ADI公司的ADP2325是雙路5A 20V同步降壓DC/DC穩(wěn)壓器,集成了兩個(gè)高邊功率MOSFET和兩個(gè)用來(lái)驅(qū)動(dòng)外接N溝MOSFET的低邊驅(qū)動(dòng)器.兩個(gè)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(shè)備,網(wǎng)絡(luò)和服務(wù)器,工業(yè)和儀表,醫(yī)療保健等.本文介紹了ADP2325主要特性,功能方框圖,多種典型應(yīng)用電路,以及評(píng)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(yīng)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(yīng)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(yīng)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(lián)單輸出應(yīng)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(yīng)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(yīng)用電路圖

圖7.ADP2325可編VIN_RISING = 8.7 V, VIN_FALLING = 6.7 V應(yīng)用電路: 3.3 V 先于1.8V起動(dòng), 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(yīng)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(píng)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(píng)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(píng)估板ADP2325-EVALZ外形圖


圖10.評(píng)估板ADP2325-EVALZ電路圖

圖11.評(píng)估板ADP2325-EVALZ PCB元件布局圖:頂層

評(píng)估板ADP2325-EVALZ材料清單(BOM):

詳情請(qǐng)見(jiàn):
http://www.analog.com/static/imported-files/data_sheets/ADP2325.pdf
和
http://www.analog.com/static/imported-files/user_guides/UG-374.pdf