138A AM / FM / WB radio design 


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 Overview: 
 SG0702 IC is a AM / FM radio frequency display clock radio, auxiliary control to the control and integration of integrated circuits. Particularly suitable for AC1602-based chip multi-band radio with a WB band to achieve a PLL frequency control, frequency of storage, 40 e-volume, auto power off timer, night lighting, stereo symbol display, battery test, battery voltage automatic shutdown function. COMS process IC with I2C bus control mode 

 Features: 
 * 4-band frequency phase-locked FM, MW, SW, WB 
 * 90 station memory: (FM: 30 MW: 30 SW: 30 scalable) 
 * Manual and automatic storage tuning mode 
 * 40 push-button electronic volume 
 * Tuning mute 
 * Antenna signal strength display: RSSI and SNR 
 * LCD4 a public-driver section 21 characters, drive 1/3BIAS 1/4DUTY 
 * External 32.168K crystal oscillator 
 * Voltage 1.8V-5.5V, 3V typical 
 * 24-hour clock function 
 * 90 minutes auto shutdown function 
 * 24 hour alarm function 
 * Any key backlight 
 * Low-voltage automatic shutdown 
 * Supporting EEPROM 24LC02 station memory (optional) 
 * Support for PWM output (voltage control, alarm beep tone) 

 Key Function Description: 

 1) POWER, SLEEP: 
 Power ON / OFF switch, "according to" Power OFF, ON, power ON, OFF ON, press more than 1S into SLEEP 90-80-70 ... 0 to cancel the SLEEP, SLEEP automatically shut down after the opening tag display. 

 2) BAND / TIME SET (band switching / time settings): 
 When the power ON switch for band FM-AM-WB-FM .... When a clock cycle the power OFF time settings. 

 3) MEM / ALON, OFF (stored radio / timer switch settings): 
 Power ON: storage station steps: MEM CH MEM storage station during 'LCD MEMO and the auxiliary display speed of 0.5 seconds flash, press MEM to confirm only the power is OFF,' according to 'set the state to enter the AL regular boot, with the UP , DOWN keys to adjust the hours, minutes. 

 4) UP DOWN / hour, minute adjustments: 
 POWER ON, the upward and downward adjustment of frequency, by more than 0.5S automatic search, POWER OFF time: with the BAND / AL / TIME SET button for the hour, minute adjustments. 

 5) M +, M-: 
 When the MEN with the POWER ON button for store page to flip up and down, calling stored directly on the P +, P-key each time the up / down flip. 

 6) VOL + VOL- 
 Potential output button, VOL UP VOL DOWN decreasing increments starting at ultra-0.5S VOL light batter function LCD display shows the corresponding MAS series. 

 7) ALERT: 
 Band and the WB into the 1-7CH, waiting to enter the 1050HZ alarm state, when the conditions are established automatically turn on the radio.