Hardware Interface Description - Wireless Data Modules

More documents

Recommendations

Info

MC55/56 Hardware Interface Description Confidential / Released s 8 Design example Figure 47 shows a sample application that incorporates an MC55/56 module and an external µController. This solution is typical of devices designed for audio and GSM capability, such as mobile phones, PDAs, Tablet PCs etc. The audio part is made of internal transducers (earpiece and microphone) and integrates an additional interface for connecting an external headset. This interface detects the presence of a plugged headset and verifies whether the headset key (push-to-talk key) is pressed. The charging circuit is designed to ensure trickle charging that takes effect when the battery is deeply discharged. Used components: 100Ω series resistance, Z diode 4V3, 1SS355 diode. If the charger supplies a voltage from 5.5V to 8V this arrangement will deliver an overall current of approx. 15mA (5.5V) to 37mA (8V) for trickle charging and for the application. If the application circuit draws a greater current another LDO (Low Dropout Regulator) can be added to allow for an additional parallel power supply dedicated to the application. This LDO can be connected between the positive charger input and the 3V power supply source. Caution: Trickle charging is done when the voltage of the Li-Ion battery is below 3.2V. High level of the VDD line indicates that the MC55/56 module is active. While MC55/56 is in POWER DOWN mode the application interface is switched off and must not be fed from any other source. Therefore, the application must be designed to avoid any current flow into any digital pins of the application interface. The RING0 line notifies, primarily, incoming calls. Therefore, if connected with an interrupt of the application µController, the RING0 line can be effectively used to wake up the application µController from power saving. The test points (referred to as “TPx”) can be used for downloading firmware to the MC55/56 module. TP0: GND TP1: Data transfer from MC55/56 TP2: Data transfer to MC55/56 TP3: Starts up MC55/56 (high active) The EMC measures are best practice recommendations. In fact, an adequate EMC strategy for an individual application is very much determined by the overall layout and, especially, the position of components. For example, mounting the internal acoustic transducers directly on the PCB eliminates the need to use the ferrite beads shown in the sample schematic. Disclaimer No warranty, either stated or implied, is provided on the sample schematic diagram shown in Figure 47 and the information detailed in this section. As functionality and compliance with national regulations depend to a great amount on the used electronic components and the individual application layout manufacturers are required to ensure adequate design and operating safeguards for their products using MC55/56 modules. MC55/56_hd_v02.06 Page 102 of 105 29.10.2004
MC55/56 Hardware Interface Description Confidential / Released s LCD Keypad Oscillator RESET 3V 100k BC 847 3V 2.2µF Headset plug in GPI Push to talk GPI µC RESET GPO 100k 47k V+ 47k BC 847 100nF 3V TXD RXD CTS RTS DSR DTR DCD INT GPI GPO GND TP3 TP1 33pF BC847 LDO TP0 TP2 TXD0 RXD0 CTS0 RTS0 DSR0 DTR0 DCD0 RING0 VDD 1M 100nF GND BC847 33pF BATT+ 2.2uF GSM antenna Li-Ion battery pack 1nF *) 200nF 1SS355 CRS04 100R 4V3 SI3441DV 5.5V - 8V 500mA *) Charger 33pF 3k3 NTC 10k BATT+ *) ESD protection e.g. 1/5 ESDA6V1-5W6 GSM Module IGT EMERG 47k OFF MICN1 MICP1 2k 100nF 100nF BATT_TEMP Note: RXD0, CTS0, DSR0, DCD0, RING0 can float if module is in POWER DOWN state. Use pull down resistors (>100k) if necessary. EPN1 CHARGE POWER 6R8 CCVCC CCCLK CCIO CCRST CCIN CCGND MICP2 MICN2 EPP2 EPN2 VDDLP EPP1 6R8 6R8 6R8 ESD + 2x47nF >100µF Backup of RTC 27pF 2x BLM 18HG 601 470k 3V 2x47nF ESD 27pF Figure 47: Schematic diagram of MC55/56 sample application 3V 47pF internal BAV99 ESD 2.2k 470k 100nF SIM 0R not mounted BLM 18HG 601 2x4.7nF internal ESD If internal transducers BLM 18HG 601 are placed on PCB ferrite beads are not 10pF necessary 4x BLM 18HG 601 2.7k 22µF 470k 3V Phone jack MC55/56_hd_v02.06 Page 103 of 105 29.10.2004
Page 1 and 2:
MC55/56 Hardware Interface Descript
Page 3 and 4:
Page 5 and 6:
Page 7 and 8:
Page 9 and 10:
Page 11 and 12:
Page 13 and 14:
Page 15 and 16:
Page 17 and 18:
Page 19 and 20:
Page 21 and 22:
Page 23 and 24:
Page 25 and 26:
Page 27 and 28:
Page 29 and 30:
Page 31 and 32:
Page 33 and 34:
Page 35 and 36:
Page 37 and 38:
Page 39 and 40:
Page 41 and 42:
Page 43 and 44:
Page 45 and 46:
Page 47 and 48:
Page 49 and 50:
Page 51 and 52: MC55/56 Hardware Interface Descript
Page 101: MC55/56 Hardware Interface Descript
Page 105: MC55/56 Hardware Interface Descript
show all

Hardware Interface Description - Wireless Data Modules

Create successful ePaper yourself

Delete template?

Save as template?