TIME TO DIGITAL CONVERTERS

Time-to-Digital Converters

Time-to-digital converters (TDCs) are devices used to measure time intervals from less than 1ns to several seconds with resolution as fine as 10ps. The first time-to-digital converters were developed for scientific and research purposes. They were considered a combination of a time-to-analog (TAC) and analog-to-digital (ADC) converter.

The ScioSense (previously acam) Time to Digital Converters are used in applications that were previously analog based. They offer much higher resolution and lower current consumption than their analog counterparts. This low current consumption makes these time to digital converters ideal for wireless applications.

Advantages

Ultra Low Current Consumption with standby current as low as only few µA.
Up to 8 STOP Channels
Automatic Calibration of the Measured Value
External Reference Clock in the Range of 1 to 40 MHz.

Products

TDC-GP22

TDC-GP21

TDC-GP2

TDC-GPX2

TDC-GPX

AS6501

Integrated Digital Time To Digital Converters

Thanks to modern CMOS-technology it is possible to integrate fully digital time to digital converters into a single chip. The high precision of the digital time measurement—with resolution down to 10ps—in combination with the large dynamic range (up to 30 Bit), the high stability over temperature and supply voltage and the possibility of low cost production thanks to the CMOS technology make them the first choice for industrial applications.

Additional Information

TDC MEASURING METHOD

INTEGRATED DIGITAL TIME-TO-DIGITAL CONVERTERS

Digital TDCs are integrated circuits for high precision time interval measurement, and this is done without any analog components. These time-of-flight sensors became real, thanks to the innovations in semiconductor technology made over the years. They use the propagation delays of simple logical gates (i.e. inverters) for fine quantization of time intervals. Due to the enormous achievements in signal speed, especially in the CMOS sector, it has become possible to implement such TDCs in standard CMOS technology with a resolution in the picosecond range. Nowadays we can integrate system solutions into a single chip that is efficient, low power, space-saving, and low cost.

Digital TDCs can be split into two groups:

Absolute delay time TDCs
Relative delay time TDCs

ABSOLUTE DELAY TIME TDC

This type of time-to-digital converter uses the absolute propagation time of signals through simple logical elements for fine quantisation of time intervals. (see figure below)

In other words, it determines how many inverter cycles the measured time interval consists of. The figure shows the principle of operation. Clever circuit set-ups, redundant elements and special layout methods on the chip enable the exact reconstruction of the number of basic time intervals. The resolution strictly depends upon the basic delay time in the chip. Resolutions in the range of 14 -100 ps can be achieved by a simple set-up of the measuring core and the use of a state-of-the art CMOS process. The propagation delay itself depends on temperature and supply voltage. Therefore the measured value must be calibrated. This is done by measuring one and two periods of a reference oscillator. Ideally this measurement and the following calculation is done by the TDC itself.

Absolute delay time TDCs have the following advantage:

The delay time of the inverter can be precisely adjusted and stabilized by using a phase controlled loop (PLL). It is independent from supply voltage and temperature.
Good pulse-pair resolution
Multi-hit capability

Customer-specific Integrated TDCs

The use of pure digital circuit design makes it easy to build on the performance features of the standard products and improve specific technical data. Accordingly, ScioSense (previously acam) develops optimized TDC’s which are tailored to the specific measuring requirements of the customer.

Additional measuring modes
Additional mathematical operations for on-chip data processing (e.g. high performance 32 floating point units with focus on low power consumption)
Memory (FIFO, EEPROM…)
Various interfaces
µC cores

The wealth of experience ScioSense (previously acam) has gathered assures the ability to integrate all necessary functions on a single circuit and so to provide a system-on-chip solution.

Implementation Examples

TDC-S1 is a TDC with 25ps standard deviation for use in the ATV (Automatic Transport Vehicle) that will supply the ISS (International Space Station). The high resolution is all the more impressive as this TDC is realized on a radiation hard process.

