S-35390A-T8T1G Seiko Instruments, S-35390A-T8T1G Datasheet - Page 19

• Manufacturer Part Number: S-35390A-T8T1G
• Description: IC RTC I2C 2-WIRE 8-TSSOP
• Manufacturer: Seiko Instruments
• Type: Clock/Calendarr

Specifications of S-35390A-T8T1G

• Time Format: HH:MM:SS (12/24 hr)
• Date Format: YY-MM-DD-dd
• Interface: I²C, 2-Wire Serial
• Voltage - Supply: 1.3 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-TSSOP
• Function: Clock/Calendar/Alarm/Battery Backup/Interrupt
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 1.3 V
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• Rtc Bus Interface: Serial (2-Wire, I2C)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Memory Size: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 728-1007-2

Status register 1
reading
Rev.3.0
Low Power Supply Voltage Detection Circuit
Circuits Power-on and Low Power Supply Voltage Detection
The S-35390A has a low power supply voltage detection circuit, so that users can monitor drops in the power supply
voltage by reading the BLD flag (B1 in the status register 1). There is a hysteresis width of approx. 0.15 V (Typ.) between
detection voltage and release voltage (refer to “
detection circuit does the sampling operation only once in one sec for 15.6 ms.
If the power supply voltage decreases to the level of detection voltage (V
sampling operation stops. Once “1” is detected in the BLD flag, no sampling operation is performed even if the power
supply voltage increases to the level of release voltage or more, and “1” is held in the BLD flag. After initialization, or once
the BLD flag is read, the BLD flag is automatically set to “0” to restart the sampling operation.
If the BLD flag is “1” even after the power supply voltage is recovered, the internal circuit may be in the indefinite status. In
this case, be sure to initialize the circuit. Without initializing, Read in the next BLD flag is done after sampling, the BLD flag
gets reset to “0”. In this case, be sure to initialize although the BLD flag is in “0” because the internal circuit may be in the
indefinite status.
Figure 23 shows the changes of the POC flag and BLD flag due to V
Sampling pulse
POC flag
BLD flag
Detection voltage
_00
BLD flag
BLD flag
reading
V
DD
V
DD
15.6 ms
Figure 22 Timing of Low Power Supply Voltage Detection Circuit
1 s
Figure 23 POC Flag and BLD Flag
Hysteresis width
0.15 V approximately
1 s
Seiko Instruments Inc.
Characteristics (Typical Data)”). The low power supply voltage
Stop
Low power supply
voltage detection
voltage
DD
fluctuation.
DET
) or less, “1” is set to the BLD flag so that
2-WIRE REAL-TIME CLOCK
Release voltage
Stop
Low power supply
voltage detection
voltage
S-35390A
Stop
V
19
SS