ltm4612 Linear Technology Corporation, ltm4612 Datasheet
ltm4612
Available stocks
Related parts for ltm4612
ltm4612 Summary of contents
Page 1
... DC/DC power supply. Included in the package are the switching controller, power FETs, inductor and all support components. Operating over an input voltage range 36V, the LTM4612 supports an output voltage range of 3.3V to 15V, set by a single resistor. Only bulk input and output capacitors are needed to fi ...
Page 2
... LTM4612IV#PBF LTM4612IV#PBF LTM4612MPV#PBF LTM4612MPV#PBF Consult LTC Marketing for parts specifi ed with wider operating temperature ranges. *The temperature grade is identifi label on the shipping container. For more information on lead free part marking, go to: This product is only offered in trays. For more information go to: ELECTRICAL CHARACTERISTICS operating temperature range, otherwise specifi ...
Page 3
... Ceramic, 150μF Bulk C OUT V = 24V 12V IN OUT = 24V 200μF OUT V = 36V 12V IN OUT V = 24V 12V IN OUT 12V OUT OUT SS/TRACK FCB (Note 3) (Note 3) LTM4612 MIN TYP MAX UNITS 4 3 μA 1.85 A 2.72 A 4 0.05 0 0.3 0 0.3 ...
Page 4
... Specifi cations over the –40°C to 125°C internal operating temperature range are assured by design, characterization and correlation with statistical process controls. The LTM4612I is guaranteed to meet specifi cations over the 4 l The denotes the specifi ...
Page 5
... IN OUT OUT I IN 0.2A/DIV V OUT 5V/DIV 500μs/DIV SOFT-START CAPACITOR: 3.9nF 10μF CERAMIC CAPACITORS AND IN 1 47μF OSCON CAPACITOR LTM4612 (Refer to Figure 18) Effi ciency vs Load Current with 12V (FCB = 0) OUT 100 OUT 5V ...
Page 6
... LTM4612 TYPICAL PERFORMANCE CHARACTERISTICS Start-Up with 24V to 12V at IN OUT –55°C OUT A V OUT 5V/DIV I IN 1A/DIV 500μs/DIV 4612 G10 SOFT-START CAPACITOR: 3.9nF 10μF CERAMIC CAPACITORS AND IN 1 47μF OSCON CAPACITOR Step-Down Ratio IN OUT 36 SEE FREQUENCY ADJUSTMENT SECTION ...
Page 7
... Power Output Pins. Apply output load OUT between these pins and PGND pins. Recommend placing output decoupling capacitance directly between these pins and GND pins (see the LTM4612 Pin Confi guration below). V (Pins B7, C7): Top FET Drain Pins. Add more capa- ...
Page 8
... LTM4612 PIN FUNCTIONS COMP (Pins A11, D11): Current Control Threshold and Error Amplifi er Compensation Point. The current com- parator threshold increases with this control voltage. The voltage ranges from 0V to 2.4V with 0.7V corresponding to zero sense voltage (zero current). PGOOD (Pin G12): Output Voltage Power Good Indicator. ...
Page 9
... Schottky diodes. The typical switching frequency is 850kHz at full load. With current mode control and internal feedback loop compensation, the LTM4612 module has suffi cient stability margins and good transient performance under a wide range of operat- ing conditions and with a wide range of output capacitors, even all ceramic output capacitors ...
Page 10
... Operating Frequency to V Step-Down OUT The operating frequency of the LTM4612 is optimized to achieve the compact package size and the minimum output ripple voltage while still keeping high effi ciency. As shown in Figure 2, the frequency is linearly increased with larger output voltages to keep the low output cur- rent ripple. Figure 3 shows the inductor current ripple Δ ...
Page 11
... The load current can affect the frequency due to its constant on-time control. If constant frequency is a necessity, the PLLIN pin can be used to synchronize the frequency of the LTM4612 to an external clock, as shown in Figures 21 to 23. Input Capacitors LTM4612 is designed to achieve the low input conducted EMI noise due to the fast switching of turn-on and turn-off ...
Page 12
... LTM4612 APPLICATIONS INFORMATION Output Capacitors The LTM4612 is designed for low output voltage ripple. The bulk output capacitors defi ned as C with low enough effective series resistance (ESR) to meet the output voltage ripple and transient requirements. C can be low ESR tantalum capacitor, low ESR polymer capacitor or ceramic capacitor. The typical capacitance is 150μ ...
