原标题：Wolfson WM8320处理器电源管理方案

　　Wolfson 公司的WM8320是综合的处理器电源管理子系统,提供高性价比的灵活的单片解决方案,特别适合于低功率手提应用. WM8320支持ARM9, ARM11和ARM Cortex-A系列处理器,具有电源管理,系统控制以及其它用于多功能模拟测量的ADC,128位伪随机ID,带叫醒的安全RTC和系统LED输出指示电源状态和故障状态等功能,主要用在手机,智能手机,电子书,PMP,移动互联网设备(MID),电子游戏,上网本和机顶盒.本文介绍了WM8320的主要特性,方框图以及在手提媒体播放器(PMP), 手提导航设备, 数码相机, 数码相框, VOIP电话, 电子阅读器和婴儿监视器的应用框图以及WM8320评估板详细电路图.

　　Processor Power Management Subsystem

　　WM8320 is an integrated power-management subsystem which provides a cost-effective, flexible, single-chip solution for power management, specifically targeted at the requirements of a range of low-power portable applications.

　　WM8320 is specifically designed to operate as a system PMIC supporting the ARM9™, ARM11™ and ARM Cortex-A™ series processors at the heart of a range of low-power

　　applications.

　　The start-up behaviour and configuration is fully programmable in an integrated OTP non-volatile memory. This highly flexible solution helps reduce time-to-market, as changing application requirements can be very easily accommodated in the OTP contents. An external EEPROM can be used to configure the WM8320 for development purposes.

　　The WM8320 power management subsystem comprises four programmable DC-DC converters and eleven LDO regulators (four of which are low-noise for supplying sensitive analogue subsystems). The integrated OTP bootstrap circuitry controls the start-up sequencing and voltages of the converters and regulators as well as the sequencing of system clocks.

　　The DC-DC converters deliver high performance and high efficiency across a wide range of operating conditions. They are optimised to support the high load current transients seen in modern processor core domains. DC-DC3 / DC-DC4 can be connected together and operated in ‘dual’ mode to support an increased current load of up to 1.6A.

　　An on-chip regulator provides power for always-on PMIC functions such as register map and the RTC. The device provides autonomous backup battery switchover. A low-power

　　LDO is included to support ‘Alive’ processor power domains external to the WM8320.

　　A 12-bit Auxiliary ADC supports a wide range of applications for internal as well as external analogue sampling, such as voltage detection and temperature measurement.

　　WM8320 includes a crystal oscillator and an internal RC oscillator to generate all clock signals for autonomous system start-up and processor clocking. A Secure Real-time Clock (SRTC) and alarm function is included, capable of waking up the system from low-power modes. A watchdog function is provided to ensure system integrity.

　　To maximise battery life, highly-granular power management enables each function in the WM8320 subsystem to be independently powered down through a control interface or

　　alternatively through register and OTP-configurable GPIOs. The device offers a standby power consumption of <10uA, making it particularly suitable for portable applications.

　　The WM8320 is supplied in a 7x7mm 169-ball BGA package, ideal for use in portable systems. The WM8320 forms part of the Wolfson series of audio and power management solutions, and is widely register compatible with the WM831X family of PMIC devices.

　　WM8320主要特性:

　　Power Management

　　2 x DC-DC buck converter (0.6V - 1.8V, up to 1.2A, DVS)

　　2 x DC-DC buck converter (0.85V - 3.4V, up to 1A)

　　1 x LDO regulator (0.9V - 3.3V, 300mA, 1)

　　2 x LDO regulators (0.9V - 3.3V, 200mA, 1)

　　3 x LDO regulators (0.9V - 3.3V, 100mA, 2)

　　2 x Low-noise LDO regulators (1.0V - 3.5V, 200mA, 1)

　　2 x Low-noise LDO regulators (1.0V - 3.5V, 150mA, 2)

　　1 x‘Alive’ regulator (0.8V – 1.55V, up to 10mA)

　　System Control

　　I2C or SPI compatible primary control interface

　　Comprehensive interrupt scheme

　　Watchdog timer and system reset control

　　Autonomous power sequencing and fault detection

　　OTP memory bootstrap configuration function

　　Additional Features

　　Auxiliary ADC for multi-function analogue measurement

　　128-bit pseudo-random unique ID

　　Secure Real-Time Clock with wake-up alarm

　　12 x configurable multi-function (GPIO) pins

　　Comprehensive clocking scheme: low-power 32kHz RTC crystal oscillator, GPIO clock output and 4MHz RC clock for power management

　　System LED outputs indicating device power state, and fault status

　　Package Options

　　7x7mm, 169-ball BGA package, 0.5mm ball pitch

　　WM8320应用:

　　Cellular Handsets

　　Smartphones

　　Electronic Books

　　Portable Media Players

　　Mobile Internet Devices

　　Electronic Gaming Devices

　　Netbooks

　　Set Top Box

　　图1.WM8320方框图

　　应用案例:

　　图2. WM8320在手提媒体播放器的应用

　　图3. WM8320在手提导航设备管理的应用

　　图4. WM8320在数码相机的应用

　　图5. WM8320在数码相框的应用

　　图6. WM8320在VOIP电话的应用

　　图7. WM8320在电子阅读器(eBook)的应用

　　图8. WM8320在婴儿监视器的应用

　　WM8320评估板

　　WM8320 Evaluation Board

　　图9.WM8320评估板电路图(控制接口和其它)

　　图10.WM8320评估板电路图(GPIO)

　　图11.WM8320评估板电路图(地线连接)

　　图12.WM8320评估板电路图(LDO连接)

　　图13.WM8320评估板电路图(DC-DC连接)

　　图14.WM8320评估板电路图(连接器)

　　图15.WM8320评估板电路图(测试点)

　　图16.WM8320评估板主板电路图(USB接口)

　　图17.WM8320评估板主板电路图(2线接口电平转移)

　　图18.WM8320评估板主板电路图(动态引导EEPROM)

　　图19.WM8320评估板主板电路图(重置和状态LED)

　　图20.WM8320评估板主板电路图(电源插头)

　　图21.WM8320评估板主板电路图(USB电源)

　　图22.WM8320评估板主板电路图(Bench电源)

　　图23.WM8320评估板主板电路图(GPIO上拉/下拉)

　　图24.WM8320评估板主板电路图(LDO和DC-DC输出)

　　图25.WM8320评估板主板电路图(密你板连接器,ON和重置)

　　图26.WM8320评估板主板电路图(插头参考表)

　　图27.WM8320评估板主板电路图(插头参考表)