MAX8855A MAXIM [Maxim Integrated Products], MAX8855A Datasheet
MAX8855A
Related parts for MAX8855A
MAX8855A Summary of contents
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... Two enable inputs allow the turning on/off of each out- put individually, resulting in great flexibility for system- level designs. A reference input is provided to facilitate output-voltage tracking applications. The MAX8855/ MAX8855A are available in a 32-pin TQFN (5mm x 5mm) package with 0.8mm max height. Applications ASIC/CPU/DSP Power Supplies ...
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... Lead Temperature (soldering, 10s) .................................+300°C Soldering Temperature (reflow) .......................................+260°C ) ...........29°C ...............1.7°C 600mV, PGND_ = GND, R SS_ REFIN = -40°C to +85°C, typical values are CONDITIONS MAX8855 (Note 3) MAX8855A V IN 1MHz switching, no load VDD 1MHz switching VDL DD V VDD T V ...
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... 3. 8855A +25° 0.605V +85° +25° 0.610V +85°C A MAX8855 V = 2.35V to 2.6V VDD V = 2.30V to 2.6V MAX8855A VDD V = 2.6V to 3.6V VDD -2A LX_ 3. -2A LX_ 2.5V IN High-side sourcing and freewheeling T = +25° ...
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... THERMAL SHUTDOWN Thermal-Shutdown Threshold (Independent Channels) Thermal-Shutdown Hysteresis Note 2: All devices 100% production tested at T Note 3: V must equal V and be equal to or greater than V VDD VDL ( 3.3V, MAX8855/MAX8855A, circuit of Figure 6, T IN1 IN2 EFFICIENCY vs. LOAD CURRENT WITH 3.3V INPUT 100 1.2V 70 OUT_ ...
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... Dual, 5A, 2MHz Step-Down Regulators ( 3.3V, MAX8855/MAX8855A, circuit of Figure 6, T IN1 IN2 SWITCHING FREQUENCY vs. TEMPERATURE 1100 1080 1060 1040 1020 1000 980 960 940 920 900 -40 -15 10 AMBIENT TEMPERATURE (°C) SHUTDOWN SUPPLY CURRENT vs. SUPPLY VOLTAGE IN1 IN2 VDL VDD ...
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... Dual, 5A, 2MHz Step-Down Regulators ( 3.3V, MAX8855/MAX8855A, circuit of Figure 6, T IN1 IN2 OUTPUT PEAK CURRENT LIMIT vs. OUTPUT VOLTAGE 0.8 1.1 1.4 1.7 2.0 2.3 2.6 OUTPUT VOLTAGE (V) OUTPUT TRACKING (EN1 = EN2) V OUT1 V OUT2 V PWRGD1 V PWRGD2 1ms/div DDR TRACKING 1.8V, 0.9V 6 _______________________________________________________________________________________ Typical Operating Characteristics (continued) = +25°C, unless otherwise noted.) ...
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Dual, 5A, 2MHz Step-Down Regulators PIN NAME Power-Good Open-Drain Output for Regulator 1. PWRGD1 is high impedance when V ≥ 0 PWRGD1 V FB1 REFIN thermal shutdown is activated, or when V External Reference Input for Regulator ...
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... Figure 1 shows the MAX8855/MAX8855A functional diagram. The MAX8855/MAX8855A provide both peak and valley current limits to achieve robust short-circuit protection. During the high-side MOSFET’s on-time, if the drain- source current reaches the peak current-limit threshold ...
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... SOFT-START 2 + REFIN - FB1 ERROR AMPLIFIER COMP1 COMP LOW DETECTOR FROM SS2 (0.6V FB2 ERROR AMPLIFIER COMP2 COMP LOW DETECTOR THERMAL REF SHUTDOWN MAX8855/MAX8855A Figure 1. Functional Diagram _______________________________________________________________________________________ CURRENT-LIMIT COMPARATOR UVLO DC CIRCUITRY + IN2 V IN1 DD CONTROL LOGIC EN1 REF CLOCK THERMAL SHUTDOWN1 CURRENT-LIMIT PWM ...
