The radio part is necessary to convert the GMSK-RF-signals from the antenna to the
baseband and vice versa.
In the receiving direction, the signals are split in the I- and Q-component and fed to the A/D-converter of the logic part. In the transmission direction, the GMSK-signal is
generated with the Direct Modulator by modulation of the I- and Q-signals, which are
generated in the baseband section. After the modulation the RF-signals are amplified by
a buffer-limiter and, for the GSM900 path, filtered with a SAW-Filter. Finally, the power amplifier (PA) is attached to reach the output power.
Transmitter and Receiver are never active at the same time. Simultaneous
reception in the EGSM 900 and GSM 1800 band is impossible as well as
simultaneous transmission in both bands. However the monitoring band
(monitoring timeslot) in the TDMA-frame can be chosen independently of the
receiving or transmitting band (RX- and TX timeslot of the band).
The RF-part is designed for dualband operation (EGSM 900, GSM 1800) and consists of
the following main components:
1. 26MHz reference crystal Z1500
2. TX-Filter in GSM section Z1600
3. Transmitter power amplifier RF9340 with integrated regulator Z1700
4. Front-End-Module including RX-/TX-switch and EGSM 900/GSM1800 receiver SAW-
filters D1740
5. Infineon Limiter/Buffer PMB2256 to amplify the RF signals from the modulator to
drive the PA D1600
6. Infineon Smarti DC2 PMB6256 with the following functionality D1785:
• Integrated active part of the 26MHz crystal oscillator
• PLL for local oscillator LO1
• LO1-VCO
• Direct conversion receiver with channel filtering
• Direct Modulator
• Active part of the reference oscillator including buffer
The voltage regulator for the RF-part is located inside the ASIC D361.(see chapter 5.2).It
generates the required 2,85V “RF-Voltages” named VCC2_8 and VCC_SYN.(VCC_SYN
is also named VCC2 and behind R1451VCC_OSC)
The following components are supplied by:
VCC2_8
• Limiter amplifier
The voltage regulator RFREG 1 is controlled by the signal SLEEPQ (RF_EN
RFREG2 is controlled by he signal VCXOEN_UC connected to SLEEP1_N
. Both signals are provided by the EGOLD+ (SLEEPQ (GSM TDMA-Timer H16) /
H1)
VCXOEN_UC
Circuit diagram
(Miscellaneous R6)).
VCC_SYN
• Modulators
• RX mixers
• VCO
• PLL
• 26 MHz reference oscillator
(RF REG G2)),
(on/off Control
CC2_8
SYN
4.3 Frequency generation
4.3.1 Synthesizer: The discrete VCXO (26MHz)
The reference oscillator is a 26 MHz voltage controlled crystal oscillator. It has two main
tasks:
• It is used as reference for the synthesizer phase/frequency detector (Smarti
internal circuit)
• It gives the clock for the processor (E-Gold)
The main block is realized as an internal transistor cell with a Colpitts structure. The 26
MHz quartz crystal is connected to a tuning circuit that allows a fine-tuning of the
frequency. A current mirror, acting as buffer and amplifier followed by a LC resonant
circuit makes the signal to fit the E-Gold clock signal requirements. ON/OFF signal
(VCC_OSC) comes from the ASIC via the resistor R1451. For temperature
measurements of the VCXO a temperature resistance (R700) is used. The resistor is
placed near the VCXO. The measurement result TVCXO is reported to the EGOLD+
(Analog Interface P3) via R138 as the signal TENV. The frequency of the reference oscillator
can be adjusted by the EGOLD+ via a PNM- modulated AFC-signal.
The signal leaves the SMARTI as BB_SIN26M at pin 4 to be further used from the
EGOLD+ (D171
The required voltage VCC_SYN is provided by the ASCI D361
The local oscillator (LO1) consists of a PLL inside the Smarti DC (D720), an external loop
filter. The VCO is build in.
The first local oscillator is needed to generate frequencies which enables the transceiver IC
to demodulate the receiver signal and to perform the channel selection in the TX part. The
LO1/PLL part is switched on with PLLON (
). The PLL settings are programmed by the 3 wire bus RFCLK (pin 1), RFDATA (pin2)
F16)
and RFSTR (
times for GSM1800.
This LO1 frequency range
The required voltage VCC_SYN is provided by the ASIC D361
pin 5) from the EGOLD+ (D171 (GSM TDMA Timer
pin3). The LO frequency is 4 times the RX/TX frequency for EGSM 900 and 2
The mechanical antenna switch for the differentiation between the internal and external
antenna.
External
to / from
lexer
di
4.5 Frontendmodul (Electrical Antenna Switch)
EGSM900/GSM1800 <> Receiver/Transmitter
The frontend has two functions.
- to select the different GSM bands
- to switch between RX and TX mode
Inside the frontendmodul SAW filters are integrated in the RX paths.
For dual band mode the FEM needs two supply voltages (VC1, VC2) that are directly
provided by the Smarti DC (FEM1 and FEM2). The following logical table shows the
different modes of the FEM.
Mode Selection Vc. 1 Vc.2 Vc.3
EGSM900 RX LOW LOW LOW
EGSM900 TX HIGH LOW LOW
GSM1800 RX LOW LOW LOW
GSM1800 TX LOW HIGH LOW
GSM1900 RX LOW LOW HIGH
GSM1900 TX LOW HIGH LOW
Two balanced SAW filters are integrated to have good stop-band attenuation in the GSM
and the PCN RX paths.
