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LX7186A 1.4 MHz 1A Synchronous Buck Converter Evaluation Board

Microsemi Proprietary and Confidential. User Guide Revision 1.0

2

2

Product Description

The LX7186A is 1.4 MHz fixed frequency, current-mode, synchronous PWM buck (step-down) DC-to-DC 
converter, capable of driving a 1 A load with high efficiency, and excellent line and load regulation. The 
devices integrate synchronous P-channel and N-channel power MOSFET switches with low on-
resistance. They accept an input voltage range from 2.5 V to 5.5 V and will enter 100% duty cycle at 
dropout making them ideal for powering portable equipment that runs from a single Li-ion battery.

A standard series of inductors (available from several different manufacturers) is optimized for use with 
the LX7186A. This feature greatly simplifies the design of switch-mode power supplies.

The converter includes standard safety features, such as over-current, short-circuit, and thermal 
shutdown protection. This device is available in SOT23-5L and UDFN 2x2 6L packages.

2.1

Applications

Datacom
Portable devices
Smart phone

2.2

Key Features

Input supply range: 2.5 V–5.5 V
Output adjustable from 0.6 V–~VIN
100% duty cycle in dropout
Integrated NMOS and PMOS switches
Current mode control
1 A maximum output current
Fixed 1.4 MHz frequency
High efficiency: up to 98%
Built-in soft-start
Built-in OV, UV, and OT protection
Built-in short circuit protection
RoHS-compliant and Halogen-free
SOT23-5L or UDFN 2x2 6L packages

Содержание LX7186A

Страница 1: ...User Guide LX7186A 1 4 MHz 1A Synchronous Buck Converter Evaluation Board...

Страница 2: ...Revision 1 0 1 2 Product Description 2 2 1 Applications 2 2 2 Key Features 2 3 Evaluation Board Schematic 3 4 Basic Connection Instructions 4 5 Recommended Operating Conditions 5 5 1 Setting the Outpu...

Страница 3: ...r Guide Revision 1 0 1 1 Revision History The revision history describes the changes that were implemented in the document The changes are listed by revision starting with the most current publication...

Страница 4: ...n battery A standard series of inductors available from several different manufacturers is optimized for use with the LX7186A This feature greatly simplifies the design of switch mode power supplies T...

Страница 5: ...rietary and Confidential User Guide Revision 1 0 3 3 Evaluation Board Schematic The following illustrations show the evaluation board schematic for the LX7186A and LX7186A UDFN device Figure 1 LX7186A...

Страница 6: ...Evaluation Board Microsemi Proprietary and Confidential User Guide Revision 1 0 4 4 Basic Connection Instructions The following illustration shows how to connect the evaluation board to the power sup...

Страница 7: ...recommended operating conditions for the LX7186A evaluation board Table 1 Recommended Operating Conditions Description Symbol Min Max Unit Input voltage VIN 2 5 5 5 V Output current IOUT 0 1 A Operat...

Страница 8: ...crosemi Proprietary and Confidential User Guide Revision 1 0 6 6 PCB Layout of Evaluation Board The LX7186A evaluation board is four layers The following illustrations depict each of the board s four...

Страница 9: ...LX7186A 1 4 MHz 1A Synchronous Buck Converter Evaluation Board Microsemi Proprietary and Confidential User Guide Revision 1 0 7 Figure 6 LX7186A Bottom Layer Figure 7 LX7186A UDFN Top Silkscreen...

Страница 10: ...LX7186A 1 4 MHz 1A Synchronous Buck Converter Evaluation Board Microsemi Proprietary and Confidential User Guide Revision 1 0 8 Figure 8 LX7186A UDFN Top Layer Figure 9 LX7186A UDFN Bottom Layer...

Страница 11: ...Description Reference Qty 1 Miscellaneous Components Microsemi IC LX7186A U1 1 2 Miscellaneous Components Test Point SW VIN VOUT GND GND 5 3 Miscellaneous Components Terminal VIN VOUT GND GND 4 4 Mis...

Страница 12: ...ck Converter Evaluation Board Microsemi Proprietary and Confidential User Guide Revision 1 0 10 8 Efficiency Plot The following graph shows LX7186A efficiency at a voltage output of 2 5 V Figure 10 LX...

Страница 13: ...tial User Guide Revision 1 0 11 9 Dynamic Load Response The following graphs show the dynamic load response of the LX7186A device Figure 11 Dynamic Load Response with IOUT 35 mA 600 mA VIN 5 V VOUT 3...

Страница 14: ...d Microsemi Proprietary and Confidential User Guide Revision 1 0 12 10 Soft Start The following graphs show the soft start for the LX7186A device Figure 13 Startup with No Load VIN 5 V VOUT 3 3 V no l...

Страница 15: ...Converter Evaluation Board Microsemi Proprietary and Confidential User Guide Revision 1 0 13 Figure 15 Startup with 1 A Resistive Load VIN 5 V VOUT 3 3 V 1 A load Figure 16 Start up with 1 A Resistiv...

Страница 16: ...oard Microsemi Proprietary and Confidential User Guide Revision 1 0 14 Figure 17 Start up with Fast VIN Rise and 10 mA Resistive Load VIN 5 V VOUT 3 3 V 10 mA load Figure 18 Start up with Fast VIN Ris...

Страница 17: ...5 11 Ordering Information The following table lists the ordering information for the LX7186A evaluation board Table 3 Ordering Information Part Order Number Description LX7186AISE SOT23 5L LX7186AILD...

Страница 18: ...Buyer s responsibility to independently determine suitability of any products and to test and verify the same The information provided by Microsemi hereunder is provided as is where is and with all f...

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