ZXLD1370/1EV4 User Guide 1.5A 40W Buck-Boost LED Driver General Description ZXLD1370/1 EV4 Specifications The ZXLD1370/1 EV4 1.5A board uses the BuckBoost topology working at Boundary Conduction Mode. It can perform step-down or boost up power conversion according to the output LEDs load vs. input voltage. It is designed for driving a high LED current from a wide range voltage source. The board can operate from an input supply between 10V and 30V and provides an externally adjustable output current of up to 1.5A. The ZXLD1370/1 EV4 board can provide more than 40 watts of output power. Parameter Value Input Voltage 10 to 30VDC (1371) 10 to 20VDC (1370) 30 – 40W 1.5A (Adjustable) 27V ~85% 9 LEDs in series (Under Tested) 3.00 ” x 3.25” x 0.5” Yes Output Power LED Current LED Voltage Efficiency Number of LEDs XYZ Dimension ROHS Compliance Key Features Wide input voltage range: 10V to 30V Up to 1.5A output current Single pin on/off and brightness control using DC voltage or PWM Up to 1MHz switching frequency ±5% output current accuracy Inherent open-circuit LED protection High-Side Current Sense Hysteretic Control: No Compensation Adjustable output LED Current TSSOP-16EP package for large output power application RoHS compliant Evaluation Board DCLEDDC+ Applications LED+ High lumen LED Bulb Automotive high power LED lamp Figure 1: Top View Connection Instructions Input Voltage: 10 to 30VDC (DC+, DC-) LED Outputs: LED+ (Red), LED- (Black) ZXLD1370/1EV4 Rev1 September 2014 www.diodes.com Page 1 of 11 ZXLD1370/1EV4 User Guide 1.5A 40W Buck-Boost LED Driver 10V~30V DC Input R sense circuit Buck-Boost inductor ZXLD1370 or 1371 BCM driver Input DC Filter ZXLD1370 or ZXLD1371 Board MOSFET Driver + Low side MOSFET 9 LEDs 1.5A Figure 2: Block Diagram Evaluation Board Schematic Figure 3: Evaluation Board Schematic ZXLD1370/1EV4 Rev1 September 2014 www.diodes.com Page 2 of 11 ZXLD1370/1EV4 User Guide 1.5A 40W Buck-Boost LED Driver Evaluation Board Layout Figure 4: PCB Board Layout Top View Figure 5: PCB Board Layout Bottom View Quick Start Guide 1. By default, the evaluation board is preset at 1.5A LED current by R1 & R2. 2. Ensure that the DC source is switched OFF or disconnected. 3. Connect the 15VDC power supply to two test points of “DC input” on the left side of the board. 4. Connect the anode wire of external LED string to LED+ output test point. 5. Connect the cathode wire of external LED string to LED- output test point. 6. Turn on the main switch. LED string should light up. Bill of Material # Name Quantity 1 2 U1 U2 1 0 Part number ZXLD1370EST16TC or ZXLD1371EST16TC Not fitted 3 Q1 1 4 Q2 5 Q3 6 D1 Manufacturer Description Diodes Inc LED Driver TSSOP16L DMN6040SK3 Diodes Inc MOSFET 60V/20A DPAK 1 2N7002 Diodes Inc MOSFET 60V/115mA SOT23 0 Not fitted Diodes Inc Freewheeling diode 100V/3A PowerDI5 1 ZXLD1370/1EV4 Rev1 September 2014 www.diodes.com PDS3100 Page 3 of 11 ZXLD1370/1EV4 User Guide 1.5A 40W Buck-Boost LED Driver 7 8 9 10 D2 D3 Z1 L1 0 0 1 1 Not fitted Not fitted