LG KE990 - Viewty Cell Phone 100 MB User manual

Date: April, 2008 / Issue 1.0
Service Manual Model : KE990/KE990c
Service Manual
KE990/KE990c
Internal Use Only

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1. INTRODUCTION .............................. 5
1.1 Purpose................................................... 5
1.2 Regulatory Information............................ 5
2. PERFORMANCE...............................7
2.1 Supporting Standard................................7
2.2 Main Parts : Solution................................7
2.3 HW Features............................................8
2.4 HW SPEC. .............................................10
3. TECHNICAL BRIEF ........................15
3.1 General Description ...............................15
3.2 GSM Mode.............................................17
3.3 LO generation and distribution circuits...20
3.4 Off-chip RF Components .......................21
3.5 Digital Baseband (DBB/ESM6270) ........28
3.6 Subsystem(ESM6270)...........................31
3.7 Power Block...........................................38
3.8 External memory interface.....................43
3.9 H/W Sub System....................................45
3.10 Feature List..........................................61
3.11 Multimedia Chip Interface ....................67
3.12 Touch Screen Interface........................73
3.13 Main Features......................................74
3.14 Main Component..................................75
4. TROUBLE SHOOTING ...................81
4.1 RF Component.......................................81
4.2 Main Component....................................82
4.3 Checking VCTCXO Block ......................83
4.4 Checking Front-End Module Block ........85
4.5 Checking GSM Block.............................88
4.6 Power on trouble....................................94
4.7 SIM detect trouble..................................99
4.8 Key sense trouble (KEYPAD) ..............100
4.9 Keypad backlight trouble......................102
4.10 Micro SD trouble ................................104
4.11 Audio trouble......................................105
4.12 Camera trouble ..................................118
4.13 Main LCD trouble...............................121
4.14 Bluetooth trouble................................124
4.15 Touch Screen trouble.........................126
5. DOWNLOAD .................................127
5.1 Introduction ..........................................127
5.2 Downloading Procedure.......................127
5.3 Troubleshooting Download Errors .......142
5.4 Caution.................................................147
6. BLOCK DIAGRAM ........................148
6.1 GSM RF Block .....................................148
6.2 Interface Diagram ................................150
7. Circuit Diagram ............................153
8. BGM Pin Map................................163
9. PCB LAYOUT................................169
10. Calibration & RF Auto Test
Program (Hot Kimchi)................173
10.1 Usage of Hot-Kimchi..........................173
11. EXPLODED VIEW &
REPLACEMENT PART LIST ......177
11.1 EXPLODED VIEW .............................177
11.2 Replacement Parts
<Mechanic component>.....................179
<Main component> ............................183
11.3 Accessory ..........................................203
Table Of Contents
LGE Internal Use Only Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes

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LGE Internal Use Only Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes

LGE Internal Use Only Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
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1.1 Purpose
This manual provides the information necessary to repair, calibration, description and download the
features of this model.
1.2 Regulatory Information
A. Security
Toll fraud, the unauthorized use of telecommunications system by an unauthorized part (for example,
persons other than your company’s employees, agents, subcontractors, or person working on your
company’s behalf) can result in substantial additional charges for your telecommunications services.
System users are responsible for the security of own system.
There are may be risks of toll fraud associated with your telecommunications system. System users
are responsible for programming and configuring the equipment to prevent unauthorized use. The
manufacturer does not warrant that this product is immune from the above case but will prevent
unauthorized use of commoncarrier telecommunication service of facilities accessed through or
connected to it. The manufacturer will not be responsible for any charges that result from such
unauthorized use.
B. Incidence of Harm
If a telephone company determines that the equipment provided to customer is faulty and possibly
causing harm or interruption in service to the telephone network, it should disconnect telephone
service until repair can be done. A telephone company may temporarily disconnect service as long as
repair is not done.
C. Changes in Service
A local telephone company may make changes in its communications facilities or procedure. If these
changes could reasonably be expected to affect the use of the phones or compatibility with the net
work, the telephone company is required to give advanced written notice to the user, allowing the user
to take appropriate steps to maintain telephone service.
D. Maintenance Limitations
Maintenance limitations on the phones must be performed only by the manufacturer or its authorized
agent. The user may not make any changes and/or repairs expect as specifically noted in this manual.
Therefore, note that unauthorized alternations or repair may affect the regulatory status of the system
and may void any remaining warranty.
1. INTRODUCTION
1. INTRODUCTION

