ADIADP2325双路5A20V同步降压电源解决方案

ADI公司的ADP2325是双路5A 20V同步降压DC/DC稳压器,集成了两个高边功率MOSFET和两个用来驱动外接N沟MOSFET的低边驱动器.两个PWM通路可配置成两路5A或10A输出,输入电压4.5V到20V,输出电压低至0.6V,主要用在通信设备,网络和服务器,工业和仪表,医疗保健等.本文介绍了ADP2325主要特性,功能方框图,多种典型应用电路,以及评估板ADP2325-EVALZ主要特性,电路图,材料清单和PCB元件布局图.
 
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应用:

Communications infrastructure

Networking and servers

Industrial and instrumentation

Healthcare and medical

Intermediate power rail conversion

图1.ADP2325功能方框图

图2.ADP2325采用外接MOSFET的应用电路图:VIN1 = VIN2 = 12 V, VOUT1 = 1.2 V, IOUT1 = 5 A, VOUT2 = 3.3 V, IOUT2 = 5 A, fSW = 500 kHz

图3.ADP2325采用外接二极管的应用电路图:VIN1 = VIN2 = 12 V, VOUT1 = 5 V, IOUT1 = 3 A, VOUT2 = 3.3 V, IOUT2 = 1.5 A, fSW = 600 kHz

图4.ADP2325并联单输出应用电路图: VIN = 12 V, VOUT = 1.2 V, IOUT = 10 A, fSW = 300 kHz

图5.ADP2325采用MODE引脚下拉到GND的使能PFM模式应用电路图:VIN1 = VIN2 = 12 V, VOUT1 = 1.5 V, IOUT1 = 5 A, VOUT2 = 2.5 V, IOUT2 = 5 A, fSW = 600

图6.ADP2325每路间90度相移的同步应用电路图

图7.ADP2325可编VIN_RISING = 8.7 V, VIN_FALLING = 6.7 V应用电路: 3.3 V 先于1.8V起动, VIN1 = VIN2 = 12 V, VOUT1 = 3.3 V, IOUT1 = 5 A, VOUT2 = 1.8 V, IOUT2 = 5 A, fSW = 300 kHz

图8.ADP2325通路2跟踪通路1应用电路图: VIN1 = VIN2 = 12 V, VOUT1 = 2.5 V, IOUT1 = 5 A, VOUT2 = 1.25 V, IOUT2 = 5 A, fSW = 500 kHz

ADP2325评估板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℃.

评估板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

图9.评估板ADP2325-EVALZ外形图


图10.评估板ADP2325-EVALZ电路图

 图11.评估板ADP2325-EVALZ  PCB元件布局图:顶层

评估板ADP2325-EVALZ材料清单(BOM):

详情请见:
http://www.analog.com/static/imported-files/data_sheets/ADP2325.pdf
和
http://www.analog.com/static/imported-files/user_guides/UG-374.pdf