LT1765-2.5 Linear Technology, LT1765-2.5 Datasheet

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... IN 2.2 F LT1765-3.3 CERAMIC OFF ON SHDN SYNC GND LT1765/LT1765-1.8/LT1765-2.5/ Monolithic 3A, 1.25MHz Step-Down Switching Regulator DESCRIPTIO ® The LT 1765 is a 1.25MHz monolithic buck switching regulator. A high efficiency 3A, 0.09 switch is included on the die together with all the control circuitry required to construct a high frequency, current mode switching regulator ...

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... EXPOSED PAD SOLDERED TO LARGE COPPER PLANE CONDITIONS 3.3V < V < 25V (Note 0V 25V SHDN < V < 25V, 0.4V < V < 0.9V LT1765 (Adj (Note 3) LT1765-1.8 LT1765-2.5 LT1765-3.3 LT1765-5 ORDER PART NUMBER TOP VIEW 16 GND LT1765EFE 15 NC LT1765EFE-1.8 14 SYNC LT1765EFE-2 LT1765EFE-3 LT1765EFE-5 11 ...

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... Note 2: The LT1765E is guaranteed to meet performance specifications from 125 C. Specifications over the – 125 C operating junction temperature range are assured by design, characterization and correlation with statistical process controls. LT1765/LT1765-1.8/LT1765-2.5/ CONDITIONS LT1765 (Adj) LT1765 LT1765-1.8 LT1765-3 ...

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... LT1765/LT1765-1.8/LT1765-2.5/ LT1765-3.3/LT1765 TYPICAL PERFOR A CE CHARACTERISTICS FB vs Temperature (Adj) 1.220 1.215 1.210 1.205 1.200 1.195 1.190 1.185 1.180 0 50 –50 – 100 TEMPERATURE ( C) 1765 G01 SHDN Threshold vs Temperature 1.40 1.38 1.36 1.34 1.32 1.30 –50 – TEMPERATURE ( C) 4 Switch On Voltage Drop 350 ...

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... Minimum Input Voltage for 2.5V Out 3.5 3.3 3.1 2.9 2.7 2.5 0.001 0.01 0.1 1 LOAD CURRENT (A) 1765 G07 Current Limit Foldback 4 3 SWITCH CURRENT CURRENT 0 0 0.2 0.4 0.6 0.8 FEEDBACK VOLTAGE (V) LT1765/LT1765-1.8/LT1765-2.5/ SHDN Supply Current 300 V = 15V IN 250 200 150 100 0.2 0.4 0.6 0.8 1 1.2 SHUTDOWN VOLTAGE (V) 1765 G08 1.2 1765 G10 ...

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... LT1765/LT1765-1.8/LT1765-2.5/ LT1765-3.3/LT1765 CTIO S FB: The feedback pin is used to set output voltage using an external voltage divider (adjustable version) that gen- erates 1.2V at the pin when connected to the desired output voltage. The fixed voltage 1.8V, 2.5V, 3.3V and 5V versions have the divider network included internally and the FB pin is connected directly to the output ...

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... INTERNAL SHDN LT1765/LT1765-1.8/LT1765-2.5/ phase shift up to the resonant frequency of the inductor and output capacitor, then an abrupt 180 shift will occur. The current fed system will have 90 phase shift at a much lower frequency, but will not have the additional 90 shift until well beyond the LC resonant frequency ...

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... LT1765/LT1765-1.8/LT1765-2.5/ LT1765-3.3/LT1765 APPLICATIO S I FOR ATIO FB RESISTOR NETWORK If an output voltage of 1.8V, 2.5V, 3. required, the respective fixed option part, -1.8, -2.5, -3.3 or -5, should be used. The FB pin is tied directly to the output; the necessary resistive divider is already included on the part. For other voltage outputs, the adjustable part should be used and an external resistor divider added ...

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... The following formula gives maximum output current for continuous mode operation, implying that the peak to peak ripple (2x the term on the right) is less than the maximum switch current. LT1765/LT1765-1.8/LT1765-2. OUT MAX Continuous Mode Ripple Current (A) 0 ...

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... LT1765/LT1765-1.8/LT1765-2.5/ LT1765-3.3/LT1765 APPLICATIO S I FOR ATIO Table 3 VALUE I RMS PART NUMBER ( H) (Amps) Coiltcraft DO1608C-222 2.2 2.4 Sumida CDRH3D16-1R5 1.5 1.6 CDRH4D18-1R0 1.0 1.7 CDC5D23-2R2 2.2 2.2 CR43-1R4 1.4 2.5 CDRH5D28-2R6 2.6 2.6 Toko (D62F)847FY-2R4M 2.4 2.5 (D73LF)817FY-2R2M 2.2 2.7 CATCH DIODE The diode D1 conducts current only during switch off time. Peak reverse voltage is equal to regulator input voltage. ...

