LTC3714 Linear, LTC3714 Datasheet
LTC3714
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LTC3714 Summary of contents
Page 1
... Transient Response 23A Output Load Step 24V 10 F 35V OUT 0.6V TO 1.75V C + 23A OUT 270 D1* UPS840 3714 F01 LTC3714 Intel Compatible, with Internal Op Amp U 3714 is a synchronous step-down switching and OUT 20 s/DIV 1.395V V OUT (1.35V) 50mV/DIV 1.213V 23A I LOAD 10A/DIV 8A ...
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... RMS Currents .............. 50mA – ....................................................... OPV , Operating Ambient Temperature Range LTC3714EG (Note 2) .......................... – Junction Temperature (Note 3) ............................ 125 C Storage Temperature Range ................. – 150 C Lead Temperature (Soldering, 10 sec).................. 300 C ELECTRICAL CHARACTERISTICS temperature range, otherwise specifications are T SYMBOL PARAMETER Main Control Loop I ...
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... VID0 VID4 Open VID0 VID4 5V VID0 VID4 RUN/ Programmed from OSENSE 0.6V to 1.75V (Note – 1V 18V CM LTC3714 MIN TYP MAX UNITS 4 4.5 V 3.5 4.2 V – 0.5 –1.2 – 0.8 1 3.4 3 ...
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... SOURCE Short to GND Short to OPV IN Note 4: The LTC3714 is tested in a feedback loop that adjusts V achieve a specified error amplifier output voltage (I Note 5: The LTC3714 VID DAC is tested in a feedback loop that adjusts V to achieve a specified feedback voltage (V OSENSE VID code. and power ...
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... INPUT VOLTAGE (V) 3714 G04 I Voltage vs Load Current TH 2.5 FIGURE 1 CIRCUIT 2.0 1.5 CONTINUOUS MODE 1.0 DISCONTINUOUS 0.5 MODE LOAD CURRENT (A) 3714 G07 LTC3714 Start-Up RUN/SS 2V/DIV V OUT 500mV/DIV I L 5A/DIV 50ms/DIV V = 15V 1.25V OUT R = 0.125 LOAD Frequency vs Input Voltage 300 FCB = 0V FIGURE 1 CIRCUIT ...
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... LTC3714 W U TYPICAL PERFOR A CE CHARACTERISTICS On-Time vs I Current ON 10k VON 1k 100 100 I CURRENT ( A) ON 3714 G20 Maximum Current Sense Threshold vs V Voltage RNG 300 250 200 150 100 50 0 0.5 0.75 1.0 1.25 1.5 1.75 2.0 V VOLTAGE (V) RNG 3714 G10 Feedback Reference Voltage vs Temperature 0.62 0.61 0.60 0.59 0.58 –50 – ...
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... INTV LOAD CURRENT (mA 100 125 3714 G15 75 100 125 3714 G17 LTC3714 EXTV Switch Resistance CC vs Temperature –50 – TEMPERATURE ( C) 3714 G25 RUN/SS Pin Current vs Temperature 3 2 PULL-DOWN CURRENT ...
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... LTC3714 CTIO S BG (Pin 1): Bottom Gate Drive. Drives the gate of the bottom N-channel MOSFET between ground and INTV PGND (Pin 2): Power Ground. Connect this pin closely to the bottom of the sense resistor sense resistor is used, to the source of the bottom N-channel MOSFET, the (– ...
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... RUN SS SHDN – + – 0. RUN/ OPV AMP 18 OPOUT – – SGND 19 LTC3714 0.6V REF 5V REG BOOST SENSE 3 V INTV OUT VCC C OUT 1 M2 PGND ...
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... TH initiate another cycle. Continuous synchronous operation can be forced in the LTC3714 by bringing the FCB pin below 0.6V. The benefit of forced continuous operation is lower output voltage ripple, faster transient response to current load steps and a much quieter frequency spectrum so that it won’ ...
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... OFFSET 15 OPV OUT R – – – V OUT R Figure 2c LTC3714 Power CC . This capacitor is re- B through an external Schottky diode CC power from EXTV INTV . This allows power. Voltages for additional gate drive drops below 3.5V OPV ...
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... The maximum allowed sense voltage is about 1.33 times this nominal value. Connecting the SENSE Pin The LTC3714 can be used with or without a sense resistor. When using a sense resistor placed between the source of the bottom MOSFET M2 and ground. Connect the SENSE pin to the source of the bottom MOSFET so that the resistor appears between the SENSE and PGND pins ...
