UC864-G Hardware User Guide DRAFT - 29/10/07
UC864-G Hardware User Guide DRAFT - 29/10/07 This document is relating to the following products: UC864-G Reproduction forbidden without Telit Communications S.p.A.
UC864-G Hardware User Guide DRAFT - 29/10/07 Contents 1 Overview ...........................................................................................................................7 2 Mechanical Dimensions...................................................................................................8 3 UC864-G module connections ........................................................................................9 3.1 PIN-OUT.............................................................
UC864-G Hardware User Guide DRAFT - 29/10/07 10.2 General Design Rules ..........................................................................................................40 10.3 Other considerations ...........................................................................................................40 10.4 Microphone Biasing .............................................................................................................41 10.4.1 10.4.2 10.5 Balanced Microphone Biasing ....
UC864-G Hardware User Guide DRAFT - 29/10/07 14 Document Change Log ..................................................................................................66 Reproduction forbidden without Telit Communications S.p.A.
UC864-G Hardware User Guide DRAFT - 29/10/07 DISCLAIMER The information contained in this document is the proprietary information of Telit Communications S.p.A. and its affiliates (“TELIT”). The contents are confidential and any disclosure to persons other than the officers, employees, agents or subcontractors of the owner or licensee of this document, without the prior written consent of Telit, is strictly prohibited. Telit makes every effort to ensure the quality of the information it makes available.
UC864-G Hardware User Guide DRAFT - 29/10/07 1 Overview The aim of this document is the description of some hardware solutions useful for developing a product with the Telit UC864-G module. In this document all the basic functions of a mobile phone will be taken into account; for each one of them a proper hardware solution will be suggested and eventually the wrong solutions and common errors to be avoided will be evidenced.
UC864-G Hardware User Guide DRAFT - 29/10/07 2 Mechanical Dimensions The Telit UC864-G module overall dimensions are: • • • Length: Width: Thickness: 45 mm 30 mm 4.8mm Reproduction forbidden without Telit Communications S.p.A.
UC864-G Hardware User Guide DRAFT - 29/10/07 3 UC864-G module connections 3.1 PIN-OUT UC864-G uses an 80 pin Molex p.n. 53949-0878 male connector for the connections with the external applications. This connector matches the 54150-0878 models.
UC864-G Hardware User Guide DRAFT - 29/10/07 Pin 24 Signal TX_TRACE I/O O Function TX Data for debug monitor Internal Pull up Type UC864-E CMOS 2.6V Prog. / Data + Hw Flow Control 25 C103/TXD I Serial data input (TXD) from DTE CMOS 2.6V 26 C104/RXD O Serial data output to DTE CMOS 2.6V 27 C107/DSR O Output for Data set ready signal (DSR) to DTE CMOS 2.6V 28 C106/CTS O Output for Clear to send signal (CTS) to DTE CMOS 2.
UC864-G Hardware User Guide DRAFT - 29/10/07 Pin Signal I/O Function Internal Pull up Type UC864-E 58 TGPIO_20 I/O Telit GPIO20 Configurable GPIO CMOS 2.6V 59 TGPIO_04 I/O Telit GPIO4 Configurable GPIO CMOS 2.6V 60 TGPIO_14 I/O Telit GPIO14 Configurable GPIO CMOS 2.6V 61 TGPIO_15 I/O Telit GPIO15 Configurable GPIO CMOS 2.6V 62 TGPIO_12 I/O Telit GPIO12 Configurable GPIO CMOS 2.6V 63 TGPIO_10/ PCM_TX I/O Telit GPIO10 Configurable GPIO / PCM Data Output CMOS 2.
UC864-G Hardware User Guide DRAFT - 29/10/07 NOTE: If not used, almost all pins should be left disconnected.
UC864-G Hardware User Guide DRAFT - 29/10/07 4 Hardware Commands 4.1 Turning ON the UC864-G To turn on UC864- G, the pad ON# must be tied low for at least 1 second and then released. The maximum current that can be drained from the ON# pad is 0,1 mA. A simple circuit to do it is: ON# R1 Q1 Power ON impulse R2 GND NOTE: UC864-G turns fully on also by supplying power to the USB_VBUS pin (provided there's a battery on the VBATT pads).
