Si4731-DEMO Si4731 D EMO B OARD U SER ’ S G UIDE 1. Features Worldwide FM band support, 76–108 MHz Worldwide AM band support, 520–1710 kHz Auto seek/auto scan 48 FM and 48 AM station presets FM Radio Data Services (RDS) decoding (Pi Pty Ps RT CT AF displays) Automatic set time/date function via RDS Automatic Alternative Frequency (AF) switching Automatic AM channel spacing detection Single battery operation down to 0.9 V or three battery operation Adjustable parameters include Tuning spacing Seek SNR/RSSI thresholds Soft mute SNR/RSSI thresholds Channel filters Stereo and mono blend thresholds Band limits De-emphasis (50 or 75 µs) AM channel spacing detection threshold Stereo/mono indicator Volume control with mute function AM/FM band and signal quality indicator display Battery voltage indicator Calendar display 3x4 matrix keypad interface Direct input of station frequencies 2. Overview The Silicon Laboratories Si4731-DEMO board provides a complete portable AM/FM radio design with numerous enhanced features that demonstrate the capabilities of the Silicon Laboratories AM/FM and MCU product families. The Si4731-DEMO comes in a 3x3 mm 20-pin QFN package and is layout compatible with the entire Silicon Labs Si47xx radio family of FM receivers, transmitters, and transceivers. The host MCU is a Silicon Laboratories C8051F930 with internal oscillator and built-in DC-DC converter. A 79 x 101 dot matrix LCD provides the flexibility to display a variety of system information including RDS. The demo board can work with either one AA battery using the dc-dc converter of the C8051F930 MCU or three AAA batteries. Rev. 0.1 5/08 Copyright © 2008 by Silicon Laboratories Si4731-DEMO Si4731-DEMO 3. Description Figure 1 and Figure 2 shows the physical layout of the board with key components indicated. JP1 J2 J1 U1 J15 U2 J14 LCD S14 2 1 3 4 S15 U4 JP2 J3 Reset Key T1 J4 JP4 JP3 KeyPad Figure 1. Si4731-DEMO Board Top Side in Calendar Mode U3 J5 Figure 2. Si4731-DEMO Board Bottom Side 2 Rev. 0.1 Si4731-DEMO Power: S14: 3 cell / 1 cell selection S15: Power on / off Audio connectors: J14: Audio input (unused) J15: Audio headphone output Antenna selections: J1: FM whip antenna connector J2: FM SMA connector for FM conductive testing J3: AM SMA connector for AM conductive testing J4: AM air loop antenna wire connector J5: JTAG connector T1: Transformer for AM air loop operation (not shown) JP1: FM antenna input selection 3 2 1-2: FM SMA (J2) 1-3: FM whip antenna (J1) 1-4: FM headphone (J15) 4 1 JP2: AM signal input selection 4 3 1 1-2: AM ferrite loop stick 1-3: AM air loop (J4) 1-4: AM SMA (J3) 2 JP3: AM antenna type selection Open: AM ferrite loop stick antenna Short: AM air loop antenna JP4: FM PCB antenna selection Short: Embedded PCB trace as FM short antenna for Si4704/05/1x/2x Open: No PCB short antenna Main components: LCD: 79x101 dot matrix LCD U1: Silicon Laboratories Si4731 AM/FM/RDS tuner U2: Audio amplifier U3: Silicon Laboratories C8051F930 MCU U4: LDO Control interface: Reset Key: Reset button KeyPad: 3x4 matrix buttons for human interface Rev. 0.1 3 Si4731-DEMO 4. Operation This section describes the operating modes of the Si4731-DEMO board. The board provides two major modes of operation: Calendar and AM/FM radio. 4.1. Calendar Mode Upon power on, the board automatically enters the Calendar Mode and displays the following information: Year-month-day Hour-minute Day of the week Battery voltage The demo board display in Calendar Mode is illustrated in Figure 1. In Calendar Mode, the SET/9 key is used to enter the setup menu. The M+/3 and M-/7 keys are used to select different adjustable items (hour, minutes, year, day, month). The UP/4 and DOWN/8 keys are used to set the value for each selected item. The Calendar Mode date and time can also be set automatically with RDS Current Time (CT) information from a broadcast radio station as described in the following section. 