max738a Maxim Integrated Products, Inc., max738a Datasheet
max738a
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max738a Summary of contents
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... Rev 2; 1/96 Current-Mode PWM DC-DC Converters __________________General Description The MAX730A/MAX738A/MAX744A are 5V-output CMOS, step-down switching regulators. The MAX738A/ MAX744A accept inputs from 6V to 16V and deliver 750mA. The MAX744A guarantees 500mA load capa- bility for inputs above 6V and has tighter oscillator fre- quency limits for low-noise (radio) applications ...
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... Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ELECTRICAL CHARACTERISTICS (Circuit of Figure for the MAX730A 12V for the MAX738A/MAX744A, I unless otherwise noted.) PARAMETER CONDITIONS 0mA < ...
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... Current-Mode PWM DC-DC Converters ELECTRICAL CHARACTERISTICS (continued) (Circuit of Figure for the MAX730A 12V for the MAX738A/MAX744A, I unless otherwise noted.) PARAMETER CONDITIONS I = 0mA to 300mA LOAD Load Regulation I = 0mA to 750mA LOAD V+ = 9.0V, I LOAD Efficiency V+ = 12V, I LOAD V+ = 6.0V to 9.0V Supply Current V+ = 9.0V (includes switch to 12.0V current 12.0V to 16.0V ...
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... EFFICIENCY vs. OUTPUT CURRENT 100 (NOTE 6. 9. 12. 16. 200 400 600 800 1000 OUTPUT CURRENT (mA) QUIESCENT SUPPLY CURRENT vs. TEMPERATURE 3.0 MAX730A 9.0V MAX738A 12.0V 2.5 MAX744A 12.0V 2.0 1.5 1.0 0.5 (NOTES -60 -40 - 100 120 140 160 TEMPERATURE (°C) STANDBY SUPPLY CURRENT vs. TEMPERATURE 20 (NOTES 4, 5) ...
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... Figure +25°C, unless otherwise noted.) A OSCILLATOR FREQUENCY vs. SUPPLY VOLTAGE 220 210 MAX730A 200 190 180 170 160 MAX738A 150 SUPPLY VOLTAGE (V) MAX738A OSCILLATOR FREQUENCY vs. TEMPERATURE 200 190 V+ = 6.0V 180 V+ = 16.0V 170 160 150 V+ = 12. 9.0V 140 130 120 -60 -40 - TEMPERATURE (° ...
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... A 0V 200mA B 0mA C A: SWITCH VOLTAGE (LX PIN), 5V/div +12V B: INDUCTOR CURRENT, 200mA/div C: OUTPUT VOLTAGE RIPPLE, 50mV/div, AC-COUPLED C OUT = 390 12V, I OUT = 150 A MAX738A/MAX744A LINE-TRANSIENT RESPONSE A 11V OUT , 50mV/div, DC-COUPLED B: V+, 5V/div, 10.2V TO 16.0V I OUT = 750mA MAX738A/MAX744A SWITCHING WAVEFORMS, ...
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... Drain of internal P-channel power MOSFET. Supply-Voltage Input. Bypass to GND with 1µF ceramic and large-value electrolytic capaci- tors in parallel. The 1µF capacitor must be as close to V+ and GND pins as possible. No Connect—no internal connections to these pins. 5V, Step-Down, MAX738A/MAX744A LOAD-TRANSIENT RESPONSE 50ms/div FUNCTION A ...
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... They convert an unregu- lated DC voltage from 5.2V to 11V for the MAX730A, and from 6V to 16V for the MAX738A/MAX744A. The current-mode PWM architecture provides cycle-by- cycle current limiting, improved load-transient response characteristics, and simpler outer-loop design. ...
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... REF. Connect a 0.01µF bypass capacitor from REF to GND. The internal oscillator of the MAX730A typically oper- ates at 170kHz (160kHz for the MAX738A and 185kHz for the MAX744A). The MAX744A is guaranteed to operate at a minimum of 159kHz and a maximum of 212.5kHz over the operating voltage and temperature range, making it ideal for use in portable communica- tions systems ...
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... F/F SENSE AMP PWM COMPARATOR OSC MAX730A MAX738A MAX744A SS CLAMP UNDERVOLTAGE LOCKOUT Capacitor ESR rises as the temperature falls, and excessive ESR is the most likely cause of trouble at temperatures below 0°C. Sanyo OS-CON series through-hole and surface-mount tantalum capacitors exhibit low ESR at temperatures below 0°C. Refer to Table 2 for recommended capacitor values and sug- gested capacitor suppliers ...
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... For this reason, avoid using sockets, and solder the IC directly to the PC board. Use an uninterrupted ground plane if possible. ______________________________________________________________________________________ MAX730AE/M, MAX738AE/M, MAX744AE/M Capacitors Inductors L1 = 33µ 68µF, 16V C4 = 100µF, 6.3V ...
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... Step-Down, Current-Mode PWM DC-DC Converters FROM SHDN R1 SS CLAMP 510k SS 1M ±35% C1 1.23V MAX730A MAX738A MAX744A Figure 2. Block Diagram of Soft-Start Circuitry MAX730A +5.2V TO +11.0V MAX738A/MAX744A +6.0V TO +16. SHDN D1 1N5817 MAX730A R1 5 510k MAX738A OUT MAX744A C5 330pF GND REF ...
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Current-Mode PWM DC-DC Converters MAX730 EVALUATION KIT Figure 4. DIP PC Layout, Through-Hole Component Placement Diagram (1x scale) Figure 6. DIP PC Layout, Solder Side (1x scale) ______________________________________________________________________________________ 5V, Step-Down, Figure 5. DIP PC Layout, Component Side (1x scale) Figure ...
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... N. Wide SO __________________________________________________________Chip Topographies MAX730A SHDN V+ REF SS OUT CC 0.072" (1.828mm) TRANSISTOR COUNT: 274 (MAX730A) 286 (MAX738A/MAX744A); SUBSTRATE CONNECTED TO V+. 14 ______________________________________________________________________________________ __Ordering Information (continued) PART MAX738ACPA MAX738ACWE V+ MAX738AC/D LX MAX738AEPA GND MAX738AEWE OUT MAX738AMJA MAX744ACPA MAX744ACWE MAX744AC/D V+ MAX744AEPA V+ MAX744AEWE ...
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Current-Mode PWM DC-DC Converters ________________________________________________________Package Information ______________________________________________________________________________________ 45˚ 0.127mm 0.004in 5V, Step-Down, ...
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Step-Down, Current-Mode PWM DC-DC Converters ___________________________________________Package Information (continued Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim ...