TDC-GP2 T&R 2K

acam-messelectronic gmbH is now Member of the ams Group The technical content of this acam-messelectronic document is still valid. Contact information: Headquarters: ams AG Tobelbader Strasse 30 8141 Premstaetten, Austria Tel: +43 (0) 3136 500 0 e-Mail: ams_sales@ams.com Please visit our website at www.ams.com Time-to-Digital Converter Target Specification TDC-GP2 2-channel Universal Time-to-Digital Converter 26th May 2010 Document-No.: DB_GP2_e V2.0 TDC TDC-GP2 Published by acam-messelectronic gmbh © acam-messelectronic gmbh 2010 Disclaimer / Notes The information provided by this data sheet is believed to be accurate and reliable. However, no responsibility is assumed by acam for its use, nor for any infringements of patents or other rights of third parties that may result from its use. The information is subject to change without notice and is provided „as is“ without warranty of any kind (expressed or implied). Picostrain is a registered trademark of acam. All other brand and product names in this document are trademarks or service marks of their respective owners. Support For a complete listing of direct sales, distributors and sales representatives visit the acam website at: http://www.acam.de/company/distributors For technical support you can contact the acam support team in the headquarter in Germany or the Distributor in your country. The contact details of acam in Germany are: sales@acam.de 1 or by phone +49-7244-74190. acam-messelectronic gmbh - Am Hasenbiel 27 - D-76297 Stutensee-Blankenloch - Germany - www.acam.de TDC-GP2 Table of Contents 1-4 1 Overview 2 Characterisitcs & Specifications 2.1 Electrical Characteristics 2-1 2.2 Timings 2-3 2.3 Pin Description 2-6 2.4 Package Drawings 2-7 2.5 Power Supply 2-8 2.6 Register settings 3 Measurement Mode 1 4 Measurement Mode 2 5 Details and Special Functions 2-10 3.1 General Description 3-1 3.2 Measurement Flow 3-2 4.1 General Descriptionweis 4-1 4.2 Measurement Flow 4-2 4.3 Stop Masking 4-7 5.1 Oscillator 5-1 5.2 Fire-pulse Generator 5-4 5.3 Temperature Measurement 5-7 5.4 SPI-interface 5-10 5.5 Fast Initialization 5-11 5.6 Noise Unit 5-11 6 Applications 6-1 7 Miscellaneous 7-1 acam-messelectronic gmbh - Am Hasenbiel 27 - D-76297 Stutensee-Blankenloch - Germany - www.acam.de 2 Time-to-Digital-Converter 3 TDC-GP2 acam-messelectronic gmbh - Am Hasenbiel 27 - D-76297 Stutensee-Blankenloch - Germany - www.acam.de TDC-GP2 1 Overview 1.1  Introduction TDC-GP2 is the next generation of acam generalpurpose TDCs. Higher resolution and smaller package size make it ideal for cost sensitive industrial applications. With special functional blocks like a fire-pulse generator, stop-enable, temperature measurement, and clock control it is perfectly suited for ultrasonic flow-meter and heat-meter applications. 1.2  Features Measurement Mode 1 Temperature Measurement ƒƒ 2 channels with typ. 50 ps resolution rms ƒƒ 2 or 4 sensors ƒƒ Measurement range 3.5 ns to 1.8 µs (0 to ƒƒ PT500/PT1000 or higher 1.8µs between stop channels) ƒƒ 15 ns pulse-pair resolution with 4-fold multihit capability ƒƒ Very high resolution: 16 Bit eff. (0.004 °C resolution for platinum sensors) ƒƒ Ultra low current (0.08 µA when measuring ƒƒ 4 events can be measured arbitrarily against every 30 seconds) each other ƒƒ Trigger to rising or/and falling edge General ƒƒ Windowing for precise stop enable ƒƒ QFN 32 package ƒƒ I/O voltage 1.8 V to 5.5 V Measurement Mode 2 ƒƒ Core voltage 1.8 V to 3.6 V ƒƒ 1 channel with typ. 50 ps resolution rms ƒƒ 1 MHz continuous data rate max. ƒƒ Measurement range 500 ns to 4 ms ƒƒ Temperature range – 40 °C to 125 °C ƒƒ 2 x CLKHS pulse-pair resolution with 3-fold ƒƒ 4 wire SPI interface multihit capability ƒƒ Fire pulse generator ƒƒ Trigger to rising or/and falling edge ƒƒ Clock calibration unit ƒƒ Each of the 3 events can be assigned to an ƒƒ Precise stop enable by windowing adjustable measuring window with 10ns reso- ƒƒ Trigger to rising and/or falling edge lution acam-messelectronic gmbh - Am Hasenbiel 27 - D-76297 Stutensee-Blankenloch - Germany - www.acam.de 1-4 Time-to-Digital-Converter 1.3  1-5 TDC-GP2 Blockdiagram acam-messelectronic gmbh - Am Hasenbiel 27 - D-76297 Stutensee-Blankenloch - Germany - www.acam.de TDC-GP2 2 Characterisitcs & Specifications 2.1  Electrical Characteristics Absolute Maximum Ratings Supply voltage Vcc vs. GND - 0.3 to 4.0 V Vio vs. GND - 0.3 to 7.0 V Continous current into Output-Pin (Iout) 30 mA Storage temperature (Tstg) - 65 to 150 °C Junction temperature (Tj) max.125 °C Recommended Operating Conditions Symbol Parameter Conditions Min Vcc Core supply voltage* Vio > Vcc Vio I/O supply voltage tri Max Unit 1.8 3.6 V 1.8 5.5 V Normal Input Rising Time 50 ns tfa Normal Input Falling Time 50 ns tri Schmitt Trigger Rising Time 5 ms tfa Schmitt Trigger Falling Time 5 ms Ta Ambient Temperature 120 °C Tj must not exceed Typ -40 125°C *including the oscillator pins XIN, XOUT, Clk32In, Clk32Out DC Characteristics (Vio = Vcc = 3.3 V ± 0.3 V, Tj = -40 to +85°C) Symbol Parameter