UC864-G Hardware User Guide DRAFT - 29/10/07 10k For example: 1- Let's assume you need to drive the ON# pad with a totem pole output of a +3/5 V microcontroller (uP_OUT1): 1s 2- Let's assume you need to drive the ON# pad directly with an ON/OFF button: Reproduction forbidden without Telit Communications S.p.A.
UC864-G Hardware User Guide DRAFT - 29/10/07 4.2 Turning OFF the UC864-G The turning off of the device can be done in three ways: • by software command (see UC864-G Software User Guide) • by hardware shutdown • by Hardware Unconditional Restart When the device is shut down by software command or by hardware shutdown, it issues to the network a detach request that informs the network that the device will not be reachable any more. 4.2.
UC864-G Hardware User Guide DRAFT - 29/10/07 NOTE: Do not use any pull up resistor on the RESET# line or any totem pole digital output. Using pull up resistor may bring to latch up problems on the UC864-G power regulator and improper functioning of the module. The line RESET# must be connected only in open collector configuration. TIP: The unconditional hardware Restart should be always implemented on the boards and software should use it as an emergency exit procedure.
UC864-G Hardware User Guide DRAFT - 29/10/07 5 Power Supply The power supply circuitry and board layout are a very important part in the full product design and they strongly reflect on the product overall performances, hence read carefully the requirements and the guidelines that will follow for a proper design. 5.
UC864-G Hardware User Guide DRAFT - 29/10/07 5.2 General Design Rules The principal guidelines for the Power Supply Design embrace three different design steps: • the electrical design • the thermal design • the PCB layout. 5.2.1 Electrical Design Guidelines The electrical design of the power supply depends strongly from the power source where this power is drained.
UC864-G Hardware User Guide DRAFT - 29/10/07 An example of linear regulator with 5V input is: 5.2.1.2 + 12V input Source Power Supply Design Guidelines • • • • • • • The desired output for the power supply is 3.8V, hence due to the big difference between the input source and the desired output, a linear regulator is not suited and shall not be used. A switching power supply will be preferable because of its better efficiency especially with the 2A peak current load represented by UC864-G.
UC864-G Hardware User Guide DRAFT - 29/10/07 Reproduction forbidden without Telit Communications S.p.A.
UC864-G Hardware User Guide DRAFT - 29/10/07 5.2.1.3 Battery Source Power Supply Design Guidelines • The desired nominal output for the power supply is 3.8V and the maximum voltage allowed is 4.2V, hence a single 3.7V Li-Ion cell battery type is suited for supplying the power to the Telit UC864-G module. The three cells Ni/Cd or Ni/MH 3.6 V Nom. battery types or 4V PB types MUST NOT BE USED DIRECTLY since their maximum voltage can rise over the absolute maximum voltage for UC864G and damage it.
UC864-G Hardware User Guide DRAFT - 29/10/07 The constant voltage charge proceeds with a fixed voltage regulator (very accurately set to the maximum battery voltage) and hence the current will decrease while the battery is becoming charged. When the charging current falls below a certain fraction of the fast charge current value, then the battery is considered fully charged, the final charge stops and eventually starts the maintenance.
UC864-G Hardware User Guide DRAFT - 29/10/07 5.2.
UC864-G Hardware User Guide DRAFT - 29/10/07 5.2.3 Power Supply PCB layout Guidelines As seen on the electrical design guidelines the power supply shall have a low ESR capacitor on the output to cut the current peaks and a protection diode on the input to protect the supply from spikes and polarity inversion. The placement of these components is crucial for the correct working of the circuitry. A misplaced component can be useless or can even decrease the power supply performances.
UC864-G Hardware User Guide DRAFT - 29/10/07 6 Antenna The antenna connection and board layout design are the most important part in the full product design and they strongly reflect on the product overall performances, hence read carefully and follow the requirements and the guidelines for a proper design. 6.