LGE Internal Use Only Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
E. Notice of Radiated Emissions
This model complies with rules regarding radiation and radio frequency emission as defined by local
regulatory agencies. In accordance with these agencies, you may be required to provide information
such as the following to the end user.
F. Pictures
The pictures in this manual are for illustrative purposes only; your actual hardware may look slightly
different.
G. Interference and Attenuation
A phone may interfere with sensitive laboratory equipment, medical equipment, etc. Interference from
unsuppressed engines or electric motors may cause problems.
H. Electrostatic Sensitive Devices
ATTENTION
Boards, which contain Electrostatic Sensitive Device (ESD), are indicated by the sign.
Following information is ESD handling:
• Service personnel should ground themselves by using a wrist strap when exchange system boards.
• When repairs are made to a system board, they should spread the floor with anti-static mat which is
also grounded.
• Use a suitable, grounded soldering iron.
• Keep sensitive parts in these protective packages until these are used.
• When returning system boards or parts like EEPROM to the factory, use the protective package as
described.
1. INTRODUCTION
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Only for training and service purposes
2. PERFORMANCE
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2.1 Supporting Standard
2.2 Main Parts : GSM Solution
2. PERFORMANCE
Item Feature Comment
Supporting Standard GSM900/DCS1800/PCS1900
with seamless handover
Phase 2+(include AMR)
SIM Toolkit : Class 1, 2, 3, A-E
Frequency Range GSM900 TX : 880 - 915 MHz
GSM900 RX : 925 - 960 MHz
DCS1800 TX : 1710 - 1785 MHz
DCS1800 RX : 1805 - 1880 MHz
PCS1900 TX : 1850 - 1910 MHz
PCS1900 RX : 1930 - 1990 MHz
Application Standard WAP 2.0, JAVA 2.0
Item Part Name Comment
Digital Baseband Neptune (D761811BZVL): TI
Analog Baseband Triton (TWL3029): TI
RF Chip RTR6235 : Qualcomm

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2.3 HW Features
2. PERFORMANCE
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Item Feature Comment
Form Factor Slide
Battery 1) Capacity
Standard : Li-Ion, 800mAh
2) Packing Type : Soft Pack
Size Standard : 100.4 X 48.0 X 14.5 mm
Weight TBD With Battery
Volume 70cc
PCB Staggered 8Layers , 0.8t
Stand by time 250 hrs @ Paging Period 9
Charging time 3 hrs @ Power Off / 800mAh
Talk time Min : 3.0 hrs @ Power Level 7 @ GSM850 / 800mAh
RX sensitivity GSM900 : -105 dBm
DCS 1800 : -105 dBm
PCS 1900 : -105 dBm
GSM900 : 33 dBm Class4 (GSM900)
DCS 1800 : 30 dBm Class1 (PCS)
PCS 1900 : 30 dBm Class1 (DCS)
GSM900 : 27 dBm E2 (GSM900)
DCS 1800 : 26 dBm E2 (PCS)
PCS 1900 : 26 dBm E2 (DCS)
GPRS compatibility GPRS Class 12
EDGE compatibility EDGE Class 12
SIM card type Plug-In SIM
3V /1.8V
Display Main LCD
262K Color TFT (320 x 240)
Backlight : White LED
Built-in Camera 2M CMOS Camera (VGA) One button access
Status Indicator None
TX output
power
GSM/
GPRS
EDGE

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2. PERFORMANCE
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Item Feature Comment
Keypad Alphanumeric Key : 12 Function Key:
Function Key : 14 4 Key Navigation, OK, F1,
Side Key : 4 F2, CLR, SND, MOD
Total No of Keys :30 Side Key : Volume up/down,
CAM, PWR/END
ANT Main : Internal Fixed Type
System connector 18 Pin
Ear Phone Jack 18pin, 4 Pole, Stereo
PC synchronization Yes
Memory NAND Flash : 1Gbit
SDRAM : 512Mbit
Speech coding FR, EFR, HR,AMR
Data & Fax Built in Data & Fax support
Vibrator Built in Vibrator
Blue Tooth V1.2, A2DP,
MIDI(for Buzzer Function) SW Decoded 40Poly
Music Player MP3/ WMA/AAC/HE-AAC/EAAC+ With Graphic EQ
Video Player MPEG4, H.263, WMV9
Camcorder MPEG4, H.263,
Voice Recording Yes
Speaker Phone mode Yes
Support
Travel Adapter Yes
CDROM Yes
Stereo Headset Yes Optional
Data Cable Yes Optional
T-Flash Yes Optional
(External Memory)

