MAX8543 MAXIM [Maxim Integrated Products], MAX8543 Datasheet
MAX8543
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MAX8543 Summary of contents
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... They feature IN adjustable switching frequency and synchronization for noise-sensitive applications. The MAX8543/MAX8544 can start with (or without) a pre- existing bias on the output, without discharging the out- put. This feature simplifies tracking supply designs for core and I/O applications and redundant supply designs. ...
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Step-Down Controllers with Prebias Startup, Lossless Sensing, Synchronization, and OVP ABSOLUTE MAXIMUM RATINGS IN, EN, CS+, CS- to GND .......................................-0.3V to +14V BST ..........................................................-0.3V to +6V BST to GND ............................................................-0.3V to +20V DL, COMP, ILIM2, SS, SYNCO, ...
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... LX PGND ILIM2 200kΩ (MAX8544 only) LX PGND ILIM2 0.8V (MAX8543 only) LX PGND (MAX8543 only) LX PGND positive-direction current limit CS+ CS 18.2kΩ FSYNC R = 158kΩ FSYNC Measured at DH Measured 18.2kΩ, free-running mode, ...
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Step-Down Controllers with Prebias Startup, Lossless Sensing, Synchronization, and OVP ELECTRICAL CHARACTERISTICS (continued 13.2V 5V 0°C to +85°C, unless otherwise noted. Typical values are BST LX A PARAMETER POK ...
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... LX PGND ILIM2 200kΩ (MAX8544 only) LX PGND ILIM2 0.8V (MAX8543 only) LX PGND (MAX8543 only) LX PGND positive-direction current limit CS+ CS 18.2kΩ FSYNC Measured at DH Measured 18.2kΩ FSYNC I = 5mA SYNCO ...
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Step-Down Controllers with Prebias Startup, Lossless Sensing, Synchronization, and OVP ELECTRICAL CHARACTERISTICS (continued 13.2V 5V -40°C to +85°C, unless otherwise noted.) (Note 2) IN BST LX A PARAMETER POK Power-OK Threshold POK ...
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Step-Down Controllers with Prebias Startup, Lossless Sensing, Synchronization, and OVP (T = +25°C, unless otherwise noted.) A EFFICIENCY vs. LOAD CURRENT WITH 12V INPUT 100 3.3V OUT 2.5V OUT ...
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... MAX8544 STEP-LOAD RESPONSE 7.5A TO 15A TO 7.5A (5A/µs) V OUT I OUT 10µs/div MAX8544 POWER-UP WAVEFORMS OUT V POK I L 2ms/div MAX8543 POWER-UP WAVEFORMS OUT I L 2ms/div 8 _______________________________________________________________________________________ Typical Operating Characteristics (continued) MAX8544 STEP-LOAD RESPONSE 1.5A TO 15A TO 1.5A (5A/µs) MAX8543 toc08 50mV/div V OUT AC-COUPLED ...
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... V 1V/div OUT V DH 10A/div 10A/div 0 PREBIASED STARTUP (OUTPUT PREBIASED AT 1.5V) MAX8543 toc18 OUT 1. 1ms/div MAX8543 toc15 1V/div 10V/div 5V/div 5V/div 2µs/div WITH 15A LOAD MAX8543 toc17 1V/div 0V 10V/div 0V 5V 5V/div 40µs/div 5V/div 2.5V 500mV/div 10V/div 5V/div 9 ...
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... Internal 5V Linear-Regulator Output. Connect a 1µF to 10µF ceramic capacitor from VL to PGND. Connect for V IN gate drive. Input Supply Voltage the input to the internal linear regulator. Connect for V less than 5.5V. IN BODE PLOT, 600kHz, NO LOAD MAX8543 toc20 SWEEP TIME 10.000s 90° 30°/div 10kHz 100kHz 1MHz Pin Description ...
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... Setting the Current Limits section. Current-Limit Operating-Mode Selection. Connect MODE to VL for latch-off current limit or connect to GND for automatic-recovery current limit with the MAX8544. The MAX8543 always uses automatic-recovery current limit. Power-OK. POK is an open-drain output that is high impedance when the output is above 91% of its nominal regulation voltage ...
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Step-Down Controllers with Prebias Startup, Lossless Sensing, Synchronization, and OVP V = (10.8V TO 13.2V) IN C12 9 ILIM1 SYNC FSYNC ON OFF GND COMP R2 ...
