FAST ComTec TA1000B-x User manual

TA1000B-x
Fast, Very Low Noise Pulse / Timing Preamplifier
User Manual
copyright FAST ComTec GmbH
Grünwalder Weg 28a, D-82041 Oberhaching
Germany
Version 1.1, Mai 1, 2011

Warranty
ComTec GmbH II
Warranty
Equipment manufactured by FAST ComTec GmbH is warranteed against defects in materials and
workmanship for a period of twelve months from date of shipment, provided that the equipment
has been used in a proper manner as detailed in the instructions manuals. During the warranty
period, repairs or replacement will be made to FAST ComTec's discretion on a return to factory
basis. The transportation costs, including insurance to FAST ComTec is the responsibility of the
customer except for defects discovered within 30 days after receipt of the equipment, where
shiping expense will be paid by FAST ComTec.
Copyright 1988 - 2011 FAST ComTec GmbH,
D-82041 Oberhaching, Germany
All rights reserved.
This manual contains proprietary information; no part of it may be reproduced by any means
without prior written permission of FAST ComTec, Grünwalder Weg 28a, D-82041 Oberhaching,
Germany. Tel: ++49 89 66518050, FAX: ++49 89 66518040.
The information in this manual describes the hardware and the software as accurately as
possible, but is subject to change without notice.
FAST ComTec GmbH, Grünwalder Weg 28a, D-82041 Oberhaching, Germany
Tel. [phone], Geschäftsführer Dr. Wolfgang Wagner,
Handelsregister München HRB 73004

Table of Contents
ComTec GmbH III
Table of Contents
1. Description ..........................................................................................................................1-1
2. Specifications ......................................................................................................................2-1
2.1. Absolute maximum ratings.......................................................................................2-1
2.2. Technical data.........................................................................................................2-1
2.3. Power requirements ................................................................................................2-1
2.4. Diagrams.................................................................................................................2-2
2.4.1. 0 to –400mV falling edge pulse response ....................................................2-2
2.4.2. Max. output broadband noise voltage..........................................................2-4
2.4.3. Simulated frequency response ....................................................................2-7
2.5. Metal case...............................................................................................................2-7
2.6. Accessories.............................................................................................................2-7
2.7. Available options .....................................................................................................2-8

Description
ComTec GmbH 1-1
1. Description
The TA1000B-x comprises a series of fast, very low noise preamplifiers with model dependent
voltage gains of 10, 50, 100 or 200 V/V and corresponding small signal bandwidths of 710, 1000,
950 or 400 MHz respectively.
A unique feature for such high speed amplifiers is DC coupling. DC coupling avoids count rate
effects due to non DC balanced pulse trains and the corresponding charging of coupling
capacitors. This is particularly important when bursts of pulses may occur.
Basically the TA1000B is a non inverting, closed loop, voltage mode, one- or two-stage
operational amplifier design.
Input offset adjustment is provided. The input related adjustment range is approximately >±5 mV.
Each model is available with a bandwidth limited (BWL) option which further reduces the noise
floor.
WARNING: The amplifier has no thermal shutdown. Thus, be careful when connecting the output
to loads less than 50 Ohms (do not shorten the output!).
Type Nominal
Gain
[V/V]
Nominal
Gain
[dB]
Small
Signal
Band-
width
(-3dB)
Gain
Flatness
Peaking
(100ps
Rise Time
Input
Pulse)
Noise
Figure
(100MHz)
Input
Referred
LF Noise
(20Hz ...
1MHz)
(0) (1) (0) (1) (0) (2) (3) (4) (4) (5)
TA1000B-10 10 20dB 710MHz 0.00dB 6% 8dB 51.2µVrms 0.224mVp-p 0.3µVrms
TA1000B-10 BWL(6) 10 20dB 170MHz 0.00dB 0% 30.2µVrms 0.124mVp-p
TA1000B-50 50 34dB 1000MHz 0.22dB 9% 57.8µVrms 0.541mVp-p 0.5µVrms
TA1000B-50 BWL(6) 50 34dB 245MHz 0.00dB 0% 36.6µVrms 0.509mVp-p
TA1000B-100 100 40dB 950MHz 0.12dB 8% 55.9µVrms 0.542mVp-p 12.3µVrms
TA1000B-100 BWL(6) 100 40dB 245MHz 0.00dB 0% 34.2µVrms 0.318mVp-p
TA1000B-200 200 46dB 400MHz 0.00dB 0% 31.2µVrms 0.331mVp-p 13.6µVrms
TA1000B-200 BWL(6) 200 46dB 110MHz 0.00dB 0% 23.1µVrms 0.223mVp-p
Input Referred
Broadband Noise
(DC ... 12.5GHz)
(0) Simulation Results
(1) Signal input: sine wave = 200mVeff / "nominal Gain"
(2) Output Pulse Height approx. 200mVp-p, Input Rise Time 100ps
(3) defined as RMSΔ = σ = standard deviation, ref. scope pictures of output noise voltages below
(4) in 40 minutes accumulated with a 12.5GHz sampling head, ref. scope pictures of output noise voltages below
(5) measured with a HP3455A True RMS Voltmeter, this is mostly the 1/f noise
(6) BWL = Bandwidth limited option (with improved noise performance)
Fig. 1.1: Comparison chart