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2. PERFORMANCE
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2.4 HW SPEC.
Item Description Specification
1Frequency Band GSM
TX: 890 + 0.2 x n MHz
RX: 935 + 0.2 x n MHz ( n = 1 ~ 124 )
EGSM
TX: 890 + 0.2 x (n-1024) MHz
RX: 935 + 0.2 x (n-1024) MHz ( n = 975 ~ 1023 )
DCS1800
TX: 1710.2 + 0.2 x (n-512) MHz
RX: 1805.2 + 0.2 x (n-512) MHz (n = 512 ~ 885)
PCS1900
TX: 1850 + ( n-511 ) x 0.2 MHz
RX: 1930 + ( n-511 ) x 0.2 MHz (n = 512 ~ 810)
2Phase Error RMS < 5 degrees
Peak < 20 degrees
3Frequency Error < 0.1ppm
4Power Level GSM, EGSM
Level Power Toler. Level Power Toler.
533 dBm 2dB 13 17 dBm 3dB
631 dBm 3dB 14 15 dBm 3dB
729 dBm 3dB 15 13 dBm 3dB
827 dBm 3dB 16 11 dBm 5dB
925 dBm 3dB 17 9 dBm 5dB
10 23 dBm 3dB 18 7 dBm 5dB
11 21 dBm 3dB 19 5 dBm 5dB
12 19 dBm 3dB
DCS / PCS
Level Power Toler. Level Power Toler.
030 dBm 2dB 8 14 dBm 3dB
128 dBm 3dB 9 12 dBm 4dB
226 dBm 3dB 10 10 dBm 4dB
324 dBm 3dB 11 8 dBm 4dB
422 dBm 3dB 12 6 dBm 4dB
520 dBm 3dB 13 4 dBm 4dB
618 dBm 3dB 14 2 dBm 5dB
716 dBm 3dB 15 0 dBm 5dB

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2. PERFORMANCE
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Item Description Specification
5Output RF Spectrum GSM, EGSM
(due to modulation) Offset from Carrier (kHz). Max. dBc
100 +0.5
200 -30
250 -33
400 -60
600 ~ 1,200 -60
1,200 ~ 1,800 -60
1,800 ~ 3,000 -63
3,000 ~ 6,000 -65
6,000 -71
DCS / PCS
Offset from Carrier (kHz). Max. dBc
100 +0.5
200 -30
250 -33
400 -60
600 ~ 1,200 -60
1,200 ~ 1,800 -60
1,800 ~ 3,000 -65
3,000 ~ 6,000 -65
6,000 -73
6Output RF Spectrum GSM, EGSM
(due to switching transient) Offset from Carrier (kHz) Max. (dBm)
400 -19
600 -21
1,200 -21
1,800 -24

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2. PERFORMANCE
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Item Description Specification
6Output RF Spectrum DCS / PCS
(due to switching transient) Offset from Carrier (kHz). Max. (dBm)
400 -22
600 -24
1,200 -24
1,800 -27
7Spurious Emissions Conduction, Emission Status
GSM, EGSM
8Bit Error Ratio BER (Class II) < 2.439% @-102dBm
DCS / PCS
BER (Class II) < 2.439% @-102dBm
9Rx Level Report accuracy
10 SLR 8 3 dB
Frequency (Hz) Max.(dB) Min.(dB)
100 -12 -
200 0 -
300 0 -12
11 Sending Response 1,000 0 -6
2,000 4 -6
3,000 4 -6
3,400 4 -9
4,000 0 -
12 RLR 2 3 dB
Frequency (Hz) Max.(dB) Min.(dB)
100 -12 -
200 0 -
300 2 -7
500 *-5
13 Receiving Response 1,000 0 -5
3,000 2 -5
3,400 2 -10
4,000 2
*Mean that Adopt a straight line in between 300 Hz
and 1,000 Hz to be Max. level in the range.

