isl97636 Intersil Corporation, isl97636 Datasheet
isl97636
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isl97636 Summary of contents
Page 1
... Data Sheet 8-Channel LED Driver The ISL97636 is an integrated power LED driver that controls 8 channels of LED current for LCD backlight applications. The ISL97636 is capable of driving typically 72 (8x9) pieces of 3.5V/30mA or 80 (8x10) pieces of 3.2V/20mA LEDs. The ISL97636’s contains 8 channels of voltage controlled current sources with typical currents matching of ± ...
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... Typical Application Circuit VBL 24V 2 ISL97636 V = 34.5V, 30mA PER STRING OUT ISL97636 FAULT OVP 16 VIN 24 PGND VDC 17 PGND 18 22 IIN0 15 COMP IIN1 14 PWMI/EN 6 IIN2 13 11 RSET IIN3 12 IIN4 10 5 GND IIN5 9 IIN6 8 IIN7 7 FN6570.0 May 9, 2008 ...
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... FET Σ DRIVER LOGIC ILIMIT IMAX HIGHEST VF STRING REFERENCE DETECT GENERATOR + + - - FAULT DETECT ISL97636 + + - - PWM/OC/SC FIGURE 1. ISL97636 BLOCK DIAGRAM 34.5V, 30mA PER STRING ( LEDS OVP PGND IIN0 IIN0 OC, SC DETECT IIN7 OC, SC DETECT TEMP SENSOR FAULT/DETECT FN6570.0 May 9, 2008 ...
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... SWILimit Boost FET Current Limit r Internal Boost Switch ON-Resistance DS(ON) 4 ISL97636 Thermal Information Thermal Resistance (Typical, Notes 1, 2) θ QFN . . . . . . . . . . . . . . . . . . . . . . Thermal Characterization (Typical, Note QFN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...
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... ILEDmax Maximum LED Current Per Channel FAULT PIN Ifault Fault Pull-down Current Vfault FAULT Clamp Voltage with Respect to V IlxStartup LX Start-up Current 5 ISL97636 = -40°C to +85° 12V 5V CONDITION MIN VIN = 18V, 72 LEDs, 20mA each 8.2µH with DCR 106mΩ +25° ...
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... FIGURE 4. 3 EFFICIENCY 10µH WITH DCR = 500mΩ, 1mm 4x4.7µF/50V O 2.0 1.5 12V/1mA 1.0 12V/20mA 0.5 0.0 -0.5 6V/20mA -1.0 6V/1mA -1.5 -2 CHANNELS FIGURE 6. CHANNEL-TO-CHANNEL CURRENT MATCHING 6 ISL97636 9S8P - 18V 86 84 7S8P - 18V 9S6P - 18V 8.2µH 72 IHLP-2525BD-01 70 DCR = 106mΩ ...
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... FIGURE 10 50% PWM DIMMING (54LEDs, 20mA 12V 8.2µH) IN FIGURE 12 50% PWM DIMMING (54 LEDs, 20mA, LED V = 12V ISL97636 (Continued 100 FIGURE 9. LX, VIIN, IL AND I FIGURE 11. I FIGURE 13 50% PWM DIMMING (54 LEDs, 20mA, AT PWM DIMMING (54 LEDS, ...
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... Typical Performance Curves FIGURE 14. LX ZOOM IN AT 50% DIMMING (54 LEDs, 20mA 12V) IN FIGURE 16. RIPPLE VOLTAGE ZOOM IN (54 LEDs ISL97636 (Continued) FIGURE 15. RIPPLE VOLTAGE (54 LEDs 12V, 20mA EACH 12V, 20mA IN EACH 4x4.7µF/50V) OUT = 4x4.7µF/50V) OUT FN6570.0 May 9, 2008 ...
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... O Boost compensation pin 23 VIN S Input voltage for the device and LED power 24 VDC S De-couple capacitor for internally generated supply rail. If 2.7V < VBL+ < 5.5V, apply VDC directly with a supply voltage of 2.7V to 5.5V 9 ISL97636 ISL97636 (24 LD QFN) TOP VIEW GND 1 GND 2 FPWM ...
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... AC/DC adapter without rendering a noticeable visual nuisance. The number of LEDs that can be driven by ISL97636 depends on the type of LED chosen in the application. The ISL97636 is capable of boosting up to 34.5V and typically driving 9 LEDs in series for each of the 8 channels, enabling a total of 72 pieces of the 3 ...
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... Furthermore, should the boost output of the ISL97636 reach the OVP limit or should the lower over-temperature threshold be reached, all channels which are not “good” will immediately be considered as “ ...
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... ISL97636 off. This monitoring happens on a cycle-by-cycle basis in a self protecting way. Additionally, the ISL97636 monitors the voltage at the LX and OVP pins. At start-up, a fixed current is injected out of the LX pins and into the output capacitor. The device will not start-up unless the voltage at LX exceeds 1.2V. Furthermore, ...
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... CH0 Open Circuit Upper OTP not with infinite triggered and resistance VIIN0 < VSC 5 CH0 LED Open Upper OTP not Circuit but has triggered and paralleled Zener VIIN0 < VSC 13 ISL97636 LX LX O/P SHORT OVP FET DRIVER VSC VSC THRM THRM REF SHDN SHDN ...
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... – ISL97636 TABLE 1. PROTECTIONS TABLE (Continued) FAILED CHANNEL ACTION CH0 goes off until chip cooled and then comes back on with current reduced to 76%. Further OTP triggers result in reduction to 53%, then 30%. CH0 OFF CH0 remains ON and has highest VF, thus VOUT increases. Any channel at below 50% of the target current will fault out after 400µ ...
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... Thus the higher the inductance, the lower the peak current capability. The ISL97636 current limit may also have to be taken into account. Output Capacitors The output capacitor acts to smooth the output voltage and supplies load current directly during the conduction phase of the power switch ...
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... Cc2, in range of 100nF, may be needed to create a pole to cancel the output capacitor ESR’s zero effect for stability. The ISL97636 evaluation board is configured with Rc1 of 500Ω, Cc1 of 33nF, and Cc2 of 0, which achieves stability. In the actual applications, these values may need to be tuned empirically but the recommended values are usually a good starting point ...
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... C10 33n R7 C12 500 0.1µ/10V C11 1µ/10V 1 SMBCLK PGND 2 SMBDAT PGND 3 FPWM ISL97636 4 PWMO 5 GND PWMI/EN 6 PWMI/ 36.6k NOTES: FOR 2 LAYERS BOARD, LAYOUT PGND (NOISY GROUND) ON TOP LAYER AND AGND (QUIET GROUND) ON BOTTOM LAYER. TIE PGND AND AGND ONLY AT ONE POINT BY DOING ...
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... Package Outline Drawing L24.4x4D 24 LEAD QUAD FLAT NO-LEAD PLASTIC PACKAGE Rev 2, 10/06 4.00 PIN 1 INDEX AREA (4X) 0.15 TOP VIEW ( TYP ) ( TYPICAL RECOMMENDED LAND PATTERN 18 ISL97636 4X A 20X 24X ± BOTTOM VIEW ± SIDE VIEW ( 20X 24X 24X 0 ...