LT1376CS Linear Technology, LT1376CS Datasheet

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... For low input voltage applications with 3.3V output, see LT1507. This is a functionally identical part that can operate with input voltages between 4.5V and 12V. , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. D2 ...

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... LT1376IS8-5 1376I5 LT1376HVIS8 376HVI TOP VIEW 1 16 GND GND BOOST FB/SENSE GND SW 11 BIAS 6 SHDN GND 8 GND S PACKAGE 16-LEAD PLASTIC NARROW SO θ = 50°C/ W WITH FUSED CORNER PINS JA CONNECTED TO GROUND PLANE OR LARGE LANDS ORDER PART NUMBER LT1376CS LT1376IS LT1376HVCS LT1376HVIS 13756fd ...

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ELECTRICAL CHARACTERISTICS temperature range, otherwise specifications are at T unless otherwise noted. PARAMETER Reference Voltage (Adjustable) Sense Voltage (Fixed 5V) Sense Pin Resistance Reference Voltage Line Regulation Feedback Input Bias Current Error Amplifier Voltage Gain Error Amplifier Transconductance V Pin ...

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LT1375/LT1376 ELECTRICAL CHARACTERISTICS temperature range, otherwise specifications are at T unless otherwise noted. PARAMETER Shutdown Thresholds Minimum Synchronizing Amplitude (LT1375 Only) Synchronizing Range (LT1375 Only) SYNC Pin Input Resistance Note 1: Stresses beyond those listed under Absolute Maximum Ratings may ...

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W U TYPICAL PERFORMANCE CHARACTERISTICS Shutdown Pin Bias Current 500 CURRENT REQUIRED TO FORCE SHUTDOWN (FLOWS OUT OF PIN). AFTER SHUTDOWN, 400 CURRENT DROPS TO A FEW µA 300 200 8 AT 2.38V STANDBY THRESHOLD (CURRENT FLOWS OUT OF PIN) ...

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LT1375/LT1376 W U TYPICAL PERFORMANCE CHARACTERISTICS Maximum Load Current 10V OUT 1. 10V OUT L = 20µH 1. 10µH 1.00 0. 5µH 0.50 0. ...

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PIN FUNCTIONS V : This is the collector of the on-chip power NPN switch. IN This pin powers the internal circuitry and internal regulator when the BIAS pin is not present. At NPN switch on and off, ...

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LT1375/LT1376 W BLOCK DIAGRAM connected to an external voltage higher than 3V, bias power will be drawn from the external source (typically the regulated output voltage). This will improve efficiency if the BIAS pin voltage is lower than regulator input ...

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U U APPLICATIONS INFORMATION LT1375/LT1376 AMPLIFIER Q2 V GND C Please read the following if divider resistors are increased above the suggested values − OUT = Table ...

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LT1375/LT1376 U U APPLICATIONS INFORMATION pin when output voltage is low. The equivalent circuitry is shown in Figure completely off during normal operation. If the FB pin falls below 1V, Q1 begins to conduct current and reduces ...

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U U APPLICATIONS INFORMATION Example: with L = 2µ 5V, and V OUT ( ) 2 ⎛ ⎞ ⎛ 500 10 • • ⎝ ⎠ ⎝ ...

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... INFORMATION 5. After making an initial choice, consider the secondary things like output voltage ripple, second sourcing, etc. Use the experts in the Linear Technology’s applica- tions department if you feel uncertain about the final choice. They have experience with a wide range of inductor types and can tell you about the latest devel- opments in low profile, surface mounting, etc ...

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U U APPLICATIONS INFORMATION discharge surges, such as when the regulator output is dead shorted, do not harm the capacitors. Unlike the input capacitor, RMS ripple current in the output capacitor is normally low enough that ripple cur- rent rating ...

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LT1375/LT1376 U U APPLICATIONS INFORMATION regulator input voltage. Average forward current in normal operation can be calculated from − OUT IN OUT ( ) = I D AVG V IN This formula will not yield ...

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U U APPLICATIONS INFORMATION IN INPUT R HI SHDN latch low under low source voltage conditions. UVLO prevents the regulator from operating at source voltages where these problems might occur. Threshold voltage for lockout is about ...

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LT1375/LT1376 U U APPLICATIONS INFORMATION (magnetic) radiation is minimized by keeping catch diode, switch pin, and input bypass capacitor leads as short as possible. E field radiation is kept low by minimizing the length and area of all traces connected ...

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U U APPLICATIONS INFORMATION PARASITIC RESONANCE Resonance or “ringing” may sometimes be seen on the switch node (see Figure 7). Very high frequency ringing following switch rise time is caused by switch/diode/input capacitor lead inductance and diode capacitance. Schot- tky ...

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LT1375/LT1376 U U APPLICATIONS INFORMATION practice therefore to simply use the worst-case value and assume that RMS ripple current is one half of load current. At maximum output current of 1.5A for the LT1376, the input bypass capacitor should be ...

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U U APPLICATIONS INFORMATION 8.0 7.5 (A) (B) 7.0 (C) 6.5 6.0 (D) 5.5 5.0 0.001 0.01 0.1 LOAD CURRENT (A) Figure 9. Minimum Input Voltage C2 0.1µF BOOST INPUT LT1376-5 2N3905 + SENSE V ...

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LT1375/LT1376 U U APPLICATIONS INFORMATION introduce multiple poles into the feedback loop. The inductor and output capacitor on a conventional step- down converter actually form a resonant tank circuit that can exhibit peaking and a rapid 180° phase shift at ...

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U U APPLICATIONS INFORMATION 77dB at low frequency, rolling off to unity-gain at 20kHz. Phase shows a two-pole characteristic until the ESR of the output capacitor brings it back above 10kHz. Phase mar- gin is about 60° at unity-gain. Analog ...

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LT1375/LT1376 U U APPLICATIONS INFORMATION How Do I Test Loop Stability? The “standard” compensation for LT1376 is a 3.3nF capacitor for C , with While this compensation will C C work for most applications, the “optimum” value ...

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U U APPLICATIONS INFORMATION Keep in mind that this procedure does not take initial component tolerance into account. You should see fairly clean response under all load and line conditions to ensure that component variations will not cause problems. One ...

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LT1375/LT1376 U U APPLICATIONS INFORMATION POSITIVE-TO-NEGATIVE CONVERTER The circuit in Figure classic positive-to-negative topology using a grounded inductor. It differs from the standard approach in the way the IC chip derives its feedback signal, however, because the ...

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U U APPLICATIONS INFORMATION INDUCTOR VALUE Unlike buck converters, positive-to-negative converters cannot use large inductor values to reduce output ripple voltage. At 500kHz, values larger than 25µH make almost no change in output ripple. The graph in Figure 19 shows ...

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LT1375/LT1376 U U APPLICATIONS INFORMATION surface mount solid tantalum capacitor, but the final capacitor chosen must be looked at carefully for ESR characteristics. Ripple Current in the Input and Output Capacitors Positive-to-negative converters have high ripple current in both the ...

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... MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .006" (0.15mm) 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. ...

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... High Efficiency Monolithic Step-Down Regulator LTC1878 High Efficiency Monolithic Step-Down Regulator LTC3404 1.4MHz High Efficiency, Monolithic Synchronous Step-Down Regulator Burst Mode is a registered trademark of Linear Technology Corporation. Linear Technology Corporation 28 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 FAX: (408) 434-0507 ● ...