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2. PERFORMANCE
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Item Description Specification
14 STMR 13 5 dB
15 Stability Margin > 6 dB
16 Distortion dB to ARL (dB) Level Ratio (dB)
-35 17.5
-30 22.5
-20 30.7
-10 33.3
033.7
731.7
10 25.5
17 Side Tone Distortion Three stage distortion < 10%
18 <Change> System frequency 2.5ppm
(13 MHz) tolerance
19 <Change>32.768KHz tolerance 30ppm
20 Power consumption Full power : < 340mA (GSM850) ; < 260mA (DCS / PCS)
Standby : - Normal Mode 4.0mA(Max. power)
- Using Test mode on DSP Sleep function 6mA
21 Talk Time GSM850/Level7 (Battery 800mA):210 Min
GSM850/Level12(Battery 800mA):350 Min
PCS1900/Level5 (Battery 800mA):310 Min
PCS1900/Level10(Battery 800mA):390 Min
22 Standby Time Under conditions, at least 200 hours: Brand new and full
800mAh battery Full charge, no receive/send and keep GSM
in idle mode. Broadcast set off. Signal strength display
labove. Backlight of phone set off.
23 Ringer Volume At least 80 dB under below conditions:
1. Ringer set as ringer.
2. Test distance set as 50 cm
24 Charge Voltage Fast Charge : < 600 mA
Slow Charge: < 60 mA
25 Antenna Display Antenna Bar Number Power
4-90 dBm ~ -86 dBm
3-95 dBm ~ -91 dBm
2-100 dBm ~ -96 dBm
1-105 dBm ~ -101 dBm
0~-105 dBm

Item Description Specification
26 Battery Indicator Battery Bar Number Voltage
0(included Blinking) 3.65V ~ 3.35V
13.71V ~ 3.66V
23.78V ~ 3.72V
33.91V ~ 3.79V
44.20V ~ 3.92V
27 Low Voltage Warning 3.5 0.03 V (Call)
3.6 0.03 V (Standby)
28 Forced shut down Voltage 3.35 0.03 V
29 Battery Type 1 Li-Ion Battery
Standard Voltage = 3.7 V
Battery full charge voltage = 4.2 V
Capacity: Min 930mAh
30 Travel Charger Switching-mode charger
Input: 100 ~ 240 V, 50/60Hz
Out put: 5.1V, 700mA
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2. PERFORMANCE
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LGE Internal Use Only Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
3. TECHNICAL BRIEF
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3.1 General Description
The KE990/KE990c supports EGSM-900, DCS-1800, and PCS-1900 based GSM/GPRS/EDGE. All
receivers and transmitter use the radioOne 1Zero-IF architecture to eliminate intermediate
frequencies, directly converting signals between RF and baseband. The quad-band GSM transmitters
use a baseband-to-IF upconversion followed by an offset phase-locked loop that translates the
GMSKmodulated or 8-PSK-modulated signal to RF.
A generic, high-level functional block diagram of KE990/KE990c is shown in Figure 3-1. One antenna
collects base station forward link signals and radiates handset reverse link signals. The antenna
connects with receive and transmit paths through a FEM(Front End Module).
3. TECHNICAL BRIEF
Quadrature
Upconverter
Quadrature
Downconverter
Quadrature
Downconverter
Quadrature
Downconverter
LPF & DC
Correction
LO generation
& Distribution
LPF & DC
Correction
LPF & DC
Correction
Dugital IO s
& controls
LPF
Quadrature
Upconverter
LPF
BPF
BPF
BPF
BPF
PLL #1
VCO
LPF
F ref
F ref
RTR6275_TCXO
VDDM
PLL #2
VCO
F ref
LPF
Ctls
Power
Detector
GSM1900
Rx BPF
GSM1800
Rx BPF
SW
H-BPF
L-BPF G900
Tx BPF
pad
pad
GSM/EDGE PA
PM6635-3P
Input Power
Management Voltage Regulators General Housekeeping User Interfaces IC Interfaces
Phone
VCTCXO
RTR6275_TCXO
MSM_TCXO
ESM6270
DAC_REF
GSM850
Rx BPF
FM Radio
Module
Bluetooth
Module
1
2
3
5
4
GESM/DCS1800/
PCS1900
1. RTR6235 for GSM/EDGE Tx
2. RTR6235 for GSM/EDGE Rx
3. PM6635-3P for Power
Management
4. FM radio Module
5. Bluetooth RF Module
[Fig 3.1] Block diagram of RF part
1QUALCOMM’s branded chipset that implements a Zero-IF radio architecture.

