LTC3448 Linear Technology, LTC3448 Datasheet
LTC3448
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LTC3448 Summary of contents
Page 1
... Supply current during operation is only 32µA (linear regulator mode) and drops to <1µA in shutdown. The 2.5V to 5.5V input voltage range makes the LTC3448 ide- ally suited for single Li-Ion battery-powered applications. 100% duty cycle provides low dropout operation, extend- ing battery life in portable systems ...
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... OVL OVL OUT OUT V = 2.5V to 5.5V (LDO 0. 90%, FB OUT Duty Cycle < 35% LDO, 1mA to 10mA (Note 9) www.DataSheet4U.com ORDER PART NUMBER TOP VIEW LTC3448EMS8E 8 RUN 7 SYNC 9 6 FREQ 5 SW MS8 PART MARKING = 40° LTBMK MIN TYP MAX ±30 ● 0.5880 ...
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... )(43°C/ Note 4: The LTC3448 is tested in a proprietary test mode that connects V to the output of the error amplifier. FB Note 5: Dynamic supply current is higher due to the gate charge being delivered at the switching frequency. LRO is “linear regulator operation.” The ● ...
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... LTC3448 W U TYPICAL PERFOR A CE CHARACTERISTICS (From Figure1a Except for the Resistive Divider Resistor Values) Efficiency vs Input Voltage 100 V = 1.8V OUT I = 100mA 95 OUT T = 25° 30mA 85 OUT 600mA OUT INPUT VOLTAGE (V) 3448 G01 Efficiency vs Load Current ...
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... Load Step V OUT 100mV/DIV AC COUPLED I LOAD 250mA/DIV I L 500mA/DIV 3448 G16 1.5V OUT I = 50mA TO 600mA LOAD C = 10µF OUT LTC3448 www.DataSheet4U.com Dynamic Supply Current vs Temperature 320 LOAD 300 280 2.25MHz 260 1.5MHz 240 220 200 –50 – 100 TEMPERATURE (° ...
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... LTC3448 W U TYPICAL PERFOR A CE CHARACTERISTICS (From Figure 1a Except for the Resistive Divider Resistor Values) Load Step V OUT 100mV/DIV AC COUPLED I LOAD 250mA/DIV I L 500mA/DIV V = 3.6V 10µs/DIV 1.5V OUT I = 100mA TO 600mA LOAD CTIO S V (Pin 1): Feedback Pin. This pin receives the feedback ...
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... At very light loads, the LTC3448 will automatically skip pulses to maintain output regulation. Low Ripple LDO Mode Operation At load currents below I LTC3448 will switch into very low ripple, linear regulating operation (LRO). In this mode, the current is sourced from LTC3448 www.DataSheet4U.com MODE ...
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... OUT are turned off. The control loop is stabilized by the load capacitor and requires a minimum value of 2µF. The LTC3448 will change back to switching mode and turn off the LDO when the load current exceeds approximately 11mA. When MODE is connected to an intermediate voltage level (i ...
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... Thus, a 720mA rated inductor should be enough for most applications (600mA + 120mA). For better efficiency, choose a low DC-resis- tance inductor. If the LTC3448 used in auto LDO mode, inductor values less than 1µH should not be used. LTC3448 www.DataSheet4U.com ⎛ ...
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... The choice of which style inductor to use often depends more on the price vs size requirements and any radiated field/EMI requirements than on what the LTC3448 requires to operate. Table 1 shows some typical surface mount inductors that work well in LTC3448 applications. Table 1. Representative Surface Mount Inductors ...
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... LTC3448 GND Figure 5. Setting the LTC3448 Output Voltage Efficiency Considerations The efficiency of a switching regulator is equal to the output power divided by the input power times 100 often useful to analyze individual losses to determine what is limiting the efficiency and which change would produce the most improvement. Efficiency can be expressed as: Efficiency = 100% – ...
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... where example, consider the LTC3448 in dropout at an input voltage of 2.7V, a load current of 600mA and an ambient temperature of 70°C. From the typical perfor- mance graph of switch resistance, the R P-channel switch at 70°C is approximately 0.52Ω. There- fore, power dissipated by the part is: ...
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... V node Keep the (–) plates of C Design Example As a design example, assume the LTC3448 is used in a single lithium-ion battery-powered cellular phone application. The V 4.2V 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. Efficiency at both low ...
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... 2. 5. RUN V OUT 4.7µF LTC3448 CER 3 MODE 6 1 FREQ SYNC GND 9 3448 F09a C : TAIYO YUDEN JMK212BJ475MG TAIYO YUDEN JMK212BJ475MG OUT *MURATA LQH32CN2R2M11 ...
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... Load Step V OUT 100mV/DIV AC COUPLED I LOAD 100mA/DIV I L 500mA/DIV V = 3.6V 20µs/DIV 1.5V OUT I = 100µA TO 200mA LOAD Note: Performance data measured on the LTC3448 with external resistors 100 V OUT 1.5V C OUT 15µF 22pF 474k 216k V OUT 100mV/DIV AC COUPLED I LOAD 250mA/DIV I L 500mA/DIV ...
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... TYPICAL APPLICATIO S Single Li-Ion 1.2V/600mA Regulator for High Efficiency and Small Footprint 2.2µ RUN V OUT 4.7µF LTC3448 CER 3 MODE FREQ FB 7 SYNC GND 9 3448 TA07 C : TAIYO YUDEN JMK212BJ475MG TAIYO YUDEN JMK212BJ475MG OUT *MURATA LQH32CN2R2M33 ...
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... RUN V OUT 4.7µF LTC3448 CER 316k 3 MODE FREQ 1. SYNC GREATER 2.5MHz 316k EXTERNAL CLOCK GND 9 3448 TA13 LTC3448 www.DataSheet4U.com V OUT 2.5V C 600mA OUT 10µF C CER FF 22pF Load Step 3448 TA12c V = 3.6V 40µs/DIV 2.5V OUT I = 100µA TO 600mA ...
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... LTC3448 PACKAGE DESCRIPTIO 3.5 ±0.05 1.65 ±0.05 2.15 ±0.05 (2 SIDES) 0.25 ± 0.05 RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS PIN 1 TOP MARK (NOTE 6) 0.200 REF Package 8-Lead Plastic DFN (3mm × 3mm) (Reference LTC DWG # 05-08-1698) 0.675 ±0.05 PACKAGE OUTLINE 0.50 BSC 2.38 ±0.05 (2 SIDES) 3.00 ±0.10 1.65 ± 0.10 ...
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... TYP 0.53 ± 0.152 (.021 ± .006) (.043) DETAIL “A” MAX SEATING PLANE 0.22 – 0.38 (.009 – .015) TYP LTC3448 www.DataSheet4U.com BOTTOM VIEW OF EXPOSED PAD OPTION 2.06 ± 0.102 (.081 ± .004) 1 1.83 ± 0.102 (.072 ± .004) 8 0.52 (.0205) ...
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... LTC3448 RELATED PARTS PART NUMBER DESCRIPTION LT1616 500mA (I ), 1.4MHz, High Efficiency Step-Down OUT DC/DC Converter LT1776 500mA (I ), 200kHz, High Efficiency Step-Down OUT DC/DC Converter LTC1877 600mA (I ), 550kHz, Synchronous Step-Down OUT DC/DC Converter LTC1879 1. 550kHz, Synchronous Step-Down OUT DC/DC Converter LTC3403 600mA (I ), 1.5MHz, Synchronous Step-Down OUT ...