LTC1142-ADJ Linear Technology, LTC1142-ADJ Datasheet
LTC1142-ADJ
Related parts for LTC1142-ADJ
LTC1142-ADJ Summary of contents
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... R MOSFET and resistance of the inductor and current sense resistor. The LTC1142 series is ideal for applications requiring dual output voltages with high conversion efficiencies over a wide load current range in a small amount of board space. , LTC and LT are registered trademarks of Linear Technology Corporation. ...
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... Lead Temperature (Soldering, 10 sec)................. 300 ORDER PART + NUMBER SENSE FB1 SHUTDOWN 1 3 LTC1142CG SGND1 4 LTC1142HVCG PGND1 5 NDRIVE LTC1142-ADJ NC 8 PDRIVE IN2 INT V 12 CC2 I 13 TH2 – SENSE PACKAGE, 28-LEAD SSOP T = 125 C, ...
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... V in Regulation OUT SENSE OUT OUT C = 390pF 700mA T LOAD C = 3000pF (Pins 6, 9, 20, 23 LTC1142HV-ADJ Only LTC1142HV-ADJ Only LTC1142, LTC1142HV I = 700mA LOAD 700mA LOAD 10 LTC1142 4V < < 12V < V < ...
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... Note 3: In applications where R and power A time increases approximately 40%. Note 4: The LTC1142/LTC1142HV-ADJ/LTC1142HV/LTC1142L-ADJ are not tested and quality-assurance sampled at – These specifications are guaranteed by design and/or correlation. Note 5: The LTC1142L-ADJ allows operation down HARA TERISTICS C 3.3V Output Efficiency 100 ...
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... SHUTDOWN 3 (Pin 2): When grounded, the 3.3V section operates normally. Pulling Pin 2 high holds both MOSFETs off and puts the 3.3V section in micropower shutdown mode. Requires CMOS logic-level signal with t Do not “float” Pin 2. LTC1142/LTC1142L/LTC1142HV CE C HARA TERISTICS C Supply Current in Shutdown ...
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... SENSE 3 (Pin 28): Connects to internal resistive divider which sets the output voltage for the 3.3V section. Pin 28 is also the (–) input for the current comparator on the 3.3V section. LTC1142HV-ADJ/LTC1142L-ADJ + SENSE 1 (Pin 1): The (+) Input to the Section 1 Current Comparator. A built-in offset between Pins 1 and 28 in conjunction with R for this section ...
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... SHUTDOWN 2 (Pin 17): When grounded, the section 2 regulator operates normally. Pulling Pin 17 high holds LTC1142/LTC1142L/LTC1142HV both MOSFETs off and puts section 2 in micropower shutdown mode. Requires CMOS logic signal with t t < not “float” Pin 17. ...
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... The output voltage is sensed by an internal voltage divider – connected to Sense , Pin 28 (14) (LTC1142) or external divider returned Pin 2 (16) (LTC1142-ADJ voltage comparator V and a gain block G compare the divided output voltage with a reference voltage of 1.25V. To optimize efficiency, the LTC1142 series automatically switches between two modes of operation, Burst Mode and continuous mode ...
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... MOSFETs and D1 are selected. Finally are selected and the loop is compensated. Since the OUT 3.3V and 5V sections in the LTC1142 are identical and similarly section 1 and section 2 in the LTC1142HV-ADJ/ LTC1142L-ADJ are identical, the process of component selection is the same for both sections. The circuit shown in Figure 1 can be configured for operation input voltage of 20V ...
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... MAXIMUM OUTPUT CURRENT (A) Figure 2. Selecting R L and C Selection for Operating Frequency T Each regulator section of the LTC1142 uses a constant off- time architecture with t determined by an external OFF timing capacitor C . Each time the P-channel MOSFET T switch turns on, the voltage reset to approximately T 3 ...
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... APPLICATIO S I FOR ATIO eased at the expense of efficiency. If too small an inductor is used, the inductor current will decrease past zero and change polarity. A consequence of this is that the LTC1142 may not enter Burst Mode operation and efficiency will be severely degraded at low currents. Inductor Core Selection Once the minimum value for L is known, the type of inductor must be selected ...
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... Figure 4). When C output ripple at low frequencies will be large enough to trip the voltage comparator. This causes Burst Mode operation to be activated when the LTC1142 would nor- mally be in continuous operation. The output remains in regulation at all times. must be less ...
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... W U section) less the gate charge current. For V shifts by an OUT LTC1142 DC supply current for each section is 160 A with no load, and increases proportionally with load up also begins to LOAD to a constant 1.6mA after the LTC1142 has entered continuous mode. Because the DC bias current is ...
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... A similar calculation for the 3.3V section results in the component values shown in Figure 14. LTC1142HV-ADJ/LTC1142L-ADJ Adjustable Applications When an output voltage other than 3. required, the LTC1142 adjustable version is used with an external resistive divider from V lated output voltage is determined by: V OUT = 0.007(63 – 25) = 0.27. The required R ...
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... Check the following in your layout: OUT 1. Are the signal and power grounds segregated? The LTC1142 signal ground [Pin 3 (17) for the LTC1142, Pin R 4 (18) for LTC1142-ADJ] must return to the (–) plate of SENSE The power ground returns to the source of the ...
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... ADJ]? This capacitor carries the MOSFET driver peak currents. 6. Are the shutdown Pins 2 and 16 for the LTC1142 (Pins 3 and 17 for the LTC1142-ADJ) actively pulled to ground during normal operation? Both Shutdown pins are high impedance and must not be allowed to float. Both pins can be driven by the same external signal if needed ...
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... R1 52.3k 100pF KRL SL-1/2-R050J SENSE1, SENSE2 L1: COILTRONICS CTX25-4 L2: COILTRONICS CTX33-5 Figure 11. LTC1142HV-ADJ Dual Regulator with 3.6V/2A and 5V/2A Outputs LTC1142/LTC1142L/LTC1142HV W U With the addition current is generated through R1 causing an offset of: V OFFSET If V > 5A) OFFSET OUT Burst Mode operation is prevented from occurring. Since ...
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... V OUT1 2.5V/1.5A 1000pF + C OUT1 220 F 10V 2 D1 N-CH R2 MBRS130T3 Si9410DY 49. 49.9k 100pF KRL SL-C1-1/2-1R075J SENSE1 R : KRL SL-C1-1/2-1R050J SENSE2 Figure 12. LTC1142HV-ADJ High Efficiency Regulator with 3.3V/2A and 2.5V/1.5A Outputs + C IN3 22 F 0.22 F 25V 2 P-CH Si9433DY SENSE3 0.033 OUT3 3.3V/3A 1000pF 28 D1 MBRS130T3 N- OUT3 Si9410DY 100 F ...
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... SENSE2 L1: COILTRONICS CTX50-4 L2: COILTRONICS CTX25-4 Figure 15. LTC1142HV-ADJ High Efficiency Power Supply Providing 3.3V/2A with Built-In Battery Charger 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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... LTC1142/LTC1142L/LTC1142HV U TYPICAL APPLICATIONS Figure 16. LTC1142HV-ADJ Output Current vs Trickle Charge Set Resistance (R ) for the Circuit in Figure 15 Using a 0.1 Current Sense Resistor R X Note: For additional high efficiency circuits, see Application Note 54. PACKAGE DESCRIPTIO 0.205 – 0.212** (5.20 – 5.38) 0 – 8 0.0256 0.005 – 0.009 0.022 – 0.037 (0.65) (0.13 – ...