4.2. AM/FM Radio Mode From Calendar Mode, the POWER button is used to enter AM/FM Radio Mode which displays the following information: 1. Signal SNR indicator 2. Signal RSSI indicator 3. Band frequency indicator 4. Battery voltage indicator 5. Band frequency unit indicator 6. Stereo/mono indicator 7. Volume indicator 8. Band indicator 9. RDS information The demo board display in AM/FM Radio Mode is illustrated in Figure 3 and Figure 4: 6 1 3 2 4 7 5 8 9 Figure 3. LCD Display in FM Radio Mode 4 Rev. 0.1 Si4731-DEMO 1 3 2 4 7 5 8 Figure 4. LCD Display in AM Radio Mode 4.2.1. Band Selection In Radio Mode, the BANDS/0 key is used to switch between the AM and FM bands. 4.2.2. Time/Date Auto Set Many radio stations broadcast RDS data including clock/time CT information. The AM/FM demo board can capture this information to automatically set the time and date. In FM Mode, when RDS CT information is received, the CT indicator will be displayed. The MEM/AL/1 button can be used to update the calendar date and time with the CT information. CT information is not available on all radio stations and is normally sent only once per minute. 4.2.3. Alternative Frequency (AF) Switching The AM/FM demo board monitors RDS for alternate frequency (AF) information. When RDS alternative frequency information is received, the AF indicator will be displayed. If the signal quality of the currently tuned station degrades, the radio will automatically change to one of the alternative frequency stations. 4.2.4. Tune/Seek In Radio Mode, pressing the UP/4 or DOWN/8 button for less than 0.5 s will tune the frequency by the preset step size. Holding the button for longer than 0.5 s but less than 3 s will perform a station seek. 4.2.5. Scan In Radio Mode, the MSCAN/5 button is used to scan for all valid stations in the selected band and will automatically save them into preset selections. After a scan operation, the M+/3 and M-/7 keys will cycle through the preset station list. Scan operation can be aborted by pressing MSCAN/5 again, or by pressing the UP/4 or DOWN/8 key. 4.2.6. Parameter Settings In Radio Mode, the SET/9 key is used to select the parameter setup menu as illustrated in Figure 5 and Figure 6. The M+/3 or M-/7 keys will cycle through the available items in the menu. The UP/4 or DOWN/8 keys are used to set the desired value for each item. Select “Yes” under “Factory Def” to go back to the factory default settings for all items. Rev. 0.1 5 Si4731-DEMO Figure 5. LCD Display in FM Setup Menu Figure 6. LCD Display in AM Setup Menu 4.2.7. Digit Keys In Radio Mode, the FUNC/DIGIT key is used to switch the keypad to digital input mode. A “Dig” indicator is displayed in this mode and all keys marked with a digit are used to input a channel frequency. A frequency is considered valid if it lies within the band limits. If a non-valid frequency is entered, the closest band limit will be entered and displayed. 4.2.8. Volume The VOL+/2 or VOL–/6 keys are used to adjust the volume up or down. The board audio output will be muted when volume is at the lowest setting. 4.2.9. AM Channel Spacing Auto Set In AM Mode, the MEM/AL/1 key will automatically detect and set the channel spacing to either 9 or 10 kHz. The detection criterion determines which channel spacing results in more valid stations during a band scan. The number for the detection threshold is adjustable as described in Table 2. This operation can be aborted by pressing the MEM/AL/1 key again. 