No, PinPoint^® uses piezoelectric transducers and therefore is not sensitive magnetic fields and does not produce a magnetic field.

Due to the very low current used by PinPoint^®, interference through the power supply is very unlikely. However, we do recommend using “star points” and good tracking policies to give optimal isolation.

No, the transducers within PinPoint^® are not sensitive to magnetic fields.          

We do specify sensitivity to gravity and linear acceleration, but because PinPoint^® uses a balanced ring as the vibrating structure, it is very resilient to gravity, linear acceleration and vibration.

No. If you use the analogue output of PinPoint^®, we recommend using an anti-aliasing filter in the signal path to the analogue to digital converter (ADC), to reduce the aliasing of noise to in-band frequencies.

In analogue output mode it will give a potentially useful rate measurement output above the preset ‘maximum’ rate range, but performance (i.e. linearity) is not guaranteed.

The nominal zero bias is ½Vdd; 1.65V. The maximum specified rate range is scaled to occur at ±1.0V of the nominal zero bias. The scale factor remains linear to at least 10% beyond the ‘specified’ limit of ±1.0V (i.e. ±300º/s) to allow for tolerances, and beyond this linear range the output will not be guaranteed to be linear and will saturate when it is within approximately 100mV below the supply rail. So, a PinPoint® gyro configured to ±300º/s ‘maximum’ rate range will actually measure up to ±465º/s [(1,650mV – 1,000mV – 100mV)÷ 3.3mV/º/s = 165º/s].

The internal ADC has a Successive Approximation Register (SAR) architecture.

The simple answer is ‘Yes’. To answer the question more fully we need to consider the two output modes of PinPoint^®; analogue and digital.

Analogue Output:
There are two possible methods of improving the output resolution and accuracy; (i) Oversampling and, (ii) Switching the measurement range.

(i) Over-sampling; assuming you are, say, digitizing the output at 1,000Hz (i.e. every 1ms) and converting through a 10-bit ADC. By over-sampling, say at 4,000Hz (i.e. every 250µs), and then averaging the four measurements, this
will improve the output accuracy as it will filter the noise from the gyro. This improves accuracy, but not resolution.

(ii) Switching the measurement range; with PinPoint® it’s possible to change the measurement range from, say 300º/s to 75º/s, this will have an effect of a fourfold increase in resolution. To do this you will need to have the ability to ‘talk’ to the gyro through the SPI interface. Through the SPI you can alter the scale factor of the analogue output. It is necessary to ‘reset’ the gyro, in other words it will be effectively switched off and on again, a process which can take
up to 0.3s. This will not have any adverse effect on the function or performance of the gyro, but it is a consideration for the application system design.

Digital Output:
In the case of digital output mode the option of over-sampling is redundant. Through the SPI the rate range can be switched between any of the six pre-determined values; 75º/s, 150º/s, 300º/s or 900º/s. This doesn’t involve a hard-reset of the gyro as described above for the analogue output mode, and so no loss of signal occurs.

As currently configured PinPoint^® is specified to deliver full performance up to 900º/s from both the analogue and digital output channels, but it is in fact capable of measuring above this.

The gyro output, in analogue output mode, clamps at 1,250º/s and should not saturate or invert below this level of rate input. The digital output mode is clipped at 1,024°/s.

PinPoint^® is inherently an analogue sensor which provides an optional digital output. The ASIC has an internal 10-bit ADC but with oversampling it is effectively a 12-bit ADC. This is explained further below.

The internal ADC has a resolution of 10-bits, and a full scale range of +/-1.024V. If, for the purpose of explanation, we consider the +/-300°/s dynamic measurement range only, then the Technical Datasheet (CRMnnn-00-0100-132) defines the analogue scale factor as 3mV/°s. So, the 10bit ADC has a full scale range of +/-341.333°/s [i.e. 1.024V ÷
3mV/°/s].

Internally, the PinPoint^® gyro ASIC is sampling at the resonant frequency of the silicon MEMS ring sensor, which is approximately 22kHz. It is continually calculating a running total of the last 16 samples, which is a 14-bit number. On the falling edge of the SPI_CLK, the 14-bit number is sign extended to a 16-bit number and output to the host. If bit 16 is ‘1’ the sign is –ve, if it is ‘0’ sign is +ve. Bit 15 is not used.