4.6.1 Receiver: EGSM900/GSM1800 – Filter to Demodulator
From the antenna switch, up to the demodulator the received signal passes the following
blocks to get the demodulated baseband signals for the EGOLD+:
Filter LNA
Inside Z650 Smarti Smarti Smarti
The EGSM900, GSM1800 filters are located inside the frontend module. The Filter
Filter:
are centred to a frequency of 942,5MHz for EGSM900, 1847,5MHz for GSM1800.
The LNA´s (EGSM900/GSM1800) are located inside the Smarti. The LNA can be
LNA:
switched in HIGH (On) and LOW (Off) mode and is controlled by the Smarti depending on
EGOLD+ information.
Demodulator:
The amplified RF signal is converted by a quadrature demodulator to the final
outputsignals at baseband frequency. The LO signals are generated by a divider by 4 for
the GSM900 band and by a divider by 2 for GSM1800 band.
The resulting in-phase and quadratursignals are fed into two baseband low pass filters and
the PGC amplifier chain. The baseband filter provide a suppression of inband-blocking and
adjacent channel interferers.
After baseband filtering the signal is fed into a PGC amplifier chain. The baseband
PGC:
amplifier offers 78 dB programmable gain with 2 dB steps. Due to the high baseband gain
(58 dB), DC offsets can corrupt the signal at the baseband outputs. Differential offset
voltages are reduced by an internal offset compensation circuit. The control is realised
through the EGOLD+ signals (RFDATA; RFCLK; RFSTR.
The Smarti DC consists of a direct conversion receiver for GSM 900/1800.
4.7.1 Transmitter: Modulator and Limited Amplifier
The GMSK modulated signal is generated in the direct modulator. That means, that the
modulators are working directly on the final output frequency. The LO frequency is divided
by 2 or 4, depending on the GSM band. There are two modulators, one for the two higher
bands and the other for the two lower bands..
The required voltages VCC_SYN and VCC2_8 are provided by the ASIC D361
from EGOLD+
The actual signal is fed into a limiting amplifier which also provides a signal path for the
high band and one for the low band
to PA
Mode Selection
EGSM900 limiter enable HIGH LOW
GSM1800 limiter enable HIGH HIGH
Pin9 / EN (TXON1/D171_J14)) Pin10 / BS (OSW1/D720_25)
Top View IC Overview
The next stage in the low band line-up is a TX saw filter.
In the high band no SAW filter is required.
The output signals (CS_PA_IN , and GSM_PA_IN) from the limited amplifier are led to the
power amplifier (Z1700) passing a matching circuit. contains two separate 3-stage amplifier
chains for GSM 900 and GSM 1800. The control of the output power is handled via one
Vapc port. The power control circuit itself is integrated in the PA module. The EGOLD
generates the power control signal PA-RAMP. The band selection switching is done via
OSW1 from the Smarti IC.
The required voltage BATT+ is provided by the battery.
The required voltage VCC2_8 for the power control circuit is provided by the ASIC D361.
The EGOLD+ contains a 16-bit micro-controller (µC part), a GSM analog Interface (EGAIM), a DSP
computing core (DSP part) and an interface for application-specific switch-functions.
The µC part consists of the following:
• Micro-controller
• System interfaces for internal and external peripheries
• On-chip peripheries and memory
The Controller Firmware carries out the following functions:
• Control of the Man Machine Interface (keypad, LCD, sensing element, control of the illumination,...)
• GSM Layer 1,2,3 /GPRS
• Control of radio part (synthesizer, AGC, AFC, Transmitter, Receiver...),
• Control of base band processing (EGAIM)
• Central operating system functions (general functions, chip select logic, HW driver, control of mobile
The EGAIM part contains the interface between the digital and the analogue signal processing:
• 2 Sigma Delta A/D converters for RX signal, and for the necessary signals for the charge control and
temperature measurement. For this, the converter inputs are switched over to the various signals via
the multiplexer.
• 2 D/A converters for the GMSK-modulated TX signal,
• 1 D/A converter for the Power Ramping Signal,
• 1 Sigma Delta A/D and D/A converter for the linguistic signal.
The battery temperature is measured via the voltage divider R1387, R138 by the EGOLD+
Interface P2).
For this, the integrated Σ∆ converter of the RX-I base band branch is used. This Σ∆
(Analog
converter compares the voltage of TBAT and TENV internally. Through an analogue multiplexer, either
the RX-I base band signal, or the TBAT signal and the TENV signal is switched to the input of the
converter. The signal MEAS_ON from the EGOLD+
measurement The ambient temperature TENV is measured directly at of the EGOLD+
Interface P3)
.
(GSM TDMA-TIMER H15) activates the battery voltage
(Analog
Measurement of the Battery Voltage
The measurement of the battery voltage is done in the Q-branch of the EGOLD+, for this BATT+ is
connected via a voltage divider R143, R146 to the EGOLD+
does the switching between the baseband signal processing and the voltage measurement.
The Microphone signals (MICN2, MIP2, MICP1, MICN1) arrive at the voiceband part of the EGOLG+.
For further operations the signals will be converted into digital information, filtered, coded and finally
formed into the GMSK-Signal by the internal GMSK-Modulator. This so generated signals (RF_I, RF_IX,
RF_Q, RF_QX) are given to the Bright IC in the transmitter path.
D/A conversion of EP-Path signals incl. decoding
Arriving at the baseband-Part the demodulated signals (RF_I, RF_IX, RF_Q, RF_QX) will be filtered
and A/D converted. In the voiceband part after decoding (with help of the µC part) and filtering the
signals will be D/A converted amplified and given as (EPP1_FIL, EPN1_FIL) to the Power Supply ASIC.