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... MOSFET switching losses but requires larger inductance and/or capacitance in order to maintain low output ripple voltage. The operating frequency of LTC3714 applications is deter- mined implicitly by the one-shot timer that controls the on-time t of the top MOSFET switch. The on-time is set ...
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... R VON1 OUT VON VON2 0.01 F 10k 10k LTC3714 INTV 2N5087 C C 3714 F04b (4b) Selection OUT is required to filter the square IN ...
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... FCB pin sets a minimum voltage SEC below which continuous operation is forced has risen above its minimum 1N4148 TG • LTC3714 EXTV SW CC • 1:N FCB SENSE R3 BG SGND PGND Connection nor- SEC V SEC ...
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... Minimum Off-Time and Dropout Operation The minimum off-time t time that the LTC3714 is capable of turning on the bottom MOSFET, tripping the current comparator and turning the MOSFET back off. This time is generally about 250ns. The minimum off-time limit imposes a maximum duty cycle of ...
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... Good bypassing is necessary to supply the high transient currents required by the MOSFET gate drivers. Applica- tions using large MOSFETs with a high input voltage and high frequency of operation may cause the LTC3714 to exceed its maximum junction temperature rating or RMS current rating. Most of the supply current drives the ...
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... CC boosted output supply is available. CC External Gate Drive Buffers until CC The LTC3714 drivers are adequate for driving up to about 60nC into MOSFET switches with RMS currents of 50mA The follow Applications with larger MOSFET switches or operating at ...
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... APPLICATIO S I FOR ATIO Soft-Start and Latchoff with the RUN/SS Pin The RUN/SS pin provides a means to shut down the LTC3714 as well as a timer for soft-start and overcurrent latchoff. Pulling the RUN/SS pin below 1.5V puts the LTC3714 into a low quiescent current shutdown ( ...
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... It is often useful to analyze individual losses to determine what is limiting the efficiency and which change would produce the most improvement. Although all dissipative elements in the circuit produce losses, four main sources account for most of the losses in LTC3714 circuits losses. These arise from the resistances of the MOSFETs, inductor and PC board traces and cause the efficiency to drop at high output currents ...
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... LTC3714 2 PGND VCC 4 INTV 0 EXTV VID4 18 OPOUT IN 17 – LTC3714 186 013 . . . 2 in the MOSFET – 013 . . 24V C IN ...
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... RNG INTV and GND, corresponding to a 50mV nominal sense CC voltage. Next, the gain of the LTC3714 error amplifier must be determined. The change in I change in the output current is The corresponding change in the output voltage is deter- mined by the gain of the error amplifier and feedback divider ...
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... FCB 0 EXTV 5V OSENSE CC 25 VID3 VID4 18 OPV OPOUT IN 17 – LTC3714 pin voltage when the error TH pin voltage must be set – SENSE OUT RNG 003 . 0 A – ...
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... BOOST 7 VID0 8 VID1 9 VID2 RUN/ PGOOD 13 V RNG Figure 10. LTC3714 Layout Diagram C VCC LTC3714 28 INTV EXTV VID4 24 VID3 23 V OSENSE ION ...
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... VID0-VID4 interface circuitry must return to SGND SENSE OUT OUT LTC3714 decoupling capacitor C CC and PGND pins. CC closely to the B pin decoupling capacitor C IN and PGND pins. TO PGND PGND (PIN 2) SENSE TO SENSE (PIN 3) PGND C C OUT OUT V OUT ...
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... LTC3714 U TYPICAL APPLICATIO Performance Data for Intel Compatible Mobile Microprocessor Power Supply with Active Voltage Positioning Line Transient Reponse from V 50 s/DIV 17V Load Transient Reponse for 5V/DIV V OUT 50mV/DIV AC COUPLED 3714 TA02 Efficiency 1.35V OUT 8.5V ...
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... DPSLP U G Package 28-Lead Plastic SSOP (5.3mm) (Reference LTC DWG # 05-08-1640) 1.73 – 1.99 (.068 – .078) .65 (.0256) BSC .05 – .21 .25 – .38 (.002 – .008) (.010 – .015) Crusoe is a trademark of Transmeta Corporation. LTC3714 3.3V 200k 200k IRF7811 35V OUT ...
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... V RON 200k 200k 9 8 VID2 VID1 0 200k 10 7 RUN/SS VID0 BOOST ON 0. PGOOD RNG CMDSH-3 3 SENSE 220pF LTC3714 20k PGND SGND BG 10nF 21 28 INTV 100pF FCB V IN 0.1 F 200k VID4 ...