BQ3287AMT- [TI]
Real-Time Clock RTC Module; 实时时钟RTC模块
| 型号： | BQ3287AMT- |
| 厂家： | 
TEXAS INSTRUMENTS |
| 描述： | Real-Time Clock RTC Module |
| 文件： | 总6页 (文件大小：79K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
bq3287/bq3287A
(
)
Real-Time Clock RTC Module
➤ Calendar in day of the week, day
of the month, months, and years
with automatic leap-year adjust-
ment
bq3287A version is identical to the
bq3287, with the addition of the RAM
clear input.
Features
➤ Dir ect clock/ca len da r r epla ce-
m en t for IBM® AT-com pa t ible
computers and other applications
The bq3287 is a fully compatible
r e a l-t im e clock for I B M AT-
compatible computers and other ap-
p lica t ion s . T h e b q 3 2 8 7 w r it e -
pr ot ect s t h e clock, ca len da r, a n d
storage registers during power fail-
u r e. Th e in t egr a l ba cku p en er gy
source then maintains data and op-
erates the clock and calendar.
➤ Programmable square wave out-
➤ Functionally compatible with the
put
DS1287/DS1287A and MC146818A
➤ Three individually maskable in-
➤ 114 bytes of general nonvolatile
terrupt event flags:
storage
- Periodic rates from 122 µs to
➤ Integral lithium cell and crystal
500 ms
➤ 160 ns cycle time allows fast bus
As shipped from Benchma rq, the
real time clock is turned off to maxi-
mize battery capacity for in-system
operation.
- Time-of-day alarm once per
operation
second to once per day
➤ Selectable Intel or Motorola bus
timing
- End-of-clock update cycle
➤ B e t t e r t h a n on e m in u t e p e r
➤ 14 bytes for clock/calendar and
The bq3287 is functionally equiva-
lent to the bq3285, except that the
battery (16, 20) and crystal (2, 3)
pins are not accessible. These pins
are connected internally to a coin
cell and quartz crystal. The coin cell
is sized to provide 10 years of data
retention and clock operation in the
absence of power. For a complete de-
scription of features, operating con-
dit ion s, elect r ica l ch a r a ct er ist ics,
bus timing, and pin descriptions, see
the bq3285 data sheet.
control
month clock accuracy
➤ BCD or binary format for clock
and calendar data
General Description
➤ Time of day in seconds, minutes,
Th e CMOS bq3287/bq3287A is a
low-power microprocessor periph-
eral providing a time-of-day clock
and 100-year calendar with alarm
fea t u r es a n d ba t t er y oper a t ion .
O t h e r fe a t u r e s in clu d e t h r e e
maskable interrupt sources, square-
wave output, and 114 bytes of gen-
e r a l n on vola t ile s t or a ge. Th e
and hours
- 12- or 24-hour format
- Optional daylight saving
adjustment
Pin Connections
Pin Names
AD0–AD7 Multiplexed address/data
RST
SQW
NC
Reset input
input/output
MOT
24
1
V
CC
Square wave output
No connect
MOT
CS
Bus type select input
Chip select input
NC
NC
23
22
2
3
SQW
NC
4
NC/RCL
NC
AD
AD
AD
AD
AD
AD
AD
21
20
19
18
17
16
15
14
13
0
1
2
3
4
5
6
5
RCL
RAM clear input
(bq3287A only)
AS
Address strobe input
Data strobe input
6
INT
7
RST
DS
NC
DS
8
9
VCC
VSS
+5V supply
Ground
R/W
INT
Read/write input
10
11
12
R/W
AS
CS
AD
7
Interrupt request output
V
SS
24-Pin DIP Module
PN328701.eps
Sept. 1996 D
1
bq3287/bq3287A
Absolute Maximum Ratings
Symbol
Parameter
Value
Unit
Conditions
VCC
DC voltage applied on VCC relative to VSS
-0.3 to 7.0
V
DC voltage applied on any pin excluding VCC
relative to VSS
VT
V
VT ≤ VCC + 0.3
-0.3 to 7.0
0 to +70
-20 to +70
-40 to +70
-40 to +70
-10 to +70
-20 to +70
260
°C
°C
°C
°C
°C
°C
°C
Commercial
Extended “I”
Commercial
Extended “I”
Commercial
Extended “I”
For 10 seconds
TOPR
Operating temperature
Storage temperature
Temperature under bias
TSTG
TBIAS
TSOLDER Soldering temperature
Note:
Permanent device damage may occur if Absolu te Ma xim u m Ra tin gs are exceeded. Functional opera-
tion should be limited to the Recommended DC Operating Conditions detailed in this data sheet. Expo-
sure to conditions beyond the operational limits for extended periods of time may affect device reliability.
Recommended DC Operating Conditions (T = T
)
OPR
A
Symbol
VCC
Parameter
Supply voltage
Minimum
Typical
Maximum
Unit
V
4.5
0
5.0
5.5
0
VSS
VIL
VIH
Supply voltage
0
-
V
Input low voltage
Input high voltage
-0.3
2.2
0.8
V
-
VCC + 0.3
V
Note:
Typical values indicate operation at TA = 25°C.
