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M41T00AUD_12 Datasheet, PDF (1/42 Pages) STMicroelectronics – Serial real-time clock (RTC) with audio | |||
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M41T00AUD
Serial real-time clock (RTC) with audio
Features
Combination real-time clock with audio
â Serial real-time clock (RTC) based on M41T00
â Audio section provides:
â 300 mW differential audio amplifier
â 256 and 512 Hz tone generation
â â33 to +12 dB gain, 3 dB steps (16 steps
plus MUTE)
â 0 °C to 70 °C operation
â Small DFN16 package (5 mm x 4 mm)
Real-time clock details
â Superset of M41T00
â 3.0 to 3.6 V operation
â Timekeeping down to 1.7 V
â Automatic backup switchover circuit
â Ultra-low 400 nA backup current at 3.0 V
(typ)
â Suitable for battery or capacitor backup
â On-chip trickle charge circuit for backup
capacitor
â 400 kHz I2C bus
â M41T00 compatible register set with counters
for seconds, minutes, hours, day, date, month,
years, and century
â Automatic leap year compensation
â HT bit set when clock goes into backup
mode
â RTC operates using 32,768 Hz quartz crystal
â Calibration register provides for
adjustments of â63 to +126 ppm
â Oscillator supports crystals with up to 40
kΩ series resistance, 12.5 pF load
capacitance
â Oscillator fail detect circuit OF bit indicates
when oscillator has stopped for four or more
cycles
DFN16 (5 mm x 4 mm)
Audio section
â Power amplifier
â Differential output amplifier
â Provides 300 mW into 8 Ω
(THD+N = 2% (max), fin = 1 kHz)
â Summing node at audio input
â Inverting configuration with summing
resistors into the minus (-) terminal
â 0 dB gain with 10 kΩ feedback resistor and
20 kΩ input summing resistors
â Signal input centered at VDD/2
â 1.6 VP-P analog input range (max)
â 256 or 512 Hz signal multiplexing with analog
input to provide audio with beep tones
â Volume control, 4-bit register
â Allows gain adjustment from â33 dB to
+12 dB
â 3 dB steps
â MUTE bit
â Audio automatically shuts off in backup mode
February 2012
Doc ID 13480 Rev 5
1/42
www.st.com
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