isl97635a Intersil Corporation, isl97635a Datasheet
isl97635a
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isl97635a Summary of contents
Page 1
... Fault/Status register. There are selectable short-circuit thresholds and the switching frequency can be programmed between 600kHz and 1.2MHz. Available in the 24 Ld 4mmx4mm QFN, the ISL97635A operates from -40°C to +85°C with input voltage ranging from 6V to 24V for high LEDs count applications. 1 ...
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... Typical Application Circuit VBL 24V 2 ISL97635A V = 34.5V, 30mA PER STRING OUT ISL97635A FAULT OVP 16 VIN 24 PGND VDC 17 PGND 18 22 IIN0 15 COMP SMBCLK 1 IIN1 14 SMBDAT 2 IIN2 13 PWMI/EN 6 IIN3 12 PWMO 4 IIN4 10 11 IIN5 9 RSET 3 FPWM 5 GND FN6564.2 December 22, 2008 ...
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... DETECT GENERATOR + + - - REGISTERS + + PWM BRIGHTNESS CONTROL - - DEVICE CONTROL PWM/OC/SC FAULT/STATUS IDENTIFICATION AM DC BRIGHTNESS CONTROL CONFIGURATION FIGURE 1. ISL97635A BLOCK DIAGRAM 34.5V, 30mA PER STRING ( WHITE LEDS OVP PGND IIN0 OC, SC DETECT IIN5 OC, SC DETECT FAULT/STATUS REGISTER TEMP SENSOR FAULT/STATUS REGISTER FN6564 ...
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... SWILimit Boost FET Current Limit r Internal Boost Switch ON-Resistance DS(ON) 4 ISL97635A Thermal Information Thermal Resistance (Typical, Notes 1, 2) θ QFN . . . . . . . . . . . . . . . . . . . . . . Thermal Characterization (Typical, Note QFN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...
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... HD:STA this Period, the First Clock is Generated. t Repeated Start Condition Setup Time SU:STA t Stop Condition Setup Time SU:STO t Data Hold Time HD:DAT 5 ISL97635A = -40°C to +85° 12V 5V CONDITION V = 18V, 54 LEDs, 20mA each 8.2µH IN with DCR 106mΩ +25° 12V, 54 LEDs, 20mA each 8.2µ ...
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... Maximum LED Current Per Channel LEDmax PWM GENERATOR (Note 4) FPWM Generated PWM Frequency DPWM Duty Cycle of Generated PWM (DC-to-PWM) t Maximum PWMI Off-Time Before Shutdown MAX_PWM_OFF 6 ISL97635A = -40°C to +85° Rising above > VUVLO VDC capacitor < 10µF ...
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... I (mA) O FIGURE 4. 3 EFFICIENCY 10µH WITH DCR = 500mΩ, 1mm 4x4.7µF/50V O 7 ISL97635A = -40°C to +85° 12V 12 VDC = 5. 7S6P - 18V 82 9S6P - 18V ...
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... V = 18V PWM DUTY CYCLE (%) FIGURE 8. PWM DIMMING LINEARITY FIGURE 10 50% PWM DIMMING 8 ISL97635A (Continued) 1.0 0.9 12V/20mA 0.8 0.7 0.6 0 FIGURE 7. CURRENT MATCHING vs DUTY CYCLE 100 FIGURE 11. I 200Hz 10kHz ...
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... Typical Performance Curves FIGURE 12 50% PWM DIMMING LED FIGURE 14. LX ZOOM IN AT 50% DIMMING 9 ISL97635A (Continued) FIGURE 16. RIPPLE VOLTAGE ZOOM IN FIGURE 13 50% PWM DIMMING FIGURE 15. RIPPLE VOLTAGE December 22, 2008 FN6564.2 ...
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... IIN1 I 15 IIN0 I 16 OVP I 17, 18 PGND S 19 FAULT O 22 COMP O 23 VIN S 24 VDC S 10 ISL97635A ISL97635A (24 LD QFN) TOP VIEW SMBCLK 1 SMBDAT 2 FPWM 3 PWMO 4 GND 5 PWMI/ SMBus serial clock input SMBus serial data input and output Connect a capacitor between FPWM and GND to set the DPWM frequency. FPWM = 5.4µ ...
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... AC/DC adapter without rendering a noticeable visual nuisance. The number of LEDs that can be driven by ISL97635A depends on the type of LED chosen in the application. The ISL97635A is capable of boosting up to 34.5V and typically driving 9 LEDs in series for each of the 6 channels, enabling a total of 54 pieces of the 3 ...
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... LED PWM CONTROL The ISL97635A provides four different PWM dimming methods, as described in the following. Each of these methods results in PWM chopping of the current in the LEDs for all 6 channels to provide an average LED current. During the on-periods, the LED current will be defined by the value of R and BRTDC, as described in Equations 1 and 2 ...