DC Electrical Characteristics (T = T
, V
= 5V ± 10%)
A
OPR CC
Symbol
Parameter
Minimum Typical Maximum
Unit
Conditions/Notes
VIN = VSS to VCC
ILI
Input leakage current
-
-
-
-
± 1
± 1
µA
AD0–AD7, INT and SQW
in high impedance
ILO
Output leakage current
µA
VOH
VOL
Output high voltage
Output low voltage
2.4
-
-
-
-
V
V
IOH = -1.0 mA
IOL = 4.0 mA
0.4
Min. cycle, duty = 100%,
IOH = 0mA, IOL = 0mA
ICC
Operating supply current
-
7
15
mA
VSO
Supply switch-over voltage
Power-fail-detect voltage
-
3.0
-
V
V
VPFD
4.0
4.17
4.35
Internal 30K pull-up
(bq3287A only)
IRCL
Input current when RCL = VSS
-
-
-
-
185
µA
µA
IMOTH
Input current when MOT =
VCC
-185
Internal 30K pull-down
Note:
Typical values indicate operation at TA = 25°C, VCC = 5V.
Sept. 1996 D
2
bq3287/bq3287A
Power-Down/Power-Up Timing (T = T
A
OPR)
Symbol
Parameter
Minimum
300
Typical
Maximum
Unit
µs
Conditions
tF
VCC slew from 4.5V to 0V
VCC slew from 0V to 4.5V
-
-
-
-
tR
100
µs
Internal write-protection
period after VCC passes VPFD
on power-up.
tCSR
CS at VIH after power-up
20
10
-
-
200
-
ms
Data-retention and time-
keeping time
tDR
years TA = 25°C.
Note:
Clock accuracy is better than ± 1 minute per month at 25°C for the period of tDR.
Ca u tion : Nega tive u n d er sh oots below th e a bsolu te m a xim u m r a tin g of -0.3V in ba tter y-ba ck u p m od e
m a y a ffect d a ta in tegr ity.
Power-Down/Power-Up Timing
Sept. 1996 D
3
bq3287/bq3287A
24-Pin MT (T-type module)
24-Pin MT (T-type module)
Dimension
Minimum
0.360
0.015
0.015
0.008
1.320
0.685
0.590
0.090
0.120
0.100
Maximum
0.375
-
A
A1
B
C
D
E
0.022
0.013
1.335
0.700
0.620
0.110
0.130
0.120
e
G
L
S
All dimensions are in inches.
Sept. 1996 D
4
bq3287/bq3287A
Data Sheet Revision History
Change No.
Page No.
Description
Address strobe input
Nature of Change
1
1
Clarification
Was 4.1 min, 4.25 max;
is 4.0 min, 4.35 max
1
2
2
1
Power-fail detect voltage VPFD
Was : “As shipped from Benchmarq, the backup cell
is electrically isolated from the memory. ”
Is: “As shipped from Benchmarq, the backup cell is
electrically isolated from the active circuitry. ”
Clarification
Changed temperature from N (industrial, -40 to
+85°C) to I (extended, -20 to +70°C)
2
3
2, 4
2
Specification change
Changed values
IRCL max. was 275; is now 185. Pull-up = 30K
IMOTH max. was -275; is now -185. Pull-down = 30K
Notes:
Change 1 = Nov. 1992 B changes from June 1991 A.
Change 2 = Nov. 1995 C changes from Nov. 1992 B.
Change 3 = Sept. 1996 D changes from Nov. 1995 C.
Ordering Information
bq3287
MT -
Tem p er a tu r e:
blank = Commercial (0 to +70°C)
I = Extended* (-20 to +70°C)
Pa ck a ge Op tion :
MT = T-type module
RAM Clea r Op tion :
A = RAM clear on pin 21
no mark = No connect on pin 21
Device:
bq3287 Real-Time Clock Module
*Contact factory for availability.
Sept. 1996 D
5
IMPORTANT NOTICE
Texas Instruments and its subsidiaries (TI) reserve the right to make changes to their products or to discontinue
any product or service without notice, and advise customers to obtain the latest version of relevant information
to verify, before placing orders, that information being relied on is current and complete. All products are sold
subject to the terms and conditions of sale supplied at the time of order acknowledgement, including those
pertaining to warranty, patent infringement, and limitation of liability.
TI warrants performance of its semiconductor products to the specifications applicable at the time of sale in
accordance with TI’s standard warranty. Testing and other quality control techniques are utilized to the extent
TI deems necessary to support this warranty. Specific testing of all parameters of each device is not necessarily
performed, except those mandated by government requirements.
CERTAIN APPLICATIONS USING SEMICONDUCTOR PRODUCTS MAY INVOLVE POTENTIAL RISKS OF
DEATH, PERSONAL INJURY, OR SEVERE PROPERTY OR ENVIRONMENTAL DAMAGE (“CRITICAL
APPLICATIONS”). TI SEMICONDUCTOR PRODUCTS ARE NOT DESIGNED, AUTHORIZED, OR
WARRANTED TO BE SUITABLE FOR USE IN LIFE-SUPPORT DEVICES OR SYSTEMS OR OTHER
CRITICAL APPLICATIONS. INCLUSION OF TI PRODUCTS IN SUCH APPLICATIONS IS UNDERSTOOD TO
BE FULLY AT THE CUSTOMER’S RISK.
In order to minimize risks associated with the customer’s applications, adequate design and operating
safeguards must be provided by the customer to minimize inherent or procedural hazards.
TI assumes no liability for applications assistance or customer product design. TI does not warrant or represent
that any license, either express or implied, is granted under any patent right, copyright, mask work right, or other
intellectual property right of TI covering or relating to any combination, machine, or process in which such
semiconductor products or services might be or are used. TI’s publication of information regarding any third
party’s products or services does not constitute TI’s approval, warranty or endorsement thereof.
Copyright 1999, Texas Instruments Incorporated
相关型号：
©2020 ICPDF网 联系我们和版权申明