The digital scale factor for a dynamic range of +/-300°/s is 24 bits/°/s, or 1/24°/s per lsb. The range of the ADC is +/-341.333°/s (see above). That implies an ADC of 14 bits [i.e. 682.666°/s ÷ 1/24°/s = 16,384 = 214].

By oversampling the signal, the apparent resolution of the ADC has been improved from 10 bits to 14 bits. However, the improvement is only achieved because of the noise that is inherent in the sensor signal. It is well understood that the effective resolution of an ADC can be improved by the addition of noise and oversampling. The apparent resolution of the ADC improves by 1 bit for every doubling of the sample rate. However, the effectiveresolution only improves as the square root of the increase in sampling rate (the additional noise subsides as the square root of the oversamples).

So, although the 16 times oversampling has given an apparent increase in resolution of 4 bits, the effective increase in resolution is actually 2 bits. For that reason, the ADC in the PinPoint® is described as "effectively a 12 bit ADC".

The temperature sensor is a functional block on the ASIC inside the gyro. It is used to perform internal thermal compensation of the gyro. It is provided as an output in the digital SPI message and thus can be used by the system for overall thermal compensation. It’s not available on the analogue output.

Vref is generated to provide a voltage which tracks half of the supply voltage, that it Vdd/2. Vref is used internal to PinPoint^® and therefore it is important that it maintains stability and is not disrupted in any way. Since the maximum recommended Vdd is 3.6V, the voltage on Vref_cap is unlikely to exceed 1.8V. As far as the capacitor is concerned, we would recommend a 100nF value rated to 10V and it should be of the X7R ceramic type, mounted close to the Vref_cap pin. The track from the capacitor to the Vref_cap pin should not pass through a PCB via. The minimum rated voltage for the capacitor should be 6V, but to reduce stress on the capacitor and increase reliability, we recommend a rating of 10V. In summary, we recommend that the Vref_cap should be: 100nF, X7R MLCC, SMT package mounted close to the Vref_cap pin, rated at 10V and avoiding the use of vias.

PinPoint^® is primarily an analogue gyroscope. A digital block is used to digitise the analogue signal and output it in a digital data stream, on the SPI bus. The ADC used within Pinpoint is effectively a 10 bit device and with oversampling, the resolution becomes effectively 14bits, but the accuracy typically 12bits. In general, the analogue output provides slightly better performance.

If the user needs an analogue signal, then the recommendation is to use the analogue output.

If the user intends to process the data digitally, then the SPI is recommended. If higher performance is required, it is recommended that a higher accuracy ADC scheme be used instead, where performance can be enhanced with high sampling rates, and digital filtering.

For PinPoint^®,  four additional capacitors are needed for correct operation.

You can, but it is important that the Vref maintain stable and is not disrupted in any way. We recommend that the Vref_cap signal is adequately buffered with a ultra-high impedence voltage follower.

Yes, that is one of the features of an SPI bus. The “Slave Select”, (SS) pins are used to select each individual device.

If the digital output is used, then the resolution is taken as the least significant bit of the data in the message. This resolution depends on the rate range the gyroscope has been set up for. The datasheet provides the scale factor in terms of lsbs/°/s. The reciprocal of this number gives the weighting of the lsb, or the digital resolution.

If the analogue output is used, then the best resolution achievable can be taken as either the bottom part of the Allan Variance plot, i.e. the bias instability for the device. An alternative definition for analogue resolution is the minimum observable difference observable at the output for a change to the input. This is related to noise and is normally taken as the input signal which will cause the output to be greater than the noise output.

PinPoint^® is manufactured in Japan at Silicon Sensing Products which is located at the same address as Silicon Sensing Systems Japan, inside the Sumitomo Precision Products complex.

Yes, indeed, PinPoint^® has been used by a number of our customers for such applications. Its low noise coupled with high resilience to shock and vibration makes it an ideal choice. PinPoint^® will measure the angular rate and provide an output proportional to angular motion on the camera. This signal can be used to drive servo motors to keep the camera pointing in the desired direction or maintaining the desired angular rate, removing the unwelcomed disturbances. Alternatively, the signal can be applied to the video signal or image to displace the signal, compensating the unwelcome disturbances in the process. 

No. It has been designed for high volume applications with a superior performance to cost ratio. It is therefore not economic to consider repairing a damaged device.

Q: I see that it’s possible to change the dynamic range on the PinPoint® gyro, can this be done ‘on the fly’, in other words when our application needs the lower rate range and higher resolution, can we ‘switch’ to a lower rate range and will it give us higher resolution?

