MMA5124KW datasheet(21/55 Pages) FREESCALE

21 / 55 page

Sensors

Freescale Semiconductor, Inc.

MMA51xxKW

3.3.1

VBUF, VREG, and VREGA Regulator Capacitor

The internal regulators require an external capacitor between each of the regulator pins (VBUF, VREG, or VREGA) and the as-

sociated the VSS / VSSA pin for stability. Figure 1 shows the recommended types and values for each of these capacitors.

3.3.2

VCC, VBUF, VREG, and VREGA Under-Voltage Monitor

A circuit is incorporated to monitor the supply voltage (VCC) and all internally regulated voltages (VBUF, VREG, and VREGA). If

any of internal regulator voltages fall below the specified under-voltage thresholds in Section 2, the device will be reset. If VCC

falls below the specified threshold, PSI5 transmissions are terminated for the present response. Once the supply returns above

the threshold, the device will respond to the next detected sync pulse. Reference Figure 9.

Figure 9. VCC Micro-Cut Response

VCC

POR

VREG

Time

VBUF

VREGA

VCC under-voltage detected

Response Terminated

IDATA

VCC micro-cut occurs

MMA5124KW Datasheet(PDF) 21 Page - Freescale Semiconductor, Inc