IS32BL3554 BOOST TYPE LED DRIVER WITH 4-CHANNEL CURRENT SOURCE

Transcription

1 ISBL BOOST TYPE LED DRIVER WITH -CHANNEL CURRENT SOURCE DESCRIPTION The ISBL is a white LED driver for backlight applications based on a highly efficient boost controller operating over a wide input voltage range of.v to V. The ISBL contains four regulated current sources with.% (Typ.) current matching between strings for a uniform LED brightness. Each current source can be programmed via an external resistor to drive from 0mA to 0mA. A fast slew rate current source allows high frequency and narrow pulse width dimming signals to achieve a very high contrast ratio. The device operating frequency can be adjusted from 0.MHz to MHz. The ISBL has safety protection features to prevent damage during fault conditions. Protection features include an internal soft-start circuit to prevent a high inrush current during start up, open/short LED protection to automatically disable a faulty current source, over temperature protection (OTP), cycle-by-cycle current limit, under voltage lockout (UVLO), programmable OVP, VOUT short / Schottky diode open protection and Schottky Diode short-circuit protection. FEATURES Input voltage range:.v to V -Channel LED current sinks, 0mA per string LED current adjustable from 0mA to 0mA String-to-string current matching accuracy:.% Adjustable operating frequency: 00kHz to MHz External PWM dimming High contrast ratio Less than µa shutdown current Programmable soft-start Built-in protection features - OCP, OTP, UVLO - Open/short LED protection - Programmable OVP - Schottky Diode/inductor short-circuit protection Automotive AEC-Q00 Qualified QUICK START Figure : Photo of ISBL Evaluation Board RECOMMENDED EQUIPMENT V, A power supply LED load board Excel Calculator download from the ISSI website ABSOLUTE MAXIMUM RATINGS V power supply All LED channels must be connected to an LED load. Caution: Do not exceed the conditions listed above, otherwise the board will be damaged. PROCEDURE The ISBL evaluation board is fully assembled and tested. Follow the steps listed below to verify board operation. Caution: Do not turn on the power supply until all connections are completed. ) Connect the ground terminal of the power supply to the and the positive terminal to the. Or connect the DC power to the connector (DC IN). ) Turn on the power supply and pay attention to the supply current. If the current exceeds A, please check for circuit fault. ORDERING INFORMATION Part No. Temperature Range Package ISBL-ZLA-EB -0 C ~ + C (Automotive) etssop-6, Lead-free Table : Ordering Information For pricing, delivery, and ordering information, please contacts ISSI s analog marketing team at analog@issi.com or (0) Integrated Silicon Solution, Inc. Rev. C, 07//0

2 ISBL BOOST TYPE LED DRIVER WITH -CHANNEL CURRENT SOURCE EVALUATION BOARD OPERATION ISBL evaluation board drives four strings of WLEDs. There are three variable resistors used for adjusting the operating frequency (W ), OVP voltage (W ) and LED current (W ). A clockwise rotation will increase the resistance resulting in a lower operating frequency, lower OVP and lower LED current. Use an ohmmeter to measure the adjusted resistance value. The default parameters of the evaluation board are: V IN = V, V OUT = V, f OSC = MHz (W = 9kΩ), V OVP = 9V (W = kω), I CH = 0mA (W =.kω), R CS = 0.Ω, L /L =0µH. Note that W, W and W are set at the factory. The operating temperature is from -0 C to + C. Please follow the suggested procedures below when modifying the DEMO board parameters.. W Set Switch Frequency Clockwise rotation of W will adjust the switching frequency (f OSC ) from MHz to 00kHz and the inductor L /L peak current (I PEAK ) will increase from.a to.7a. Caution: An I PEAK of.7a is too high for the installed 0µH inductor L /L. A higher I PEAK current will affect other component selections such as inductor L /L and current sense resistor RCS (R R ). We recommend a lower f OSC by using a 7µH inductor instead of 0µH to keep I PEAK below.a. Note: A higher inductor value will reduce the PWM dimming contrast. For the default L /L value, the contrast is 000:. Choosing a smaller inductor like.7µh will increase the contrast to 000:(Max.). Notice that the inductor should be higher than L CCM(Min.).. W Overvoltage Protection V OVP can be adjusted from 0.6V to 0V by W. V OVP should be set to. times V OUT to ensure OVP function. The ISBL operation is unstable if V OVP is set to less than V OUT.. W LED Current The LED channel current (I CH ) can be adjusted from ma to 0mA by W. R CS = 0.Ω is calculated by setting V IN = V, V OUT = V, I CH = 0mA, L /L = 0µH, f OSC = MHz. R CS should be reduced when I CH = 0mA and f OSC is less than MHz or the IC will enter into the power limit mode.. Excel Calculator W, W and W cannot be randomly changed. Please use the ISBL Excel Calculator to define the system parameters. It is recommended to maintain the switching duty cycle less than 70% when I CH > 0mA and f OSC > 0.MHz. Otherwise the switching MOSFET and Diode will have large power losses, will heat up resulting in reduced power conversion efficiency. For operation with T A > C, the MOSFET should be thermally protected with the addition of a heat sink. Also the temperature stability of magnetic saturation current for inductor and the temperature stability of compensation capacitor for COMP should be selected for elevated temperature operation. VIN Vo DIM EN EN R6 0k DIM R7 0k R C uf/0v R 00k W 0-00K C7 0nF C6.uF C R 00k R 00k R k R k C L/L 0uH U VIN EN DIM RT COM ISBL OUT CS OVP CH CH CH CH Iset 6 0 R R R C CH CH CH CH R9' R9 6.k 0--0K R 0.7R W Q N06 R 0.7R FB D SS0 C9 0nF C0 0nF C C uf/00v uf/00v V0 CH CH CH CH C 0pF R0 M R K 0--00K W Vo X0 ISBL Figure : ISBL Application Schematic Integrated Silicon Solution, Inc. Rev. C, 07//0

