Low Noise Factory LNF-PBA User manual

[e-mail]
lownoisefactory.com
Low Noise Factory AB
Nellickevägen 24,
412 63 Göteborg,
Sweden
Date
2023
-11-22
Manual
LNF-PBA
Low Noise Power Block

Manual
LNF
-PBA
Low Noise Power Block
Date
2023
-11-22
[e-mail]
lownoisefactory.com
Low Noise Factory AB
Nellickevägen 24,
412 63 Göteborg
, Sweden
2
Contents
1. Introduction....................................................................................................................................................... 3
2. Specifications .................................................................................................................................................... 3
3. Before First Use ................................................................................................................................................. 4
4. Front and Rear Panels ....................................................................................................................................... 4
4.1. Front Panel .................................................................................................................................................... 4
4.2. Rear Panel...................................................................................................................................................... 5
5. Installation ........................................................................................................................................................ 5
6. Mains Voltage and Fusing.................................................................................................................................. 6
6.1. LNF-PBA 115/230 VAC version - Mains Voltage and Fusing ........................................................................ 6
6.2. LNF-PBA 100 VAC version............................................................................................................................. 7
7. Using the Instrument......................................................................................................................................... 7
8. Maintenance and Service .................................................................................................................................. 8
9. Pinout................................................................................................................................................................. 8

Manual
LNF
-PBA
Low Noise Power Block
Date
2023
-11-22
[e-mail]
lownoisefactory.com
Low Noise Factory AB
Nellickevägen 24,
412 63 Göteborg
, Sweden
3
1. Introduction
LNF-PBA is a ±12 VDC low noise linear power supply designed to power LNF’s line of HEMT power supplies. It is
provided in two versions: one which accepts the mains voltage of either 115/230 VAC (selectable on the rear
panel) or another which operates at 100 VAC. The front panel has eight output connectors, all delivering the ±12
VDC.
2. Specifications
Input
Parameter
Mains Voltage
Minimum
Nominal
Maximum
Unit
AC Input voltage range
100
115
230
87
104
209
100
115
230
110
132
264
VAC
AC Input Power
100
115
230
100
100
100
W
Input Frequency
AC input frequency
47
63
Hz
Output
Parameter
Description/Conditions
Minimum
Nominal
Maximum
Unit
Efficiency
55
%
Noise
Ripple and noise
2
3
mV
PK-PK
Maximum
Output Current
+12V
-12V
1.7
1.7 A
Load Regulation
Output change for 50% load change
-0.05
0.05
%
Environmental
Parameter
Description/Conditions
Minimum
Nominal
Maximum
Unit
Storage Temperature
-40
85
°C
Operating Temperature
5
40
°C
Relative Humidity1
Non-Condensing
5
80
%RH
1The LNF-PBA is for indoor use only, pollution degree 2.

Manual
LNF
-PBA
Low Noise Power Block
Date
2023
-11-22
[e-mail]
lownoisefactory.com
Low Noise Factory AB
Nellickevägen 24,
412 63 Göteborg
, Sweden
4
Physical
Weight
3.21 kg
Dimensions
256 (W) x 98 (H) x 156 (D) millimeters
Safety
•IEC 61010-1:2010 3rd edition
Electromagnetic Compatibility
•Compliant with EMC directive IEC 61326-1:2012
3. Before First Use
After unpacking, make a visual inspection to ensure that there is no damage to the unit. If any damage is found,
please contact the factory prior to taking it into operation.
4. Front and Rear Panels
4.1. Front Panel
Both (115/230 and 100 VAC) versions of the LNF-PBA have the same front panel. For details, please
see Figure 1.
Figure 1 LNF-PBA - front panel
Readout of current
load from +12 VDC
8 x ±12 VDC output connectors
Earth and Common access

Manual
LNF
-PBA
Low Noise Power Block
Date
2023
-11-22
[e-mail]
lownoisefactory.com
Low Noise Factory AB
Nellickevägen 24,
412 63 Göteborg
, Sweden
5
4.2. Rear Panel
The rear panel is not the same for 155/230 VAC and 100 VAC versions. For details, please refer to
Figure 2 and Figure 3.
Figure 2 LNF-PBA 155/230 VAC version - rear panel
Figure 3 LNF-PBA 100 VAC version - rear panel
5. Installation
The instrument must be installed on a flat and solid surface with at least 5 cm of clearance on the topside and
right side where the air-intake and outlet are located.
The connection to the mains must be made with a cord compatible with IEC 60320-C14 with an earth prong. The
instrument must be connected to an outlet with protective earth.
Selected mains voltage
indicator/fuse cartridge
Mains switch
AC inlet
Fuse cartridge
AC inlet
Mains switch

