Datasheet LT4423 (Analog Devices) - 10
| Hersteller | Analog Devices |
| Beschreibung | 28V, 2A Ideal Diode and Load Switch |
| Seiten / Seite | 18 / 10 — Data Sheet. LT4423. WALL ADAPTER INPUT. B230A. OUT. TO LOAD. BATTERY. … |
| Dateiformat / Größe | PDF / 456 Kb |
| Dokumentensprache | Englisch |
Data Sheet. LT4423. WALL ADAPTER INPUT. B230A. OUT. TO LOAD. BATTERY. 1.9V TO 28V. 4.7µF. 4.7kΩ. LNJ237W82RA. SHDN. GND. STATUS
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Data Sheet LT4423 WALL ADAPTER INPUT D2 LT4423 B230A IN OUT TO LOAD BATTERY C1 1.9V TO 28V R1 4.7µF 4.7kΩ D1 LNJ237W82RA SHDN GND STATUS
014
Figure 13. Automatic Switchover of Load Between a Battery and a Wall Adapter 5V Power Ride-Through
In a diode-OR configuration, multiple diode cathodes are connected in parallel, with the final output voltage set by the highest cathode potential. The LT4423 is well suited for these applications, with its ability to disable the power path whenever OUT exceeds IN by approximately 20mV or more, allowing no more than 1µA of reverse current. The low reverse leakage and the ability to stand-off 28V, and turn off under reverse bias make the LT4423 a high- performance diode replacement. Figure 14 demonstrates a diode-OR application with a super-cap charger to provide load power ride-through in the event of input power loss. The LTC3625 charges two supercapacitors to a sum of 4.8V. Two LT4423s form a diode-OR circuit between the main 5V input and the supercapacitor 4.8V output. The cathodes of the LT4423s connect to a load or a downstream voltage regulator. If the main 5V supply is operating, load power is delivered from the 5V supply. Should the main 5V supply be removed, the 4.8V path turns on, and load power is derived from the supercapacitors.
LT4423 TO REGULATOR IN OUT COUT 22µF SHDN STATUS N/C GND LT4423 LTC3625 4.8V IN OUT VIN = 5V VIN VOUT C1 CTL SW1 R1 C2 10µF 287kΩ EN L1 SW2 100F 3.3µH PFI SHDN STATUS N/C VMID R2 V GND SEL PFO C3 100kΩ PGOOD 100F GND PROG R3 143kΩ
015
Figure 14. Riding through Loss of Primary Power Supply analog.com
Rev. 0 10 of 18 Document Outline Features Applications General Description Simplified Application Diagram TABLE OF CONTENTS Revision History Specifications Absolute Maximum Ratings Pin Configurations and Function Descriptions Typical Performance Characteristics Block Diagram Theory of Operation Applications Information USB PD 3.0 and Back-Up Battery Supply Automatic Power Path Control 5V Power Ride-Through High-Voltage Load Switch with Load Sharing and Undervoltage Lockout Layout and Thermal Considerations Typical Applications High-Load Current Application Reverse Input Voltage Protection Related parts Outline Dimensions Ordering Guide
Data Sheet LT4423 WALL ADAPTER INPUT D2 LT4423 B230A IN OUT TO LOAD BATTERY C1 1.9V TO 28V R1 4.7µF 4.7kΩ D1 LNJ237W82RA SHDN GND STATUS
014
Figure 13. Automatic Switchover of Load Between a Battery and a Wall Adapter 5V Power Ride-Through
In a diode-OR configuration, multiple diode cathodes are connected in parallel, with the final output voltage set by the highest cathode potential. The LT4423 is well suited for these applications, with its ability to disable the power path whenever OUT exceeds IN by approximately 20mV or more, allowing no more than 1µA of reverse current. The low reverse leakage and the ability to stand-off 28V, and turn off under reverse bias make the LT4423 a high- performance diode replacement. Figure 14 demonstrates a diode-OR application with a super-cap charger to provide load power ride-through in the event of input power loss. The LTC3625 charges two supercapacitors to a sum of 4.8V. Two LT4423s form a diode-OR circuit between the main 5V input and the supercapacitor 4.8V output. The cathodes of the LT4423s connect to a load or a downstream voltage regulator. If the main 5V supply is operating, load power is delivered from the 5V supply. Should the main 5V supply be removed, the 4.8V path turns on, and load power is derived from the supercapacitors.
LT4423 TO REGULATOR IN OUT COUT 22µF SHDN STATUS N/C GND LT4423 LTC3625 4.8V IN OUT VIN = 5V VIN VOUT C1 CTL SW1 R1 C2 10µF 287kΩ EN L1 SW2 100F 3.3µH PFI SHDN STATUS N/C VMID R2 V GND SEL PFO C3 100kΩ PGOOD 100F GND PROG R3 143kΩ
015
Figure 14. Riding through Loss of Primary Power Supply analog.com
Rev. 0 10 of 18 Document Outline Features Applications General Description Simplified Application Diagram TABLE OF CONTENTS Revision History Specifications Absolute Maximum Ratings Pin Configurations and Function Descriptions Typical Performance Characteristics Block Diagram Theory of Operation Applications Information USB PD 3.0 and Back-Up Battery Supply Automatic Power Path Control 5V Power Ride-Through High-Voltage Load Switch with Load Sharing and Undervoltage Lockout Layout and Thermal Considerations Typical Applications High-Load Current Application Reverse Input Voltage Protection Related parts Outline Dimensions Ordering Guide