Generation of the PA Control Signal (PA_RAMP)
The RF output power amplifier needs an analogue ramp up/down control voltage. For this the system
interface on EGOLD+ generates 10 bit digital values which have to be transferred serially to the power
ramping path. After loading into an 10 bit latch the control value will be converted into the corresponding
analogue voltage with a maximum of ~2V
• GSM Transparent Data Services and Transparent Fax
• calculation of the Frame Check Sequence for a RLP frame used for GSM NonTransparent Data
Services
• support of the GSM ciphering algorithm
Real Time Clock (integrated in the EGOLD+):
The real time clock is powered via a separate voltage regulator inside the Power Supply ASIC. Via a
capacitor, data are kept in the internal RAM during a battery change for at least 30 seconds. An alarm
function is also integrated with which it is possible to switch the phone on and off.
5.1.4 SRAM
Memory for volatile data
A52 A55/C55
Memory Size: 4 Mbit 2 Mbit
Data Bus: 16Bit 16Bit
5.1.5 FLASH
A52 A55/C55
Memory Size: 32Mbit 64Mbit (8 Mbyte)
Data Bus: 16 Bit 16 Bit
5.1.6 SIM
SIM cards with supply voltages of 1.8V and 3V are supported.
The vibration motor is mounted in the lower case. The electrical connection to the PCB is realised with
pressure contacts.
6 Power Supply
6.1 Power Supply ASIC
The power supply ASIC will contain the following functions:
• Powerdown-Mode
• Sleep Mode
• Trickle Charge Mode
• Power on Reset
• Digital state machine to control switch on and supervise the µC with a watchdog
• Voltage regulator
• Low power voltage regulator
• Additional output ports
• Voltage supervision
• Temperature supervision with external and internal sensor
• Battery charge control
2C interface
• I
• Audio multiplexer
• Audio amplifier stereo/mono
• 16 bit Sigma/Delta DAC with Clock recovery and I
• Bandgap reference*
2S
INFO:
* Bandgap reference
The p-n junction of a semiconductor has a bandgap-voltage. This bandgap-voltage is almost
independent of changes in the supply voltage and has a very low temperature gradient. The bandgapvoltage is used as reference for the voltage regulators.
The ASIC can be used in different operating modes:
Mode
Power down
mode with
minimum activity
Start Up Mode ON_OFF
Full operating
mode
Active Mode
(submode of Full
operating mode)
Sleep Mode with
special low
current operating
mode for the
LDOs
(submode of Full
operating mode)
Pin
Requirements
ON/OFF
ON/OFF2
VDD_CHARGE
ON_OFF2
VDD_CHARGE
CHARGE_UC
In this mode, the µC(EGOLD+) controls the
SLEEP1_N
TC_ON
CHARGE_uC
Description
In power down mode the current consumption
of the ASIC is very low. The inputs for switch
on conditions (ON/OFF-PinH2, ON/OFF2-PinJ3
,VDD_CHARGE-PinC3), the LPREG, Bandgap
reference and the POR cells are active. All
other blocks are switched off, so the battery is
not discharged. This state is called “phone off.
Start Up Mode can be initiated by
ON_OFF(PinH2) or ON_OFF2(PinC3). In this
mode a sequential start-up of references,
oscillator, voltage supervision and regulators is
controlled by digital part. In failure case (under
voltage, over voltage or time out of the µC
reaction)., the ASIC is shut down.
All blocks are active. Trickle charge is switched
off. The blocks fast charge and charge monitor
can be active only in this mode. These modes
will be activated with VDD_CHARGE(PinC3) or
CHARGE_UC(PinH4). The name of this mode
is “phone on” or “active mode”. The border
between the startup phase and the active mode
is the rising edge of the RESET2_N (PinG1)
signal. This will allow the µC(EGOLD+) to start
working.
charging block and most of the failure cases.
The ASIC can be controlled by the TWI
interface (I2CC-PinJ2, I2CD-PinG3, I2CI-
PinE2), interrupts can be sent by the ASIC.
Further, the temperature and the voltages are
supervised (in case of failure, the uC will be
informed). In case of watchdog failure, over
voltage or power on reset, the ASIC will be
switched off immediately. The mono and stereo
audio block can be switched on in active mode.
A low level at the signal VCOEN_UC (PinH1)
will switch the phone from the mode “PHONE
ON” to sleep mode. This mode can be
activated out of the active mode. In sleep mode
trickle charge, fast charge, supply over voltage
detection, supply under voltage detection,
audio function are switched off. LDO under
voltage detection, clock and all reference
voltages are active. LDOs are working in low
current mode. The possibility to supply the
ASIC from VDD_CHARGE (PinC3) with the
internal LDO is switched off. Only the battery
can be used for supply. This mode is called
“phone stand-by”.
Trickle charge
mode to be able
to support
charging of the
battery
Pin
Requirements
VDD_CHARGE
EXT_PWR
Description
In case of a rising edge at VDD_CHARGE
(PinC3) the ASIC goes from power down to
interim mode. In this mode, the oscillator and
the reference are started. The fuses are read
in. If the voltage is high enough (after a delay
time of 1 ms to filter a ringing), the internal
signal EXT_PWR is going to H and the power
up continues. The ASIC shuts off if the voltage
is below threshold. In Trickle Charge Mode,
first the charge unit starts and charges the
battery in case of under voltage. After reaching
this threshold voltage or if the battery has
enough voltage from the beginning, a start up
similar to the regular startup mode is initiated.
In case of voltage drop under battery threshold,
the first trickle charging can be started again
until the Active Mode is entered. In this case,
the internal VDDREF regulator, the reference
generator and oscillator are started and the
ASIC is supplied by VDDREF. If any failure is
detected, the ASIC is switched off.
