BQ3285P-SB2 ,RTC IC with 114x8 NVSRAMfeatures and bat-➤ Functionally compatible with theand hourstery operation. Other
BQ3285S-SB2 ,RTC IC with 114x8 NVSRAMfeatures in-DS1285clude three maskable interrupt- 12- or 24-hour formatsources, square wave output, ..
BQ3285S-SB2TR ,RTC IC with 114x8 NVSRAMBlock DiagramAD –AD Multiplexed address/data input/0 7Pin DescriptionsoutputMOT Bus type select inp ..
BQ3285S-SB2TRG4 ,RTC IC with 114x8 NVSRAM 24-SOIC 0 to 70bq3285Real-Time Clock (RTC)
BQ3287AMT-SB2 ,RTC Module With 114x8 NVSRAM, RAM Clear Input on A Version
BQ3287EMT ,Real-Time Clock RTC Module
BUZ22 ,N-Channel SIPMOS Power Transistor BUZ 22® SIPMOS Power Transistor• N channel• Enhancement mode• Avalanche-rated Pin 1 Pin 2 ..
BUZ272 ,P-Channel SIPMOS Power TransistorCharacteristicsDrain- source breakdown voltage V V(BR)DSSV = 0 V, I = -0.25 mA, T = 25 ˚C -100 - -G ..
BUZ305 , SIPMOS Power Transistor (N channel Enhancement mode Avalanche-rated)
BUZ30A ,Low Voltage MOSFETsBUZ 30A® SIPMOS Power Transistor• N channel• Enhancement mode• Avalanche-rated Pin 1 Pin 2 Pin 3G D ..
BUZ30A ,Low Voltage MOSFETsCharacteristics, at T = 25˚C, unless otherwise specifiedj Parameter Symbol Values Unitmin. typ. max ..
BUZ30A. ,Low Voltage MOSFETsCharacteristicsDrain- source breakdown voltage V V(BR)DSSV = 0 V, I = 0.25 mA, T = 25 ˚C 200 - -GS ..
BQ3285-BQ3285P-SB2-BQ3285S-SB2-BQ3285S-SB2TR-BQ3285S-SB2TRG4
RTC IC with 114x8 NVSRAM
Features Direct clock/calendar replace-
ment for IBM® AT-compatible
computers and other applications Functionally compatible with the
DS1285
Closely matches MC146818A
pin configuration 114 bytes of general nonvolatile
storage 160ns cycle time allows fast bus
operation Selectable Intel or Motorola bus
timing Less than 0.5μA load under bat-
tery operation 14 bytes for clock/calendar and
control BCD or binary format for clock
and calendar data Calendar in day of the week, day
of the month, months, and years,
with automatic leap-year adjust-
ment Time of day in seconds, minutes,
and hours
12- or 24-hour format
Optional daylight saving
adjustment Programmable square wave out-
put Three individually maskable in-
terrupt event flags:
Periodic rates from 122μs to
500ms
Time-of-day alarm once per
second to once per day
End-of-clock update cycle 24-pin plastic DIP or SOIC
General DescriptionThe CMOS bq3285isa low-power
microprocessor peripheral providing time-of-day clock and 100-year cal-
endar with alarm features and bat-
tery operation. Other featuresin-
clude three maskable interrupt
sources, square wave output, and 114
bytesofgeneral nonvolatile storage.
The bq3285 write-protectsthe clock,
calendar, and storage registers during
power failure.A backup battery
then maintains data and operatesthe
clock andcalendar.
The bq3285isa fully compatible
real-time clock for IBM AT com-
patible computers and other appli-
cations. The only external compo-
nents area 32.768kHz crystal and backup battery
bq3285
Real-Time Clock (RTC)
Pin NamesAD0–AD7 Multiplexed address/data
input/output
MOT Bus type select input Chip select input Address strobe input Data strobe input
R/W Read/write input
INT Interrupt request
output
RST Reset input
SQW Square wave output
RCL RAM clear input 3V backup cell input
X1–X2 Crystal inputs No connect
VCC +5V supply
VSS Ground
Pin ConnectionsSLUS028A - JUNE 1991 - REVISED - MAY 2004
