ADGM3144BCCZ-R2 datasheet(22/30 Pages) AD

22 / 30 page

Data Sheet

ADGM3144

THEORY OF OPERATION

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Rev. 0 | 22 of 30

Internal Error Status

Where an internal error is detected in the part, it is flagged in the

internal error status bits [7:6] of the SWITCH_DATA register. An

internal error results from an error in the configuration of the part at

power-up.

INTERNAL OSCILLATOR FEEDTHROUGH

The ADGM3144 has an internal oscillator running at a nominal

10MHz. This oscillator drives the charge pump circuitry that pro-

vides the actuation voltage for each of the switch gate electrodes.

Although this oscillator is very low power, the 10MHz signal is

coupled to the switch and can be considered a noise spur on the

switch channels. The magnitude of this feedthrough noise spur is

specified in Table 1 and is typically −92.5dBm when one switch is

on. The VDD level and temperature changes affect the frequency of

the noise spur. For the maximum and minimum frequency ranges

over temperature and voltage supply range, see Table 1.

TYPICAL OPERATING CIRCUIT

Figure 62 shows the typical operating circuit for the ADGM3144.

VDD is connected to 3.3V. EP connects to GND internally. It is

recommended to connect GND using one large pad on the PCB

to short together GND with EP. Figure 62 shows the ADGM3144

configured to use the internal oscillator as the reference clock to

the driver IC control circuit. Decoupling capacitors are required on

VCP and VDD. Place a 0.1nF capacitor rated to at least 100V DC as

close as possible to VCP. Place a 0.1μF capacitor rated to at least

16V DC as close as possible to VDD.

Figure 62. Typical Operating Circuit in the Parallel Digital Interface Mode

ADGM3144BCCZ-R2 データシート(PDF) 22 Page - Analog Devices