PAMS Technical Documentation
Loopset LPS-1/2
Original 10/98
PAMS
Loopset LPS-1/2
Amendment
Number
Date Inserted By Comments
10/98 OJuntune Original
Technical Documentation
AMENDMENT RECORD SHEET
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Technical Documentation
CONTENTS
Loopset LPS-1/2 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Introduction 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Basic Specification 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
List of Modules 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Technical Specifications 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Functional Description 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Modes of Operation 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Loopset detection 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Loop Adapter 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Magnetic Loop 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Specification 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Reception Specifications 7. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Ratings 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Automatic Gain Control (AGC 7. . . . . . . . . . . . . . . . . . . . . . . .
Magnetic Field frequency response window 8. . . . . . . . .
Functional Blocks 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Distortion and noise 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Microphone response window 9. . . . . . . . . . . . . . . . . . . . .
External Signals and Connections 10. . . . . . . . . . . . . . . . . . . . . .
Exploded View of LPS-1/2 12. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Assembly parts of LPS-1/2 12. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Parts List of LPS–1/2 (Version 6.1) Code: 0201179 13. . . .
Loopset LPS-1/2
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Loopset LPS-1/2
Loopset LPS-1/2
Introduction
Hearing impaired people, who use hearing aids (HA), have problems in
using cellular phones. They can’t identify speech, partly due to poor
S/N–ratio and partly because of interference. Most HA have poor protec-
tion for interferences. By using the Loopset the interference problems are
minimized. LPS–1 is designed for 5100 and 6100 series phones. LPS–2
is compatible with Communicator N9110 .
The Loopset has been developed for hearing aid users to allow them to
use mobile phones. It is based on induction technology. These kind of
induction devices are widely used with hearing aids, but never before im-
plemented with cellular phones.
All hearing aids have support for induction loop, ie. they have a little tele-
coil inside. This coil can capture the signal supplied to the loop.
Standard hearing aids have two operation modes; M–mode for normal
microphone use and T–mode for telecoil use
Technical Documentation
The T–mode is used in places where the inductive loop has been as-
sembled, for example in public halls, churches and places of assembly.
The reason for T–mode use is much better S/N–ratio.
The Loopset provides clear acoustic quality. Automatic gain control (AGC)
in the Loopset ensures that there is the correct field strength in the Loop-
set. The Loopset also dampens backgroud noise to make it easier to con-
verse in a noisy environment, in the car for instance.
The Loopset can be used with all the mobile phones, which supports nor-
mal headset and vibra alarm. Vibra is needed just for call indication. The
earpiece of a headset is replaced by a wireloop. Loopset has also inte-
grated microphone.
The earpiece of a headset is replaced by a wireloop. Loopset has also
integrated microphone.
The function is very simple and the use is environmentally friendly. Loop-
set is passed around the neck. The system doesn’t disturb anybody due
to the silent service. When the phone is set to auto–answer mode, a user
don’t have to do anything but switch the hearing aid to T–mode.
Loopset is an economic and simple solution for hearing aid users. Most
hearing aids are compatible to this kind of wireless handsfree.
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Basic Specification
Loopset LPS-1/2
List of Modules
Name of module Type name Material code Note
LPS–1 Product LPS–1 0630146
LPS–1 Module LPS–1 0201179
Assembly parts MLPS1 0261661
LPS–2 Product LPS–2 0630201
Assembly parts MLPS2 0261898
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Loopset LPS-1/2
Recommended batteries:
Type Size Min Vout Max Vout Rated ca-
Zinc Air
Hearing Aid
Battery
Mercuric
Hearing Aid
Battery
Alkaline Battery
675 (LR44) 1.15 1,40 550 mAh 68 day (and hour).
675 (LR44) 1.25 1,45 280 mAh 35 day (and hour).
LR44 1.25 1,45 150 mAh 19 day (and hour).
Technical Specifications
The Nokia LPS–1 Loopset is powered by three hearing aid batteries and
comes pre–packaged with six zinc air batteries.