UC864-G Hardware User Guide DRAFT - 29/10/07 6.2 • • • • Install the antenna in a place covered by the GSM/WCDMA signal. The Antenna must be installed to provide a separation distance of at least 20 cm from all persons and must not be co-located or operating in conjunction with any other antenna or transmitter; Antenna shall not be installed inside metal cases Antenna shall be installed also according Antenna manufacturer instructions. 6.
UC864-G Hardware User Guide DRAFT - 29/10/07 7 Logic level specifications Where not specifically stated, all the interface circuits work at 2.6V CMOS logic levels. The following table shows the logic level specifications used in the Telit UC864-G interface circuits: For 2.6V CMOS signals: Absolute Maximum Ratings -Not Functional UC864-G Parameter Min Max Input level on any digital pin when on Input voltage on analog pins when on -0.3V +3.0V -0.3V +3.
UC864-G Hardware User Guide DRAFT - 29/10/07 7.1 Reset signal Signal RESET Function Phone reset I/O I PIN Number 54 RESET is used to reset the UC864-G module. Whenever this signal is pulled low, UC864-G is reset. When the device is reset it stops any operation. After the release of the reset UC864-G is unconditionally shut down, without doing any detach operation from the network where it is registered.
UC864-G Hardware User Guide DRAFT - 29/10/07 8 Serial Ports The serial port on the Telit UC864-G is the interface between the module and OEM hardware. 2 serial ports are available on the module: • MODEM SERIAL PORT • MODEM SERIAL PORT 2 (DEBUG) 8.1 MODEM SERIAL PORT Several configurations can be designed for the serial port on the OEM hardware, but the most common are: • RS232 PC com port • microcontroller UART @ 2.
UC864-G Hardware User Guide DRAFT - 29/10/07 The signals of the UC864-G serial port are: RS232 Pin Number 1 2 3 4 5 6 7 8 9 Signal DCD dcd_uart RXD tx_uart TXD rx_uart DTR dtr_uart GND DSR dsr_uart RTS rts_uart CTS cts_uart RI - ri_uart UC864-G Pad Number 32 Name Usage Data Carrier Detect 26 Transmit line *see Note Output from the UC864-G that indicates the carrier presence Output transmit line of UC864-G UART 25 Receive line *see Note Input receive of the UC864-G UART 29 Data Terminal Ready I
UC864-G Hardware User Guide DRAFT - 29/10/07 8.2 RS232 level translation In order to interface the Telit UC864-G with a PC com port or a RS232 (EIA/TIA-232) application a level translator is required.
UC864-G Hardware User Guide DRAFT - 29/10/07 An example of level translation circuitry of this kind is: The RS232 serial port lines are usually connected to a DB9 connector with the following layout: Reproduction forbidden without Telit Communications S.p.A.
UC864-G Hardware User Guide DRAFT - 29/10/07 8.3 5V UART level translation If the OEM application uses a microcontroller with a serial port (UART) that works at a voltage different from 2.6 - 3V, then a circuitry has to be provided to adapt the different levels of the two set of signals. As for the RS232 translation there are a multitude of single chip translators.
UC864-G Hardware User Guide DRAFT - 29/10/07 NOTE: The UART input line TXD (rx_uart) of UC864-G is NOT internally pulled up with a resistor, so there may be the need to place an external 47KΩ pull-up resistor, either the DTR (dtr_uart) and RTS (rts_uart) input lines are not pulled up internally, so an external pull-up resistor of 47KΩ may be required. A power source of the internal interface voltage corresponding to the 2.
UC864-G Hardware User Guide DRAFT - 29/10/07 9 USB Port UC864-G includes an integrated universal serial bus (USB) transceiver, compliant with USB 2.0 specification, for interfacing UC864-G to a computer as a USB peripheral or connecting the UC864-G to other peripherals. It supports the USB low-speed (1.5 Mbits/s) and full-speed (12 Mb/s) modes. In HSDPA (High Speed download Packet Access) mode, the downlink data speed rates up to 7.2Mbps.