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Only for training and service purposes
In the GSM receive path, the received RF signals are applied through their bandpass filters and down-
converted directly to baseband in the RTR6235 transceiver IC.
These baseband outputs are routed to the ESM IC for further signal processing.
The GSM/EDGE transmit path employs one stage of up-conversion and, in order to improve efficiency,
is divided into phase and amplitude components to produce an open-loop Polar topology:
1. The on-chip quadrature up-converter translates the GMSK-modulated signal or 8- PSK modulated
signal, to a constant envelope phase signal at RF;
2. The amplitude-modulated (AM) component is applied to the ramping control pin of Polar power
amplifier from a DAC within the ESM
KE990/KE990c power supply voltages are managed and regulated by the PM6635 Power
Management IC. This versatile device integrates all wireless handset power management, general
housekeeping, and user interface support functions into a single mixed signal IC. It monitors and
controls the external power source and coordinates battery recharging while maintaining the handset
supply voltages using low dropout, programmable regulators.
The device’s general housekeeping functions include an ADC and analog multiplexer circuit for
monitoring on-chip voltage sources, charging status, and current flow, as well as user-defined off-chip
variables such as temperature, RF output power, and battery ID. Various oscillator, clock, and counter
circuits support IC and higher-level handset functions. Key parameters such as under-voltage lockout
and crystal oscillator signal presence are monitored to protect against detrimental conditions.
3. TECHNICAL BRIEF
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3.2 GSM Mode
3.2.1 GSM Receiver
The Dual-mode KE990/KE990c’s receiver functions are split between the three RFICs as follows:
■ EGSM-900, DCS-1800 and PCS-1900 modes both use the RTR6235 IC only.Each mode has
independent front-end circuits and down-converters, but they share common baseband circuits (with
only one mode active at a time). All receiver control functions are beginning with SBI2-controlled
parameters.
RF Front end consists of antenna, antenna switch module (LMSP43QA-538) which includes four RX
saw filters (EGSM-900, DCS-1800 and PCS-1900). The antenna switch module allows multiple
operating bands and modes to share the same antenna. In KE990/KE990c, a common antenna
connects to one of six paths: 1) GSM 900 Tx (Low Band Tx’s share the same path), 2) GSM1800/1900
Tx (High Band Tx’s share the same path), 3) EGSM900 Rx, 4) GSM1800 Rx, 5) GSM1900 Rx.
EGSM900, DCS1800, and PCS1900 operation is time division duplexed, so only the receiver or
transmitter is active at any time and a frequency duplexer is not required.
The EGSM900, DCS1800, and PCS1900 receiver inputs of RTR6235 are connected directly to the
transceiver front-end circuits(filters and antenna switch module).
EGSM900, DCS1800, and PCS1900 receiver inputs use differential configurations to improve
common-mode rejection and second-order non-linearity performance. The balance between the
complementary signals is critical and must be maintained from the RF filter outputs all the way into the
IC pins.
Since EGSM900, DCS1800, and PCS1900 signals are time-division duplex (the handset can only
receive or transmit at one time), switches are used to separate Rx and Tx signals in place of frequency
duplexers - this is accomplished in the switch module.
2The RFIC operating modes and circuit parameters are ESM-controlled through the proprietary 3-line Serial Bus Interface (SBI). The Application
Programming Interface (API) is used to implement SBI commands. The API is documented in AMSS Software - please see applicable AMSS
Software documentation for details.
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3. TECHNICAL BRIEF
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[Table 3.2.1] Antenna Switch Module Control logic

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The EGSM900, DCS1800, and PCS1900 receive signals are routed to the RTR6235 through band
selection filters and matching networks that transform single-ended 50-Ω•sources to differential
impedances optimized for gain and noise figure. The RTR input uses a differential configuration to
improve second-order inter-modulation and common mode rejection performance. The RTR6235 input
stages include ESMcontrolled gain adjustments that maximize receiver dynamic range.
The amplifier outputs drive the RF ports of the quadrature RF-to-baseband downconverters. The
downconverted baseband outputs are multiplexed and routed to lowpass filters (one I and one Q)
having passband and stopband characteristics suitable for GMSK or 8-PSK processing. These filter
circuits include DC offset corrections. The filter outputs are buffered and passed on to the ESM6270 IC
for further processing
3. TECHNICAL BRIEF
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[Fig 3.2.2] RTR6235 RX feature