6.1.2 Power Supply Functions:
Functions
Switching on the
mobile phone
Pin
Requirements
ON_OFF,
ON_OFF2,
VDD_CHARGE
Sequence
There are 3 different possibilities to switch on
the phone by external pins:
- VDD_CHARGE (PinC3) with rising edge
after POR or high level at end of POR
signal
- ON/OFF (PinH2) with falling edge
- ON/OFF2 (PinJ3) with rising edge
In order to guarantee a defined start-up
behavior of the external components, a
sequential power up is used and the
correct start up of these blocks is
supervised. In active mode, a continuous
signal at watchdog is needed to keep the
system running. If the signals fails, the
ASIC will switch to power down mode. It
must be guaranteed that each start-up
condition does not interfere and block the
other possible startup signals. In case of
failure during start-up, the device will go
back to power down mode. To guarantee
that VDDCHARGE (PinC3) is always
sensed we must be able to detect whether
the VDDCHARGE (PinC3) will have a
rising edge during POR (this can happen in
case of an empty battery). Therefore this
signal is sensed as level sensitive at the
end of POR and edge sensitive after POR
signal.
WDOG As soon as the first WDOG (PinH3) pin rising is
detected during the TE4 timer, the device start
the watchdog monitoring procedure. Standard
switch off of the phone is the watchdog. The
first edge of watchdog is rising. If a falling edge
is detected as the first transient the device will
go to power down mode again and the whole
phone is switched off. Rising and falling edges
must be detected alternated. With any edge on
WDOG (PinH3) pin a counter will be loaded.
The next - compared to the previous edge inverted edge must occur between end of T1,
and end of T2. If the signal occurs before end
of T1 or is not detected until end of T2, the
device will go to power down mode
immediately after the violation of the watchdog
criteria occurs.
T1 min. 0,327s/ typ. 0,360s/ max. 0,400s
T2 min. 2,600s/ typ. 2,860s/ max. 3,178s
Power-On-Reset
(POR)
RESET_N
RESET2_N
To guarantee a correct start-up of the ASIC, a
power on reset is needed at first power supply
ramping. Therefore a static/dynamic power on
reset circuit is added, which creates a reset
each time the power supply is connected. After
POR the ASIC starts up the reference and the
oscillator, read in the fuse content and goes
back to power down mode. If the power supply
will drop under the POR threshold a
synchronous reset is done and the ASIC will go
to power down mode independently of the
previous operating mode.
Voltage Supply
Logics
REG1
(2.9V)
The linear controller is designed for 2.9V(±2%)
and a maximum load current of 140 mA.
Voltage and current for the external Logic is
supplied from the internal 2.9V logic regulator.
The operating voltage VREG1 is kept constant
up to the maximum rated load current. A
reference voltage for the regulator circuit is
generated from a bandgap reference
Voltage Supply
Logics
REG2
(1,92V)
The linear controller is designed for
1.82V(±3%) and a maximum load current of
300 mA.
The REG2 supplies the Baseband Processor.
For a high power application, the power has to
be dissipated outside of the chip. This is done
with a series diode at the input of REG2, which
will force the regulator to a lower input voltage
and therefore lower power dissipation.
220 mA.
It will consist basically of an internal operation
amplifier, an integrated p-channel output
transistor as well as a capacitor (C = 2.2µF) for
stabilizing the voltage. The required reference
voltage for the regulating circuit will be
generated internally via a bandgap. The
negative feedback of the regulating circuit shall
be done via chip-internal resistances.
Voltage Supply
RF
VREGRF1,
RF_EN,
RESET_N
The linear controller is designed for 2.85V(min.
2.79V, max. 2.91V) and a maximum load
current of 120 mA.
Voltage and current for RF-VCO and
Transceiver is supplied from the internal 2.85V
LDO. The operating voltage RF12LDO is kept
constant up to the maximum rated load current.
A reference voltage for the regulator circuit is
generated from a bandgap reference. A low
noise must be guaranteed.
RF1LDO is controlled by RF_EN. If it is set to
high, the regulator is enabled. The control
method can be modified by TWI interface
between external and internal control mode. If
internal control mode is set, RF1LDO can only
be enabled by TWI bit. In external mode,
RF1LDO can only be enabled by RF_EN.
RF1LDO is released with rising edge of
RESET_N signal.
Voltage Supply
RF
VREGRF2,
SLEEP1_N,
SLEEP2_N,
POWER_ON
The linear controller is designed for 2.85V(min.
2.79V, max. 2.91V) and a maximum load
current of 180 mA.
Voltage and current for RF-VCO and
Transceiver is supplied from the internal 2.85V
LDO. The operating voltage RF2LDO is kept
constant up to the maximum rated load current.
A reference voltage for the regulator circuit is
generated from a bandgap reference. A low
noise must be guaranteed.
RF2LDO is controlled by VCXO_EN (PinH1). If
it is set to high, the regulator is enabled. The
control method can be modified by TWI
interface between external and internal control
mode. If internal control mode is set, RF2LDO
can only be enabled by TWI bit. In external
mode, RF2LDO can only be enabled by
VCXO_EN (PinH1).
RF2LDO is released with rising edge of
POWER_ON signal.
VREGA The linear controller is designed for 2.9V(min.
2.84V, max. 2.96V) and a maximum load
current of 190 mA.
BATT+ (PinA9) is used for the whole stereo
analog supply. The DAC digital VDDDAC
(PinC6), Low Noise Bandgap, Mono- and
Stereoamplifier supplies are connected to
VREGA (PinB9). The AUDIO performances are
guaranteed only, if the VREGA supplies all the
stereo path.
