin = 6 to 40 VDC. It provides an adjustable output current ≤1.2A, which is set via an external resistor and controlled by the ZLED7x20’s integrated high-side output current-sensing circuit and high speed internal 40V power switch. An external control signal, which can be a DC voltage, PWM, or microcontroller-generated waveform, on the ADJ pin can also be used to linearly adjust a continuous output current or to control a gated output current. High efficiency: up to 98% Single pin on/off and brightness control using DC voltage or PWM Very few external components needed for operation Footprint compatible with our ZLED7000 depending on the application. Available Support Evaluation Kit Physical Characteristics Operating junction temperature: -40°C to 125°C Switching frequency: up to 1MHz The output can be turned off by applying a voltage lower than 0.2V to the ADJ pin, which puts the ZLED7x20 in a low-current standby state. ZLED7x20 Family Selection Matrix The ZLED7x20 enables diverse industrial and consumer lighting applications requiring high driving currents, wide operating voltage range, high efficiency, and variable brightness control. It offers over-temperature and LED open-circuit protection. The ZLED7x20 can also minimize bill-ofmaterial costs because very few external components are required for most applications. Only a resistor, a diode, an inductor, and three capacitors are needed for a typical basic application. Product Max. Current Output Package ZLED7020 1.2A SOT89-5 ZLED7320 1.0A DFN-5 ZLED7520 0.75A DFN-5 ZLED7720 0.35A DFN-5 ZLED7x20 Typical Application Circuit Features Rs Vs = 6 to 40 VDC Up to 1.2A output current D1 Internal 40V power switch Wide DC input voltage range 6 to 40 VDC Output current accuracy: 3% (typical) Vin Dimming ratio: 1200:1 LED open-circuit protection Thermal shutdown protection (C1) C2 0.1µF LX GND LED String L1 ZLED7x20 ADJ (C3) I SENSE 33µH to 220µH For more information, contact ZMDI via [email protected]. © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.40 — June 11, 2014. All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. ZLED7x20 Family High Current 40V LED Driver with Internal Switch ZLED7x20 Block Diagram 6 to 40 VDC Rs VS D1 4 ISENSE (C1) C2 VCC 0.1µF 5 VIN (C3) n LED VDDA Power Supply, Oscillator, and UnderVoltage Detection (UV) VDDD 1 ISENSE LX VIN Power MOS UV ISENSE And Driver POR VREF SD L1 33µH to 220µH DR SD 500kΩ 3 Shutdown ADJ ISENSE ZLED7X20 POR Trim LX GND 2 Typical Applications Illuminated LED signs and other displays Interior/exterior LED lighting LED street and traffic lighting (low voltage) MR16 LED spot lights Architecture/building LED lighting Retrofit LED lighting fixtures LED backlighting General purpose industrial and consumer LED applications Ordering Information Product Code Description ZLED7020-ZI1R ZLED7020 – High Current (1200mA) 40V LED Driver with Internal Switch SOT89-5 (Tape & Reel) ZLED7320-ZI1R ZLED7320 – High Current (1000mA) 40V LED Driver with Internal Switch DFN-5 (Tape & Reel) ZLED7520-ZI1R ZLED7520 – High Current (750mA) 40V LED Driver with Internal Switch DFN-5 (Tape & Reel) ZLED7720-ZI1R ZLED7720 – High Current (350mA) 40V LED Driver with Internal Switch DFN-5 (Tape & Reel) ZLED7020KIT-D1 ZLED7020-D1 Demo Board, 1 ZLED-PCB8 and 5 ZLED7020 ICs Kit ZLED-PCB8 Test PCB with a 5W white high brightness (HB) LED, cascadable to a multiple LED string Printed Circuit Board (PCB) Sales and Further Information Package www.zmdi.com [email protected] Zentrum Mikroelektronik Dresden AG Global Headquarters Grenzstrasse 28 01109 Dresden, Germany ZMD America, Inc. 1525 McCarthy Blvd., #212 Milpitas, CA 95035-7453 USA Central Office: Phone +49.351.8822.306 Fax +49.351.8822.337 USA Phone 1.855.275.9634 Phone +1.408.883.6310 Fax +1.408.883.6358 European Technical Support Phone +49.351.8822.7.772 Fax +49.351.8822.87.772 DISCLAIMER: This information applies to a product under development. Its characteristics and specifications are subject to change without notice. Zentrum Mikroelektronik Dresden AG (ZMD AG) assumes no obligation regarding future manufacture unless otherwise agreed to in writing. The information furnished hereby is believed to be true and accurate. However, under no circumstances shall ZMD AG be liable to any customer, licensee, or any other third party for any special, indirect, incidental, or consequential damages of any kind or nature whatsoever arising out of or in any way related to the furnishing, performance, or use of this technical data. ZMD AG hereby expressly disclaims any liability of ZMD AG to any customer, licensee or any other third party, and any such customer, licensee and any other third party hereby waives any liability of ZMD AG for any damages in connection with or arising out of the furnishing, performance or use of this technical data, whether based on contract, warranty, tort (including negligence), strict liability, or otherwise. European Sales (Stuttgart) Phone +49.711.674517.55 Fax +49.711.674517.87955 Zentrum Mikroelektronik Dresden AG, Japan Office 2nd Floor, Shinbashi Tokyu Bldg. 4-21-3, Shinbashi, Minato-ku Tokyo, 105-0004 Japan ZMD FAR EAST, Ltd. 3F, No. 51, Sec. 2, Keelung Road 11052 Taipei Taiwan Phone +81.3.6895.7410 Fax +81.3.6895.7301 Phone +886.2.2377.8189 Fax +886.2.2377.8199 Zentrum Mikroelektronik Dresden AG, Korea Office U-space 1 Building 11th Floor, Unit JA-1102 670 Sampyeong-dong Bundang-gu, Seongnam-si Gyeonggi-do, 463-400 Korea Phone +82.31.950.7679 Fax +82.504.841.3026 © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.40 — June 11, 2014. All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. ZLED7x20 Family High Current 40V LED Driver with Internal Switch Contents 1 2 3 IC Characteristics .......................................................................................................................................................... 6 1.1 Absolute Maximum Ratings ................................................................................................................................... 6 1.2 Operating Conditions ............................................................................................................................................. 