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ADI公司的ADP2325是雙路5A 20V同步降壓DC/DC穩壓器,集成了兩個高邊功率MOSFET和兩個用來驅動外接N溝MOSFET的低邊驅動器.兩個PWM通路可配置成兩路5A或10A輸出,輸入電壓4.5V到20V,輸出電壓低至0.6V,主要用在通信設備,網絡和服務器,工業和儀表,醫療保健等.本文介紹了ADP2325主要特性,功能方框圖,多種典型應用電路,以及評估板ADP2325-EVALZ主要特性,電路圖,材料清單和PCB元件布局圖. The ADP2325 is a full featured, dual output, step-down dc-to-dc regulator based on a current mode architecture. The ADP2325 integrates two high-side power MOSFETs and two low-side drivers for the external N-channel MOSFETs. The two pulse-width mod-ulation (PWM) channels can be configured to deliver dual 5 A outputs or a parallel-to-single 10 A output. The regulator operates from input voltages of 4.5 V to 20 V, and the output voltage can be as low as 0.6 V. The switching frequency can be programmed from 250 kHz to 1.2 MHz, or it can be synchronized to an external clock to minimize interference in multirail applications. The dual PWM channels run 180° out of phase, thereby reducing input current ripple as well as reducing the size of the input capacitor. The bidirectional synchronization pin can be programmed at a 60°, 90°, or 120° phase shift to provide for a stackable, multi-phase power solution. The ADP2325 can be configured to operate in pulse frequency modulation (PFM) mode at a light load for higher efficiency or in forced PWM mode for noise sensitive applications. External compensation and soft start provide design flexibility. Independent enable inputs and power-good outputs provide reliable power sequencing. To enhance system reliability, the device includes undervoltage lockout (UVLO), overvoltage protection (OVP), overcurrent protection, and thermal shutdown. The ADP2325 operates over the −40℃ to +125℃ junction temperature range and is available in a 32-lead LFCSP_WQ package. ADP2325主要特性: Input voltage: 4.5 V to 20 V ±1% output accuracy Integrated 48 mΩ typical high-side MOSFET Flexible output configuration Dual output: 5 A/5 A Parallel single output: 10 A Programmable switching frequency: 250 kHz to 1.2 MHz External synchronization input with programmable phase shift or internal clock output Selectable PWM or PFM mode operation Adjustable current limit for small inductors External compensation and soft start Startup into precharged output Supported by ADIsimPowerTM design tool ADP2325應用: Communications infrastructure Networking and servers Industrial and instrumentation Healthcare and medical Intermediate power rail conversion 
圖1.ADP2325功能方框圖
圖2.ADP2325采用外接MOSFET的應用電路圖:VIN1 = VIN2 = 12 V, VOUT1 = 1.2 V, IOUT1 = 5 A, VOUT2 = 3.3 V, IOUT2 = 5 A, fSW = 500 kHz
圖3.ADP2325采用外接二極管的應用電路圖:VIN1 = VIN2 = 12 V, VOUT1 = 5 V, IOUT1 = 3 A, VOUT2 = 3.3 V, IOUT2 = 1.5 A, fSW = 600 kHz
圖4.ADP2325并聯單輸出應用電路圖: VIN = 12 V, VOUT = 1.2 V, IOUT = 10 A, fSW = 300 kHz
圖5.ADP2325采用MODE引腳下拉到GND的使能PFM模式應用電路圖:VIN1 = VIN2 = 12 V, VOUT1 = 1.5 V, IOUT1 = 5 A, VOUT2 = 2.5 V, IOUT2 = 5 A, fSW = 600
圖6.ADP2325每路間90度相移的同步應用電路圖
圖7.ADP2325可編VIN_RISING = 8.7 V, VIN_FALLING = 6.7 V應用電路: 3.3 V 先于1.8V起動, VIN1 = VIN2 = 12 V, VOUT1 = 3.3 V, IOUT1 = 5 A, VOUT2 = 1.8 V, IOUT2 = 5 A, fSW = 300 kHz
圖8.ADP2325通路2跟蹤通路1應用電路圖: VIN1 = VIN2 = 12 V, VOUT1 = 2.5 V, IOUT1 = 5 A, VOUT2 = 1.25 V, IOUT2 = 5 A, fSW = 500 kHz ADP2325評估板ADP2325-EVALZ Evaluation Board for the ADP2325, Dual 5 A, 20 V, Synchronous Step-Down Regulator with Integrated High-Side MOSFET The ADP2325 evaluation board, ADP2325-EVALZ, is a complete, dual, 5 A step-down regulator solution that allows users to evaluate the performance of the ADP2325 with a near ideal printed circuit board (PCB) layout. The two pulse-width modulation (PWM) channels can be configured to deliver dual, 5 A outputs or a parallel-to-single, 10 A output. The switching frequency can be programmed between 250 kHz and 1.2 MHz, or it can be synchronized to an external clock with a programmed 60°, 90°, or 120° phase shift, which provides the possibility for a stackable multiphase power solution. The outputs of the ADP2325 evaluation board are preset to 1.2 V and 3.3 V for Channel 1 and Channel 2, respectively. With the PWM mode selected, the switching frequency is set to 500 kHz. Different output voltage settings and configurations can be achieved by changing appropriate passive components or jumper settings. The ambient temperature operating range is −0℃ to +85℃. 評估板ADP2325-EVALZ主要特性: Input voltage: 4.5 V to 20 V ±1% output voltage accuracy Integrated 48 mΩ typical on-resistance high-side MOSFET Flexible output configuration Dual output: 5 A/5 A Parallel single output: 10 A Programmable switching frequency: 250 kHz to 1.2 MHz External synchronization input with programmable phase shift, or internal clock output Selectable PWM or PFM mode operation Adjustable current limit for small inductor External compensation and soft start Startup into precharged output
圖9.評估板ADP2325-EVALZ外形圖
圖10.評估板ADP2325-EVALZ電路圖
圖11.評估板ADP2325-EVALZ PCB元件布局圖:頂層 評估板ADP2325-EVALZ材料清單(BOM):
詳情請見: 
ADP2325[2].pdf
(846.52 KB)
UG-374[2].pdf
(708.73 KB)
來源：網絡 |