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Step-Down Controllers with Prebias Startup, Lossless Sensing, Synchronization, and OVP Table 1. Suggested Components for Figure 1 DESIGNATION QTY C4A, C4B, C4C C6A, C6B C9, C10 ...
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... R3 3 COMP CS- R1 Figure 2. Typical Applications Circuit with 3.3V (±10%) Input, 2.5V Output 15A, and 500kHz Switching Frequency 14 ______________________________________________________________________________________ BST MAX8543 PGND 7 CS+ C11 C4A C4B C4C C4D V = 2.5V OUT 15A ...
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Step-Down Controllers with Prebias Startup, Lossless Sensing, Synchronization, and OVP Table 2. Suggested Components for Figure 2 DESIGNATION QTY C4A, C4B, C4C, 4 C4D C5 1 C6A, C6B C9, ...
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... The MAX8543/MAX8544 SS also feature prebias startup; therefore, both external power MOSFETs are kept off if the voltage higher than that at SS. This allows the MAX8543/MAX8544 to start up into a prebiased output without pulling the output voltage down. Before the MAX8543/MAX8544 can begin the soft-start ...
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... N be used for more accurate current sensing. The MAX8543/MAX8544 have four selectable peak current- limit thresholds that are selected using ILIM (MAX8543) or ILIM1 (MAX8544). See Table 3 for the current-limit settings. For more information on the current limit, see the Setting the Current Limits section ...
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... S The MAX8543/MAX8544 can also be synchronized to an external clock by connecting the clock signal to FSYNC. When using an external clock, select R the free-running frequency is within ±30% of the clock fre- quency. In addition, the MAX8544 has a synchronization output (SYNCO) that provides a clock signal that is 180° ...
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... Setting the Current Limits The valley current limit employs a current foldback scheme. The MAX8543 has a fixed valley current-limit threshold of 130mV, and a fixed foldback ratio (P 23%. The foldback ratio is the current-limit threshold when the output (output shorted to ground), divided by the threshold when the output is at its nominal regulated value ...
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... Similarly the value of the inductor valley VALLEY current at maximum load, R DS(ON) resistance of the low-side MOSFET at the highest oper- ating junction temperature. Peak inductor current-limit threshold (V possible settings through ILIM (MAX8543) or ILIM1 (MAX8544) as shown in Table 3 below. The resulting current limit is calculated as − ...
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... Step-Down Controllers with Prebias Startup, Lossless Sensing, Synchronization, and OVP MOSFET Selection The MAX8543/MAX8544 drive two or four external, logic-level, n-channel MOSFETs as the circuit switch elements. The key selection parameters are: 1) On-resistance (R ): the lower, the better. DS(ON) 2) Maximum drain-to-source voltage ( least 20% higher than the input supply rail at the high-side MOSFET’ ...
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Step-Down Controllers with Prebias Startup, Lossless Sensing, Synchronization, and OVP MOSFET Snubber Circuit Fast switching transitions cause ringing because of res- onating circuit parasitic inductance and capacitance at the switching nodes. This high-frequency ringing occurs at LX’s rising and falling ...
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... The controller uses a current-mode control scheme that regulates the output voltage by forcing the required cur- rent through the external inductor, so the MAX8543/ MAX8544 use the voltage drop across the DC resistance of the inductor or the alternate series current-sense resis- tor to measure the inductor current ...
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Step-Down Controllers with Prebias Startup, Lossless Sensing, Synchronization, and OVP zEA × × 2π pEA × × 2π The crossover frequency should be much higher C ...
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Step-Down Controllers with Prebias Startup, Lossless Sensing, Synchronization, and OVP pMOD ⎛ ⎞ × × LOAD S π × × ⎜ ESR ⎟ OUT + × ⎝ ⎠ ...
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... Lossless Sensing, Synchronization, and OVP Table 4. Suggested Component Manufacturers MANUFACTURER Central Semiconductor Coilcraft International Rectifier Kamaya Panasonic Sanyo Sumida Taiyo Yuden TDK Vishay/Siliconix Pin Configurations TOP VIEW GND COMP 3 MAX8543 CS- 6 CS+ 7 ILIM 8 ILIM2 1 GND COMP 4 MAX8544 FB ...
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Step-Down Controllers with Prebias Startup, Lossless Sensing, Synchronization, and OVP (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information www.maxim-ic.com/packages.) Maxim cannot assume responsibility for use of ...