6 1.3 Electrical Parameters ............................................................................................................................................. 7 1.4 Typical Operation Graphs ...................................................................................................................................... 8 Circuit Description ....................................................................................................................................................... 13 2.1 ZLED7x20 Overview ............................................................................................................................................ 13 2.2 Control of Output Current via External Sense Resistor Rs .................................................................................. 13 2.3 Control of Output Current via an External DC Control Voltage on the ADJ Pin ................................................... 13 2.4 Additional Requirements if the VIN Input Voltage has a High Slew Rate .............................................................. 14 2.5 Control of Output Current via a PWM Signal on the ADJ Pin............................................................................... 14 2.6 Control of Output Current via a Microcontroller Signal on the ADJ Pin ................................................................ 14 2.7 Shutdown Mode ................................................................................................................................................... 14 2.8 ZLED7x20 Protection Features ............................................................................................................................ 15 2.8.1 Thermal Shut-down Protection ..................................................................................................................... 15 2.8.2 LED Open Load Protection ........................................................................................................................... 15 Application Circuit Design ........................................................................................................................................... 16 3.1 Applications ......................................................................................................................................................... 16 3.2 Thermal Considerations for Application Design ................................................................................................... 18 3.2.1 Temperature Effects of Load, Layout, and Component Selection ................................................................ 18 3.2.2 Temperature Effects of Low Supply Voltage VIN ........................................................................................... 18 3.3 External Component Selection ............................................................................................................................ 18 3.3.1 Sense Resistor Rs ........................................................................................................................................ 18 3.3.2 Inductor L1.................................................................................................................................................... 19 3.3.3 Bypass Capacitor C1 .................................................................................................................................... 20 3.3.4 De-bouncing Capacitor C2 ........................................................................................................................... 21 3.3.5 Capacitor C3 for Reducing Output Ripple..................................................................................................... 22 3.3.6 Diode D1....................................................................................................................................................... 22 3.4 Application Circuit Layout Requirements ............................................................................................................. 22 4 ESD Protection ............................................................................................................................................................ 23 5 Pin Configuration and Package ................................................................................................................................... 23 5.1 SOT89-5 Package Pin-out and Dimensions for the ZLED7020 ........................................................................... 23 5.2 DFN-5 Package Pin-out and Dimensions for the ZLED7320, ZLED7520 and ZLED7720 ................................... 25 6 Ordering Information ................................................................................................................................................... 27 7 Related Documents ..................................................................................................................................................... 27 8 Glossary ...................................................................................................................................................................... 27 9 Document Revision History ......................................................................................................................................... 28 Data Sheet June 11, 2014 © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.40. All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 4 of 28 ZLED7x20 Family High Current 40V LED Driver with Internal Switch List of Figures Figure 1.1 ZLED7x20 Supply Operating Current vs. Input Supply Voltage (VIN = 6 to 40 V) ................................................... 8 Figure 1.2 ZLED7x20 Supply Quiescent Shutdown Current vs. Input Supply Voltage (VIN = 6 to 40 V) .................................. 8 Figure 1.3 Efficiency (%) vs. Input Supply Voltage (VIN = 6 to 40 V) Per Number of LEDs (Rs=0.10Ω, L1=47μH).................. 9 Figure 1.4 Efficiency vs. Input Supply Voltage (VIN = 6 to 40 V) Per Number of LEDs (Rs=0.15Ω, L1=47μH) ........................ 