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... The current in the boost power switch is monitored and the switching terminated in any cycle where the current exceeds the current limit. The ISL97635A includes a soft-start feature where this current limit starts at a low value (375mA). This is stepped up to the final 3A current limit in seven further steps of 375mA ...
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... ISL97635A channel will be considered an “open circuit”. Furthermore, should the boost output of the ISL97635A reach the OVP limit or should the lower over-temperature threshold be reached, all channels which are not “good” will immediately be considered as “open circuit”. Detection of an “open circuit” ...
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... OVP level, the input protection FET will also be switched off. Over-Temperature Protection (OTP) The ISL97635A includes two over-temperature thresholds. The lower threshold is set to +130°C. When this threshold is reached, any channel which is outputting current at a level significantly below the regulation target will be treated as “ ...
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... OVP pin monitored for excursions below 20% of OVP threshold 16 ISL97635A TABLE 1. PROTECTIONS TABLE FAILED CHANNEL ACTION GOOD CHANNELS ACTION CH0 ON and burns power CH1 through CH5 Normal CH0 goes off until chip cooled and Same as CH0 then comes back on with current reduced to 76% ...
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... R/W = read enable at high; write enable at low SLAVE ADDRESS Master to Slave Slave to Master SLAVE ADDRESS W A COMMAND CODE Master to Slave Slave to Master 17 ISL97635A HIGH t HD:DAT t SU:DAT FIGURE 19. SMBUS INTERFACE COMMAND CODE FIGURE 20. WRITE BYTE PROTOCOL 8 ...
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... Output Channel Reserved Reserved Register 18 ISL97635A used in other backlight controller specifications to avoid confusion. Therefore, if the device is in the write mode where bit the slave address byte is 0x58 or 01011000b. If the device is in the read mode where bit the slave address byte is 0x59 or 01011001b ...
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... An SMBus Write Byte cycle to register 0x00 sets the PWM brightness level only if the backlight controller is in SMBus 19 ISL97635A TABLE 2B. DATA BIT DESCRIPTIONS DATA BIT DESCRIPTIONS PWM_MD = PWM mode select bit (1 = absolute brightness change), default = 0 PWM_SEL = Brightness control select bit (1 = control by PWMI control by SMBus), default = 0 ...
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... Brightness control select bit (1 = control by PWMI control by SMBus) default = 0 BL_CTL = BL On/Off ( Off) default = 0 FIGURE 24. DESCRIPTIONS OF DEVICE CONTROL REGISTER 20 ISL97635A programmed in the SMBus register 0x00, i.e. DPST (Display Power Saving Technology) mode as shown in Equation 15: DPST Brightness Where: Cbt = Current brightness setting from SMBus register 0x00 ...
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... ISL97635A • A fault will not be reported in the event the BL is commanded on and immediately off by the system. • When FAULT is set will remain at 1 even if the signal which sets it goes away. FAULT will be cleared when the BL_CTL bit of the Device Control Register is toggled or when written low ...
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... Manufacturer ID is not implemented REV[2..0] = Silicon rev (Rev 0 through Rev 7 allowed for silicon spins) 22 ISL97635A 1_CH_SD BL_STAT OV_CURR Bit 4 (R) Bit 3 (R) Bit 2 (R) = Two LED output channels are shutdown (1 = shutdown OK) ...
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... Bit 6 (R/W) Bit 5 (R/W) BIT ASSIGNMENT 2 levels of Short-Circuit Thresholds ( 3.1V, accuracy ±15%) VSC[1..0] FSW[2] 2 levels of Switching Frequencies (1 = 1,200kHz 600kHz) FIGURE 28. DESCRIPTIONS OF CONFIGURATION REGISTER 23 ISL97635A BRTDC4 BRTDC3 BRTDC2 Bit 4 (R/W) Bit 3 (R/W) Bit 2 (R/W) BIT FIELD DEFINITIONS users to set the boost conversion switching frequency between 1.2MHz and 600kHz. ...
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... Thus, the higher the inductance, the lower the peak current capability. The ISL97635A 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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... Schottky diode must be used. Applications High Current Applications Each channel of the ISL97635A can support up to 35mA. For applications that need higher current, multiple channels can be grouped to achieve the desirable current. For example, the cathode of the last LED can be connected to IIN0 to IIN2 ...
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... For information regarding Intersil Corporation and its products, see www.intersil.com 26 ISL97635A Compensation The ISL97635A has two main elements in the system; the Current Mode Boost Regulator and the op amp based multi-channel current sources. The ISL97635A incorporates a transconductance amplifier in its feedback path to allow the user some levels of adjustment on the transient response and better regulation ...
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... C11 1µ/10V 1 SMBCLK PGND SMBCLK 2 SMBDAT SMBDAT PGND C13 27n/6.3V 3 FPWM ISL97635A C14 4 220n/6.3V PWMO 5 GND GND 6 PWMI/EN 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 ...
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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 28 ISL97635A 4X A 20X 24X ± BOTTOM VIEW ± SIDE VIEW ( 20X 24X 24X 0 ...