BZX84B39 74435572200 Diodes Inc Wurth 11 C1 12 C2 C3, C3A, 13 C4, C4A 14 C5 15 C6 16 C7 17 C8 18 C9, C10 19 C11 20 R1 21 R2 R3, R5, R6, R8, 22 R11, R14 23 R4 24 R7 25 R9, R10 26 R12 27 R13 28 R15, R17 R16, R18, 29 R19 30 R20 1 2 C0805C102K3RACTU C1206C104K5RAC7867 Kemet Kemet 39V 350mW Zener Diode SOT23 22µH/11A SMD 18.3x18.3x9mm 1000pF Cer Cap 25V 10% X7R 0805 1µF Cer Cap 50V 10% X7R 1206 4 2 1 1 1 2 0 2 1 C1812X106K050T GRM31CR72A105KA01L GRM21BR61E106KA73L C0805C104K5RACTU C1206X475K050T C1812X225K050T Not fitted CRA2010-FKR250CT RLP73K3AR15JTE Holy Stone Murata Murata Kemet Holy Stone Holy Stone 10µF Cer Cap 50V 10% X7R 1812 1µF Cer Cap 100V 10% X7R 1206 10µF Cer Cap 25V 10% X5R 0805 0.1µF Cer Cap 50V 10% X7R 0805 4.7µF Cer Cap 35V 10% X7R 1206 2.2µF Cer Cap 50V 10% X7R 1812 Bourns Bourns 0.25Ω Resistor 1W 1% 2010 0.15Ω Resistor 2W 1% 2512 6 1 1 2 1 1 2 CRCW08050000Z0EA RC0805FR-071K3L RC0805FR-0747KL RC0805FR-0736KL RC0805FR-072R2L RC0805FR-075R11L RC0805FR-0720KL Vishay Yageo Yageo Yageo Yageo Yageo Yageo 0 Ω Resistor 1/8W 0805 1.3kΩ Resistor 1/8W 1% 0805 47kΩ Resistor 1/8W 1% 0805 36kΩ Resistor 1/8W 1% 0805 2.2Ω Resistor 1/8W 1% 0805 5.1Ω Resistor 1/8W 1% 0805 20kΩ Resistor 1/8W 1% 0805 3 1 RC0805FR-071KL RC0805FR-0782KL Yageo Yageo 31 J1 32 PL1 Vin, GND, PWM, TP1, LEDA, 33 LEDK 1 1 1776244-2 800-10-003-10-001000 TE Connectivity Mill-Max 1kΩ Resistor 1/8W 1% 0805 82kΩ Resistor 1/8W 1% 0805 TERM BLOCK 2POS SIDE ENTRY 5MM SIP HEADER 3 POS 6 5121K-ND Keystone Test point ZXLD1370/1EV4 Rev1 September 2014 www.diodes.com Page 4 of 11 ZXLD1370/1EV4 User Guide 1.5A 40W Buck-Boost LED Driver OPERATION In Buck-boost mode the LED current is sensed by the series resistor (R1//R2). An output from the control loop drives the input of a comparator. The comparator drives the gate of the external NMOS switch transistor via ‘GATE’ pin. When the NMOS switch is on, current flows from VIN, via (R1//R2), inductor and switch to ground and increases until a high value is reached. Then, GATE goes low, the switch turns off and the current flows through (R1//R2), the inductor, D1 and the LED, to ‘VIN’ (Buck-boost mode). When the inductor current has gone low, ‘GATE’ goes high, and the cycle of events repeats. The circuit oscillates. The average current in the LEDs is equal to the average of the maximum and minimum threshold currents. The ripple current (hysteresis) is equal to the difference between the thresholds. The average current in the LED is always less than the average current in the inductor and the ratio between these currents is set by the values of resistors R9 and R10. The peak current in the LED is equal to the peak current in the inductor. The control loop keeps the average LED current at the level set by the voltage on the ‘ADJ’ pin. Loop compensation is achieved by C1. PWM Terminal (PWM output current control/dimming) The LED current can be adjusted digitally, by applying a low frequency PWM logic signal to the ‘PWM’ pin to turn the controller on and off. This will produce