LTC3717 Linear, LTC3717 Datasheet
LTC3717
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LTC3717 Summary of contents
Page 1
... B320A 2 V OUT 1.25V 10A OUT 0.68 H 180 Si7840DP B320A VCC 3717 F01a LTC3717 Wide Operating Range, TM Step-Down Controller U ® 3717 is a synchronous step-down switching TM TM (QDR ) memory termination. The controller . IN Efficiency vs Load Current 100 V OUT ...
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... REF 0V 50mV RNG FB REF INTV , RNG CC FB REF/2 RUN/SS Pin Rising RUN/SS Pin Falling U W ORDER PART NUMBER TOP VIEW 1 16 BOOST LTC3717EGN PGND INTV CC GN PART MARKING 8 9 EXTV ...
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... FB REF I = 5mA PGOOD Note 3: The LTC3717 is tested in a feedback loop that adjusts V a specified error amplifier output voltage (I and power Note 4: The LTC3717E is guaranteed to meet performance specifications from Specifications over the – operating temperature range are assured by design, characterization and correlation with statistical process controls ...
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... LTC3717 W U TYPICAL PERFOR A CE CHARACTERISTICS Efficiency vs Load Current 100 1.25V OUT FIGURE 1 CIRCUIT 0 0.01 0 100 LOAD CURRENT (A) 3717 G06 Load Regulation 2. 1.25V OUT –0.1 –0.2 –0.3 –0.4 –0.5 FIGURE 1 CIRCUIT –0 ...
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... V (V) RNG = 1V RNG 1.50 1.40 1.30 1.20 1.10 1.00 0.90 0.80 0. 110 130 70 3717 G20 LTC3717 RUN/SS Latchoff Thresholds vs Temperature 5.0 4.5 LATCHOFF ENABLE 4.0 3.5 LATCHOFF THRESHOLD 3.0 125 –50 – TEMPERATURE ( C) 3717 G15 Maximum Current Sense Threshold vs RUN/SS Voltage, V RNG 160 140 120 100 ...
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... LTC3717 CTIO S RUN/SS (Pin 1): Run Control and Soft-Start Input. A capacitor to ground at this pin sets the ramp time to full output current (approximately 3s/ F) and the time delay for overcurrent latchoff (see Applications Information). Forcing this pin below 0.8V shuts down the device. ...
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... W 9 EXTV CC 4.7V + – INTV CC FCNT ON SWITCH I REV LOGIC SHDN OV Q5 RUN SS SHDN – + 0.6V C RUN/ REF C 4 LTC3717 1.192V BNGP 5V REG BOOST INTV OUT BG VCC M2 12 PGND 13 ...
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... Figure 1. External component selection is primarily deter- mined by the maximum load current and begins with the selection of the sense resistance and power MOSFET switches. The LTC3717 uses the on-resistance of the syn- chronous power MOSFET for determining the inductor current. The desired amount of ripple current and operating frequency largely determines the inductor value ...
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... U U APPLICATIO S I FOR ATIO the LTC3717 and external component values and a good guide for selecting the sense resistance is: V RNG R SENSE 10 • I OUT MAX ( ) An external resistive divider from INTV the voltage of the V pin between 0.5V and 2V resulting RNG in nominal sense voltages of 50mV to 200mV. Additionally, ...
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... LTC3717 U U APPLICATIO S I FOR ATIO on-time t of the top MOSFET switch. The on-time is set ON by the current into the I pin according to ION Tying a resistor R from V to the time inversely proportional For a step-down con- ...
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... Fault Condition: Current Limit The maximum inductor current is inherently limited in a current mode controller by the maximum sense voltage. In the LTC3717, the maximum sense voltage is controlled by the voltage on the V the maximum sense voltage and the sense resistance determine the maximum allowed inductor valley current. ...
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... LTC3717 U U APPLICATIO S I FOR ATIO time that the LTC3717 is capable of turning on the bottom MOSFET, tripping the current comparator and turning the MOSFET back off. This time is generally about 300ns. The minimum off-time limit imposes a maximum duty cycle the maximum duty cycle is reached, ...
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... U U APPLICATIO S I FOR ATIO When the voltage on RUN/SS reaches 1.5V, the LTC3717 begins operating with a clamp on I 0.9V. As the RUN/SS voltage rises to 3V, the clamp raised until its full 2.4V range is available. This takes an additional 1.3s/ F. The pin can be driven from logic as shown in Figure 5. Diode D1 reduces the start delay while ...
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... LTC3717 U U APPLICATIO S I FOR ATIO efficiency source, such as an output derived boost net- work or alternate supply if available loss. The input capacitor has the difficult job of IN filtering the large RMS input current to the regulator. It must have a very low ESR to minimize the AC I sufficient capacitance to prevent the RMS current from causing additional upstream losses in fuses or batteries ...
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... Place C compact area. It may help to have some components on the bottom side of the board. • Place LTC3717 chip with pins facing the power components. Keep the components connected to pins close to LTC3717 (noise sensitive components). • Use an immediate via to connect the components to ground plane including SGND and PGND of LTC3717 ...
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... SW RNG 13 PGND VCC 11 INTV EXTV REF CC Figure 7. LTC3717 Layout Diagram close to the power IN decoupling capacitor C CC and PGND pins. CC closely to the B pin decoupling capacitor C CC and PGND pins – – ...
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... PGOOD RNG 13 I PGND TH 12 SGND BG C VCC 4 INTV EXTV REF CC LTC3717 28V B320A M1 35V IRF7811W 3 V OUT 1.5V L1 10A 1 OUT 270 IRF7822 B320A 2 3717 TA01 sn3717 3717fs 17 ...
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... R ON 510k 2200pF C : TAIYO YUDEN TMK432BJ106MM SANYO, OS-CON 16SP270 OUT1 C : TAIYO YUDEN JMK316BJ106ML OUT2 L1: TOKO 919AS-1R8N 18 High Voltage Half (V ) Power Supply CMDSH-3 LTC3717 16 RUN/SS BOOST PGOOD RNG 13 I PGND TH 12 SGND BG C VCC 4 ...
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... TYP .015 .004 45 .053 – .068 (0.38 0.10) (1.351 – 1.727) 0 – 8 TYP .008 – .012 (0.203 – 0.305) LTC3717 .189 – .196* (4.801 – 4.978) .009 (0.229 REF .150 – .157** (3.810 – 3.988) ...
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... LTC3413 Monolithic DDR Memory Termination Regulator Burst Mode is a registered trademark of Linear Technology Corporation. Linear Technology Corporation 20 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 FAX: (408) 434-0507 Typical Application 1.25V 1.4MHz D B CMDSH-3 LTC3717 16 1 RUN/SS BOOST PGOOD ...