Description
ComTec GmbH 1-2
Typical applications for the TA2000B are:
 Pre-amp for ultra fast detectors (MCP, PMT, …)
 Oscilloscope and transient recorder pre-amp
 High precision Time-of-Flight
 Photon-/Ion-counting
 Wideband signal processing
Fig. 1.2: TA1000B-10 simplified schematic
Fig. 1.3: TA1000B-50 / -100 / -200 simplified schematic

Specifications
ComTec GmbH 2-1
2. Specifications
2.1. Absolute maximum ratings
Supply: (100 ms max.) ......................................................................... 25V
Signal input: ........................................................................................... 2.5 V
ESD rating: ................................................................................. 23000 V HBM
.......................................................................................200 V MM
2.2. Technical data
Voltage gain: TA1000B-10: .......................................... non inverting, 20dB / x10
TA1000B-50: .......................................... non inverting, 34dB / x50
TA1000B-100: ....................................... non inverting, 40dB / x100
TA1000B-200: ....................................... non inverting, 46dB / x200
Input connector: .............................................................BNC, 50 Ohm, DC coupled
...........................................................AC coupling option available
Output connector: .................................................. BNC, low impedance, DC coupled
...................................................... 50 Ohm output option available
Output voltage: ................................................................................... max. 1.3 V
Output current: ............................................................................... max. 150 mA
Slew rate: TA1000B-10 (2 V step) ..................................................1600 V/µs
TA1000B-10 BWL (2 V step) ............................................530 V/µs
Input offset voltage: ................................................................................ max. 1.5 mV
.............................................................................. typ. 2.0 µV/°C
Input offset adjustment: ........................................................................................ > 5 mV
2.3. Power requirements
Supply connectoer: ...........................................................................2.1 mm center pin
Supply voltage: ............................................................................. nominal +12 VDC
voltage range: ........................................................+10 … +18 VDC
...................................................................false polarity protection
Supply power: ............................................................................................. 2.5 W

Specifications
ComTec GmbH 2-2
2.4. Diagrams
2.4.1. 0 to –400mV falling edge pulse response
TA1000B-10 (x10), Input 20mV/div, Output 100mV/div
TA1000B-50 (x50), Input 5mV/div, Output 100mV/div
TA1000B-10BWL (x10), In 20mV/div, Out 100mV/div
TA1000B-50BWL (x50), In 5mV/div, Out 100mV/div
The scope pictures are taken using a
TEK11801C digital sampling scope with a
SD20 20 GHz loop-
through sampling head for input signals and a SD22 12.5GHz
low noise sampling head for output signals