UC864-G Hardware User Guide DRAFT - 29/10/07 10 Audio Section Overview The Base Band Chip of the UC864-G Telit Module provides two different audio blocks; both in transmit (Uplink) and in receive (Downlink) direction: “MT lines” should be used for handset function, “HF lines” is suited for hands -free function (car kit). These two blocks can be active only one at a time, selectable by AXE hardware line or by AT command.
UC864-G Hardware User Guide DRAFT - 29/10/07 10.1 Microphone Paths Characteristic and Requirements TIP: Being the microphone circuitry the more noise sensitive, its design and layout must be done with particular care. Both microphone paths are balanced and the OEM circuitry should be balanced designed to reduce the common mode noise typically generated on the ground plane. However an unbalanced circuitry can be also used for particular OEM application needs.
UC864-G Hardware User Guide DRAFT - 29/10/07 TIP: Definition of the nominal sensitivity of the microphone lines. The nominal sensitivity of the microphone lines indicates the voltage level on the UC864-G pins present during "normal spoken" conditions. For a handset , the "normal spoken” conditions take place when the talker mouth is 7cm far from the microphone ; under these conditions the voice will produce an acoustic pressure of -4,7dBPa @1kHz on the microphone membrane .
UC864-G Hardware User Guide DRAFT - 29/10/07 TIP: Environment consideration For handsfree/car kit microphone, you must take into account the voice attenuation, due to the distance between the microphone itself and the talker, when designing the external microphone amplifier. Not only, you must consider that the microphone will pick up also ambient noise; to overcome this problem it is preferable to set the gain of the microphone 10dB lower with respect to the calculated value for a nominal sensitivity.
UC864-G Hardware User Guide DRAFT - 29/10/07 10.2 General Design Rules There are several configurations for the audio paths, but the most effective difference is between balanced and unbalanced microphone configuration. It is highly recommended to keep the whole microphone path balanced even if this means having 2 wires connecting the microphone instead of one needed (plus ground) in the unbalanced case.
UC864-G Hardware User Guide DRAFT - 29/10/07 10.4 Microphone Biasing The electret microphones usually need a biasing voltage to work properly. Refer to your microphone provider for the characteristics required. NOTE: The microphones have a hot wire were the positive biasing must be connected. Usually it is indicated by a + symbol or a red point. If the polarity of the bias is reversed, then the microphone will not work properly. For this reason be sure to respect the mic. biasing polarity. 10.4.
UC864-G Hardware User Guide DRAFT - 29/10/07 NOTE: In the balanced application the resistors R2 and R3 must have the same value to keep the circuit balanced. NOTE: The cable to the microphone should not be shielded, instead a twisted pair cable shall be used. NOTE: The microphone sensitivity changes with the value of R2 and R3. Usually the microphones are characterized with 2kΩ biasing resistance, so try to keep the sum of R2 and R3 around 2kΩ. Refer to your microphone manufacturer for the mic.
UC864-G Hardware User Guide DRAFT - 29/10/07 NOTE: In the unbalanced application the capacitor C3 shall be > 200nF otherwise the frequency response will be cut at low band frequencies (down to 300Hz). This capacitor can be placed close to the MIC- pad (MIC_HF- or MIC_MT- depending on the audio path chosen) or if possible it should be placed close to the shielded cable connector.
UC864-G Hardware User Guide DRAFT - 29/10/07 10.5 Microphone Buffering As seen previously, a microphone shall be connected to the input pins of UC864-G through a buffer amplifier that boosts the signal level to the required value. Again the buffered microphone circuitry can be balanced or unbalanced: where possible it is always preferable a balanced solution. The buffering circuit shall be placed close to the microphone or close to the microphone wire connector. 10.5.