an average output current proportional to the duty cycle of the control signal. During PWM operation, the device remains powered up and only the output switch is switched by the control signal. The device can be shut down by taking the PWM pin to < 0.4V with a short to 0V or suitable open collector NPN, or open drain NMOS transistor, for >15ms. In the shutdown state, most of the circuitry inside the device is off and the quiescent current will be typically 90μA. ZXLD1370/1EV4 Rev1 September 2014 www.diodes.com Page 5 of 11 ZXLD1370/1EV4 User Guide 1.5A 40W Buck-Boost LED Driver Functional Performance (9 series LEDs @1.5A) MFG Board Type Diodes Inc ZXLD1370/1EV4 Module Board ZXLD1370/1EV4 Rev1 September 2014 www.diodes.com VIN (VDC) IIN (A) PIN (W) VLED (V) ILED (A) PLED (W) Fs Switching Freq (Hz) Efficiency (%) 10 5.04 50.4 27.43 1.42 39.01 412K 77.5 12 4.40 52.7 28.00 1.55 43.40 404K 82.4 15 3.34 50.1 27.26 1.55 42.25 416K 84.3 18 2.68 48.3 27.36 1.52 41.59 420K 86.1 20 2.37 47.4 27.20 1.51 41.07 460K 86.7 24 1.92 45.9 27.48 1.44 39.57 510K 86.0 30 1.53 45.9 27.40 1.44 39.46 560K 85.5 Page 6 of 11 ZXLD1370/1EV4 User Guide 1.5A 40W Buck-Boost LED Driver Functional Performance Efficiency (%) vs Vin LED Current (A) vs Vin ZXLD1370/1EV4 3 90 LED Current [A] Efficiency [%] 95 ZXLD1370/1EV4 85 80 2 1 0 75 5 10 15 20 25 30 35 5 10 15 20 25 30 Vin [VDC] Vin [VDC] Figure 2. LED Current vs. Vin Figure 1. Efficiency vs. Vin LED Current (%) vs Vin ZXLD1370/1EV4 LED Current [%] 8 4 0 -4 -8 5 10 15 20 25 30 35 Vin [VDC] Figure 3. LED Current (%) vs. Vin ZXLD1370/1EV4 Rev1 September 2014 www.diodes.com Page 7 of 11 35 ZXLD1370/1EV4 User Guide 1.5A 40W Buck-Boost LED Driver Waveform #1 (Voltage across Drain and Source, Vin=15VDC, ILED=1.5A) ZXLD1370/1EV4 Board Condition: IN=15VDC; OUT=9 LEDs in series / 1.5A Waveform #2 (Voltage across Drain and Source, Vin=20VDC, ILED=1.5A) ZXLD1370/1EV4 Board Condition: IN=20VDC; OUT=9 LEDs in series / 1.5A ZXLD1370/1EV4 Rev1 September 2014 www.diodes.com Page 8 of 11 ZXLD1370/1EV4 User Guide 1.5A 40W Buck-Boost LED Driver Waveform #3 (Voltage across Drain and Source, Vin=24VDC, ILED=1.5A) ZXLD1370/1EV4 Board Condition: IN=24VDC; OUT=9 LEDs in series / 1.5A Waveform #4 (Voltage across Drain and Source, Vin=30VDC, ILED=1.5A) ZXLD1370/1EV4 Board Condition: IN=30VDC; OUT=9 LEDs in series / 1.5A ZXLD1370/1EV4 Rev1 September 2014 www.diodes.com Page 9 of 11 ZXLD1370/1EV4 User Guide 1.5A 40W Buck-Boost LED Driver Waveform #5 (Output Voltage Ripple, Vin=20VDC, ILED=1.5A) ZXLD1370/1EV4 Board Condition: IN=20VDC; OUT=9 LEDs in series / 1.5A ZXLD1370/1EV4 Rev1 September 2014 www.diodes.com Page 10 of 11 ZXLD1370/1EV4 User Guide 1.5A 40W Buck-Boost LED Driver IMPORTANT NOTICE DIODES INCORPORATED MAKES NO WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, WITH REGARDS TO THIS DOCUMENT, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE (AND THEIR EQUIVALENTS UNDER THE LAWS OF ANY JURISDICTION). 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