M41T00AUD:Serial real-time clock (RTC) with audio

The M41T00AUD is a low-power serial real-time clock (RTC) with an integral audio section with tone generator and 300 mW output amplifier. The RTC is a superset of the M41T00 with enhancements such as a precision reference for switchover, an oscillator fail detect circuit, and storing of the time at power-down. The audio section includes a summing amplifier (inverting) at the input. An 8 kHz low-pass filter follows that with a 16-step programmable gain stage next. A 256 or 512 Hz audio tone can be switched into the filter in place of the input signal. From the gain stage, the 300 mW amplifier drives the output pins.

The M41T00AUD has a built-in power sense circuit which detects power failures and automatically switches to the backup input when VCCis removed. Backup power can be supplied by a capacitor or by a battery such as a lithium coin cell. The device includes a trickle charge circuit for charging the capacitor.

The RTC includes a built-in 32.768 kHz oscillator controlled by an external crystal. Eight register bytes are used for the clock/calendar functions and are superset compatible with the M41T00. Two additional registers control the audio section and the trickle charger. The 10 registers are accessed over a 400 kHz I2C bus. The address register increments automatically after each byte READ or WRITE operation thus streamlining transfers by eliminating the need to send a new address for each byte to be transferred.

Typical data retention times will be in excess of 5 years with a 50 mAh 3 V lithium cell.

Key Features

  • Combination real-time clock with audio
    • 300 mW differential audio amplifier
    • Audio section provides:
      • 300 mW differential audio amplifier
      • 256 and 512 Hz tone generation
      • –33 to +12 dB gain, 3 dB steps (16 steps plus MUTE)
    • 0 °C to 70 °C operation
    • Small DFN16 package (5 mm x 4 mm)
  • Real-time clock details
    • Calibration register provides for adjustments of –63 to +126 ppm
    • Oscillator supports crystals with up to 40 kΩ series resistance, 12.5 pF load capacitance
    • Automatic backup switchover circuit
      • Ultra-low 400 nA backup current at 3.0 V (typ)
      • Suitable for battery or capacitor backup
      • On-chip trickle charge circuit for backup capacitor
    • 400 kHz I2 C bus
    • M41T00 compatible register set with counters for seconds, minutes, hours, day, date, month, years, and century
      • Automatic leap year compensation
      • HT bit set when clock goes into backup mode
      • Automatic backup switchover circuit
        • Ultra-low 400 nA backup current at 3.0 V (typ)
        • Suitable for battery or capacitor backup
        • On-chip trickle charge circuit for backup capacitor
      • 400 kHz I2 C bus
    • RTC operates using 32,768 Hz quartz crystal
      • Calibration register provides for adjustments of –63 to +126 ppm
      • Oscillator supports crystals with up to 40 kΩ series resistance, 12.5 pF load capacitance
      • Automatic backup switchover circuit
        • Ultra-low 400 nA backup current at 3.0 V (typ)
        • Suitable for battery or capacitor backup
        • On-chip trickle charge circuit for backup capacitor
      • 400 kHz I2 C bus
      • M41T00 compatible register set with counters for seconds, minutes, hours, day, date, month, years, and century
        • Automatic leap year compensation
        • HT bit set when clock goes into backup mode
        • Automatic backup switchover circuit
          • Ultra-low 400 nA backup current at 3.0 V (typ)
          • Suitable for battery or capacitor backup
          • On-chip trickle charge circuit for backup capacitor
        • 400 kHz I2 C bus
    • Oscillator fail detect circuit OF bit indicates when oscillator has stopped for four or more cycles
  • Audio section
    • Allows gain adjustment from –33 dB to +12 dB
    • 3 dB steps
    • MUTE bit
    • Volume control, 4-bit register
      • Allows gain adjustment from –33 dB to +12 dB
      • 3 dB steps
      • MUTE bit
      • 1.6 VP-Panalog input range (max)
    • Audio automatically shuts off in backup mode
Product Specifications
DescriptionVersionSize
DS5259: Serial real-time clock (RTC) with audio5.0376 KB
Application Notes
DescriptionVersionSize
AN3060: Applications guide for serial real-time clocks (RTCs)3.0878 KB
AN1011: Battery technology used in NVRAM and real-time clock (RTC) products from ST4.0248 KB
AN934: How to use the digital calibration feature in TIMEKEEPER® and serial real-time clock (RTC) products4.1123 KB
AN4641: Integrating TIMEKEEPER® and real-time clock supervisor functions1.0479 KB
AN923: Managing century information using serial real-time clocks and TIMEKEEPER® NVRAMs4.0142 KB
AN1572: Power-down time-stamp function in serial real-time clocks (RTCs)2.0171 KB
AN1336: Power-fail comparator for NVRAM supervisory devices2.0127 KB
AN1012: Predicting the battery life and data retention period of NVRAMs and serial RTCs4.1439 KB
AN2583: Understanding and applying the M41T00AUD real-time clock with audio1.2211 KB
Brochures
DescriptionVersionSize
Serial real-time clock ICs1.0827 KB
Product Certifications
DescriptionVersionSize
Products Underwriter Laboratories (UL) Information2.1543 KB
Clocks and Timers Software
Part NumberManufacturerDescription
STSW-SRTC001STI2C code for Serial RTC
STSW-SRTC002STSPI code -Serial RTC
Sample & Buy
Part NumberPackagePacking TypeOperating Temperature (°C) (min)Operating Temperature (°C) (max)Unit Price (US$) *QuantityNVRAM size (B)ECCN (EU)ECCN (US)Country of Origin
M41T00AUDD1FDFN16 5X4X0.9Tape And Reel0701.8811000-NECEAR99MALAYSIA
Quality & Reliability
Part NumberPackageGradeRoHS Compliance GradeMaterial Declaration**
M41T00AUDD1FDFN16 5X4X0.9IndustrialEcopack2
Serial real-time clock (RTC) with audio M41T00AUD
串行实时时钟(RTC)应用指南 M41T60
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How to use the digital calibration feature in TIMEKEEPER® and serial real-time clock (RTC) products M41T60
集成TIMEKEEPER® 与实时时钟监控器功能 M41T60
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预测NVRAM 和串行RTC 的电池寿命和数据保存期限 M4Z28-BR00SH
理解和使用带有音频的M41T00AUD实时时钟 M41T00AUD
Predicting the battery life and data retention period of NVRAMs and serial RTCs M4T28-BR12SH
Predicting the battery life and data retention period of NVRAMs and serial RTCs M4Z28-BR00SH