9 ‡ Figure 1.5 Efficiency vs. Input Supply Voltage (VIN = 6 to 40 V) Per Number of LEDs (Rs=0.30Ω, L1=47μH) ..................... 10 Figure 1.6 Output Current Variation vs. Input Supply Voltage (VIN = 6 to 40 V) Per Number of LEDs (Rs = 0.15Ω, L1 = 47μH) ............................................................................................................................................................................. 10 Figure 1.7 Sense Voltage vs. Operating Temperature (Rs=0.10Ω, L1=47μH, VIN = 40 V) .................................................... 11 Figure 1.8 Dimming Rate with 100Hz Square Wave Control Signal (PWM) at ADJ Pin (current rise time=7.85μs) ............. 11 Figure 1.9 LED Open-Circuit Protection (Rs=0.30Ω, L1=47μH, VIN = 24 V) .......................................................................... 12 Figure 3.1 Basic ZLED7x20 Application Circuit with Output Current Determined only by Rs ................................................ 16 Figure 3.2 Basic ZLED7x20 Application Circuit with Output Current Controlled by External DC Voltage .............................. 16 Figure 3.3 Basic ZLED7x20 Application Circuit with Output Current Set by External Square Wave Voltage (PWM) ............ 17 Figure 3.4 Basic ZLED7x20 Application Circuit with Output Current Controlled by External Microcontroller Signal .............. 17 Figure 5.1 ZLED7020 Pin Configuration – SOT89-5 Package............................................................................................... 23 Figure 5.2 SOT89-5 Package Dimensions for the ZLED7020 ............................................................................................... 24 Figure 5.3 ZLED7320, ZLED7520 & ZLED7720 Pin Configuration — DFN-5 Package......................................................... 25 Figure 5.4 DFN-5 (DFN4*4-05L) Package Dimensions for the ZLED7320, ZLED7520 & ZLED7720 ................................... 26 List of Tables Table 3.1 Recommended Values for Sense Resistor Rs (ADJ pin floating at nominal voltage V REF=1.2V) .......................... 18 Table 5.1 ZLED7020 Pin Descriptions—SOT89-5 Package................................................................................................. 23 Table 5.2 ZLED7320, ZLED7520 & ZLED7720 Pin Descriptions — DFN-5 Package .......................................................... 25 Data Sheet June 11, 2014 © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.40. All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 5 of 28 ZLED7x20 Family High Current 40V LED Driver with Internal Switch 1 IC Characteristics Note: Exceeding the maximum ratings given in this section could cause operation failure and/or cause permanent damage to the ZLED7x20. Exposure to these conditions for extended periods may affect device reliability. 1.1 Absolute Maximum Ratings No. PARAMETER 1.1.1 Input voltage (also see specification 1.2.2) 1.1.2 ISENSE pin voltage SYMBOL CONDITIONS MAX UNIT -0.3 50 V VIN≥5V VIN-5V VIN+0.3V V VIN<5V -0.3V VIN+0.3V V VIN VISENSE MIN TYP 1.1.3 LX pin output voltage VLX -0.3 50 V 1.1.4 ADJ pin input voltage VADJ -0.3 6 V 1.1.5 LX pin switch output current ILX 1.5 A 1.1.6 Power dissipation PTOT 0.5 W 1.1.7 ESD performance 1.1.8 Junction temperature 1.1.9 Junction to ambient thermal resistance 1.1.10 1.2 Storage temperature Human Body Model ±3.5 kV TJ RθJA 150 °C SOT89-5 package 100 K/W DFN5 package 130 K/W 150 °C MAX UNIT TS -55 Operating Conditions No. PARAMETER SYMBOL CONDITIONS MIN TYP 1.2.1 Operating junction temperature TJ -40 125 °C 1.2.2 Input voltage (also see specification 1.1.1) VIN 6 40 V Data Sheet June 11, 2014 © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.40. All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 6 of 28 ZLED7x20 Family High Current 40V LED Driver with Internal Switch 1.3 Electrical Parameters Test conditions for the following specifications are Tamb = 25°C typical and VIN = 12V unless otherwise noted. Production testing of the chip is performed at 25°C unless otherwise stated. Functional operation of the chip and specified parameters at other temperatures are guaranteed by design, characterization, and process control. No. 1.3.1 PARAMETER Quiescent supply current SYMBOL CONDITIONS IINQoff Output off—ADJ pin grounded IINQon Output switching—ADJ pin floating 1.3.2 Mean current sense threshold voltage 1.3.3 Sense threshold hysteresis 1.3.4 ISENSE pin input current ISENSE VSENSE = VIN -0.1V 1.3.5 Internal reference voltage measured at ADJ pin VREF ADJ pin floating 1.3.6 Resistance between VREF and ADJ pin RADJ 1.3.7 External DC brightness control voltage on ADJ pin VADJ 1.3.8 DC on-off control voltage on ADJ pin for switching ZLED7x20 from active state to quiescent state VADJoff DC off-on control voltage on ADJ pin for switching ZLED7x20 from quiescent state to active state VADJon 1.3.9 1.3.10 LX switch continuous current VSENSE MIN TYP MAX UNIT 90 120 160 μA 450 600 μA 100 103 mV 97 VSENSEHYS ±15 % 8 μA 1.2 V 500 KΩ 0.3 1.2 V VADJ falling 0.15 0.2 0.25 V 0.2 0.25 0.3 V VADJ rising ILXmean_0 ZLED7020 1.2 A ILXmean_3 ZLED7320 1.0 A ILXmean_5 ZLED7520 0.75 A ILXmean_7 ZLED7720 0.35 A 1 μA 0.4 Ω 1.3.11 LX switch leakage current 1.3.12 LX switch on resistance RLX 1.3.13 Minimum switch on time tONmin LX switch on 200 ns 1.3.14 Minimum switch off time tOFFmin LX switch off 200 ns 1.3.15 Dimming rate Data Sheet June 11, 2014 ILX(leak) DDIM 0.27 1 LED, f =100Hz, Vin=15V, L1 = 27μH 1200:1 © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.40. All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 7 of 28 ZLED7x20 Family High Current 40V LED Driver with Internal Switch No. PARAMETER SYMBOL 1.3.16 Recommended operating frequency maximum fLXmax 1.3.17 Recommended output switch duty cycle range at fLXmax DLX 1.3.18 Propagation delay of internal comparator tPD 1.3.19 Thermal shutdown temperature TSD 1.3.20 Thermal shutdown hysteresis TSD-HYS 1.4 CONDITIONS MIN TYP 0.3 MAX UNIT 1 MHz 0.9 50 ns 150 °C 20 K Typical Operation Graphs The curves are valid for the typical application circuit and T amb = 25°C unless otherwise noted. ZLED7x20 Supply Operating Current vs. Input Supply Voltage (VIN = 6 to 40 V) Icc(uA) Figure 1.1 600 500 400 300 200 100 0 5 10 15 20 25 30 35 40 Vin(V) ZLED7x20 