LTC1698ES Linear Technology, LTC1698ES Datasheet
LTC1698ES
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LTC1698ES Summary of contents
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... MARGIN pin provides 5% output voltage adjustment. A power good flag and overvoltage input are provided to ensure proper power supply conditions. An auxiliary 3.3V logic supply is included that supplies up to 10mA of output current. , LTC and LT are registered trademarks of Linear Technology Corporation OUT ...
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... FB ISNSGND ISNS I = –10mA OPTODRV OVPIN 0V 1.233V ISNSGND ISNS INFORMATION ORDER PART TOP VIEW NUMBER SYNC LTC1698EGN AUX LTC1698ES COMP LTC1698IGN SNS LTC1698IS SNSGND GN PART MARKING 7 10 PWRGD 8 9 OVPIN 1698 S PACKAGE 1698I 16-LEAD PLASTIC SO = 125 C, = 130 C/W (GN 125 C, = 110 C/W (SO) ...
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ELECTRICAL CHARACTERISTICS temperature range, otherwise specifications are at T SYMBOL PARAMETER V AUX V Auxiliary Supply Voltage AUX Current Limit Amplifier I I Input Current ISNSGND SNSGND I I Input Current ISNS SNS V Current Limit Threshold ILIMTH (V – ...
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LTC1698 W U TYPICAL PERFOR A CE CHARACTERISTICS V vs Temperature FB 1.248 1.242 1.236 1.230 1.224 1.218 50 –50 – 100 125 150 TEMPERATURE ( C) 1698 G01 I Threshold vs Temperature ...
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W U TYPICAL PERFOR A CE CHARACTERISTICS V vs Temperature AUX 3.465 0mA LOAD 3.424 3.383 3.341 3.300 3.259 3.218 3.176 3.135 50 75 –50 – 100 125 150 TEMPERATURE ( C) ...
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LTC1698 W U TYPICAL PERFOR A CE CHARACTERISTICS I vs SYNC Frequency VDD 4700pF 3300pF ...
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CTIO S V (Pin 1): Power Supply Input. For isolated applica- DD tions, a simple rectifier from the power transformer is used to power the chip. This pin powers the opto driver, the V supply ...
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LTC1698 W BLOCK DIAGRA V AUX 14 SYNC 15 MARGIN 7 OPTODRV 5 PWRGD OPERATIO (Refer to Block Diagram) The LTC1698 is a secondary-side synchronous rectifier controller designed to work with the LT3781 primary-side synchronous controller chip ...
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U OPERATIO (Refer to Block Diagram) catch MOSFETs Q3 and Q4 are off. As soon as transistors Q1 and Q2 turn on, the flux in the power transformer T1 forces the body diodes of Q3 and Q4 to conduct, and ...
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LTC1698 U U APPLICATIO S I FOR ATIO Undervoltage Lockout In UVLO (low V voltage) the drivers FG and CG are shut DD off and the pins OPTODRV PWRGD and I AUX forced low. The LTC1698 allows the ...
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U U APPLICATIO S I FOR ATIO drivers TG and BG go high. The pulse transformer T2 generates a negative slew at the SYNC pin and forces the secondary MOSFET driver high and low. ...
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LTC1698 U U APPLICATIO S I FOR ATIO MARGIN Adjustment The MARGIN input is used for adjusting the programmed output voltage linearly by varying the current flowing into and out of the pin. Forcing 100 A into the pin moves ...
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U U APPLICATIO S I FOR ATIO supply must cross the isolation boundary. Coupling this signal requires an element that will withstand the isolation potentials and still transfer the loop error signal. Optocouplers are widely used for this function due ...
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LTC1698 U U APPLICATIO S I FOR ATIO A series RC network can be added in parallel with R2 (Figure 7) to provide a zero for the feedback loop fre- quency compensation. The opto driver will drive a capacitive load ...
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U U APPLICATIO S I FOR ATIO If the application generates a bigger current sense voltage, a potential divider can be easily obtained by adding a resistor across C2. With this additional resistor, the volt- age sensed by the current ...
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LTC1698 U U APPLICATIO S I FOR ATIO Power Transformer Selection The forward transformer provides DC isolation and deliv- ers energy from the primary to the secondary. Unlike the flyback topology, the transformer in the forward converter is not an ...
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U U APPLICATIO S I FOR ATIO Once the value of the inductor has been determined, an inductor with sufficient DC current rating is selected. Core saturation must be avoided under all operating conditions. Under start-up conditions, the converter sees ...
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LTC1698 U U APPLICATIO S I FOR ATIO MOC207 BOLD LINES INDICATE HIGH CURRENT PATHS V IN 36V TO 72V • • • • LT3781 V REF + – ISOLATION ...
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U TYPICAL APPLICATIO S • • • • LTC1698 1698f 19 ...
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LTC1698 U TYPICAL APPLICATIO S • • • • 20 1698f ...
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U TYPICAL APPLICATIO S • • • • LTC1698 1698f 21 ...
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LTC1698 PACKAGE DESCRIPTIO .254 MIN .0165 .0015 RECOMMENDED SOLDER PAD LAYOUT .007 – .0098 (0.178 – 0.249) .016 – .050 (0.406 – 1.270) NOTE: 1. CONTROLLING DIMENSION: INCHES INCHES 2. DIMENSIONS ARE IN (MILLIMETERS) 3. DRAWING NOT TO SCALE *DIMENSION ...
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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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... N-Channel MOSFET Synchronous Drivers Operation up to 72V Maximum www.linear.com Efficiency vs Load Current V = 36V 48V 72V LOAD CURRENT (A) 1698 TA01 Efficiency vs Load Current V = 36V 48V 72V (XX) OUT 1698 TA02 Resistor SENSE LT/TP 0203 2K • PRINTED IN THE USA LINEAR TECHNOLOGY CORPORATION 2000 1698f ...