UC864-G Hardware User Guide DRAFT - 29/10/07 The buffer gain is given by the formula: Gain = R604 R606 = R605 R607 The C636 and C637 capacitors are placed in order to cut off the gain at higher frequencies than the transmitted GSM band, the cutoff frequency (-3dB) should be 3500Hz in order to have -1dB at 3kHz. The cutoff frequency is given by the formula: freq.
UC864-G Hardware User Guide DRAFT - 29/10/07 10.5.2 Buffered Unbalanced (Single Ended) Microphone GE863 Mic+ To GE863 2,7nF GE863 M ic- 6,8nF The above schematic can be used for a single ended (buffered unbalanced) microphone; the required biasing circuitry is not included.
UC864-G Hardware User Guide DRAFT - 29/10/07 1 1 freq. = = [Hz] 2π * R719 * C 726 2π * R711* C 727 The buffer bandwidth at -3dB shall be 4KHz. Note that the biasing of the operational amplifier is given for the inverting amplifier by the series divider R714-R715. The 100nF capacitor C719 is needed to filter the noise that could be coupled to that divider.
UC864-G Hardware User Guide DRAFT - 29/10/07 C726= 1/ (2π*4000*R719)= 7.10 *10 -9 F C727= 1/ (2π*4000*R711)= 2,65 *10 -9 F modified in 6,8nF (fc1=4181Hz ) and 2,7nF (fc2=3931Hz) because of commercial values . Reproduction forbidden without Telit Communications S.p.A.
UC864-G Hardware User Guide DRAFT - 29/10/07 11 OUTPUT LINES (Speaker) 11.1 Short description The Telit UC864-G provides two audio paths in receive section. Only one of the two paths can be active at a time, selectable by AXE hardware line or by AT command.
UC864-G Hardware User Guide DRAFT - 29/10/07 11.2 Output Lines Characteristics UC864-G; “Ear_MT” Differential output path • line coupling: • line type: • output load resistance : • max. load capacitance • differential output impedance: • signal bandwidth: • differential output voltage • SW volume level step • number of SW volume steps DC differential 32 Ω 500pF(max.) 1 Ω (max) @1.02KHz 150 - 4000 Hz @ -3 dB 1060mVrms (typ.
UC864-G Hardware User Guide DRAFT - 29/10/07 11.
UC864-G Hardware User Guide DRAFT - 29/10/07 11.4 Handset Earphone Design As seen previously, a 32Ω earpiece can be directly connected to the output pads EAR_MT+ and EAR_MT- of the UC864-G. This solution is often the more cost effective, reducing the components count to a minimum.
UC864-G Hardware User Guide DRAFT - 29/10/07 The resulting gain and high pass cut can be obtained with the formula: Gain = freq. = R3 R2 1 [Hz] 2π * R3 * C 4 And an example of internal Ear amplifier could be: +12dB UC864-E Some amplifier require a low impedance load at high frequency in order to avoid auto oscillation, this can be made with a capacitor (100nF) in series with a resistor (15Ω).
UC864-G Hardware User Guide DRAFT - 29/10/07 11.6 Car Kit Speakerphone Design For the car kit speaker phone function the power output requirement is usually at least 4W, therefore an amplifier is needed to boost the UC864-G output. The design of the amplifier shall comply with the following guidelines: • • • • • • The input to the amplifier MUST be taken from the “Ear_HF” audio path of UC864-G, because of its echo canceller parameters suited to a car cabin use.
UC864-G Hardware User Guide DRAFT - 29/10/07 12 General Purpose I/O The general-purpose I/O pads can be configured to act in three different ways: • Input • Output • Alternate function (internally controlled) Input pads can only be read and report the digital value (high or low) present on the pad at the read time; output pads can only be written or queried and set the value of the pad output; an alternate function pad is internally controlled by the UC864-G firmware and acts depending on the function impl
UC864-G Hardware User Guide DRAFT - 29/10/07 12.1 Logic level specifications Where not specifically stated, all the interface circuits work at 2.6V CMOS logic levels. The following table shows the logic level specifications used in the UC864-G interface circuits: Absolute Maximum Ratings -Not Functional UC864-G Parameter Min Max Input level on any digital pin when on Input voltage on analog pins when on -0.3V +3.0V -0.3V +3.0 V For 2.
