Sensors

Freescale Semiconductor, Inc.

21

MMA685x

3.3

Voltage Regulators

Separate internal voltage regulators supply the analog and digital circuitry. External filter capacitors are required, as shown in

Figure 1. The voltage regulator module includes voltage monitoring circuitry which indicates a device reset until the external sup-

ply and all internal regulated voltages are within predetermined limits. A reference generator provides a stable voltage which is

used by the

ΣΔ converters.

Figure 7. Power Supply

Figure 8. Voltage Monitoring

TRACKING

REGULATOR

VOLTAGE

REGULATOR

REFERENCE

GENERATOR

DIGITAL

LOGIC

DSP

OTP

ARRAY

PRIMARY

OSCILLATOR

ΣΔ

CONVERTER

BIAS

GENERATOR

TRIM

TRIM

BANDGAP

REFERENCE

SET DEVRES Flag

MONITOR

BANDGAP

GROUND LOSS

MONITOR

POR

Note: No external access to reference voltage

Limits verified by characterization only