Supply Quiescent Shutdown Current vs. Input Supply Voltage (VIN = 6 to 40 V) Icc(uA) Figure 1.2 250 200 150 100 50 0 5 10 15 20 25 30 35 40 Vin(V) Data Sheet June 11, 2014 © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.40. All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 8 of 28 ZLED7x20 Family High Current 40V LED Driver with Internal Switch † Efficiency (%) vs. Input Supply Voltage (VIN = 6 to 40 V) Per Number of LEDs (Rs=0.10Ω, L1=47μH) Effiency(%) Figure 1.3 1 0.95 0.9 0.85 0.8 0.75 0.7 0.65 0.6 Rs=0.10Ω 1LED 3LED 7LED 10LED 5 10 15 20 25 30 35 40 Vin(V) ‡ Efficiency vs. Input Supply Voltage (VIN = 6 to 40 V) Per Number of LEDs (Rs=0.15Ω, L1=47μH) Effiency(%) Figure 1.4 1 0.95 0.9 0.85 0.8 0.75 0.7 0.65 0.6 Rs=0.15Ω 1LED 3LED 7LED 10LED 5 10 15 20 25 30 35 40 Vin(V) † ‡ Minimum Vin depends on number of LEDs. Minimum Vin depends on number of LEDs. Data Sheet June 11, 2014 © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.40. All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 9 of 28 ZLED7x20 Family High Current 40V LED Driver with Internal Switch ‡ Efficiency vs. Input Supply Voltage (VIN = 6 to 40 V) Per Number of LEDs (Rs=0.30Ω, L1=47μH) Effiency(%) Figure 1.5 1 Rs=0.30Ω 0.95 1LED 3LED 0.9 0.85 7LED 10LED 0.8 0.75 0.7 0.65 0.6 5 10 15 20 25 30 35 40 Vin(V) Figure 1.6 § Output Current Variation vs. Input Supply Voltage (VIN = 6 to 40 V) Per Number of LEDs (Rs = 0.15Ω, L1 = 47μH) 0.7 0.69 Rs=0.15Ω Iout(A) 0.68 0.67 1LED 3LED 7LED 10LED 0.66 0.65 0.64 0.63 0.62 0.61 0.6 5 10 15 20 25 30 35 40 Vin(V) § Minimum Vin depends on number of LEDs. Data Sheet June 11, 2014 © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.40. All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 10 of 28 ZLED7x20 Family 40VDC Sense Voltage vs. Operating Temperature (Rs=0.10Ω, L1=47μH, VIN = 40 V) VSENSE (mV) Figure 1.7 Vsense(mV) High Current 40V LED Driver with Internal Switch 99.4 99.2 99.0 98.8 98.6 98.4 98.2 98.0 97.8 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 110 Temperature (°C) Figure 1.8 Dimming Rate with 100Hz Square Wave Control Signal (PWM) at ADJ Pin (current rise time=7.85μs) Timebase -3.00 ms 1.00ms/div 500kS 50 MS/s Data Sheet June 11, 2014 温度(℃) Trigger Stop Edge © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.40. All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. C1 HFR -50mV Positive 11 of 28 ZLED7x20 Family High Current 40V LED Driver with Internal Switch Figure 1.9 LED Open-Circuit Protection (Rs=0.30Ω, L1=47μH, VIN = 24 V) Timebase -5.2 s Roll 5.00s/div 500kS 10 kS/s Data Sheet June 11, 2014 Trigger C1 DC Stop 15.0V Edge Negative © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.40. All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 12 of 28 ZLED7x20 Family High Current 40V LED Driver with Internal Switch 2 Circuit Description 2.1 ZLED7x20 Overview The ZLED7x20 is a continuous-mode inductive step-down converter LED driver for driving single or multiple series-connected LEDs from a voltage input higher than the LED voltage (Vin = 6 to 40 VDC; see section 3.2.2 for important details). The ZLED7x20 provides an adjustable output current (1.2A maximum for ZLED7020; 1.0A maximum for ZLED7320; 0.75A maximum for ZLED7520; 0.35A maximum for ZLED7720), which is nominally set via an external sense resistor Rs and controlled by the ZLED7x20’s integrated high-side output current-sensing circuit and output switch. An external control signal (e.g., DC voltage, PWM waveform, or microprocessor signal) on the ADJ pin can be used to linearly adjust the output for continuous, variable, or gated-output current. See page 3 for a block diagram of the ZLED7x20. The output can be turned off by applying a voltage ≤0.2V (typical) to the ADJ pin, which puts the ZLED7x20 in a low-current standby state. See section 2.7 for a description of this shutdown mode. Only a resistor, a diode, an inductor, and three capacitors are needed for a typical basic application. Refer to the application circuits in section 3 for the location of the components referenced in the following sections. 2.2 Control of Output Current via External Sense Resistor Rs External sense resistor Rs, which is connected between the VIN and ISENSE pins as shown in Figure 3.1, sets IOUTnom, the nominal average output current. Equation (1) can be used to calculate the nominal output current, which is the LX switch output current ILX if the ADJ pin is floating (VADJ = VREF =1.2V). See section 3.3.1 for recommended values for Rs in a typical basic application and section 3.4 for layout guidelines for Rs. Note that the peak IOUTnom including ripple (see section 3.3.5) must not exceed the maximum current specifications (1.3.10). IOUTnom 2.3 0.1V Rs (1) Control of Output Current via an External DC Control Voltage on the ADJ Pin An external DC voltage (VADJ) input on the ADJ pin can control brightness by setting the output current to a value below the nominal average current IOUTnom determined by RS. With this method, the output current can be adjusted from 25% to 100% of IOUTnom. The DC voltage source must be capable of driving the ADJ pin’s input impedance RADJ (500kΩ ± approximately 25%; internal pull-up resistor to VREF). See Figure 3.2 for a typical application circuit. The nominal average output current IOUTdc resulting from an external DC control voltage VADJ can be calculated via equation (2) where 0.3V≤ VADJ ≤1.2V: IOUTdc Data Sheet June 11, 2014 0.083 VADJ RS © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.40. All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. (2) 13 of 28 ZLED7x20 Family High Current 40V LED Driver with Internal Switch Brightness is 100% if VADJ = VREF, the internal reference voltage, which can be measured on the ADJ pin when it is floating (1.2V, typical). If VADJ ≥ 1.2V, the current is automatically clamped at 100% brightness. Note: Absolute maximum VADJ= 6V. 2.4 Additional Requirements if the VIN Input Voltage has a High Slew Rate The analog dimming input ADJ can be used for implementing a soft-start function of the LEDs by connecting a capacitor to ground. The soft-start time constant is determined by the product of the internal pull-up resistor (500k typical) and the external capacitor. Important: If the supply voltage VIN might have a high slew rate (> 1V/µs) when powered on, a resistor that is 1k must be placed in series with the capacitor to guarantee correct power-on timing for the ZLED7x20 and proper loading of the current sense trimming data into the appropriate register. This resistor is not necessary if the capacitor is 470pF. If the ADJ pin is controlled from an external voltage source or PWM signal, a series resistor is strongly recommended for noise immunity reasons and to avoid bulk current injection. 