VREGA is controlled with TWI registers directly
by the µC.
Voltage Supply
RTC
VLPREG The linear controller is designed for 2.00V(min.
1.9V, max. 2.1V) and a maximum load current
of 1 mA.
The output voltage can be adjusted to four
different values with TWI register by the µC.
The selectable values are 2.00(default), 1.82,
1.92 and 2.07V. LP-LDO is always working and
will switch of only with POR signal.
Voltage Supply
SIM
VREGSIM The linear controller is designed for 2.9V(min.
2.84V, max. 2.96V) and a maximum load
current of 60 mA. The output voltage can be
adjusted to a different value with TWI register
by the µC to 1.8V(min. 1.76V, max. 1.84V).
This regulator can be activated by TWI register
, but only in active mode. If the regulator is in
power down, the output is pulled down by a
transistor to avoid electrostatic charging of
VREGSIM (PinB8)
Charge Support CHARGE_UC,
CHARGE,
VDDCHARGE,
AVDD,
SENSE_IN,
TBAT
A charge support will be integrated for
controlling the battery charge function. It
consists basically of a temperature sensor, an
external charge FET, an integrated High-side
driver for the external FET with an external
resistor between the source and the gate of the
charge FET.
In the case of a rising edge at the
CHARGE_UC(PinH4) the power source will be
switched on. In this way the charge FET
becomes conducting, provided that the
integrated temperature comparator does not
give the signal for extreme temperature and
that no over voltage is present at the VDD. In
the case of falling slope at the
CHARGE_UC(PinH4), the current source is
switched off and the pull-up resistor will make
sure that the charge FET is blocked after a
definite time.
Temperature switchoff becomes effective at
approx. T>60°C.
Voltage
supervision
The levels of regulator REG1 and REG2 and
also the supply voltage BATT+ are supervised
with comparators.
In active mode the regulators are supervised
permanently. If the voltage is under the
threshold, the pin RESET_N2 (PinG1) stay Low
and the ASIC goes back to the power down
mode. If the voltage is longer than Tmin under
threshold voltage, the RESET_N2 (PinG1) is
going to Low (Missing Watchdog signal ->
phone switched off). The level of regulator
REG1 and REG2 will be supervised
permanently. If the voltage doesn’t reach the
threshold value at switch on, the RESET_N2
(PinG1) will stay low and the ASIC will go back
to power down mode. The voltages are sensed
continuously and digitally filtered with a time
constant Tmin. If the regulator voltage is under
threshold longer than Tmin, the RESET_N2
(PinG1) signal change to low and the µC will go
to RESET condition (Missing Watchdog signal -
> phone switched off).
Powersupply
supervision
VDD If the battery voltage BATT+ exceeds VDD
high, everything is switched off immediately
within 1µs. Only the pull-up circuitry for the
external charge PMOS are active and will
discharge the gate of the external PMOS
VDDA supervision VDDA To provide a short circuit protection at output of
VDDA (PinA9) and output of stereo buffer a
voltage supervision is implemented. If the
VDDA output is less then this threshold, the
VDDA will be switched off for 128ms. After this
time the VDDA will be started again. The VDDA
supervision starts 60ms after startup of VDDA.
Battery
temperature
supervision
Charging is stopped, when over temperature
occurs. Within 128ms, 3 values are measured.
When these 3 values are identical status can
be changed. The supervision is active in fast
charge or trickle charge mode. Voltage on pin
TBAT (PinB3) becomes smaller when
temperature increases. If Vbat < (Vref_exe Vhyst) charging is disabled. Only when Vtbatt >
Vref_exe charging is enabled again.
Device
temperature
supervision
To protect the ASIC, the temperature is
supervised. The temperature is polled every
128ms and is filtered as in battery temperature
supervision. If over temperature is detected, a
bit in the STATUS register is set and an
interrupt is generated. Monitoring is started
only in active mode.
Analog switch
Outport
The level can be defined by the bit
out_port_high of the TWI register. The high
level can be derived of VREG2 or VREG3.
Additional a pull down transistor is connected
to this node.
interface with an additional interrupt pin to
inform the µC about special conditions.
The interface can handle clock rates up to 400
kHz.
Audio mode
functions
Four audio amplifiers are integrated to support
these modes:
1. Supply the speaker in the phone with audio
signals including the possibility of
handsfree switch on and off. This is the
AUDIO MONO MODE.
2. Supply the speaker in the phone with
ringing signal (RINGER MODE)
3. Transfer a key click, generated in digital
part to the speaker. (KEY-CLICK
FUNCTION)
4. Supply of stereo head set with stereo
signal with short circuit protection. This is
called the AUDIO STEREO MODE. These
different modes with gain and multiplexing
can be controlled via TWI. Also the output
can be switched to TRI-STATE via TWI
interface.
Audio Mono Mode VREGA
MONO1
MONO2
VREFEX_M
This mode is the main function of the amplifier.
The two amplifiers are used as differential
mono amplifier to drive the speaker in the
phone as external load. This differential
approach allows delivering an optimum of
power to the speaker also in low voltage mode.
Both amplifier paths are inverting amplifiers
with external AC coupling at the input to
compensate offset failures. The gain can be
adjusted with the TWI interface. The output
stage of the amplifiers must be able to drive a
low impedance load as an external speaker for
the handsfree application.
General parameters: Gain can be adjusted for
each channel separately in steps of 1.5dB in
the range of 21dB to –54 dB and in steps of 3
dB in the range of –54dB to –75dB. The signals
for the amplifier are connected via an audio
multiplexer with 3 pairs of input signals.
