VSMC’s VS8801A with Adaptive ASPWM Controlled Technology, by driving up to eight PWM converter channels in sequence, provides a new and effective tool for power-management control of new generations of portable devices such as: smartphones, PDAs, MP4-players … This controller familly are designed to offer advanced specifications which are fully adapted to common and particular demands from portable device designers.

With up to eight phases, each capable of up to 1MHz operation, the VS8801A can be used to build 8 separate channels of DC/DC converters that provide energy to various types of load with excellent efficiency, low ripples, and with lowest external component count.

For energy-saving reasons while all the loads is turned off, the VS8801A offers a stand-by mode, where the quiescent current does not exceed 50μA typically. In this stand-by mode just the stand-by LDOs remain active.

FEATURES
· High efficiency DC/DC converter controller system
· Low operating voltage range, from 3 V to 5.5V portable device standard batteries.
· Stand-by mode with low current consumption
· Selectable step-down converter as pre-regulator: 1.8V, 2.5V and 3.3V
· Programable step-down slope control, suitable for wide range of application
· Switching loss minimization
· 8 channels with independent programmable output controllers:
- 4 step-down controllers
- 2 step-up controllers
- 1 white-LED controller
- 1 negative voltage power supply controller
· Stand-by regulator with 1mA current capability
· 8 separated voltage feedback circuits for each channel
· Power-on reset functionality
· Internal watchdog reset
· Internal crystal oscillator with 32,768 Hz output
· Un-used channels can be segregated-off from the system without power-consumption
· Commutation with host-CPU through SPI / I2C serial bus
· PLCC-84 standard package or (8mm x 8mm) FBGA package with 0.5 ball-pitch (options)

APPLICATIONS
· Portable media players and MP3 players
· Feature phones and smart phones
· Other portable electronic equipment
· Eight switching converters
– Four buck (step-down) converters
– Two converter available in Low Power mode for high efficiency at low load currents
– Two boost (step-up) converters
– One buck-boost (step-up) converter for negative output voltage
– One constant current boost White LED driver
– High efficiency (typically 90%+) from 5% to 100% of programmed maximum current in active mode
– Converters drive external MOSFET(s) directly
· Switching converters feature all-digital loop control technology
– Real-time analysis provides optimal power system control and operation
– Precise supply-to-supply matching and tracking
– Programmable power-up and -down slew rates
– Programmable load connection and shedding
– Smaller inductors and capacitors yield reduced size and cost

· Three LDOs
– Three low-noise LDOs with separate pins-out.
· Input voltage range: 3 to 5.5 Volts
· Dynamic programming for all PWM cotroller and LDO power rails
· Power-up supply characteristics can be modified without hardware changes by reprogramming the device’s E2PROM
· Capable of stand-alone operation using the parameters loaded from the E2PROM at start-up
– No serial interface with host required
– Utilize device pins for status / control
· Integrated system support
- Real time clock (RTC) with 32,768 Hz clock-pulse output.
- Watchdog-timer (WDT)
– Programmable host controller interrupt output
– Power Good and Power-on-Reset outputs
· Remote management via I2C, SPI interface to host processor
· Operates from a low-cost 32,768 KHz crystal or external clock input
– Provides buffered 32,768 KHz output to internal RTC and the external system
· Low power consumption
– 50 μA in shutdown mode with RTC enabled
· PLCC-84 standard package or FBGA package with 0.5 ball-pitch (options)