LTC3408 LINER [Linear Technology], LTC3408 Datasheet
LTC3408
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LTC3408 Summary of contents
Page 1
... P-channel MOSFET connects eliminating power loss through the inductor. IN The input voltage range is 2. making the LTC3408 ideally suited for single Li-Ion battery-powered applica- tions. 100% duty cycle provides low dropout operation, extending battery life in portable systems. Switching frequency is internally set at 1.5MHz, allowing the use of small surface mount inductors and capacitors ...
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... REF Input Current REF Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: The LTC3408E is guaranteed to meet performance specifications from 0°C to 70°C. Specifications over the –40°C to 85°C operating 2 U PACKAGE/ORDER I FOR ATIO ...
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... OUTPUT CURRENT (mA) Oscillator Frequency vs Temperature 1. 3.6V IN 1.65 1.60 1.55 1.50 1.45 1.40 1.35 1.30 –50 – TEMPERATURE (°C) LTC3408 (From Figure 1) Efficiency vs Output Current 100 T = 25° 1.5V 90 OUT 1000 OUTPUT CURRENT (mA) 3408 G03 Oscillator Frequency vs Supply Voltage 1 ...
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... LTC3408 W U TYPICAL PERFOR A CE CHARACTERISTICS Frequency vs V OUT 1600 T = 25° 3.6V IN 1400 1200 1000 800 600 400 0 0.2 0.4 0.6 0.8 1.0 1.2 V (V) OUT 3408 G08 R vs Temperature DS(ON) 0 2. 4.2V IN 0.5 MAIN SWITCH 0.4 0.3 SYNCHRONOUS SWITCH 0.2 BYPASS SWITCH 0 4. –50 – 100 125 TEMPERATURE (° ...
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... Do not leave RUN floating. REF (Pin 6): External Reference Input. Controls the output voltage to 3× the applied voltage at REF. Also turns on the bypass MOSFET when V Exposed Pad (Pin 9): Connect to GND, Pin 3. LTC3408 3408 G17 20µs/DIV REF I ...
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... TAIYO YUDEN JMK212BJ106MN 3403 F01 Figure 1. Typical Application Main Control Loop The LTC3408 uses a constant frequency, current mode step- down architecture. The main (P-channel MOSFET), syn- chronous (N-channel MOSFET) and bypass (P-channel MOSFET) switches are internal. During normal operation, the internal main switch is turned on each cycle when the ...
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... An important detail to remember is that at low input supply voltages, the R increases (see Typical Performance Characteristics). Therefore, the user should calculate the power dissipa- to exceed V , tion when the LTC3408 is used at 100% duty cycle with OUT IN low input voltage (See Thermal Considerations in the Applications Information section). Low Supply Operation The LTC3408 will operate with input supply voltages as low as 2 ...
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... The choice of which style induc- tor to use often depends more on the price versus size requirements and any radiated field/EMI requirements than on what the LTC3408 requires to operate. Table 1 shows some typical surface mount inductors that work well in LTC3408 applications. Table 1. Representative Surface Mount Inductors ...
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... ESR make them ideal for switching regulator applications. Because the LTC3408’s control loop does not depend on the output capacitor’s ESR for stable operation, ceramic capacitors can be used freely to achieve very low output ripple and small circuit size ...
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... where example, consider the LTC3408 in dropout at an input voltage of 2.7V, a load current of 600mA (0.9V ≤ con- < 1.2V) and an ambient temperature of 70°C. With V L 1.2V, the entire 600mA flows through the main P-channel FET. From the typical performance graph of switch resis- tance, the R approximately 0.52Ω ...
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... MOSFETs. 3. Keep the (–) plates of C Design Example to its steady state OUT As a design example, assume the LTC3408 is used in a can be monitored for single lithium-ion battery-powered cellular phone applica- tion. The V down to about 2.7V. The load current requirement is a maximum of 0.6A but most of the time it will be in standby mode, requiring only 2mA ...
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... Fixed Output Voltages Available, ThinSOT Package ) Synchronous Up to 91% Efficiency, V OUT MS10 Package 300MHz to 3GHz, Temperatrue Compensated, LTC5505-1: –28dBm to 18dBm, LTC5505-2: –32dBm to 12dBm, V www.linear.com ● 4.7µ LTC3408 4.7µF CER RUN V OUT 3403 F07 10k 6 * MURATA LQH32CN4R7M11 REF ** GND TAIYO YUDEN JMK212BJ475MG † ...