Ringer function RINGIN In ringer mode the ringing signal is transferred
via the amplifier to the speaker to eliminate the
additional buzzer. The speaker is controlled
with a rectangular signal RINGIN (PinG9). Input
signal is digital signal with variable frequency.
Amplitude is adjusted by TWI register.
For start-up a smaller time constant must be
used to allow a fast switch on behavior. Ringing
function can be started at any time. If the audio
is off, the start-up is done with RINGER time
constant. If audio is starting with AUDIO startup, the time constant is switched to RINGER
mode, too. If the audio amplifier is already up
and running, the RINGIN (PinG9) is connected
to the amplifier and audio signal is muted due
to open multiplexer.
Key click function Pushing a key of the phone can be combined
with a key click. This function is also realized
with the audio amplifier in pulsed mode. The
ASIC creates a digital PWM signal. Frequency
of the PWM signal is 3.5 kHz.
The start-up is similar to the ringer function. If
the audio is off, the start-up is done with
KEYCLICK time constant. If audio is starting
with AUDIO start-up, the time constant is
switched to KEYCLICK mode, too. If the audio
amplifier is already up and running, the
KEYCLICK is connected to the amplifier and
audio signal is muted due to open multiplexer.
Audio Multiplex
Matrix
AUDIOA1
AUDIOA2
AUDIOB1
AUDIOB2
AUDIOC1
AUDIOC2
Each of the three input sources should be
switched to Mono and Stereo outputs.
Furthermore a conversion can be done.
Following sources:
- Mono differential
- Mono Single Ended (both channels
parallel)
- Stereo
The DAC can be switched off for using the
analog external inputs. This principle will allow
to do each combination and have different
modes for stereo and mono in parallel.
I2S Interface CLO,
WAO,
DAO
The I2S Interface is a three-wire connection
that handles two time multiplexed data
channels. The three lines are the clock (CLO),
the serial data line (DAO) and the word select
line (WAO). The master I2S also generates the
appropriate clock frequency for CLO set to 32
times the sampling rate (FS)
VDDDAC For digital to analog conversion a 16-bit sigma
delta converter is used. Digital input signal is
delivered with an I2S interface. The I2S
interface should be 16-bit format. To be able to
work with all possible operating modes, the
sampling frequency can vary from 8kHz to
48kHz. The performance of the audio output
signal must be guaranteed over the full range
the human ear is able to hear. This means for
FS=8kHz the noise at frequencies higher than
FS/2 must be suppressed. This is done by DSP
and a single ended 2
nd
order Low Pass filter.
The clock for the I2S will be varied accordingly
to the sampling frequency. Therefore a clock
recovery based on CLO signal of the I2S can
be implemented. This clock recovery must
smooth any jitter of this clock to reduce the
noise of the DAC.
PLL VDDPLL
PLLOUT
The PLL will have three frequency modes to
produce a 32xCLO clock for the DSP and the
DAC. The loop filter is realized with an external
RC circuit. This PLL also contains a lock
detector circuit.
Audio Stereo
Mode
VDDSTEREO
STEREO1
STEREO2
STEREOM
For stereo mode 2 single ended buffers are
used. These buffers will be supplied by the
additional regulator with 2.9 Volt to be more
stable against the GSM ripple on the battery
voltage. Also reference voltage for the buffers
is generated by a high precision, low noise
bandgap reference for better performance. An
external capacitor is needed to filter this
reference additionally. The gain steps for the
programmable gain amplifier is identical with
the mono amplifier. No keyclick and ringer
needed for the stereo part. Gain can be
controlled with the TWI. The connected
speaker has an impedance of typical 16 Ohm.
To guarantee an ANTI-POP noise a digital
startup is implemented. This will allow a soft
start of the VMID and creates a “clean” audio
band during the startup. For eliminating
external coupling capacitors for the speaker, an
additional amplifier creates virtual ground (for
both speakers). Accordingly to this, the max
current of the virtual ground has to be the
double of the normal output amplifier. Due to
the power amplifier offset a DC current appear
in the headset. Gain can be adjusted for each
channel separately in steps of 1.5dB in the
range of 21dB to –54 dB and in steps of 3 dB in
the range of –54dB to –75dB
6.2 Battery
As a standard battery a LiIon battery with a nominal capacity of 3,7 Volt/700mAh is used.
The battery is charged in the unit itself. The hardware and software is designed for LiIon with 4.2V
technology.
Charging is started as soon as the phone is connected to an external charger. If the phone is not
switched on, then charging takes place in the background (the customer can see this via the “Charge”
symbol in the display). During normal use the phone is being charged (restrictions: see below).
Charging is enabled via a PMOS switch in the phone. This PMOS switch closes the circuit for the
external charger to the battery. The EGOLD+ takes over the control of this switch depending on the
charge level of the battery, whereby a disable function in the POWER SUPPLY ASIC hardware can
override/interrupt the charging in the case of over voltage of the battery (only for Manganese Chemistry
Battery types e.g. NEC).
With the new slim Lumberg IO connector we lose the charger recognition via SB line. Now we measure
the charge current inside the POWER SUPPLY ASIC with a current monitor.
The charging software is able to charge the battery with an input current within the range of 350-600mA.
If the Charge-Fet is switched off, then no charging current will flow into the battery (exception is trickle
charging, see below).