A: The simple answer is ‘Yes’.  To answer the question more fully we need to consider the two output modes of PinPoint®; analogue and digital.

Analogue Output:

There are two possible methods of improving the output resolution and accuracy; (i) Over-sampling and, (ii) Switching the measurement range.

(i) Over-sampling; assuming you are, say, digitizing the output at 1,000Hz (i.e. every 1ms) and converting through a 10-bit ADC.  By over-sampling, say at 4,000Hz (i.e. every 250µs), and then averaging the four measurements, this will improve the output accuracy as it will filter the noise from the gyro.  This improves accuracy, but not resolution.

(ii) Switching the measurement range; with PinPoint® it’s possible to change the measurement range from say 300º/s to 75º/s, this will have an effect of a fourfold increase in resolution.  To do this you will need to have the ability to ‘talk’ to the gyro through the SPI interface.  Through the SPI you can alter the scale factor of the analogue output.  It is necessary to ‘reset’ the gyro, in other words it will be effectively switched off and on again, a process which can take up to 0.3s.  This will not have any adverse effect on the function or performance of the gyro, but it is a consideration for the application system design.

Digital Output:

In the case of digital output mode the option of over-sampling is redundant.

Through the SPI the rate range can be switched between any of the four pre-determined values; 75º/s, 150º/s, 300º/s or 900º/s.  This doesn’t involve a hard-reset of the gyro as described above for the analogue output mode, and so no loss of signal occurs.

Yes this is possible and allows the user to set up the gyro depending on its orientation in the application.

Analogue Output: If the analogue rate output is being used, then via the SPI digital interface it is possible for the host system to set the analogue measurement range.

Digital Output: The host system can set the required measurement range.

Q: We have another sensor on the same SPI (with a different slave select, /SS). I understand we need to separate DATA_OUT by a gate to achieve high Z if the device is deselected. The question is, do we also need to separate DATA_IN or DCLK, to prevent the CRM100 from getting unwanted commands?

A: DATA_IN and DCLK do not need to be separated. PinPoint^® would only respond to commands if the /SS input line is taken low.

The checksum is calculated before the SPI registers are loaded. When this is carried out, the Data Bytes are stored and updates to them are inhibited. The Checksum is then calculated on the Status Byte and these 4 Data Bytes. The Status Byte however can continue to be updated for a short time after the Checksum has been calculated. Therefore when the Status Byte, 4 Data Bytes and the Checksum are loaded into the SPI register there is a chance that the Checksum is incorrect. It is therefore advised that if a Checksum Error is detected that the Status Byte should still be interrogated for the Status, such as BIT Fault. 

The measurement range of CRM102.1/CRM202.1 is three times that of CRM100/CRM200.  The confusion arises because the CRM102.1 and CRM202.1 datasheets only document the 900deg/s range selection (the second highest range, equivalent to 300deg/s on the CRM100/CRM200).  However, as noted on the web page, the CRM102.1/CRM202.1 gyros are capable of sensing up to 2700deg/s.  In order to do this the rate range selection need to be set for the highest rate range for the device.  By comparing their datasheets with those of the CRM100/CRM200, the method for achieving this can be deduced.  In summary, in digital mode, set the Command Message bits 4 & 3 (RR1 and RR0) to '00'.  In analogue mode, set pins SEL0 and SEL1 both to ground.

• Datasheet
• Brochure
• CRM100 Decal
• CRM100 Gerber
• CRM100 Solid Model
• CRM100 Symbol
• CRM100 Library Part
• CRM 3-axis Gerber
• CRM SPI Flowchart
• CRM Sample Code
• CRM100 MDS
• PinPoint Presentation

• Datasheet
• Brochure
• CRM100 Decal
• CRM100 Gerber
• CRM100 Library Part
• CRM100 Solid Model
• CRM100 Symbol

• Datasheet
• Brochure
• PinPoint Presentation
• CRM200 Gerber
• CRM200 Solid Model
• CRM200 Symbol
• CRM200 Library Part
• CRM200 MDS
• CRM 3-axis Gerber
• CRM Sample Code
• CRM SPI Flowchart

• Datasheet
• Brochure
• CRM200 Gerber
• CRM200 Library Part
• CRM200 Solid Model
• CRM200 Symbol
• CRM200 Decal

• User Manual

• User Manual

• User Manual
• 400046-0300 CAD file