2.5 Control of Output Current via a PWM Signal on the ADJ Pin An external pulse width modulation (PWM) control signal input on the ADJ pin can be used for brightness or gated on/off control of the output current by driving the output current to a value below the nominal average current determined by RS. See Figure 3.3 for a typical application circuit. The PWM or gated on/off control signal can be within the range of 0 to 5 V. The logic high level must be higher than 1.2V and the logic low level must be below 0.2V. It must be capable of driving the ADJ pin’s input impedance RADJ (approximately 500kΩ; internal pull-up resistor to VREF). 2.6 Control of Output Current via a Microcontroller Signal on the ADJ Pin An external control signal from the open drain output of a microcontroller can provide on/off or PWM brightness control by driving the ADJ pin. See Figure 3.4 for a typical application circuit. Diode D2 and resistor R1 shown in Figure 3.4 suppress any negative high-amplitude spikes on the ADJ input due to the drain-source capacitance of the FET in the microcontroller’s output. Negative spikes on the ADJ input could cause output current errors or unintended ZLED7x20 operation. The signal input to the ADJ pin must be capable of driving the ADJ pin’s input impedance RADJ (approximately 500kΩ; internal pull-up resistor to VREF). 2.7 Shutdown Mode If the ADJ pin voltage VADJ is ≤ VADJoff (0.2V ± 0.05V), the supply current and output on the LX pin are quiescent at a low standby level (IINQoff = 120μA nominal). Raising the ADJ pin voltage so that VADJ ≥ VADJion (0.25V ± 0.05V) will switch the output back to full operational mode. Data Sheet June 11, 2014 © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.40. All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 14 of 28 ZLED7x20 Family High Current 40V LED Driver with Internal Switch 2.8 2.8.1 ZLED7x20 Protection Features Thermal Shut-down Protection The ZLED7x20 automatically protects itself from damage due to over-temperature conditions. If the ZLED7x20’s temperature exceeds the thermal shutdown threshold (T SD = 150°C, typical), the ZLED7x20 will shut down. To avoid erratic ZLED7x20 operation, a 20K hysteresis (TSD-HYS) is applied that prevents it from returning to operation until its temperature falls below the hysteresis threshold (T SD - TSD-HYS). Also refer to section 3.2 for additional thermal considerations. 2.8.2 LED Open Load Protection As a step-down converter, the ZLED7x20 has inherent open-load circuit protection. Since the L1 inductor is connected in series with the LED string, the current flow is interrupted if the load is open and the LX output of the ZLED7x20 will not be damaged. This provides an advantage over other products such as boost converters, for which the internal switch can be damaged by back EMF forcing the drain above its breakdown voltage. Data Sheet June 11, 2014 © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.40. All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 15 of 28 ZLED7x20 Family High Current 40V LED Driver with Internal Switch 3 Application Circuit Design 3.1 Applications The ZLED7x20 is designed for applications requiring features such as high-speed switching, variable brightness control, operation with voltages up to 40V, high efficiency, or protection from over-temperature, or open LED circuit conditions. Typical applications include MR16/MR11 LED spotlights, LED street lights, parabolic aluminized reflector (PAR) LED lights, and other general purpose industrial and consumer LED applications. Figure 3.1, Figure 3.2, Figure 3.3, and Figure 3.4 demonstrate basic application circuits for the four options for controlling output current described in section 2. Figure 3.1 Basic ZLED7x20 Application Circuit with Output Current Determined only by Rs Rs Vs = 6 to 40 VDC D1 Vin C1 C2 0.1µF LED String L1 ZLED7X20 LX ADJ Figure 3.2 C3 I SENSE GND Basic ZLED7x20 Application Circuit with Output Current Controlled by External DC Voltage Rs Vs = 6 to 40 VDC D1 C1 C2 0.1µF Vin (0.3V to 1.2V) June 11, 2014 LX + _ Data Sheet LED String L1 ZLED7X20 ADJ DC C3 I SENSE GND © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.40. All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 16 of 28 ZLED7x20 Family High Current 40V LED Driver with Internal Switch Figure 3.3 Basic ZLED7x20 Application Circuit with Output Current Set by External Square Wave Voltage (PWM) Rs Vs = 6 to 40 VDC D1 C1 C2 0.1µF Vin PWM (0V to ~5V) C3 I SENSE LED String L1 ZLED7X20 ADJ LX GND Figure 3.4 Basic ZLED7x20 Application Circuit with Output Current Controlled by External Microcontroller Signal Rs Vs = 6 to 40 VDC D1 C1 C2 0.1µF Vin R1 10kΩ Micro- ADJ Data Sheet June 11, 2014 D2 LED String L1 ZLED7X20 LX processor GND C3 I SENSE GND © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.40. All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 17 of 28 ZLED7x20 Family High Current 40V LED Driver with Internal Switch 3.2 Thermal Considerations for Application Design 3.2.1 Temperature Effects of Load, Layout, and Component Selection Do not exceed the package power dissipation limits by driving high load currents or by operating the chip at high ambient temperatures. Power dissipation also increases if the efficiency of the circuit is low as could result from selecting the wrong coil or from excessive parasitic output capacitance on the switch output. See the layout guidelines in section 3.4. 