Page 13
... To further limit current in the event of an overload condi- tion, the LTM4612 provides foldback current limiting. If the output voltage falls by more than 50%, then the maximum output current is progressively lowered to about one sixth of its full current limit value ...
Page 14
... An optimized gate driver for the MOSFET and a noise cancellation network are installed inside the LTM4612 to achieve the low radiated EMI noise. Figure 8 shows a typical example for the LTM4612 to meet the Class B of CISPR 22 radiated emission limit ...
Page 15
... LFM 4.0 0LFM 400LFM 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0 105 AMBIENT TEMPERATURE (°C) Figure 13. No Heat Sink with 24V to 12V IN OUT LTM4612 . Table 3 provides the ap- JA for Figures 11 to 16. A complete explanation JA 5.0 200 4.5 LFM 4.0 0LFM 400LFM 3.5 3.0 2.5 2.0 1.5 1.0 0 AMBIENT TEMPERATURE (°C) 4612 F10 Figure 11 ...
Page 16
... LTM4612 APPLICATIONS INFORMATION 5.0 4.5 4.0 0LFM 200LFM 3.5 3.0 2.5 2.0 1.5 1.0 0 AMBIENT TEMPERATURE (°C) Figure 15. No Heat Sink with 36V IN Table 2. Output Voltage Response Versus Component Matrix (Refer to Figure 20) TYPICAL MEASURED VALUES VENDORS PART NUMBER Murata GRM32ER61C476KEI5L (47μF , 16V) Murata GRM32ER61C226KE20L (22μF , 16V OUT ...
Page 17
... Figures 10, 13 Heat Sink Manufacturer Wakefi eld Engineering Safety Considerations The LTM4612 modules do not provide isolation from There is no internal fuse. If required, a slow blow OUT fuse with a rating twice the maximum input current needs to be provided to protect each unit from catastrophic failure ...
Page 18
... Design IN V OUT CLOCK SYNC C1 10μF 50V PLLIN 100k 100k PGOOD OUT RUN ON/OFF V COMP FB LTM4612 INTV CC FCB DRV CC f MARG0 MARGIN SET CONTROL TRACK/SS MARG1 R fSET 191k MPGM 1% SGND PGND R1 C4 392k 0.01μF 5% MARGIN , 3 ...
Page 19
... PGOOD LTM4612 RUN COMP C8 INTV CC 10μF 50V DRV CC f SET TRACK/SS SGND Figure 21. 2-Phase, Parallel 12V at 10A Design LTM4612 V OUT 15V OUT1 OUT2 22pF 22μF 220μF R 16V 16V FB 4.12k 4612 F20 CLOCK SYNC 0° PHASE ...
Page 20
... MPGM 50V C7 SGND PGND 0.15μF 5% MARGIN 10V C11 10μF R7 50V R3 100k V V PLLIN D IN 100k V PGOOD OUT LTM4612 RUN COMP FCB INTV CC 12V TRACK MARG0 DRV 100k MARG1 f 10μF SET 50V TRACK/SS MPGM R9 SGND PGND 6.24k Figure 22. 2-Phase, 12V and 10V at 5A Design CLOCK SYNC 0° ...
Page 21
... FCB INTV CC 5V TRACK MARG0 DRV 100k MARG1 f 10μF SET MPGM 50V TRACK/ SGND PGND fSET2 22.1k 100k LTM4612 CLOCK SYNC 0° PHASE OUT C6 + 22pF 22μF 220μF 6.3V 6.3V MARGIN CONTROL R1 R FB1 392k 13.7k CLOCK SYNC 180° PHASE 3 ...
Page 22
... LTM4612 PACKAGE DESCRIPTION PIN NAME Pin Assignment Tables (Arranged by Pin Function) PIN NAME PIN NAME ...
Page 23
... However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa- tion that the interconnection of its circuits as described herein will not infringe on existing patent rights bbb 6.9850 5.7150 4.4450 3.1750 1.9050 0.6350 0.0000 0.6350 1.9050 3.1750 4.4450 5.7150 6.9850 LTM4612 4612f 23 ...
Page 24
... Pin Compatible with the LTM4600, LGA Package Synchronizable, PolyPhase Operation, LTM4603-1 Version Has No Remote Sensing, Pin Compatible with the LTM4601, LGA Package 2.375V ≤ V ≤ 5.5V, 0.8V ≤ Ultralow Noise, with PLL, Output Tracking and Margining, LTM4612 Pin Compatible 2.4V ≤ V ≤ 5.5V; 0.6V ≤ ≤ V ≤ ...