MEMS / PDM

A HIGH PERFORMANCE PDM INPUT FOR ANY AUDIO ANALYZER

DCC-1448 for R&D


Simple, transparent digital audio connectivity: Connects to any software based analyzer via USB or use SPDIF to add PDM to an existing hardware-based analyzer

High performance 24 bit converter with full control over parameters and clock for PSRR and other interface-specific tests

Acoustically silent for placement in anechoic chambers

PQC-3048 for QC

Ruggedized for production environments

Simplified connectors for increased throughput and zero setup errors. USB for power and control, and a pluggable phoenix connector to interface with the device under test

Ready for integration into an automated test sequence; delivers exact same results as R&D model for greatest possible QC assurance

PDM 1 bit digital audio to 24-bit PCM

Portland Tool & Die PDM interfaces add a high performance PDM input to any audio analyzer, enabling comprehensive characterization of MEMS (Micro-Electro-Mechanical-Systems) microphones and other devices with a 1-bit PDM (Pulse Density Modulation) output.

Typically seen in modern smartphones, MEMS microphones are becoming more and more popular due to their low cost, but without a PDM input, engineers have been forced to make their measurements in the analog domain using homemade jigs that were at best incomplete, and at worst completely unreliable.

With PT&D interfaces, conversion from the 1-bit PDM signal to a 24-bit PCM signal occurs entirely in the digital domain for maximum fidelity, and the units are completely acoustically silent, making them ideal for using inside an anechoic chamber ( a useful feature since MEMS microphones can only drive a short cable).

Both models can connect with two microphones simultaneously. In the R&D lab, this is useful for evaluating matched pairs of mics or characterizing finished products. On the production line, it enables faster test throughput.

Special Interface-specific tests

In addition to converting the MEMS microphone’s 1-bit PDM output to a 24-bit, 48kHz PCM signal, the R&D model also includes features to measure characteristics unique to MEMS microphones. These include a programmable clock for measuring performance relative to sample rate, a programmable power supply for measuring performance relative to supply voltage and a power supply rejection impairment generator for measuring power supply rejection ratio (PSRR).

Fully compatible with any audio analyzer 

All PT&D interfaces support high quality USB audio streaming. Depending on the model, PT&D interfaces can also connect via SPDIF. USB is ideal for software based analyzers such as Listen Soundcheck. For hardware-based analyzers such as an AP 2700 Series or Rohde & Schwarz UPV, SPDIF or USB audio can be used.

AUDIO CONNECTIVITY OPTIONS

USB AUDIO

Appears in OS like any other USB external audio interface. Ideal for software-based analyzers like Listen SoundCheck or hardware analyzers that can access USB audio streams. Mac or Windows.

[Supported on all models]

SPDIF AUDIO

Offers more flexibility in handling audio data streams than USB. Ideal for hardware-based analyzers with a DIO or connection to software-based analyzers that use an ASIO-supported external audio interface.
[Supported on DCC-1448 for R&D only]

CONTROL OPTIONS

WINDOWS CONTROL APP

Control every parameter from the command line. Integrate into a master test application, or call from your analyzer control software. Appears natively within Listen SoundCheck.

[Supported on all models]

TOUCHSCREEN

Access every parameter directly from the front panel for on-the-fly configuration changes or troubleshooting. Save test setups to on-board memory.

[Supported on DCC-1448 for R&D only]

SPECIFICATIONS

DCC-1448

PQC-3048

PDM Data Input500 kHz to 4 MHz sample rate
Mono or Stereo multiplex
1.5 to 5.5 V logic level
Selectable 5, 50, 100, 200, or 400 pF input capacitance
Selectable open or closed circuit
BNC Connector
500 kHz to 4 MHz sample rate
Mono or Stereo multiplex
PDM Data Output24 bit, 48 kHz sample rate
USB Audio – Windows and Mac compatible
24 bit, 48 kHz sample rate
USB Audio – Windows and Mac compatible
Data inputOn/OffAlways On
Selectable Capacitance5, 50, 100, 200 or 400 pF5 pF Fixed
InterfaceSPDIF, USBUSB Only
Vdd DC Power Supply0 to 5.5 V DC
10 mAmp current limit
Selectable power supply rejection impairment waveform generator

Sine or Square waveform
20 to 20 kHz frequency
0 to 1 Vpp AC waveform amplitude

Banana style binding post style connector
0 to 3.3 V DC
10 mAmp current limit
PSR Impairment GeneratorSine or Square waveform, 20 Hz - 20 kHz, 0 - 1 Vpp waveform amplitudeNo
Control InterfaceTouchscreen, USBUSB Only
Dimensions (H x W x D)86mm x 271mm x 211mm30mm x 64mm x 135mm
Weight1.6 kg0.18kg
Power12 VDC, 24W power input supplied with universal 100 to 240 VAC, 50 to 60 Hz power supplyUSB Bus powered

Portland Tool & Die
3252 NW Bauer Woods Dr
Portland, OR, 97229