Technical Documentation
Rated Time of Lop-
pacity
set. Speech in 1.0h
days (4,2%). Con-
sumption 8mA of
the current.
The ”auto answer” feature of the phone allows the users to be ”hands
free” while using either the Nokia LPS–1 Loopset or headset accessories.
The interface between Loopset and phone is similier to a headset. Except
the hight impedance input.
Name of function Specification
Supply voltage
Supply current
Unit Max. dimensions (mm)
(W x H x D)
LPS–1 41x36x18 Weight 60g
2,7 ... 4,5 V
current peak<16 mA (nominal 5–6mA)
Notes
Functional Description
Modes of Operation
When the Loopset is identified the audio of the phone will be routed to the
Loopset and the identification voltage is turned ON. Mic bias voltage 1.5
V is turned ON only in call state.
When the phone is turned off also the Loopset is in off–mode.
Loopset detection
In XMIC line there is a (47 + 2.2) k pull–up in phone. A microphone is a low
resistance pull down compared to that.
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Technical Documentation
When there is no call going, AUXOUT is in high impedance state and XMIC
is pulled up. When loopset is connected, XMIC is pulled down. XMIC is
connected to HeadsetInt line (in MAD), so an interrupt is given due to both
connection and disconnection.
During a call there is bias voltage (1.5 V) in AUXOUT . The state of HeadsetInt
can’t be sure. It is better to disable loopset interrupt during a call and poll from
EAD line (AD converter in CCONT) to see if loopset is disconnected. Actually
disconnection of a headset without remote control switch could be seen in
HookInt, but headset with the switch could not.
Loop Adapter
Connection resistance must be under 3mΩ.
Magnetic Loop
The magnet field is based on the IEC 118–4 and BS 6083 part 4 stan-
dard.
Loopset LPS-1/2
Specification
Reception Specifications
Type of Function Specification Notes
Impedance 100k ohm +/– 5 % at 1 kHz
Frequency responce See figure 1
Magnetic field 100mA/m (RMS) 3dB ref.
1kHz=0dB
400mA/m +12dB,125 ms RMS–
peaks
Loop Current 700mA(RMS) 3dB ref. 1kHz
=>0dB
2,8A (RMS), 125 ms RMS
peaks =>+12dB
Automatis Gain Control Response time <35 ms
Resetting time 0,5–5dB/s
Signal to Noise Ratio 48 dB nominal level (46 mVrms)/ 1kHz
The strength of the magnetic
field measured next to the
ear. (or measured in the horizontal plate and 170mm trip
from the curve of the loop.)
Ratings
Determined as defined by IEC 268 using signal limited to frequency range
300 ... 3400 Hz.
Automatic Gain Control (AGC
Automatic gain control value is >30 decibels
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Loopset LPS-1/2
Magnetic Field frequency response window
dBr
+10
+5
+1 dB
+3 dB
0
–5
–5 dB
–3 dB
–3 dB
–10
Technical Documentation
+3 dB+3 dB
+3 dB
–3 dB–3 dB
–15
–20
300 Hz 3 kHz
1k 2k 4k500250
Figure 1. Magnetic field frequency response window of Loopset.
Functional Blocks
Table 1. Transmission Specifications
Object Specification Notes
Output impedance 1600 ohm +/– 30% 1kHz
Frequency response See Figure 2
Sensitivity –48 dB +6/–3 dB at 1kHz 0dBv/PA
Sensitivity dBm0 –13 dBm0 +6/–3 dBm0 at 1kHz 0dBv/PA – 4,7 dBPA
Sensitivity –59 dB +6/–3 dB at 1kHz 0dBv/PA.
Sensitivity dBm0 –24 dBm0 +6/–3 dBm0 at 1kHz
Directivity mic (acuctic) OMNI–directional
Signal to Noise Ratio 55 dB 1Pa/1kHz
Distortion and noise
Total distortion: Max 3 % 300...3400Hz with sound pressure 0 dBPa
at the microphone.