6 Rev. 0.1 Si4731-DEMO 5. Human interface There are 12 keys for controlling the demo board as shown in Figure 7: MEM/AL/1 VOL+/2 M+/3 MSCAN/5 VOL-/6 M-/7 BANDS/0 FUNC/DIGIT SET/9 UP/4 DOWN/8 POWER Figure 7. Human Interface Keys Each key can have a different function under each operating condition: Calendar/Powerdown Mode: Radio function is disabled. LCD displays Calendar. Buttons can be used to set time, etc. Radio AM/FM Mode: Tuner IC works in powerup mode (FM or AM). Radio function is enabled. LCD displays the radio station parameters. Buttons are used to adjust radio settings. Digital Input Mode: Tuner IC works in powerup mode (FM or AM). Radio function is enabled. LCD displays the radio station parameters. The buttons are used for direct digit input of station frequencies. The functions of the buttons are summarized in Table 1: Table 1. Key Function Description Button/Mode Calendar Mode Tuner Off Radio AM/FM Mode Tuner On MEM/AL/1 None FM Mode: Used to adjust calendar using received RDS CT. AM Mode: Used to automatically detect and set the channel spacing. POWER Enable radio Disable radio function and enter calendar mode. (Radio parameters will be saved to Flash). SET Enter calendar setup menu Enter radio setup menu. (Parameter list in Table 2) BANDS None Change between FM and AM band. In setup menu, change the current calendar item by one step. In setup menu, change the current parameter by one step. In radio mode, tune up or down by one step. Fast parameter setting Fast parameter setting. None Scan for all valid stations and save them to presets. UP/ DOWN Hold Time < 0.5 s 0.5 s < Hold Time <3s Hold Time >3s MSCAN Perform a station seek. Note: Combination keying is entered and exited from Radio Mode by pressing and holding the SET key then pressing the BANDS key. A combination of the SET and the MSCAN keys will cycle through the available display items. Rev. 0.1 7 Si4731-DEMO Table 1. Key Function Description (Continued) Button/Mode Calendar Mode Tuner Off Radio AM/FM Mode Tuner On M+/ M– In setup menu, select next calendar item. In setup menu, select next adjustable item. In radio mode, tune to the next preset station. None Increase or decrease volume 1 step. Vol+ / Vol– <3s >3s Quickly increase or decrease volume. FUNC/DIGIT None Shift the keyboard between normal function and digital input mode. Combination keying None A: Radio IC version B: Firmware version C: Varactor reading D: AGC status Note: Combination keying is entered and exited from Radio Mode by pressing and holding the SET key then pressing the BANDS key. A combination of the SET and the MSCAN keys will cycle through the available display items. The FM and AM radio parameters which can be configured from setup menu are listed below in Table 2. Table 2. Radio Configuration Parameters FM Parameter 8 AM Parameter Spacing: 50/100/200 kHz Default: 100 kHz Spacing: 1/9/10 kHz Default: 9 kHz RSSI Seek: 0–127 dBµV Default: 20 dBµV RSSI Seek: (0–63 dBµV Default: 25 dBµV SNR Seek: 0–127 dB Default: 03 dB SNR Seek: 0–63 dB Default: 05 dB Pre-emphasis: 50 or 75 µs Default: 75 µs Pre-emphasis: 00 disable, 50 µs Default: 00 Band High Threshold: Max 108 MHz Default:107.90 MHz Band High Threshold: Max 1710 kHz Default:1710 kHz Band Low Threshold: min 76 MHz Default: 87.50 MHz Band Low Threshold: min 520 kHz Default: 522 kHz Channel Filter: 00/40/60/80/100 kHz Default: 00 (Auto) Channel Filter: 1/2/3/4/6 kHz Default: 2 kHz RClock: 0: AFC disable 32763~32773 Default: 32768 RClock: 0 AFC disable 32763~32773 Default: 32768 Smute Rate: 0–255 Default: 64 Smute Rate: 0–255 Default: 64 Smute SNR: 0–15 dB Default: 4 dB Smute SNR: 0–63 dB Default: 10 dB Smute Attenuation: (0–31 dB) Default: 16 dB Smute Attenuation: 0–63 dB Default: 16 dB Rev. 0.1 Si4731-DEMO Table 2. Radio Configuration Parameters (Continued) Blend Mono: 0–127 dBµV Default: 30 dBµV Smute Slop: 1–5 Default: 2 Blend Stereo: 0–127 dBuV Default: 49dBuV Set Factory Default: