MAX1954AEUB Maxim Integrated Products, MAX1954AEUB Datasheet
MAX1954AEUB
Specifications of MAX1954AEUB
Available stocks
Related parts for MAX1954AEUB
MAX1954AEUB Summary of contents
Page 1
... Output-Current Capability ♦ 93% Efficiency ♦ All-N-Channel-MOSFET Design for Low Cost ♦ No Current-Sense Resistor Needed ♦ Internal Digital Soft-Start ♦ Small 10-Pin µMAX Package ® Applications PART MAX1954AEUB MAX1954AEUB+ +Denotes lead-free package. TOP VIEW Features Ordering Information TEMP RANGE PIN-PACKAGE - + µMAX - + µ ...
Page 2
Low-Cost, Current-Mode PWM Buck Controller with Foldback Current Limit ABSOLUTE MAXIMUM RATINGS IN GND...........................................................-0. BST..................................................................-6V to +0.3V BST to GND ............................................................-0.3V to +20V ................................................... -0. DL, COMP to GND.......................................-0.3V ...
Page 3
Low-Cost, Current-Mode PWM Buck Controller with Foldback Current Limit ELECTRICAL CHARACTERISTICS (continued 5V 5V +85 C, unless otherwise noted.) IN BST LX A PARAMETER SOFT-START Soft-Start Period Soft-Start Levels ...
Page 4
Low-Cost, Current-Mode PWM Buck Controller with Foldback Current Limit ELECTRICAL CHARACTERISTICS (continued +85 C, unless otherwise noted.) (Note 2) IN BST LX A PARAMETER Current-Sense Amplifier Voltage ...
Page 5
Low-Cost, Current-Mode PWM Buck Controller with Foldback Current Limit (T = +25°C, unless otherwise noted.) A EFFICIENCY vs. LOAD CURRENT 100 V = 2.5V OUT 1.5V OUT ...
Page 6
Low-Cost, Current-Mode PWM Buck Controller with Foldback Current Limit (T = +25°C, unless otherwise noted.) A LOAD TRANSIENT V OUT AC-COUPLED I OUT 5A s/div HEAVY-LOAD SWITCHING WAVEFORMS LOAD ...
Page 7
Low-Cost, Current-Mode PWM Buck Controller with Foldback Current Limit PIN NAME High-Side Drain Current-Sense Input. HSD senses the voltage at the drain of the high-side, N-channel MOSFET. 1 HSD Connect to the high-side MOSFET drain using a Kelvin connection. Compensation ...
Page 8
Low-Cost, Current-Mode PWM Buck Controller with Foldback Current Limit SHUTDOWN COMPARATOR 0.5V COMP 2.36V CLAMP ERROR AMPLIFIER FB REFERENCE AND SOFT-START DIGITAL-TO-ANALOG CONVERTER FOLDBACK CURRENT- During the second half of the cycle, the high-side MOSFET turns off and the low-side ...
Page 9
Low-Cost, Current-Mode PWM Buck Controller with Foldback Current Limit 5.5V V HSD 5.5V TO 13. Figure 1. MAX1954A Typical Application Circuit 5.5V HSD C1 IN 0.22 F ...
Page 10
Low-Cost, Current-Mode PWM Buck Controller with Foldback Current Limit When the output is shorted, the foldback current limit reduces the current-limit threshold linearly to 20% of the nominal value to reduce the power dissipation of components and the input current. ...
Page 11
Low-Cost, Current-Mode PWM Buck Controller with Foldback Current Limit Table 1. Suggested Components PART DESIGNATOR 0.22µF, 10V X7R ceramic capacitor C1 Kemet C0603C224M8RAC 1µF, 6.3V X5R ceramic capacitor C2 Taiyo Yuden JMK212BJ106MG 10µF, 16V X5R ceramic capacitor C3 Taiyo Yuden ...
Page 12
Low-Cost, Current-Mode PWM Buck Controller with Foldback Current Limit The MAX1954A features a low-power shutdown mode. Use an open-collector, NPN transistor to pull COMP low and shut down the IC. COMP must be pulled below 0.25V to shut down the ...
Page 13
Low-Cost, Current-Mode PWM Buck Controller with Foldback Current Limit choose the high-side MOSFET (N1) that has conduction losses equal to switching loss at nominal input voltage and output current. The selected MOSFETs must have an R that satisfies the current-limit ...
Page 14
Low-Cost, Current-Mode PWM Buck Controller with Foldback Current Limit where V is the input voltage and f IN frequency. Choose a R power rating that meets SNUB the specific application’s derating rule for the power dissipation calculated. The input filter ...
Page 15
Low-Cost, Current-Mode PWM Buck Controller with Foldback Current Limit output filtering. For other types of capacitors, due to the higher capacitance and ESR, the frequency of the zero created by the capacitance and ESR is lower than the desired closed-loop ...
Page 16
Low-Cost, Current-Mode PWM Buck Controller with Foldback Current Limit The error-amplifier gain mEA then calculated as OUT mEA ...
Page 17
Low-Cost, Current-Mode PWM Buck Controller with Foldback Current Limit Typical Operating Circuit 5.5V IN HSD BST V HSD 5.5V TO 13. MAX1954A LX COMP DL N PGND GND FB ______________________________________________________________________________________ TRANSISTOR COUNT: 2963 PROCESS: ...
Page 18
... 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. 18 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2005 Maxim Integrated Products ...