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Microphone response window
dBr
+10
+5
+1 dB
+3 dB
0
–5
–5 dB
–3 dB
–10
–3 dB
Loopset LPS-1/2
+3 dB+3 dB
+3 dB
–3 dB–3 dB
–15
–20
300 Hz 3 kHz
1k 2k 4k500250
Figure 2. Mic response window of Loopset.
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Loopset LPS-1/2
External Signals and Connections
+
Technical Documentation
AGC
Control
Vout
Phone
+
XEAR
L_GND
Vout
Battery
VOX
XMIC
SGND
Figure 3. Combined Loopset and system connector audio signals
+
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Headset mi
(from accessory to
(from phone to accesso
Technical Documentation
Loopset LPS-1/2
Table 2. X100 connector signals
PinPi
1 1 XMIC
2 2 SGND Audio signal ground.
3 3 XEAR Analog audio input
4 – ––––– Not Connected ––––––––––––––––––––––––––
5 – ––––– Not Connected ––––––––––––––––––––––––––
6 – ––––– Not Connected ––––––––––––––––––––––––––
7 4 L_GND Ground for Xear signals
Name Function Min Typ MaxUnit Description
n
in
x
10
0
1.6 kW Headset source AC impedance
put
crophone in-
phone)
Headset detection
(from accessory to
phone)
Separated from phone
GND
(from phone to accessory)
p
ry
100 400 mA Bias current
200 mV-
p–p
1.4
7
0 1.33V Headset connected (ref. SGND).
-
16 100
2.9 V No headset (ref. SGND).
380
10
47 W Output AC impedance (ref. GND)
10 nF Series output capacitance
k
1.0 V Max. input level. No load
W
nF
W Load AC impedance to SGND: Headset
Maximum signal level
Resistance to phone ground (DC) (in phone)
Series output capacitance
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Loopset LPS-1/2
Exploded View of LPS-1/2
Technical Documentation
Assembly parts of LPS-1/2
ITEM Q’TY CODE DESCRIPTION VALUE, TYPE
1 0201179 Module lps-1
2 9780224 Loop set Cable LPS–1 DMD02438
alt 9780241 Loop set Cable LPS–2 DMD04474
3 9451016 B–cover DMD02639
4 9451015 A–cover DMD02638
5 2 6290021 PT-screw 1,8x8 feznTX6
6 9451246 Battery lid DMD03654
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Loopset LPS-1/2
Parts List of LPS–1 (Version 6.1) Code: 0201179
ITEM CODE DESCRIPTION VALUE TYPE
R001 1430784 Chip resistor 15 k 5 % 0.063 W 0402
R003 1430796 Chip resistor 47 k 5 % 0.063 W 0402
R004 1430778 Chip resistor 10 k 5 % 0.063 W 0402
R005 1430804 Chip resistor 100 k 5 % 0.063 W 0402
R006 1430792 Chip resistor 33 k 5 % 0.063 W 0402
R018 1430778 Chip resistor 10 k 5 % 0.063 W 0402
R020 1430796 Chip resistor 47 k 5 % 0.063 W 0402
R021 1430804 Chip resistor 100 k 5 % 0.063 W 0402
R024 1430792 Chip resistor 33 k 5 % 0.063 W 0402
R025 1430796 Chip resistor 47 k 5 % 0.063 W 0402
R026 1430122 Chip resistor 4.7 M 5 % 0.063 W 0603
R027 1430790 Chip resistor 27 k 5 % 0.063 W 0402
R028 1430804 Chip resistor 100 k 5 % 0.063 W 0402
R031 1430778 Chip resistor 10 k 5 % 0.063 W 0402
R032 1430804 Chip resistor 100 k 5 % 0.063 W 0402