For controlling the charging process it is necessary to measure the ambient (phone) temperature and
the battery voltage. The temperature sensor will be an NTC resistor with a nominal resistance of 22kΩ
at 25°C. The determination of the temperature is achieved via a voltage measurement on a voltage
divider in which one component is the NTC. The NTC for the ambient temperature will be on the PCB
(13 MHz part).
Measurement of Battery, Battery Type and Ambient Temperature
The voltage equivalent of the temperature and battery code on the voltage separator will be calculated
as the difference against a reference voltage of the EGOLD. For this, the integrated Σ∆ converter in the
EGOLD of the RX-I base band branch will be used. Via an analogue multiplexer, either the RX-I base
band signal, the battery code voltage or the ambient temperature voltage can be switched over to the
input of the converter. The 1-Bit data stream of the converter will be subjected to a data reduction via
the DSP circuit so that the measured voltage (for battery and ambient temperature) will be available at
the end as a 10-bit data word.
Analogue to the I-branch either the RX-Q base band signal or the battery voltage can be measured in
the Q-branch. Processing in the DSP circuit will be done analogue to the I-branch. The EGOLD will be
specified internally at voltage measurement input BATT+ for an input voltage of 3V...4.5V.
Timing of the Battery Voltage Measurement
Unless the battery is charging, the measurement is made in the TX time slot. During charging it will be
done after the TX time slot. At the same time, either the battery temperature (in the I-branch) and the
battery voltage (in the Q-branch) or the ambient temperature in the I-branch can be measured (the
possibility of measurement in the Q-branch, the analogue evaluation of the battery coding, is used for
HW-Coding). Other combinations are not possible. For the time of the measurement the multiplexer in
the EGAIM must be programmed to the corresponding measurement.
Recognition of the Battery Type
The battery code is a resistor with a resistance depending on the manufacturer.
Charging Characteristic of Lithium-Ion Cells
LiIon batteries are charged with a U/I characteristic, i.e. the charging current is regulated in relation to
the battery voltage until a minimal charging current has been achieved. The maximum charging current
is approx. 600mA, minimum about 100mA. The battery voltage may not exceed 4.2V ±50mV average.
During the charging pulse current the voltage may reach 4.3V. The temperature range in which
charging of the phone may be started ranges from 5...40°C, and the temperature at which charging
takes place is from 0...45°C. Outside this range no charging takes place, the battery only supplies
current.
Trickle Charging
The POWER SUPPLY ASIC is able to charge the battery at voltages below 3.2V without any support
from the charge SW. The current will by measured indirectly via the voltage drop over a shunt resistor
and linearly regulated inside the POWER SUPPLY ASIC. The current level during trickle charge for
voltages <2.8V is in a range of 20-50mA and in a range of 50-100mA for voltages up to 3.75V. To limit
the power dissipation of the dual charge FET the trickle charging is stopped in case the output voltage
of the charger exceeds 10 Volt. The maximum trickle time is limited to 1 hour. As soon as the battery
voltage reaches 3.2 V the POWER SUPPLY ASIC will switch on the phone automatically and normal
charging will be initiated by software (note the restrictions on this item as stated below).
For battery voltages above 3.2 Volt and normal ambient temperature between 5 and 40°C the battery
can be charged with a charge current up to 1C*. This charging mode is SW controlled and starts if an
accessory (charger) is detected with a supply voltage above 6.4 Volt by the POWER SUPPLY ASIC.
The level of charge current is limited/controlled by the accessory or charger.
INFO:
* C-rate
The charge and discharge current of a battery is measured in C-rate. Most portable batteries, are
discharge with 1C. A discharge of 1C draws a current equal to the battery capacity. For example, a
battery value of 1000mAh provides 1000mA for one hour if discharged at 1C. The same battery
discharged at 0.5C provides 500mAfor two hours. At 2C, the same battery delivers 2000mA for 30
minutes. 1C is often referred to as a one-hour discharge; a 0.5 would be a two-hour, and a 0.1C a 10
hour discharge.
Restrictions
• A battery which has completely run down can not be re-charged quickly because the battery voltage
is less than 3.0V and the logic which implements the charge control cannot be operated at this low
voltage level. In this case the battery is recharged via trickle-charging. However, the charging
symbol cannot be shown in the display because at this time logic supply voltages are not operating.
The charging time for this trickle-charging (until the battery can be fast-charged from then on) is in
the range of 1 hour. If, within this time, the battery voltage exceeds 3.2V, then the POWER SUPPLY
ASIC switches on the mobile and charging continues in the Charge-Only Mode. In some
circumstances it can happen that after trickle-charging and the usually initiated switch-on procedure
of the mobile, the supply voltage collapses so much that the mobile phone switches off again. In this
case trickle charging starts again with a now raised threshold voltage of 3.75V instead of 3.2V, at
maximum for 20 minutes. The POWER SUPPLY ASIC will retry switching on the phone up to 3 times
(within 60 minutes overall).
• Charging the battery will not be fully supported in case of using old accessory (generation ‘45’ or
earlier). It is not recommended to use any cables that adapt “old” to “new” Lumberg connector. Using
such adapters with Marlin will have at least the following impact:
1) half-sine wave chargers (e.g. P35 & home station) can not be used for trickle
charging
2) normal charging might be aborted before the battery is fully charged
3) EMC compliance can not be guaranteed
• A phone with a fully charged LiIon battery will not be charged immediately after switch-on. Any input
current would cause an increase of the battery voltage above the maximum permissible value. As
soon as the battery has been discharged to a level of about 95% (due to current consumption while
use), it will be re-charged in normal charging mode.
• The phone cannot be operated without a battery.
• The phone will be destroyed if the battery is inserted with reversed polarity:
⇒ design-wise it is impossible to wrongly pole the phone. This is prevented by mechanical means.