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3. TECHNICAL BRIEF
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3.2.2 GSM Transmitter
The RTR6235 transmitter outputs(DA_HB2_OUT and DA_LB1_OUT) include on-chip output matching
inductors. 50ohm output impedance is achieved by adding a series capacitor at the output pins. The
capacitor value may be optimized for specific applications and PCB characteristics based on pass-band
symmetry about the band center frequency, the suggested starting value is shown in Figure3.2.3.
The RTR6235 IC is able to support GSM 850/900 and GSM 1800/1900 mode transmitting. This design
guideline shows a Quad-band GSM application.
Both high-band and low band outputs are followed by resistive pads to ensure that the load Presented
to the outputs remains close to 50ohm. The low-band GSM. Tx path also includes a Tx-band SAW filter
to remove noise-spurious components and noise that would be amplified by the PA and appear in the
GSM Rx band
RTR6235 GSM PA
DA_HB2_OUT
DA_LB1_OUT
HB_IN
LB_IN
HB_OUT
LB_OUT
Tx
SAW
9191
6pF
120120
68
5pF 51
[Fig 1.3] GSM Transmitter matching

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3.3 LO generation and distribution circuits
The integrated LO generation and distribution circuits are driven by internal VCOs to support various
modes to yield highly flexible quadrature LO outputs that drive all GSM/EDGE band upconverters and
downconverters; with the help of these LO generation and distribution circuits, true zero-IF architecture
is employed in all GSM band receivers and transmitters to translate the signal directly from RF to
baseband and from baseband to RF.
Two fully functional fractional-N synthesizers, including VCOs and loop filters, are integrated within the
RTR6235 IC. The synthesizer (PLL1) creates the transceiver LOs that support four GSM band
receivers and transmitters including: GSM850, EGSM900, DCS1800, and PCS1900. An external
TCXO input signal is required to provide the synthesizer frequency reference to which the PLL is
phase and frequency locked. The RTR6235 IC integrates most of PLL loop filter components on-chip
except two off-chip loop filter series capacitors, and significantly reduces off-chip component
requirement. With the integrated fractional-N PLL synthesizers, the RTR6235 has the advantages of
more flexible loop bandwidth control, fast lock time, and low-integrated phase error
3. TECHNICAL BRIEF
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3. TECHNICAL BRIEF
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3.4 Off-chip RF Components
3.4.1 VCTCXO (X100 : TG-5010LH(19.2M))
The Voltage Controlled Temperature Compensated Crystal Oscillator (VCTCXO) provides the
reference frequency for all RFIC synthesizers as well as clock generation functions within the
ESM6270 IC. The oscillator frequency is controlled by the ESM6270 IC.s TRK_LO_ADJ pulse density
modulated signal in the same manner as the transmit gain control TX_AGC_ADJ. A two-pole RC
lowpass filter is recommended on this control line.
The PM6635 IC controls the handset power-up sequence, including a special VCTCXO warm-up
interval before other circuits are turned on. This warm-up interval (as well as other TCXO controller
functions) is enabled by the ESM TCXO_EN line . The PM6635 IC VREG_TCXO regulated output
voltage is used to power the VCTCXO and is enabled before most other regulated outputs.
Any GSM mode power control circuits within the ESM6270 IC require a reference voltage for proper
operation and sufficient accuracy. Connecting the PM6635 IC REF_OUT directly to the ESM6270 IC
GSM_PA_PWR_CTL_REF provides this reference. This sensitive analog signal needs a 0.1 •ÏF low
frequency filter near to ESM side, and isolate from digital logic and clock traces with ground on both
sides, plus ground above and below if routed on internal layers.
3.4.2 Front-End Module (FL100 : LMSP43QA-538)
This equipment uses a single antenna to support all handset operating modes, with an antenna switch
module select the operating frequency and band. The active connection is ESM-selected by three
control lines (GPIO[9] and GPIO[10]). These GPIOs are programmed to be ANT_SEL0 and
ANT_SEL1 respectively.
[Table 3.4.2] Front End Module control logic