SH3000UM

POWER MANAGEMENT Description Three components make a complete system: any microcontroller, the SH3003, and a bypass capacitor. This low-cost system would consume very little power and have clock-frequency accuracy of ± 0.5%. A fourth component, a 32.768kHz crystal, raises the clock frequency accuracy to ± 0.0256% (± 256 ppm). The SH3003 can operate completely stand-alone, or under control of the microcontroller. A single-wire interface handles both bi-directional communications and the interrupt/wake-up signal from the SH3003. The SH3003 stores all configuration, calibration, parameters, and status information in a 36-byte bank of control registers. On reset, most of these are reloaded with defaults from the factory-set non-volatile memory. The microcontroller can change any settings on the fly. If some of the settings must remain fixed, a comprehensive set of write-protect bits is provided for several related groups of registers (with both permanent write-inhibit and lock/unlock capabilities). A backup power source may also be connected to the SH3003. The IC can directly accommodate 2/3-cell zinccarbon/alkaline, 2/3-cell mercury, 2/3/4-cell NiCd/NiMH, one cell Li/Li+ batteries, or a super cap. The programmable SH3003 MicroBuddy® (μBuddy®) provides all mandatory microcontroller support functions: CPU Supervisor Clock Management System Real-Time Support Auxiliary Functions MicroBuddy® Support IC for Microcontrollers Features Highly integrated • IC - 3mm x 3mm x 0.9mm, 16-lead MLP (QFN) package CPU Supervisor • Low VDD reset programmable from 2.3V to 4.3V • Watchdog timer with programmable time out periods • Both active-high and active-low reset outputs Clock Management System • Replaces high-frequency (HF) crystal or resonator • Programmable clock output from 32.768kHz to 16MHz • Speed shift between multiple clock frequencies • Adjustable spectrum spreading for EMI reduction • Directly supports microcontroller STOP function • Deep sleep with instantaneous auto-wakeup Real-Time Support • 179 year real-time clock, battery-backup capable • Dedicated 32.768kHz buffered clock output • Built-in trim for 32.768kHz oscillator to ±4ppm • Programmable periodic interrupt/wakeup timer Auxiliary Functions • 4-byte (32-bit) scratchpad RAM, loaded on reset with factory-set value (zero or optional ID code) • All settings programmable in real time, defaults restored from nonvolatile memory on reset Operates from 2.3V to 5.5V • IDD < 850μA /2MHz, < 3mA / 16MHz,