Sensors

12

Freescale Semiconductor

MMA690xQ

2.2

VOLTAGE REGULATORS

Separate internal voltage regulators supply fixed voltages to the analog and digital circuitry. External filter capacitors are

required, as shown in Figure 1-5.

The voltage regulator module includes a voltage monitoring circuitry which holds the device in reset following power-on until

internal voltages have stabilized sufficiently for proper operation. The voltage monitor asserts internal reset when the external

supply or internally regulated voltages fall below predetermined levels.

A reference generator provides a stable voltage which is used by the

ΣΔ converter. This circuit also requires an external filter

capacitor.

The voltage regulator module is illustrated in Figure 2-3 and Figure 2-4.

Figure 2-3 Power Distribution

VOLTAGE

REGULATOR

VOLTAGE

REGULATOR

REFERENCE

GENERATOR

DIGITAL

LOGIC

DSP

OTP

ARRAY

PRIMARY

OSCILLATOR

OTP

ARRAY

REFERENCE

OSCILLATOR

ΣΔ

CONVERTER

BANDGAP

REFERENCE

BIAS

GENERATOR

TRIM

TRIM

BIAS

GENERATOR

ΣΔ

CONVERTER

BANDGAP

REFERENCE