MAX1839EEP Maxim Integrated Products, MAX1839EEP Datasheet
MAX1839EEP
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MAX1839EEP Summary of contents
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... Buck Operation Synchronized to Royer Oscillator ♦ Synchronizable DPWM Frequency ♦ Pin-Selectable Brightness Control Interface ♦ SMBus Serial Interface (MAX1739) ♦ Analog Interface (MAX1739/MAX1839) Ordering Information PART TEMP. RANGE MAX1739EEP -40°C to +85°C MAX1839EEP -40°C to +85°C TOP VIEW REF 1 MINDAC 2 CCI 3 CCV ...
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Wide Brightness Range CCFL Backlight Controllers ABSOLUTE MAXIMUM RATINGS V to GND ...........................................................-0.3V to 30V BATT GND.................................................-0.3V to 34V BST SYNC .................................................................-0. BST .................................................-0. ...
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ELECTRICAL CHARACTERISTICS (continued) (V+ = 8.2V, V /SUS = V = 5.5V, MINDAC = GND PARAMETER DAC AND ERROR AMPLIFIER DAC Resolution MINDAC Input Voltage Range MINDAC Input Bias Current MINDAC Digital PWM Disable Threshold CSAV Input ...
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Wide Brightness Range CCFL Backlight Controllers ELECTRICAL CHARACTERISTICS (continued) (V+ = 8.2V, V /SUS = V = 5.5V, MINDAC = GND PARAMETER ANALOG INTERFACE BRIGHTNESS CONTROL (MODE connected to REF or GND ) CRF/SDA, CRF Input Range ...
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ELECTRICAL CHARACTERISTICS (V+ = 8.2V, V /SUS = V = 5.5V, MINDAC = GND PARAMETER SUPPLY AND REFERENCE V Input Voltage Range BATT V Quiescent Current, Shutdown BATT VL Output Voltage, Normal Operation VL Undervoltage Lockout Threshold ...
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Wide Brightness Range CCFL Backlight Controllers (V = 12V 1V, MODE = GND, Circuit of Figure 8.) IN CTL CRF MINDAC WIDE INPUT RANGE (V = 8V) BATT 4μs/div WIDE INPUT RANGE (V = ...
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1V, MODE = GND, Circuit of Figure 8.) IN CTL CRF MINDAC SYNCHRONIZED DPWM (f = 100kHz, V MODE CTL 1ms/div STARTUP (ADC SOFT-START, MODE = GND) 20ms/div LAMP-OUT VOLTAGE LIMITING ...
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Wide Brightness Range CCFL Backlight Controllers (V = 12V 1V, MODE = GND, Circuit of Figure 8.) IN CTL CRF MINDAC VL vs 5.40 NORMAL OPERATION 5.35 SHUTDOWN 5.30 5.25 5.20 5.15 ...
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NAME PIN MAX1739 MAX1839 1 REF REF 2 MINDAC MINDAC 3 CCI CCI 4 CCV CCV SH/SUS CRF/SDA CRF 7 CTL/SCL CTL 8 MODE MODE 9 CSAV CSAV 10 CTFB CTFB 11 SYNC SYNC 12 DL2 DL2 ...
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Wide Brightness Range CCFL Backlight Controllers Detailed Description The MAX1739/MAX1839 regulate the brightness of a CCFL in three ways: 1) Linearly controlling the lamp current. 2) Digitally pulse-width modulating (or chopping) the lamp current (DPWM). 3) Using both methods simultaneously ...
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Voltage and Current Control Loops The MAX1739/MAX1839 use two control loops. The cur- rent control loop regulates the average lamp current. The voltage control loop limits the maximum average primary- side transformer voltage. The voltage control loop is active during ...
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Wide Brightness Range CCFL Backlight Controllers Figure 2. Functional Diagram 12 ______________________________________________________________________________________ ...
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All backlight circuit designs can undergo a transient overvoltage condition when the laptop is plugged into the AC adapter and V increases. ...
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Wide Brightness Range CCFL Backlight Controllers brightness code of ob00000 corresponds to a 9.375% DPWM duty cycle, and a brightness code of ob11111 corresponds to a 100% DPWM duty cycle. The duty cycle changes by 3.125% per step, except codes ...
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Table 3. Brightness Adjustment Ranges (for 33:1 Dimming) POSITIVE- BRIGHTNESS SCALE ADC MODE = GND, Maximum MODE = REF CTL/SCL Brightness V V CRF/SDA MODE = GND, MODE = REF, Minimum CTL/SCL V Brightness V ...
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Wide Brightness Range CCFL Backlight Controllers ADC- 10k SMBus ADC+ 500pF DPWM SYNCHRONIZATION SIGNAL Figure 6. DPWM Synchronization optimized using R14 and R15 as shown in Figure 7. The resistor-divider can be used to force commutation as close to the ...
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With the buck switch short- ed, the center tap rises above its regulation point, which causes the CCV amplifier’s output (V low. To detect this, ...
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Wide Brightness Range CCFL Backlight Controllers a proven application that is useful for a wide range of CCFL tubes and power ranges. Table 5 shows the rec- ommended components for a 4.5W application. The MAX1739/MAX1839 require three external switches to ...
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1.1 S S(RMS CTFB N2A the average DC voltage at center top CT πV Nπ -NπV 2π ω Figure ...
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Wide Brightness Range CCFL Backlight Controllers transient that C is designed to protect against is CCV open tube at the beginning of DPWM pulses. Large C values reduce transient overshoots, but CCV can cause loss of regulation at low DPWM ...
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Write-Byte Format S ADDRESS WR 7 bits 1b Slave Address Read-Byte Format S ADDRESS WR ACK 7 bits 1b 1b Slave Address Send-Byte Format S ADDRESS WR ACK COMMAND 7 bits Start condition Shaded = Slave ...
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Wide Brightness Range CCFL Backlight Controllers LOW HIGH SMBCLK SMBDATA t t HD:STA SU:STA A = START CONDITION B = MSB OF ADDRESS CLOCKED INTO SLAVE C = LSB OF ADDRESS CLOCKED INTO SLAVE D = ...
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Table 6. Commands Description COMMAND POR PROTOCOL BYTE* STATE 0x01 Read and 0b0XXX 0x17 Write XX01 0x02 Read and 0b0XXX 0xF9 Write XX10 0x03 Read 0b0XXX 0x96 Only XX11 0x04 Read 0b0XXX 0x00 Only XX00 0x40 Read ...
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Wide Brightness Range CCFL Backlight Controllers [STATUS1–STATUS0] (POR = 0b11) The status register returns information on fault condi- tions lamp is not connected to the secondary of the transformer, the MAX1739 will detect that the lamp cur- rent ...
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Pin Configurations (continued) TOP VIEW REF 1 20 MINDAC 2 19 CCI 3 18 CCV 4 17 MAX1839 CRF 6 15 CTL 7 14 MODE 8 13 CSAV 9 12 CTFB 10 11 QSOP ______________________________________________________________________________________ Wide Brightness ...
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... Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. 26 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2001 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products ...