R033 1430780 Chip resistor 12 k 5 % 0.063 W 0402
R034 1430784 Chip resistor 15 k 5 % 0.063 W 0402
R035 1430788 Chip resistor 22 k 5 % 0.063 W 0402
R036 1430778 Chip resistor 10 k 5 % 0.063 W 0402
R037 1430778 Chip resistor 10 k 5 % 0.063 W 0402
R039 1430804 Chip resistor 100 k 5 % 0.063 W 0402
R041 1430804 Chip resistor 100 k 5 % 0.063 W 0402
R042 1430812 Chip resistor 220 k 5 % 0.063 W 0402
R043 1430804 Chip resistor 100 k 5 % 0.063 W 0402
R044 1430778 Chip resistor 10 k 5 % 0.063 W 0402
R046 1430762 Chip resistor 2.2 k 5 % 0.063 W 0402
R047 1430804 Chip resistor 100 k 5 % 0.063 W 0402
R048 1430812 Chip resistor 220 k 5 % 0.063 W 0402
C002 2610003 Tantalum cap. 10 u 20 % 10 V
3.2x1.6x1.6
C005 2610003 Tantalum cap. 10 u 20 % 10 V
3.2x1.6x1.6
C006 2320779 Ceramic cap. 100 n 10 % 16 V 0603
C008 2610101 Tantalum cap. 22 u 20 % 3.5x2.8x1.9
C009 2320592 Ceramic cap. 2.2 n 5 % 50 V 0402
C010 2320546 Ceramic cap. 27 p 5 % 50 V 0402
C015 2320580 Ceramic cap. 680 p 5 % 50 V 0402
C017 2320580 Ceramic cap. 680 p 5 % 50 V 0402
C018 2320469 Ceramic cap. Y5 V 0603
C021 2320779 Ceramic cap. 100 n 10 % 16 V 0603
C022 2320592 Ceramic cap. 2.2 n 5 % 50 V 0402
C023 2320580 Ceramic cap. 680 p 5 % 50 V 0402
C024 2320107 Ceramic cap. 10 n 5 % 50 V 0603
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Loopset LPS-1/2
C025 2320546 Ceramic cap. 27 p 5 % 50 V 0402
C026 2320779 Ceramic cap. 100 n 10 % 16 V 0603
C027 2320779 Ceramic cap. 100 n 10 % 16 V 0603
C029 2320107 Ceramic cap. 10 n 5 % 50 V 0603
C030 2320107 Ceramic cap. 10 n 5 % 50 V 0603
C031 2320779 Ceramic cap. 100 n 10 % 16 V 0603
C033 2320546 Ceramic cap. 27 p 5 % 50 V 0402
C034 2320779 Ceramic cap. 100 n 10 % 16 V 0603
C035 2320592 Ceramic cap. 2.2 n 5 % 50 V 0402
C038 2320564 Ceramic cap. 150 p 5 % 50 V 0402
C039 2320469 Ceramic cap. Y5 V 0603
C040 2320469 Ceramic cap. Y5 V 0603
C041 2320779 Ceramic cap. 100 n 10 % 16 V 0603
C053 2320584 Ceramic cap. 1.0 n 5 % 50 V 0402
C221 2320779 Ceramic cap. 100 n 10 % 16 V 0603
C261 2320546 Ceramic cap. 27 p 5 % 50 V 0402
C262 2320546 Ceramic cap. 27 p 5 % 50 V 0402
B001 5140117 Cond mic 45+– 3DB 33PF 2K D5.8/9.D5.8/9.0
Z001 3640035 Filt z>450r/100m 0r7max 0.2a 0603 0603
Z002 3640035 Filt z>450r/100m 0r7max 0.2a 0603 0603
T001 3640073 Af–transformer for manual p&p smd SMD
V400 4219922 Transistor x 2 UM6
V401 4219922 Transistor x 2 UM6
V405 4219904 Transistor x 2 UMX1 npn 40 V SOT363
V406 4219908 Transistor x 2 SOT363
N003 4340379 IC, 2xop amp 2.7/3v ssoLMC6572BIMM SSOP8
N402 4340331 IC, Power amp. LM4862 P W SO8S
X100 5409067 SM, pin header 1x04 p1.25 1a STR.
X200 5400125 SM, pcb conn 4mm f 90degree
6400039 Battery spring dmd03655
9854251 PCB LPS1 28.2X33.1X1.0 M4 24/PA
Technical Documentation
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