Texas Instruments MSP50C6xx manual Reset Circuit

Models: MSP50C6xx

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Functional Description for the MSP50C614

Rounding out the MSP50C6xx periphery is a built in pulse-density-modulated (PDM) digital-to-analog converter (DAC) with direct speaker-drive capability.

Typical connections to implement reset functionality are shown in Figure 1–3.

An external reset circuit is required to hold the reset pin low until the MSP50C6xx power supply has stabilized in the specified voltage range. In some cases, a simple reset circuit (as shown in Figure 1–3) can be used for this purpose. However, this simple circuit may not be suitable for all applica- tions. For example, if the power supply has an unpredictable rise time or has intermittent voltage sags, the device may not initialize properly. The diode and the switch shown in Figure 1–3 may be optional for some applications. The diode provides a lower impedance path for the capacitor to discharge when power is removed. This make the circuit more reliable when power is removed and quickly reapplied.

Figure 1–3. RESET Circuit

(MSP50P614 only)

VPP

IN914

To Pin 1 of Optional (Scanport) Connector

5 V

Inside the

MSP50P614

MSP50C6xx

VDD

100 k

RESET

1 k

 

 

1 F

 

(20%)

IN914

Reset

Switch

To Pin 2 of optional (scan port) connector

VSS

If it is necessary to use the software development tools to control the MSP50P614 in an application board, the 1 kresistor is needed to allow the development tool to over drive the RESET circuit on the application board.

This Diode can be omitted (shorted) if the application does not require use of the scanport interface. See Section 7.1 regarding scan port bond out.

Note:

This simple circuit may not be suitable for all applications. For example, if the power supply has an unpredictable rise time or has intermittent voltage sags, the device may not initialize properly.

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Texas Instruments MSP50C6xx manual Reset Circuit