⇒ electrically, a correctly poled battery is presumed, i.e. correct polarity must be guaranteed by
suitable QA measures at the supplier
• The mobile phone might be destroyed by connecting an unsuitable charger:
⇒ a charger voltage >15V can destroy resistances or capacitors
⇒ a charger voltage >20V can destroy the switch transistor of the charging circuit
In case the transistor fails the ASIC will be destroyed. In the case of voltages lower than 15V and an
improper current limitation the battery might be permanently damaged. A protection against grossly
negligent use by the customer (e.g. direct connection of the charge contact to the electricity supply in
a motor car) is not provided. Customer safety will not be affected by this restriction.
1 O
2 O The FET V211, switching this signal, is controlled via the
EGOLD+ signal VIBRA_UC.
7.2 Earpiece
XG250
Pin Name IN/OUT Remarks
1 EPP1 O 1st connection to the internal earpiece.
Earpiece can be switched off in the case of
accessory operation. EPP1 builds together
with EPN1 the differential output to drive the
multifunctional “earpiece” (earpiece, ringer,
handsfree function).
2 EPN1 O 2nd connection to the internal earpiece.
Earpiece can be switched off in the case of
accessory operation.
Name IN/OUT Notes
Pin
1 POWER I/O POWER is needed for charging batteries and for supplying
the accessories. If accessories are supplied by mobile,
talk-time and standby-time from telephone are reduced.
Therefore it has to be respected on an as low as possible
power consumption in the accessories.
2 GND
3 TX O Serial interface
4 RX I serial interface
5 DATA/CTS I/O Data-line for accessory-bus
Use as CTS in data operation.
6 RTS I/O Use as RTS in data-operation.
7 CLK/DCD I/O Clock-line for accessory-bus.
Use as DTC in data-operation.
8 AUDIO_L Analog O driving ext. left speaker
With mono-headset Audio_L and Audio_R differential
mode
9 AUDIO_REF Analog O mid-voltage
in stereo mode reference to
AUDIO_L and AUDIO_R in mono mode not used
10 AUDIO_R Analog O driving ext. right speaker With mono-headset Audio_L and
The Z211 is a 5-channel filter with over-voltage and ESD Protection array which is designed to provide
filtering of undesired RF signals in the 800-4000MHz frequency band Additionally the Z211 contains
diodes to protect downstream components from Electrostatic Discharge (ESD) voltages up to 8 kV.
The buzzer and the keypad clicks will be realized over the earpiece. At normal buzzer the signaling will
realized with swelling tones. At the same time a maximum sound pressure level in the coupler of 135 +/5dB(A) is fixed.
The standard sounds will be generated by the EGOLD+, the advanced sounds will be generated via
firmware running on the DSP.
8.1 Microphone
8.1.1 Mechanical
The microphone is built in the Mounting Frame Lower Part and is mechanically fixed with a rubber seal
(gasket). The contact on the PCB is realised via spiral springs, which are integrated in the gasket.
Because of usage of Unidirectional Microphone, the gasket has a front- and a back sound-inlet hole.
The front sound-inlet is acoustically tighten connected with a sound-inlet at the rear-side of the
mounting frame lower part. The back sound-inlet is acoustically tighten connected with a sound-inlet at
the bottom-side of the mounting frame lower part. The gasket of the microphone has a asymmetrical
shape in order to provide non-rotating, guaranteed covering of the sound-inlets of mounting frame lower
part to the corresponding sound-inlets at microphone gasket.
8.1.2 Electrical
Both Microphones are directly connected to the EGOLD+.(Analog Interface G2, F1-G3, H2) via the signals
MICN1, MICP1 (Internal Microphone )and MICN2, MICP2 (External Microphone/Headset). Power
The speakermodule is designed to provide optimal performance for mobile handsfree and sound ringer.
Plus independent from mobile leakage sound performance. Therefore speakermodule is a system that
has a closed front volume with sound-outlets towards the ear of the user. Backvolume of
Speakermodule is using the unused air between the antenna and the PCB. Backvolume is just used for
resonance, there is no sound output from backvolume. The speakermodule is glued to the lightguide
and contacted via two bending springs to the PCB. The lightguide itself is screwed with six screws via
the PCB to the mounting frame lower part. Two of the six screws are located besides of the connection
of speakermodule and lightguide. Therefore a good and reliable connection between speakermodule
and PCB should be provided.
8.2.2 Electrical
The internal and external Loudspeaker (Earpiece) is connected to the voiceband part of the EGOLD+
Analog Interface B1, C1) via audio amplifier inside the ASIC (D361). Input EPN1_FIL -EPP1_FIL. Output
(
for external loudspeaker AUDIO_L - AUDIO_R, for internal Loudspeaker EPP! – EPN1. The ringing
tones are generated with the loudspeaker too. To activate the ringer, the signal RINGIN from the
EGOLD+ (
The display is provided with 2,65V from the ASIC (D361). The communication with the EGOLD+ by the
LCD-Signals, directly connected to the EGOLD+
Topside of
display
Controller
8
9.2 Illumination
The light is switched via switches inside the EGOLD+. With the signalLIGHT_KB (
illumination for the keyboard is controlled, with LIGHT_LCD. (
can be switched “on” and “off”. During the TX timeslot the light is deactivated via the signal BL_OFF
The keyboard is connected via the lines KB0 – KB9 with the EGOLD+.
KB 7 is used for the ON/OFF switch. The lines KB0 – KB5 are used as output signals. In the matrix
KB6, KB8 and KB9 are used as input signals for the EGOLD+.