Manual
LNF
-PBA
Low Noise Power Block
Date
2023
-11-22
[e-mail]
lownoisefactory.com
Low Noise Factory AB
Nellickevägen 24,
412 63 Göteborg
, Sweden
6
6. Mains Voltage and Fusing
6.1. LNF-PBA 115/230 VAC version - Mains Voltage and Fusing
The instrument can be used with either 115 or 230 V mains voltage. The mains voltage is selected by
configuring the Power Entry Module on the rear panel. It is preconfigured to the voltage of your
country when you receive the instrument. Should you have to change it you need to follow the below
procedures:
1. Unplug the power cable from the instrument.
2. Open the hatch for the fuse cartridge with a slot screwdriver. See Figure 4 below for details.
3. Use a slot screwdriver to carefully pry out the red fuse cartridge – see Figure 4.
4. Replace both fuses in the fuse cartridge (see Figure 5) according to the markings on the
instrument. For 230 V use 0.5 A slow blow fuse and for 115 V use 1 A slow blow. The fuse size is
¼” x 1-¼“.
5. Rotate the fuse assembly 180 degrees and reinsert it into the power entry module.
6. Close the fuse cartridge hatch.
7. Double check that the mains voltage indicator shows the voltage you want it to be configured to.
Figure 4 LNF-PBA 115/230 VAC version – disabling fuse cartridge
Fuse cartridge hatch
Fuse cartridge

Manual
LNF
-PBA
Low Noise Power Block
Date
2023
-11-22
[e-mail]
lownoisefactory.com
Low Noise Factory AB
Nellickevägen 24,
412 63 Göteborg
, Sweden
7
Figure 5 LNF-PBA 115/230 VAC version - fuse cartridge
6.2. LNF-PBA 100 VAC version
This version of the LNF-PBA does not have an option to be reconfigured – it is preconfigured to 100
VAC only.
7. Using the Instrument
The LNF-PBA uses a transformer, rectifiers, and regulators to convert mains AC to ±12 VDC needed for LNF’s
HEMT power supplies. There are eight identical output connectors on the front panel providing the ±12 VDC to the
HEMT power supplies. All eight outputs are connected in parallel and are not galvanically isolated from each other.
There is a panel instrument on the front panel indicating how much current is drawn from the +12 VDC rail. Since
all LNF’s current and future HEMT power supplies mainly draw current from the positive rail, this current will
always be the limiting factor to how many power supplies the LNF-PBA can drive. The maximum current the
instrument can deliver is 1700 mA. The instrument has automatic current limit/foldback protection. When the
current exceeds 1700 mA, the voltage will drop below 12V. When this happens all HEMT power supplies
connected to the instrument will be affected and will not operate properly.
In the case of using of several LNF-PSs used, due to the foldback nature it is good practice to always have the
LNF-PSs displays switched off before the LNF-PBA is switched on. This is due to the inrush current related to
displays on the LNF-PSs which can start simultaneously and together overrun the current limit of the foldback and
get it to trigger unintentionally.
The table below lists typical current draw from LNF’s HEMT power supplies. It is important to place the instrument
so that the panel meter can easily be read and the mains switch can easily be reached. Only use the supplied cable
to connect the instrument to LNF’s power supply or the accessory cable LNF-CAB_PBA_PS3b.
Power supply model
+12V current at Ids = 0 mA
+12V current at maximum Ids
LNF-PS_3
70 mA
120 mA
LNF-PS3b
70 mA
150 mA
LNF-PS_EU2
35 mA
235 mA
LNF-PS4
240 mA
510 mA
LNF-PS8
260 mA
785mA
Fuses

Manual
LNF
-PBA
Low Noise Power Block
Date
2023
-11-22
[e-mail]
lownoisefactory.com
Low Noise Factory AB
Nellickevägen 24,
412 63 Göteborg
, Sweden
8
There is access to circuit common and earth on the instrument’s front panel. There is also a jumper plug included
with the instrument which can be used to connect circuits common to earth. With this feature, the instrument can
be configured to be floating or non-floating. It is highly recommended to always use it non-floating, i.e. with the
jumper plug installed, when connecting or disconnecting LNAs to your system. Once the system is in operation,
the jumper plug can be removed if a floating system is desired. This could be the case in complex electrical
systems with many ground return paths to prevent ground loops. If there is no specific reason to use it floating, it
is recommended to always leave the jumper plug installed. In floating operation, the instrument common can float
several Volts over earth (depending on your lab’s electrical system) which could cause LNA failures when
connecting or disconnecting an LNA if the Vd or Vg pin engages before the ground pin. It is therefore important to
always use the jumper plug when connecting or disconnecting LNAs.
Jumper plug
8. Maintenance and Service
There are no serviceable parts in the instrument. If the ventilation holes are clogged with dust, disconnect the
instrument from the mains supply and use a dry cloth to gently clear the ventilation holes.
9. Pinout
3-Pin male M8 connector seen from outside LNF-PBA chassis
GND
+12 V
-12 V