Conditions I32 Current 32 kHz Icc + Iio, only 32kHz os- Min Typ Max Unit 4.5 µA 260 µA 15 mA 0: -> Error routine Send SO = 0xB0, Read SI = RES_0 Send SO = 0xB1, Read SI = RES_1 Send SO = 0xB2, Read SI = RES_2 Send SO = 0xB3, Read SI = RES_3 Rhot/Rref = RES_0/RES_1 Rcold/Rref = RES_3/RES_2 Go to look-up table to get the temperatures acam-messelectronic gmbh - Am Hasenbiel 27 - D-76297 Stutensee-Blankenloch - Germany - www.acam.de 6-3 Time-to-Digital-Converter 6.1.4  TDC-GP2 Current consumption a. Time measurement 32.768kHz: are provided by the µP: < 1.3 µA 4 MHz: 0 µA in power down, 270 µA when active TDC: < 150 nA if not active, 15 mA during active time of the high-speed unit With 2 measurements per second (forth and back flow) the total consumption is < 3 µA. b. Temperature measurement A full measurement over all four ports takes less than 2.5 µAs current. Typically the temperature is measured once in 30 seconds. The average current then is about 0.085 µA. This is about 50 times less than with solutions without a TDC. c. Quiescent current Thanks to the current optimized 0.35µ technology the quiescent current is less than 150 nA typ. d. Total system current The complete current for the measuring unit (TDC, analog part, Transducer) will depend on the analog circuit part. It will be in the range of 4 to 6 µA. With a low-power µP (e.g. MSP430 series from TI) the average current consumption of the total device might be in the range of 11 to 16 µA. It is possible to operate the system from a lithium-thionylchloride AA cell for 10 years without changing the battery. At 6 years runtime it maybe even possible to work with a low-cost 3V CR2450 coin cell battery. 6-4 acam-messelectronic gmbh - Am Hasenbiel 27 - D-76297 Stutensee-Blankenloch - Germany - www.acam.de TDC-GP2 7 Miscellaneous 7.1  Bug Report 7.1.1  Quartz Oscillator Start Up time Bug: When using a quartz resonator for the oscillator the oscillation start up time is about 3 ms even with an optimized circuit. The TDC-GP2‘s automatic on-time control for the high speed clock is based on 640 µs or 1280 µs delay without any activity. In case of a quartz resonator this delay is too short and will cause malfunction. Corrective: There are several options to deal with. 1.Oscillator permanently on The possibility of switching off the high speed oscillator is added only for current saving. This oscillator needs about 270 µA when running continuously. In all application without attention to current consumption we recommend to run the high speed oscillator continuously (START_CLKHS=1). 2.Ceramic Resonator With a ceramic resonator the oscillation start up time is about 200 µs. There is no problem with TDC-GP2‘s internal delays. We recommend the use of ceramic resonators in all applications targeting ratio measurements (like ultrasonic flow metering). In all applications that need a quartz resonator and the switch-off functionality we recommend the following measures: 3.Lower Clock Frequency at CLK32In A clock with lower frequency increases the internal timer delays. In this case we recommend about 4 kHz. The timer delay is increased to 10 ms then. This is enough for a save oscillation start up time of the quartz. 4.Start/Stop Oscillator by Software Writing a „1“ or „0“ into Start_CLKHS starts or stops the oscillator by software. This way a µP can start the oscillator by command and then after 10 ms can send a measurement opcode like START_CYCLE. At the end of the measurement the µP has to switch off the oscillator by a further command. acam-messelectronic gmbh - Am Hasenbiel 27 - D-76297 Stutensee-Blankenloch - Germany - www.acam.de 7-1 Time-to-Digital-Converter 7.1.2  Bug: TDC-GP2 DIS_PHASENOISE The TDC-GP2 offers a Phase-Noise function that decouples the calibration clock from the fire pulse generator. This option was implemented to provide the necessary statistics for averaging in case the user is looking for a resolution much better than 1 LSB (about 65 ps) and has a a very strong coupling between the start and the reference clock. Because of a design bug the phase noise unit might fail in case of distortions on the power supply. This is relevant only in measurement range 2. Corrective: The phase noise unit has to be switched off by setting DIS_PHASE_NOISE = 1. In case the start is already asynchronous to the referenceclock this has no effect on the capability of averaging. 7.2  Last Changes 05.10.2006 3.2.1b&c, 5.1.3, DIS_PHASENOISE=1 required 27.11.2006 5.2.2 Additional corrections 3.2.1 Corrections Example 01.02.2007 5.3 Additional corrections for temp. measurement 26.05.2010 Various smaller error fixes. General layout change 7-2 acam-messelectronic gmbh - Am Hasenbiel 27 - D-76297 Stutensee-Blankenloch - Germany - www.acam.de TDC-GP2 acam-messelectronic gmbh - Am Hasenbiel 27 - D-76297 Stutensee-Blankenloch - Germany - www.acam.de 7-3 Data Sheet acam-messelectronic gmbh Am Hasenbiel 27 76297 Stutensee-Blankenloch Germany / Allemagne ph. +49 7244 7419 - 0 fax +49 7244 7419 - 29 e-mail: support@acam.de www.acam.de