3 ISBL BOOST TYPE LED DRIVER WITH -CHANNEL CURRENT SOURCE BILL OF MATERIALS Name Symbol Description Qty Supplier Part No. LED Driver U Boost backlight LED driver ISSI ISBL Inductor L/L IND,0µH±0%,SMD Würth Elektronik Diode D Schottky Diode, SS0 SMD SS0 Ferrite Bead FB 60@00M SMD NMOS Q 00V N-Channel MOSFET SMD Fairchild FQD9N0L R,R RES,0.7Ω,/0W,±%,SMD Yageo RL00FR-077L R,R RES,0Ω,/0W,±%,SMD Yageo RL00FR-070L R,R RES,00k,/0W,±%,SMD Yageo RC060JR-0700KL R6,R7 RES,0k,/0W,±%,SMD Yageo RC060JR-070KL R9 RES,6.k,/0W,±%,SMD Yageo RC00FR-076KL R0 RES,M,/0W,±%,SMD Yageo RC00FR-07ML R RES,k,/0W,±%,SMD Yageo RC00FR-07KL R RES,k,/0W,±%,SMD Yageo RC00FR-07KL R RES,Ω,/0W,±%,SMD Yageo RC00JR-07RL R RES,00k,/0W,±%,SMD Yageo RC00JR-0700KL R RES,k,/0W,±%,SMD Yageo RC00FR-07KL Capacitor C CAP,µF,0V,±0%,SMD Capacitor C,C CAP,µF,00V,±0%,SMD Capacitor C6 CAP,.µF,6V,±0%,SMD Yageo CC00JKX7R7BB Capacitor C7,C9,C0 CAP,0.µF,6V,±0%,SMD Yageo CC00JKX7R7BB Capacitor C CAP,0pF,6V,±0%,SMD Yageo CC00JKX7R7BB Bill of materials, refer to Figure above. W RES,0~00k W RES,0~00k W RES,0~0k R9,C,C,C Not Connect Integrated Silicon Solution, Inc. Rev. C, 07//0

4 ISBL BOOST TYPE LED DRIVER WITH -CHANNEL CURRENT SOURCE Figure : Board Component Placement Guide - Top Layer Figure : Board PCB Layout - Top Layer Integrated Silicon Solution, Inc. Rev. C, 07//0

5 ISBL BOOST TYPE LED DRIVER WITH -CHANNEL CURRENT SOURCE Figure : Board Component Placement Guide - Bottom Layer Figure 6: Board PCB Layout - Bottom Layer Copyright 0 Integrated Silicon Solution, Inc. All rights reserved. ISSI reserves the right to make changes to this specification and its products at any time without notice. ISSI assumes no liability arising out of the application or use of any information, products or services described herein. Customers are advised to obtain the latest version of this device specification before relying on any published information and before placing orders for products. Integrated Silicon Solution, Inc. does not recommend the use of any of its products in life support applications where the failure or malfunction of the product can reasonably be expected to cause failure of the life support system or to significantly affect its safety or effectiveness. Products are not authorized for use in such applications unless Integrated Silicon Solution, Inc. receives written assurance to its satisfaction, that: a.) the risk of injury or damage has been minimized; b.) the user assume all such risks; and c.) potential liability of Integrated Silicon Solution, Inc is adequately protected under the circumstances Integrated Silicon Solution, Inc. Rev. C, 07//0