AB1805-T3

Part: AB1805-T3 — Abracon (AB18X5 family; AB1805 with I²C interface)

Type: Ultra-Low-Power Real-Time Clock (RTC) with Power Management

Description: Ultra-low-power RTC with 1.5–3.6 V operation, as low as 14 nA supply current (RC oscillator, 3 V), integrated 32.768 kHz crystal oscillator, power switch, watchdog and I²C/SPI interface in a 3x3 mm QFN-16 package.

Operating Conditions:

• Supply voltage: 1.5–3.6 V
• Operating temperature: -40 to 85 °C
• Clock and RAM retention voltage: 1.5–3.6 V
• Serial interface: I²C up to 400 kHz; 3-/4-wire SPI up to 2 MHz

Absolute Maximum Ratings:

• Max system power voltage (VCC): 3.8 V
• Max battery voltage (VBAT): 3.8 V
• Input current: ±10 mA
• Output current: ±20 mA
• PSW output continuous current: 50 mA (150 mA for 1 s pulse)
• Storage temperature: -55 to 125 °C
• Lead temperature: 300 °C (hand soldering, 10 s); reflow 260 °C
• ESD: ±4000 V HBM, ±500 V CDM

Key Specs:

• Supply current at 3 V: 14 nA (RC oscillator), 22 nA (RC with autocalibration), 55 nA (crystal oscillator)
• Crystal calibration to ±2 ppm; RC calibration to ±16 ppm
• Integrated power switch of ~1 Ω
• 256 bytes of general purpose RAM
• Latch-up current: 100 mA
• Operating voltage: 1.5–3.6 V
• Operating temperature: -40 to 85 °C

Features:

• 32.768 kHz crystal oscillator with integrated load capacitor/resistor
• Integrated power-optimized RC oscillator with automatic calibration to the crystal oscillator
• Counters for hundredths, seconds, minutes, hours, date, month, year, century and weekday, with alarm on all counters
• Programmable output clock (32.768 kHz to 1 year)
• Countdown timer with repeat function
• Automatic leap year calculation
• Watchdog timer with hardware reset
• System sleep manager, external reset monitor and reset output generator
• Supercapacitor trickle charger with programmable charging current
• Automatic switchover to VBAT
• External interrupt monitor
• Programmable low-battery detection threshold and analog voltage comparator
• Schmitt trigger inputs

Applications:

• Smart cards
• Wireless sensors and tags
• Medical electronics
• Utility meters
• Data loggers
• Appliances
• Handsets
• Consumer electronics
• Communications equipment

Package:

• QFN-16, 3.0 x 3.0 mm (0.9 mm height)

• Ultra-low supply current (all at 3V):
• -14 nA with RC oscillator
• -22 nA with RC oscillator and Autocalibration
• -55 nA with crystal oscillator
• Baseline timekeeping features:
• -32.768 kHz crystal oscillator with integrated load capacitor/resistor
• -Counters for hundredths, seconds, minutes, hours, date, month, year, century, and weekday
• -Alarm capability on all counters
• -Programmable output clock generation (32.768 kHz to 1 year)
• -Countdown timer with repeat function
• -Automatic leap year calculation
• Advanced timekeeping features:
• -Integrated power optimized RC oscillator
• -Advanced crystal calibration to ± 2 ppm
• -Advanced RC calibration to ± 16 ppm
• -Automatic calibration of RC oscillator to crystal oscillator
• -Watchdog timer with hardware reset
• -256 bytes of general purpose RAM
• Power management features:
• -Integrated ~1 Ω power switch for off-chip components such as a host MCU
• -System sleep manager for managing host processor wake/sleep states
• -External reset signal monitor
• -Reset output generator
• -Supercapacitor trickle charger with programmable charging current
• -Automatic switchover to VBAT
• -External interrupt monitor
• -Programmable low battery detection threshold
• -Programmable analog voltage comparator
• I 2 C (up to 400 kHz) and 3-wire or 4-wire SPI (up to 2 MHz) serial interfaces available
• Operating voltage 1.5-3.6 V
• Clock and RAM retention voltage 1.5-3.6 V
• Operating temperature -40 to 85 °C
• All inputs include Schmitt Triggers
• 3x3 mm QFN-16 package

Date of Issue: September 16, 2014

3.0 x 3.0 mm

Page 4 of 97

Abracon Drawing #453570

Revision: C

• Smart cards
• Wireless sensors and tags
• Medical electronics
• Utility meters
• Data loggers
• Appliances
• Handsets
• Consumer electronics
• Communications equipment

Figure 1 and Table 2 show the QFN-16 pin configurations for the AB18X5 parts. Pins labeled NC must be left unconnected. The thermal pad, pin 17, on the QFN-16 packages must be connected to VSS.

Figure 1. Pin Configuration Diagram

Figure 1 and Table 2 show the QFN-16 pin configurations for the AB18X5 parts. Pins labeled NC must be left unconnected. The thermal pad, pin 17, on the QFN-16 packages must be connected to VSS.

Table 2: Pin Connections

Table 2: Pin Connections

Date of Issue: September 16, 2014

3.0 x 3.0 mm

Page 14 of 97

Abracon Drawing #453570

Revision: C

Table 10 lists the parameters of the VBAT voltage thresholds. BREF values other than those listed in the table are not supported.

For Table 10, T A = -20 °C to 70 °C, TYP values at 25 °C, VCC = 1.7 to 3.6V.

Table 4 lists the absolute maximum ratings.

Table 4: Absolute Maximum Ratings

Table 4: Absolute Maximum Ratings

Date of Issue: September 16, 2014

3.0 x 3.0 mm

Page 18 of 97

Abracon Drawing #453570

Revision: C

Note: Recommended tuning fork crystal is ABS07-120-32.768kHz-T.

Date of Issue: September 16, 2014

3.0 x 3.0 mm

Page 5 of 97

Abracon Drawing #453570

Revision: C