3.2.2 Temperature Effects of Low Supply Voltage VIN Until the supply input voltage on the VIN pin has risen above the internally-set startup threshold, the ZLED7x20’s internal regulator disables the drive to the internal power MOSFET output switch. Above this threshold, the MOSFET on-resistance is low enough for the chip to start to operate; however, if the supply voltage remains below the specified minimum (6V), the duty cycle of the output switch will be high and the ZLED7x20 power dissipation will be at a maximum. Avoid operating the ZLED7x20 under such conditions to reduce the risk of damage due to exceeding the maximum die temperature. When driving multiple LEDs, their combined forward voltage drop is typically high enough to prevent the chip from switching when VIN is below 6V, so there is less risk of thermal damage. 3.3 External Component Selection Note: Also see section 3.4 for layout guidelines for the following external components. 3.3.1 Sense Resistor Rs Table 3.1 gives values for Rs under normal operating conditions in the typical application shown in Figure 3.1. These values assume that the ADJ pin is floating and at the nominal voltage of V REF=1.2V. Note: Under the conditions given in Table 3.1, in order to maintain the switch current below the maximum value specified in section 1, 0.082Ω is the minimum value for Rs for the ZLED7020, 0.1Ω for the ZLED7320, 0.13Ω for the ZLED7520 and 0.27Ω for the ZLED7720. It is possible to use different values of Rs if the ADJ pin is driven from an external voltage. To ensure stable output current, use a 1% accuracy resistor with adequate power tolerance and a good temperature characteristic for Rs. Table 3.1 Recommended Values for Sense Resistor Rs (ADJ pin floating at nominal voltage VREF=1.2V) Nominal Average Output Current (mA) Value for RS (Ω) 1200 (maximum for ZLED7020) 0.082 1000 (maximum for ZLED7320) 0.1 750 (maximum for ZLED7520) 0.13 667 0.15 350 (maximum for ZLED7720) 0.27 333 0.3 Data Sheet June 11, 2014 © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.40. All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 18 of 28 ZLED7x20 Family High Current 40V LED Driver with Internal Switch 3.3.2 Inductor L1 The recommended range for the L1 inductor is 33μH to 220μH. Select the inductor value for L1 as needed to ensure that switch on/off times are optimized across the load current and supply voltage ranges. If the application requires a high supply voltage and low output current, inductance values at the high end of this range are recommended to minimize errors due to switching delays, which can reduce efficiency and increase ripple on the output. Also see section 3.4 for layout considerations for L1. Equations (3) and (4) can be used to calculate tON and tOFF. On Time for LX Switch (tONmin>200ns): t ON VIN VLED L * I I AVG * (R S rL R LX ) (3) Off Time for LX Switch (tOFFmin>200ns): t OFF VLED L * I VD I AVG * (R S rL ) (4) Where: Symbol Description L L1 coil inductance in H ΔI L1 coil peak-peak ripple current in A (internally set to 0.3 IAVG) VIN Supply voltage in V VLED Total forward voltage in V for LED string IAVG Nominal average LED current in A Rs External current sense resistor in Ω rL L1 coil resistance in Ω RLX LX switch resistance in Ω VD D1 diode forward voltage at the required load current in V The inductance value has an equivalent effect on tON and tOFF and therefore affects the switching frequency. For the same reason, the inductance has no influence on the duty cycle, for which the relationship of the summed LED forward voltages n * VF to the input voltage VIN is a reasonable approximation. Because the input voltage is a factor in the on time, variations in the input voltage affect the switching frequency and duty cycle. To achieve optimum performance, duty cycles close to 0.5 at the nominal average supply voltage are preferable for improving the temperature stability of the output current. Data Sheet June 11, 2014 © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.40. All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 19 of 28 ZLED7x20 Family High Current 40V LED Driver with Internal Switch Equations (5), (6), (7), and (8) provide an example of calculating tON, tOFF, operating frequency fLX, and duty cycle DLX when using a 220μH inductor for L1 and VIN=12V, Rs = 0.30Ω, rL=0.26Ω, VLED=3.4V, IAVG =333mA, VD=0.36V, and RLX=0.27Ω. Example: t ON 220H * 0.3 * 0.333A 2.64s 12V 3.4 V 0.333A * 0.3 0.26 0.27 220H * 0.3 * 0.333A 5.56s 3.4 V 0.36V 0.333A * 0.30 0.26 t OFF fLX t ON DLX 1 1 121.8kHz t OFF 2.64s 5.56s (5) (6) (7) t ON VLED 3.4 V 2.64s 0.3 VIN 12V t ON t OFF 2.64s 5.56s (8) For the L1 inductor, use a coil with a continuous current rating higher than the required mean output current and a saturation current that exceeds the peak output current by 30% to 50% for robustness against transient conditions; e.g., during start-up. 3.3.3 Bypass Capacitor C1 The bypass capacitor C1 has two functions: maintaining operating voltage and bypassing the current ripple of the switching converter. In general low ESR capacitors must be used. If the circuit is supplied by rectified line voltage, C1 must provide enough charge to maintain the ZLED7x20’s minimum operating voltage as well as the forward voltage of the LED string to keep the application working even if the rectified supply voltage periodically drops below these values. A rough estimate for the minimum capacity needed can be calculated with equation (9). C1MIN IAVG * t D I * DLX F VMAX VMAX * fLX (9) Where: Symbol Description IAVG Average nominal LED string current assuming that the contribution of the IC supply current is negligible. tD Discharge time at given AC frequency. Will be a maximum of 10ms (½ period duration) at 50Hz. ΔVMAX Peak rectified supply voltage minus LED string forward voltage or minimum ZLED7x20 supply voltage, whichever is greater. Data Sheet June 11, 2014 © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.40. All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 20 of 28 ZLED7x20 Family High Current 40V LED Driver with Internal Switch Example: For an application with 3 LEDs with 3.2V forward voltage each driven at 0.33A and supplied with rectified 24VAC, a minimum bypass capacitor C1 of 220μF or 330μF might be adequate. Compared to the calculation, a safety margin of about 50% must be added to consider temperature effects and aging. 