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... The internal reference is powered. • The IC is not in thermal overload (T Once these conditions are met, the MAX8855/ MAX8855A begin soft-start. FB2 regulates to the volt- age at SS2. During soft-start, the SS2 capacitor is Figure 3a. Startup and Sequencing Options—Two Independent Output Startup and Shutdown Waveforms 10 ______________________________________________________________________________________ ≥ ...
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Dual, 5A, 2MHz Step-Down Regulators reference with soft-start time set independently by the SS1 capacitor (see Figure 3a). For ratiometric tracking applications, connect REFIN to the center of a voltage-divider from the output of regula- tor 2 to GND (see ...
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... See the Setting the Switching Frequency section. Thermal-Overload Protection Thermal-overload protection limits the total power dissi- pation of the MAX8855/MAX8855A. Internal thermal sen- sors monitor the junction temperature at each of the regulators. When the junction temperature exceeds +165°C, the corresponding regulator is shut down, allowing the IC to cool. The thermal sensor turns the reg- ulator on after the junction temperature cools by +20° ...
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... FSYNC ⎝ ⎠ The MAX8855/MAX8855A can also be synchronized to an external clock from 500kHz to 2MHz by connecting the clock signal to FSYNC through a 10kΩ isolation resistor. The external sync frequency must be higher than the frequency that would be produced by R The two regulators switch at the same frequency as the FSYNC clock, and are 180° ...
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... ESR in the above equation is equal to that of the ESR of a single-output capacitor divided by the total number of output capacitors. The high-switching-frequency range of the MAX8855/ MAX8855A allows the use of ceramic output capacitors. Since the ESR of ceramic capacitors is typically very OUT low, the frequency of the associated transfer-function ...
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Dual, 5A, 2MHz Step-Down Regulators π × × π × × π × ...
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... Use caution when routing feedback and compensa- tion node traces; avoid routing near high dV/dt nodes (LX_) and high-current paths. Place the feed- back and compensation components as close as possible to the IC pins. • Reference the MAX8855/MAX8855A Evaluation Kit for an example layout. cathode. IN_ ...
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... Figure 6. 1MHz Typical Application Circuit ______________________________________________________________________________________ V C16 R11 DD 0.1µF 10Ω 0.22µF V VDL DD IN1 PGND1 PGND2 BST1 C6 0.1µF LX1 C9 MAX8855/ COMP1 COMP2 MAX8855A FB1 REFIN SS1 FSYNC PWRGD1 PWRGD2 EN1 EXPOSED PAD C8 IN2 C2 C23 0.1µF 10µF C19 BST2 L2 22µF C17 0.56µH 0.1µF LX2 ...
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... Dual, 5A, 2MHz Step-Down Regulators INPUT 2.35V TO 3.6V FOR MAX8855 2.30V TO 3.6V FOR MAX8855A C1 C3 10µF 0.1µF C4 C18 L1 0.1µF 47µF OUT1 1µH 0.1µF 0.9V/ 200Ω C9 10kΩ R7 C11 330pF 10kΩ 1000pF OUT2 C10 R1 OPEN 1kΩ R19 1kΩ R15 20kΩ PWRGD1 ...
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... Dual, 5A, 2MHz Step-Down Regulators Pin Configuration TOP VIEW PGND1 25 PGND1 26 27 IN1 28 IN1 MAX8855/ EN1 29 MAX8855A 30 COMP1 31 FB1 + 32 SS1 TQFN (5mm x 5mm) ______________________________________________________________________________________ PROCESS: BiCMOS PGND2 15 PGND2 14 IN2 IN2 13 For the latest package outline information and land patterns ...
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... Revised Features, Typical Operating Characteristics, and Output-Capacitor Selection 2 4/09 sections. Added the Safe-Starting into a Prebiased Output section. Added the MAX8855A to the data sheet. Added soldering temperature and Package Thermal Characteristics to Absolute Maximum Ratings. Changed Typical Operating 3 7/11 Circuit. Added new Electrical Characteristics Table. Changed input voltages in Figures 6 and 7 ...