Specifications
ComTec GmbH 2-3
TA1000B-100 (x100), Input 2mV/div, Output 100mV/div
TA1000B-200 (x200), Input 1mV/div, Output 100mV/div
TA1000B-100BWL (x100), In 2mV/div, Out 100mV/div
TA1000B-200BWL (x200), In 1mV/div, Out 100mV/div
The lower window of each plot shows details of the corresponding signals in the upper window.
There is also a (red colored) histogram of the output signal jitter at a -100mV or –130mV
threshold. The jitter's Peak-to-Peak value is visible at "PkPk" and its standard deviation in the
"RMSΔ" readout.
This jitter histogram gives a good indication of the timing accuracy and resolution that can be
expected.
And, one can very well see that the optimum threshold setting for timing measurements is often
not at half of the signal's amplitude but at some other level not too far from idle voltage where the
slew rate is at maximum.

Specifications
ComTec GmbH 2-4
2.4.2. Max. output broadband noise voltage
Normally the noise is given input referred, so to speak, it can be compared to the source signal
levels. For timing applications it is often more depicting to plot the total output noise of an
amplifier.
In the following scope pictures the output noise voltage of our TAx-amplifiers is accumulated over
10,000 waveforms corresponding to about 40 minutes of measurement time. Used was a
TEK11801C digital sampling scope with a SD22 12.5GHz sampling head. Thus, the displayed
noise voltage is accumulated over a long period and also over the full bandwidth of each
amplifier. The TAx's inputs were shortened, i.e. ZSource = 0Ω.
On the right side of each plot you can see a (red colored) histogram of all the voltage samples in
the respective picture. This gives the probability distribution of the noise voltage levels. And, you
can find some analysis data on the respective voltage distribution: Mean = average value, RMSΔ
=σ= standard deviation, PkPk = Peak-to-Peak voltage = max. – min. sample voltage, μ± 1σ=
percentage of samples that fall within ±1 standard deviation of the mean (.±2σ, ±3σrespectively).
Sampling Head alone, 2mV/div

Specifications
ComTec GmbH 2-5
TA1000B-10 (x10), 5mV/div
TA1000B-50 (x50), 10mV/div
TA1000B-10 BWL (x10), 5mV/div
TA1000B-50 BWL (x50), 10mV/div

Specifications
ComTec GmbH 2-6
TA1000B-100 (x100), 20mV/div
TA1000B-200 (x200), 20mV/div
TA1000B-100 BWL (x100), 20mV/div
TA1000B-200 BWL (x200), 20mV/div

Specifications
ComTec GmbH 2-7
2.4.3. Simulated frequency response
2.5. Metal case
Case material: ........................................ extruded aluminium sheath, Al Mg Si 0.5
Lid material: ...................................................................... die cast, GD-Al Si 12
Size: ...................................................................... 65/101 x 60 x 35 mm
Weight: .............................................................................................. 124 g
2.6. Accessories
 External wall power supply (included)
 L-clips (order no. AB-WL) for wall-/screw-mounting (optional)
Fig. 2.1: Simulated frequency response of all TAx models

Specifications
ComTec GmbH 2-8
2.7. Available options
 50 Ohm output impedance
This improves the output signal quality since reflections from the target device
(oscilloscope, multichannel analyzer, etc.) are well terminated at the TA2000's output and
do not travel many times back and force over the cable. Thus, distortion of a subsequent
pulse is largely avoided.
This option is particularly recommended when high pulse rates are expected.
The drawback, of course, is a reduction in the receiving amplitude at the target device by
a factor of 2. Or, in other words, the effective voltage gain into a 50Ωload is reduced by a
factor of 2 (-6 dB).
 Input AC coupling
An input AC coupling with 100nF can be ordered. This results in a lower frequency cut-off
of approx. 32 kHz.
 Bandwidth Limit
A bandwidth limited option is available that further reduces the noise floor (ref.
comparison chart for details on the resulting bandwidth and noise).