Does the MAX1452 contain any firmware or software?

No, the MAX1452 does not have any firmware or software.

Will this part be able to get a signal, calibrate it, and compensate?

The MAX1452 will calibrate and compensate a signal depending on the compensation values loaded into the internal calibration registers.

I have mistakenly overwritten the oscillator bits in the MAX1452 Configuration register. Can I recover the factory setting?

No. If necessary, one should re-trim the oscillator frequency.

With regards to the MAX1452, what does the C8H suffix mean?

The C8H suffix is for a new version of the chip that internally uses the VDDF signal to start operation as opposed to the standard version that uses VDD signal. We made the change from VDD to VDDF (which is a better concept and makes the startup process more robust) but it caused complications in some of the existing applications. As a result, we ended up supporting both parts: MAX1452CAE for the standard part MAX1452CAE-C8H for the new revision.

What is the smallest sensor output that can produce 4V of span (VDD = 5V) in the MAX1452 without requiring external amplification?

The smallest sensor output can be determined when the largest excitation voltage setting of 4.5V (VDD = 5V) and the largest PGA gain (234x) are applied. The applying equation is: Sensor Output (mV/V) = Span (V) / [VBDR (V) x PGA-Gain (V/V)] x 1000 The smallest possible sensor output is 4mV/V.

What is the factory setting for the flash memory content of the MAX1452?

The signal conditioner is shipped with the flash memory ERASED (0xFFFF in all memory locations), except for the Control and Configuration registers. The Control register content is 0xFF00 to place the part in digital mode; the Configuration register content is xxx0000011111111b (or X0FFhex). The xxx (3 MSBs) are the oscillator trim setting.

What are the differences between the three evaluation kits for the MAX1452?

MAX1452EVK-CS - This kit includes a compensated sensor. MAX1452EVK-US - This kit includes an uncompensated sensor. MAX1452EVK-NS - This kit includes NO sensor.

What is the VDD voltage level which indicates that the MAX1452 signal conditioner is completely turned off?

The VDD voltage level is 0.5V. This voltage will guarantee that all transistors are turned off. Reapplying VDD will cause a power-on-reset sequence.

What are the recommended values for the MAX1452 offset TC DAC and FSOTC DAC, if they are not used for first-order temperature compensation?

The offset TC DAC and FSOTC DAC can be set to any arbitrary value. However, it is recommended that they be set to non-zero values, e.g., 0x0200.

What are the limits for the bridge-excitation voltage in the MAX1452?

The bridge-excitation limits are dictated by the limits in setting the FSO DAC. This limit is specified in the data sheet as 0x4000 to 0xC000, which corresponds to approximately 1.25V to 3.75V from the FSO DAC, for VDD = 5V. In practice, the bridge-excitation voltage can be as high as 4.5V.

Do you have a SPICE model for the MAX1452 or another similar device?

Maxim does not provide a SPICE model for the MAX1452 or similar devices.

When operating in MAX1452 digital mode and the output MUX is activated for "infinite" output duration, communication is blocked for 9s before it's released to accept digital commands.How can I get around this after reading the output from a D

The power to the signal conditioner, VDD, must be cycled. If the supplied KEY and MAX1452 Evaluation Kit (EV kit) software are used, the hard_init (mode = 1) function included in the serial.dll must be executed to cycle power. In this mode (mode = 1), the prepower-cycle contents of the DACs will be automatically restored, so the power cycle operation will be transparent to the compensation process.

Should the serial cable required between the PC and KEY for the MAX1452 be a null modem (straight through) or cross cable?

The cable is a straight-through connection (basically an extension cable). One is included in the MAX1452 EV kit package.

How do I trim the MAX1452 oscillator frequency to 1MHz?

Using the MAX1452 EV kit software, enable the CLK1M and drive the TEST pin high with VDD. Then connect an oscilloscope to the CLK1M pin and change the OSC[2:0] bits in the Configuration register until the frequency of the signal on the CLK1M pin is closest to 1MHz. Note that the MAX1452 EV kit software does not allow for direct modification of the oscillator bits. Instead, a flash file with the desired oscillator bits setting must be created and then uploaded to the flash memory using the MAX1452 EV kit software. Here is the sequence of steps: 1) Save Flash to File. 2) Open the file and modify the oscillator bits. 3) Load Flash from File.

Can the MAX1452 be used in voltage-bridge-drive mode?

Yes, the MAX1452 can be configured as voltage-bridge drive by shorting the ISRC and BDR pins together.

My sensor may be at a different temperature than the MAX1452 signal conditioner. Can I still compensate the sensor?

Yes. The FSOTC DAC and offset TC DAC provide first-order temperature compensation. This is possible because the reference voltage to FSOTC DAC and offset TC DAC is the BDR (sensor-excitation) voltage, which is temperature dependent. In this case, the internal lookup tables must be filled with a constant value. The compensation process is the same as for the MAX1458/MAX1478. Consult the factory for more details.

The MAX1452 Evaluation kit software does not allow writing to the oscillator bits in the Configuration register. How can I write to these bits?

The only way to write to these bits with the MAX1452 EV kit software is to generate a flash file with the oscillator bits set to the desired value. Then, using the EV kit software, perform the "Load Flash from File" operation to write the file into flash.

What is the sensor-excitation mode of the MAX1452 signal conditioners?

The default mode is current-bridge drive. However, the MAX1452 can also be configured as voltage-bridge drive. This configuration is accomplished by shorting the ISRC and BDR pins together. Voltage-bridge drive is not possible with the MAX1455.

What is the largest sensor output that can produce 4V of span (VDD = 5V) in the MAX1452, without requiring an external circuit?

The largest sensor output can be determined when the smallest excitation voltage setting of 1.5V (VDD = 5V) and smallest PGA gain (39x) are applied. The applying equation is: sensor output (mV/V) = Span (V) / [VBDR (V) x PGA-Gain (V/V)] x 1000. The largest possible sensor output is 68mV/V.