UC864-G Hardware User Guide DRAFT - 29/10/07 12.2 Using a GPIO Pad as INPUT The GPIO pads, when used as inputs, can be connected to a digital output of another device and report its status, provided this device has interface levels compatible with the 2.6V CMOS levels of the GPIO. NOTE: If the digital output of the device to be connected with the GPIO input pad has interface levels different from the 2.
UC864-G Hardware User Guide DRAFT - 29/10/07 NOTE: During RESET the line is set to HIGH logic level. 12.6 Using the Buzzer Output GPIO7 The GPIO7 pad, when configured as Buzzer Output, is controlled by the UC864-G module and will drive with appropriate square waves a Buzzer driver. This permits to your application to easily implement Buzzer feature with ringing tones or melody played at the call incoming, tone playing on SMS incoming or simply playing a tone or melody when needed by your application.
UC864-G Hardware User Guide DRAFT - 29/10/07 12.7 Indication of network service availability The STAT_LED pin status shows information on the network service availability and Call status. In the UC864-G modules, the STAT_LED usually needs an external transistor to drive an external LED. Therefore, the status indicated in the following table is reversed with respect to the pin status.
UC864-G Hardware User Guide DRAFT - 29/10/07 12.8 RTC Bypass out The VRTC pin brings out the Real Time Clock supply, which is separate from the rest of the digital part, allowing having only RTC going on when all the other parts of the device are off. To this power output a backup capacitor can be added in order to increase the RTC autonomy during power off of the battery. NOTE: NO Devices must be powered from this pin. 12.
UC864-G Hardware User Guide DRAFT - 29/10/07 13 DAC and ADC section 13.1 DAC Converter(TBD) 13.1.1 Description The UC864-G module provides a Digital to Analog Converter. The signal (named DAC_OUT) is available on pin 40 of the UC864-G module and on pin 17 of PL102 on EVK2 Board (CS1203). The on board DAC is a 16-bit converter, able to generate a analogue value based a specific input in the range from 0 up to 65535.
UC864-G Hardware User Guide DRAFT - 29/10/07 13.1.1 Low Pass Filter Example Reproduction forbidden without Telit Communications S.p.A.
UC864-G Hardware User Guide DRAFT - 29/10/07 13.2 ADC Converter 13.2.1 Description The on board ADCs are 8-bit converters. They are able to read a voltage level in the range of 0-2.6 volts applied on the ADC pin input, store and convert it into 8 bit word. Input Voltage range AD conversion Resolution Min 0 - Max 2.6 8 <11 Units Volt bits mV The UC864-G module provides 3 Analog to Digital Converters. The input lines are: ADC_IN1 available on Pin 37 and Pin 19 of PL102 on EVK2 Board (CS1203).
UC864-G Hardware User Guide DRAFT - 29/10/07 13.3 Mounting UC864-G on your board The position of the Molex board to board connector and the pin 1 are shown in the following picture. MOVABLE RF(GPS) MOVABLE RF(GSM/WCDMA) NOTE: metal tabs present on UC864-G should be connected to GND Reproduction forbidden without Telit Communications S.p.A.
UC864-G Hardware User Guide DRAFT - 29/10/07 13.3.1 Debug of the UC864-G in production To test and debug the mounting of the UC864-G, we strongly recommend to foreseen test pads on the host PCB, in order to check the connection between the UC864-G itself and the application and to test the performance of the module connecting it with an external computer.
UC864-G Hardware User Guide DRAFT - 29/10/07 14 Document Change Log Revision Date DRAFT 29/10/07 Changes Regulatory Notices This device is compliant with Parts 15, 22 and 24 of the FCC Rules. Operation of this device is subject to the following two conditions: 1. This device may not cause harmful interference, and 2. This device must accept any interference received, including interference that may cause undesirable operations. Reproduction forbidden without Telit Communications S.p.A.