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... The SYNC pin is used to synchronize the internal oscillator to an external signal. The SYNC input must pass from a logic level low, through the maximum synchronization threshold with a duty cycle between 20% and 80%. The LT1765/LT1765-1.8/LT1765-2. input can be driven directly from a logic level output. The synchronizing range is equal to initial operating frequency up to 2MHz ...

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... LT1765/LT1765-1.8/LT1765-2.5/ LT1765-3.3/LT1765 APPLICATIO S I FOR ATIO INPUT 15V C2 C3 0.18 F 4.7 F CERAMIC BOOST LT1765-33 OFF ON SHDN FB SYNC GND 2.2nF Figure 6. Typical Application and Layout (Topside Only Shown) maximum rating. A ground plane should always be used under the switcher circuitry to prevent interplane coupling and overall noise ...

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... TOT B DIODE (0. (0. LT1765/LT1765-1.8/LT1765-2. 2A: DIE TEMPERATURE MEASUREMENT OUT If a true die temperature is required, a measurement of the SYNC to GND pin resistance can be used. The SYNC pin • resistance across temperature must first be calibrated, with no significant output load oven ...

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... LT1765/LT1765-1.8/LT1765-2.5/ LT1765-3.3/LT1765 APPLICATIO S I FOR ATIO Figure 8 shows the overall loop response with a 330pF V capacitor and a typical 100 F tantalum output capacitor. The response is set by the following terms: Error amplifier: DC gain set by g and R = 850 • 500k = 425 Pole set by C and • ...

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... The ramp is linear and rise times in the order of 100ms are possible. Since the circuit is voltage controlled, the ramp rate is unaffected by load characteristics and maximum output current is unchanged. Variants of this circuit can be used for sequencing multiple regulator outputs. LT1765/LT1765-1.8/LT1765-2. 0.18 F MBRS330T3* ...

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... LT1765/LT1765-1.8/LT1765-2.5/ LT1765-3.3/LT1765 APPLICATIO S I FOR ATIO INPUT 12V GND * SINGLE CORE WITH TWO WINDINGS COILTRONICS CTX5-1A † IF LOAD CAN GO TO ZERO, AN OPTIONAL PRELOAD MAY BE USED TO IMPROVE LOAD REGULATION D1, D3: B220A CMDSH-3 C2 0.18 F BOOST ...

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... U U APPLICATIO S I FOR ATIO INPUT 5V Figure 12. Positive-to-Negative Low Output Ripple Converter OUTPUT – LT1765/LT1765-1.8/LT1765-2. CMDSH-3 C2 0.22 F BOOST SYNC LT1765-5 FB SHDN D1 GND V C B220A C3 2 16V X5R 1800pF C F CERAMIC R 100pF C 2.4k L1: CDRH6D28-3R0 C2 0.22 F BOOST ...

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... LT1765/LT1765-1.8/LT1765-2.5/ LT1765-3.3/LT1765-5 PACKAGE DESCRIPTIO 6.60 0.10 4.50 0.10 0.65 BSC RECOMMENDED SOLDER PAD 4.30 – 4.48* (.169 – .176) 0.50 – 0.70 0.105 – 0.180 (.020 – .028) (.0041 – .0071) NOTE: 1. CONTROLLING DIMENSION: MILLIMETERS MILLIMETERS 2. DIMENSIONS ARE IN (INCHES) 3. DRAWING NOT TO SCALE * DIMENSIONS DO NOT INCLUDE MOLD FLASH. MOLD FLASH SHALL NOT EXCEED 0.150mm (.006" ...

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... Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen- tation that the interconnection of its circuits as described herein will not infringe on existing patent rights. LT1765/LT1765-1.8/LT1765-2. Package 8-Lead Plastic Small Outline (Narrow .150 Inch) (Reference LTC DWG # 05-08-1610) 0.189 – ...

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... LT1765/LT1765-1.8/LT1765-2.5/ LT1765-3.3/LT1765-5 RELATED PARTS PART NUMBER DESCRIPTION LT1370 High Efficiency DC/DC Converter LT1371 High Efficiency DC/DC Converter LT1372/LT1377 500kHz and 1MHz High Efficiency 1.5A Switching Regulators LT1374 High Efficiency Step-Down Switching Regulator LT1375/LT1376 1.5A Step-Down Switching Regulators LT1507 1.5A Step-Down Switching Regulator LT1576 1.5A Step-Down Switching Regulator LT1578 1 ...