0.33A * 10ms C1MIN 24V * 2 3 * 3.2V 135F (10) A second function of C1 is to bypass the current ripple of the switching converter and thus prevent it from disturbing a stable IC supply or backlash on the power supply circuit. For this reason, even in DC-supplied applications, the use of an adequate C1 might be useful. The defining parameters are now as shown in equation (11): C1MIN I AVG * t ON VRIPPLE (11) Where: Symbol Description IAVG Average nominal LED string current. tON On time of the internal MOSFET output switch. Note: tON must be longer than tONmin=200ns. VRIPPLE Permissible voltage ripple on the supply voltage. Example: For an application of 3 LEDs driven at 0.33A and supplied with 24VDC, a maximum ripple of 10% is allowed. The ZLED7x20 is operated at 150kHz with a duty cycle of 0.4 leading to an on time of 2.67μs. As calculated in equation 12, a capacitor C1 of 470nF may be adequate, again including a safety margin of about 50%. C1MIN 0.33A * 2.67s 367nF 24V * 0.1 (12) To achieve maximum stability over temperature and voltage, an X7R, X5R, or better dielectric is recommended while Y5V must be avoided. 3.3.4 De-bouncing Capacitor C2 External capacitor C2 minimizes ground bounce during switching of the internal MOSFET output switch. Ground bounce is typically caused by parasitic inductance and resistance due to the distance between the grounds for the power supply and the ZLED7x20 GND pin. Use a 0.1μF, X7R ceramic capacitor to ground for C2. Data Sheet June 11, 2014 © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.40. All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 21 of 28 ZLED7x20 Family High Current 40V LED Driver with Internal Switch 3.3.5 Capacitor C3 for Reducing Output Ripple If required, the C3 can be used to reduce peak-to-peak ripple current in the LED string. Low ESR capacitors should be used because the efficiency of C3 largely depends on its ESR and the dynamic resistance of the LEDs. For an increased number of LEDs, using the same capacitor will be more effective. Lower ripple can be achieved with higher capacitor values, but this will increase start-up delay by reducing the slope of the LED voltage as well as cause increased current during converter start-up. The capacitor will not affect operating frequency or efficiency. For a simulation or bench optimization, C3 values of a few μF are an applicable starting point for the given configuration. Ripple current reduction is approximately proportional to the value of C3. 3.3.6 Diode D1 The flyback diode D1 must have a continuous current rating greater than the maximum output load current and a peak current rating higher than the peak L1 coil current. Important: Use a low-capacitance, fast Schottky diode that has low reverse leakage at the maximum operating temperature and maximum operating voltage for the application to avoid excess power dissipation and optimize performance and efficiency. For silicon diodes, there is a concern that the higher forward voltage and increased overshoot from reverse recovery time could increase the peak LX pin voltage (VLX). The total voltage VLX (including ripple voltage) must not be >50V. 3.4 Application Circuit Layout Requirements The following guidelines are strongly recommended when laying out application circuits: Important: Locate the L1 inductor and the C1 input decoupling capacitor as close as possible to the ZLED7x20 to minimize parasitic inductance and resistance, which can compromise efficiency. Use low resistance connections from L1 to the LX and VIN pins. All circuit board traces to the LX pin must be as short as possible because it is a high-speed switching node. If the ADJ pin floats, all circuit board traces to the ADJ pin must be as short as possible to reduce noise pickup. Do not lay out high-voltage traces near the ADJ pin because if the board is contaminated, leakage current can affect the ADJ pin voltage and cause unintended output current. To further reduce this risk, use a ground ring around the ADJ pin. (Also see section 2.8 regarding the ZLED7x20’s protection circuitry for preventing excessive output current.) To minimize ground bounce, locate the 0.1μF external capacitor C2 as close as possible to the VIN pin and solder the ZLED7x20’s GND pin directly to the ground plane. (Also, see section 3.3.4 regarding ground bounce.) Because Rs is typically a low value resistor, it is important to consider the resistance of the traces in series with RS as part of the total current sense resistance. Use traces that are as short and wide as possible to minimize this effect. The ZLED7x20’s thermal pad must be grounded. Data Sheet June 11, 2014 © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.40. All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 22 of 28 ZLED7x20 Family High Current 40V LED Driver with Internal Switch 4 ESD Protection All pins have an ESD protection of ±3500V according to the Human Body Model (HBM). The ESD test follows the Human Body Model with 1.5 kΩ/100 pF based on MIL 883-H, Method 3015.8. 5 Pin Configuration and Package 5.1 SOT89-5 Package Pin-out and Dimensions for the ZLED7020 Figure 5.1 ZLED7020 Pin Configuration – SOT89-5 Package 1 5 LX VIN 2 GND ADJ Table 5.1 Thermal Pad 3 4 ISENSE ZLED7020 Pin Descriptions—SOT89-5 Package Pin No. LX 1 Drain of internal power switch GND 2 Ground ADJ 3 On/off and brightness control input ISENSE 4 Current adjustment input. Resistor RS from ISENSE to VIN determines the nominal average output current. IOUTnom =0.1V/RS Thermal Pad VIN Data Sheet June 11, 2014 Description (Also see section 3.3 for layout guidelines) Connect to GND. 5 Input voltage (6V to 40V). © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.40. All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 23 of 28 ZLED7x20 Family High Current 40V LED Driver with Internal Switch Figure 5.2 SOT89-5 Package Dimensions for the ZLED7020 D A D1 E1 E b1 L e b c e1 Symbol Dimension (mm) Min Max A 1.400 1.600 b 0.320 0.520 b1 0.360 0.560 c 0.350 0.440 D 4.400 4.600 D1 1.400 1.800 E 2.300 2.600 E1 3.940 4.250 e 1.500 Typical e1 2.900 3.100 L 0.900 1.100 Data Sheet June 11, 2014 © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.40. All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 