DFA1 Integrated circuit for detection of the rotation of a propeller meter with extremely low current consumption (<2uA) – contacless, non-magnetic und feedbackless.

Customer-specific Systems

On the base of the ATMD-System we also develop complete solutions and additional modules to fit your application.

Take as an example the AM-HM1 histogramming module, that was developed for RoentDek. This is a standalone PC-based 4-channel TDC with 32MB Histogram memory for fast readout of Delay-Line-Detectors developed by RoentDek. For more information, please contact RoentDek.

Another example is the Time-of-Flight Module offered by GPTA (Gesellschaft für physikalisch-technische Anwendungen). The key features of this module are virtually dead time free operation, 5 ns multihit dead time in 1 channel mode, (60±5) ps maximum resolution, an input for multicard coincidence measurements. For more information, please email sales@gpta.de

precision-measurement-tdc-cust-spec-tof-mod

Time-of-flight Module

precision-measurement-tdc-cust-spec-space

TDC-SI Module

precision-measurement-tdc-cust-spec-histogramming1

AM-HMI-Histogramming Module

Documentation & Downloads

Datasheet

Software

PCN/PDN (Product Change / Discontinuation Notes)

Datasheet

Software

PCN/PDN (Product Change / Discontinuation Notes)

Ordering Numbers

Type	Part number	Package	RoHS compl.	Shipping package
TDC-GP22:
TDC-GP22	MNR 1949	QFN32	Yes	Tray
TDC-GP22	MNR 1950	QFN32	Yes	Tape & Reel (5k)
GP22-EVA-KIT	MNR 1951	System	Yes	Box
GP22-DEMO-KIT	MNR 1979	System	Yes	Box
TDC-GP21:
TDC-GP21	MNR 1839	QFN32	Yes	Tray
TDC-GP21	MNR 1720	QFN32	Yes	Tape & Reel (3K/5K)
GP21-EVA-KIT	MNR 1781	System	Yes	Box
TDC-GP2:
TDC-GP2	MNR 1058	QFN32	Yes	Tray
TDC-GP2	MNR 1480	QFN32	Yes	Tape & Reel (2k)
TDC-GP1:
TDC-GP1	MNR 278	TQFP44	Yes	Tray
TDC-GPX:
TDC-GPX	MNR 975	TQFP100	Yes	Tray
TDC-GPX-FG	MNR 1089	TFBGA120	Yes	Tray

Ordering Numbers

Type	Part number	Package	RoHS compl.	Shipping package
TDC-GP22:
TDC-GP22	MNR 1949	QFN32	Yes	Tray
TDC-GP22	MNR 1950	QFN32	Yes	Tape & Reel (5k)
GP22-EVA-KIT	MNR 1951	System	Yes	Box
GP22-DEMO-KIT	MNR 1979	System	Yes	Box
TDC-GP21:
TDC-GP21	MNR 1839	QFN32	Yes	Tray
TDC-GP21	MNR 1720	QFN32	Yes	Tape & Reel (3K/5K)
GP21-EVA-KIT	MNR 1781	System	Yes	Box
TDC-GP2:
TDC-GP2	MNR 1058	QFN32	Yes	Tray
TDC-GP2	MNR 1480	QFN32	Yes	Tape & Reel (2k)
TDC-GP1:
TDC-GP1	MNR 278	TQFP44	Yes	Tray
TDC-GPX:
TDC-GPX	MNR 975	TQFP100	Yes	Tray
TDC-GPX-FG	MNR 1089	TFBGA120	Yes	Tray

Time-to-Digital Converters

Advantages

Products

Integrated Digital Time To Digital Converters

Additional Information

TDC MEASURING METHOD

Customer-specific Integrated TDCs

Implementation Examples

Customer-specific Systems

Documentation & Downloads

Datasheet

Application Notes

Software

PCN/PDN (Product Change / Discontinuation Notes)

Datasheet