on/off Default:off AGC Override: on/off Default: off AM Channel Spacing Detection Threshold: 1,2,3,4,5,6 Default = 2 AGC Index: 0–26 Default : 0 Set Factory Default: on/off Default:off RDS/RBDS Default: RBDS Rev. 0.1 9 Si4731-DEMO 6. Bill of Materials C8051F930 MCU with 64 kB Flash program memory, 4 kB RAM, and built-in dc-dc converter AM/FM receiver IC Si4731 with external 32768 Hz crystal oscillator support ST7588T LCD driver IC LM4910 Audio amplifier IC See Table 3 for details. Table 3. Si4731 Demo Board Bill of Materials Item Qty Reference Description Value 1 3 C1, C16, C29 CAP,SM,0603,X7R 0.47 µF 2 2 C4, C13 CAP,SM,0603,X7R 4.7 µF 3 8 C15, C23-28, C41 CAP,SM,0603,X7R 1 µF 4 6 C10, C14, C19, C37, C39–40 CAP,SM,0603,X7R 0.1 µF 5 4 C2 ,C3, C21–22 CAP,SM,0603,X7R 22 pF 6 2 C8, C12 CAP,SM,0603,X7R 220 pF 7 2 C11, C18 CAP,SM,0603,X7R 820 pF 8 3 C5–7 CAP,SM,0603,X7R 100 pF 9 4 C17, C38, C44, C46 CAP,SM,0603,X7R 1 nF 10 8 C32–36, C54–C55 ,C43 CAP,SM,0603,X7R NP 11 3 C30 ,C45, C53 RES,SM,0603 0R 12 1 C9 CAP,SM,1210,tantalum 100 µF/6.3 V 13 1 C31 CAP,SM,1210,tantalum 220 µF/4 V 14 4 R1–2, R3 ,R25 RES,SM,0603 0R 15 11 RES,SM,0603 10 kW 16 2 R5, R11 RES,SM,0603 12 kW 17 4 R20, R22–23, R28 RES,SM,0603 1 kW 18 2 R4,R6 RES,SM,0603 5k6 19 2 R8, R10 RES,SM,0603 6k8 20 3 R9, R16–17 RES,SM,0603 2 kW 21 2 R18–19 RES,SM,0603 100R 22 5 RES,SM,0603 NP 23 1 R12 RES,SM,0603 4k7 24 3 R13–14, R33 RES,SM,0603 100k 25 4 B1–4 FERRITE BEAD,SM,0805 2k5/100M 26 1 L1 IND,SM,0603 120 nH 27 1 L2 IND,SM,0603 270 nH 28 2 L3–4 RES,SM,0603 0R 29 1 U1 Si47xx, MLP20-3MM Si47xx 10 R7, R27, R29–32, R34, R36–39 R15, R21 ,R24, R26 ,R35 Rev. 0.1 Si4731-DEMO Table 3. Si4731 Demo Board Bill of Materials (Continued) 30 1 U2 LM4910,SOP8 LM4910MA 31 1 U4 REGLATOR,SOT23 XC62FP3002MR 32 1 U3 C8051F920/30-GQ,LQFP32 C8051F920/30-GQ 33 1 D1 DIODE,SM,ESD,SOT23 BAV99 34 2 D2–4 DIODE,SM,ESD,SOT23 CM1214-01ST/SO 35 1 Q1 TRANSISTOR NPN SOT23 2N3904 36 1 T1 MW AIR LOOP ANTENNA TRANSFORMER SLMWTF01 37 1 J5 CONN,TH,2X10,HDR 38 1 J4 Wire holder 39 2 Y1–2 Crystal 32.768 kHz 40 2 J14–15 Stereo earphone jack 3.5 mm 41 2 JP3–4 CONN,TH,1X2,HDR CONN,TH,1X2,HDR 42 2 JP1–2 CONN,TH,1X4,HDR CONN,TH,1X4,HDR 43 4 J10–13 CONN,TH,1X5,HDR CONN,TH,1X5,HDR 44 1 J1 BNC_VERTICAL BNC for whip 45 2 J2-3 SMA_VERTICAL SMA for FM/AM 46 1 S14 SLIDE SWITCH With 3 Double Pole Double Throw Switches inside 47 1 S15 Single Pole Double Throw Switch 48 13 S1–13 Button Switch 49 1 LCD1 LCD 101*79 dots 50 1 ANT2 MW ferrite antenna 220 µH 51 1 ANT3 MW loop antenna 10–20 µH 52 1 BAT2 Battery BOX ,AAA*3 SIZE 53 1 BAT1 Battery BOX ,AA SIZE DC–DC Power Block Circuit Part List 54 1 L5 IND,SM,1008 0.68 µH 55 1 C42 CAP,SM,0603,X7R 4.7 µF Rev. 0.1 11 Figure 8. Si4731-DEMO Board Schematic—Radio and Audio Portions Si4731-DEMO 7. Schematics 12 Rev. 0.1 Figure 9. Si4731-DEMO Board Schematic—MCU Portion Si4731-DEMO Rev. 0.1 13 Si4731-DEMO CONTACT INFORMATION Silicon Laboratories Inc. 400 West Cesar Chavez Austin, TX 78701 Tel: 1+(512) 416-8500 Fax: 1+(512) 416-9669 Toll Free: 1+(877) 444-3032 Email: [email protected] Internet: www.silabs.com The information in this document is believed to be accurate in all respects at the time of publication but is subject to change without notice. Silicon Laboratories assumes no responsibility for errors and omissions, and disclaims responsibility for any consequences resulting from the use of information included herein. Additionally, Silicon Laboratories assumes no responsibility for the functioning of undescribed features or parameters. Silicon Laboratories reserves the right to make changes without further notice. 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Other products or brandnames mentioned herein are trademarks or registered trademarks of their respective holders. 14 Rev. 0.1