24 of 28 ZLED7x20 Family High Current 40V LED Driver with Internal Switch 5.2 DFN-5 Package Pin-out and Dimensions for the ZLED7320, ZLED7520 and ZLED7720 Figure 5.3 ZLED7320, ZLED7520 & ZLED7720 Pin Configuration — DFN-5 Package LX 1 GND 2 ADJ 3 5 5 1 2 4 TOP Table 5.2 VIN ISENSE 4 3 BOTTOM ZLED7320, ZLED7520 & ZLED7720 Pin Descriptions — DFN-5 Package Pin No. LX 1 Drain of internal power switch GND 2 Ground ADJ 3 On/off and brightness control input ISENSE 4 Current adjustment input. Resistor RS from ISENSE to VIN determines the nominal average output current. IOUTnom =0.1V/RS Thermal Pad VIN Data Sheet June 11, 2014 Description (Also see section 3.3 for layout guidelines) Connect to GND. 5 Input voltage (6V to 40V). © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.40. All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 25 of 28 ZLED7x20 Family High Current 40V LED Driver with Internal Switch Figure 5.4 DFN-5 (DFN4*4-05L) Package Dimensions for the ZLED7320, ZLED7520 & ZLED7720 B j k A i k1 h g D e m f n C Symbol Dimension (mm) Min Max A 3.95 4.05 B 3.95 4.05 C 0.70 0.80 D 0.37 0.47 e 0.75 0.95 f 2.17 2.42 g h 1.50 0.41 0.51 i 0.55 j 1.70 k 1.75 k1 1.40 1.55 m 0.000 0.050 n Data Sheet June 11, 2014 0.200 © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.40. All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 26 of 28 ZLED7x20 Family High Current 40V LED Driver with Internal Switch 6 Ordering Information Ordering Information Product Sales Code Description Package ZLED7020-ZI1R ZLED7020 – High Current (1200mA) 40V LED Driver with Internal Switch SOT89-5 (Tape & Reel) ZLED7320-ZI1R ZLED7320 – High Current (1000mA) 40V LED Driver with Internal Switch DFN-5 (Tape & Reel) ZLED7520-ZI1R ZLED7520 – High Current (750mA) 40V LED Driver with Internal Switch DFN-5 (Tape & Reel) ZLED7720-ZI1R ZLED7720 – High Current (350mA) 40V LED Driver with Internal Switch DFN-5 (Tape & Reel) ZLED7020KIT-D1 ZLED7020-D1 Demo Board, 1 ZLED-PCB8 and 5 ZLED7020 ICs Kit ZLED-PCB8 Test PCB with one 5W white High Brightness (HB) LED, cascadable to one multiple LED string Printed Circuit Board (PCB) ZLED-PCB2 10 unpopulated test PCBs for modular LED string with footprints of 9 common HB LED types Printed Circuit Board (PCB) 7 Related Documents Note: X_xy refers to the current revision of the document. Document File Name ZLED7x20 Feature Sheet ZLED7X20_Family_Feature_Sheet_Rev_X_xy.pdf ZLED7020 Application Note—PCB Layout * AppNote_PCB_Layout_ZLED7020_Rev_X_xy.pdf Visit the ZLED7x20 product page http://www.zmdi.com/zled7x20-family on ZMDI’s website www.zmdi.com or contact your nearest sales office for the latest version of these documents. Note: Documents marked with an asterisk (*) are located on the LED Drivers application notes web page, http://www.zmdi.com/zled-application-notes-white-papers under the heading “Technical Documents (TN) and Application Notes (AN).” A free customer login is required to access these documents. To obtain a login account, click on Login in the upper right corner of any ZMDI web page and follow the instructions. 8 Glossary Term Description ESD Electrostatic Discharge EMF Electromagnetic Force ESR Equivalent Series Resistance PWM Pulse Width Modulation Data Sheet June 11, 2014 © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.40. All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 27 of 28 ZLED7x20 Family High Current 40V LED Driver with Internal Switch 9 Document Revision History Revision Date Description 1.00 June 27, 2011 First issue. 1.10 August 9, 2011 Update to Demo Kit description. 1.20 August 12, 2011 Update to include ZLED7520 & ZLED7720. Update for Demo Kit description 1.30 February 6, 2012 Update to include operating junction temperature. 1.40 June 11, 2014 Update to add new section 2.4 regarding requirements if VIN has a high slew rate. Updates for cover and page header imagery. Updates for ZMDI contact information. Addition of “Related Documents” and “Glossary” sections. Sales and Further Information www.zmdi.com [email protected] Zentrum Mikroelektronik Dresden AG Global Headquarters Grenzstrasse 28 01109 Dresden, Germany ZMD America, Inc. 1525 McCarthy Blvd., #212 Milpitas, CA 95035-7453 USA Central Office: Phone +49.351.8822.306 Fax +49.351.8822.337 USA Phone 1.855.275.9634 Phone +1.408.883.6310 Fax +1.408.883.6358 European Technical Support Phone +49.351.8822.7.772 Fax +49.351.8822.87.772 DISCLAIMER: This information applies to a product under development. Its characteristics and specifications are subject to change without notice. Zentrum Mikroelektronik Dresden AG (ZMD AG) assumes no obligation regarding future manufacture unless otherwise agreed to in writing. The information furnished hereby is believed to be true and accurate. However, under no circumstances shall ZMD AG be liable to any customer, licensee, or any other third party for any special, indirect, incidental, or consequential damages of any kind or nature whatsoever arising out of or in any way related to the furnishing, performance, or use of this technical data. ZMD AG hereby expressly disclaims any liability of ZMD AG to any customer, licensee or any other third party, and any such customer, licensee and any other third party hereby waives any liability of ZMD AG for any damages in connection with or arising out of the furnishing, performance or use of this technical data, whether based on contract, warranty, tort (including negligence), strict liability, or otherwise. European Sales (Stuttgart) Phone +49.711.674517.55 Fax +49.711.674517.87955 Data Sheet June 11, 2014 Zentrum Mikroelektronik Dresden AG, Japan Office 2nd Floor, Shinbashi Tokyu Bldg. 4-21-3, Shinbashi, Minato-ku Tokyo, 105-0004 Japan ZMD FAR EAST, Ltd. 3F, No. 51, Sec. 2, Keelung Road 11052 Taipei Taiwan Phone +81.3.6895.7410 Fax +81.3.6895.7301 Phone +886.2.2377.8189 Fax +886.2.2377.8199 Zentrum Mikroelektronik Dresden AG, Korea Office U-space 1 Building 11th Floor, Unit JA-1102 670 Sampyeong-dong Bundang-gu, Seongnam-si Gyeonggi-do, 463-400 Korea Phone +82.31.950.7679 Fax +82.504.841.3026 © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.40. All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 28 of 28