BQ4802YDWRG4 Datasheet, PDF (2/26 Pages) Texas Instruments – PARALLEL REAL-TIME CLOCK WITH CPU SUPERVISOR

bq4802Y
bq4802LY
SLUS464C – AUGUST 2000 – REVISED JUNE 2002
www.ti.com
These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam during
storage or handling to prevent electrostatic damage to the MOS gates.
DESCRIPTION (CONTINUED)
The bq4802Y/bq4802LY provides direct connections
for a 32.768-kHz quartz crystal and a 3-V backup
battery. Through the use of the conditional chip enable
output (CE_OUT) and battery voltage output (V_OUT) pins,
the bq4802Y/bq4802LY can write-protect and make
non- volatile external SRAMs. The backup cell powers
the real-time clock and maintains SRAM information in
the absence of system voltage. The crystal and battery
are contained within the modules for a more integrated
solution.
The bq4802Y/bq4802LY contains a temperature-
compensated reference and comparator circuit that
monitors the status of its voltage supply. When the
bq4802Y/bq4802LY detects an out-of-tolerance
condition, it generates an interrupt warning and sub-
sequently a microprocessor reset. The reset stays
active for 200 ms after V_CC rises within tolerance, to
allow for power supply and processor stabilization. The
reset function also allows for an external push-button
override.
ORDERING INFORMATION
DEVICES
TA
OPERATION
SOIC(1) (DW)
TSSOP(1) (PW)
SNAPHAT(1)(2)(3) (DSH)
SYMBOL
0°C to +70°C
5V
3.3 V
bq4802YDW
bq4802LYDW
bq4802YPW
bq4802LYPW
bq4802YDSH
bq4802LYDSH
bq4802Y
bq4802LY
(1) _{The DW, PW and DSH packages are available taped and reeled. Add an R suffix to the device type (i.e., bq4802YDWR).}
(2) _{The DSH package is available taped only.}
(3) _{The bq48SH–28x6 should be ordered to complete the SNAPHAT module and is the same part number for both 3.3-V and 5-V modules.}
CAUTION: Wave soldering of DSH package may cause damage to SNAPHAT sockets.
ABSOLUTE MAXIMUM RATINGS
over operating free-air temperature range unless otherwise noted(1)
bq4802Y
bq4802LY
Input voltage range, VCC, VT (VT ≤ VCC +0.3)
–0.3 V to 6.0 V
Operating temperature range, TJ
0°C to 70°C
Storage temperature range, Tstg
– 55°C to 125°C
Temperature under bias, TJbias
– 40°C to 85°C
Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds
300°C
(1) _{Stressesbeyondthoselistedunder“absolutemaximumratings”maycausepermanentdamagetothedevice.Thesearestressratingsonly,and}
functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not
implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
RECOMMENDED OPERATING CONDITIONS
Supply voltage, VCC
bq4802Y
bq4802LY
Input low voltage, VIL
Input high voltage, VIH
Backup cell voltage, VBC
Push button reset input low, VBC
Push button reset input high, VPBRH
MIN
MAX
4.5
5.5
2.7
3.6
–0.3
0.8
2.2 VCC + 0.3
2.4
4.0
–0.3
0.4
2.2 VCC + 0.3
UNIT
V
V
V
V
V
V
2