DS1283 Maxim Integrated Products, DS1283 Datasheet - Page 2

• Manufacturer Part Number: DS1283
• Description: Real Time Clock
• Manufacturer: Maxim Integrated Products

Specifications of DS1283

• Function: Clock, Calendar, NV Timekeeping RAM, Alarm
• Package / Case: PDIP W
• Time Format: HH:MM:SS:hh
• Rtc Memory Size: 50 B
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 2.5 V
• Mounting Style: Through Hole
• Rtc Bus Interface: Parallel

PIN DESCRIPTION
PIN DESCRIPTIONS
X1, X2 – Connections for a standard 32.768 KHz quartz
crystal. The internal oscillator circuitry is designed for
operation with a crystal having a load capacitance (C
of 6 pF. The crystal is connected directly to the X1 and
X2 pins. There is no need for external capacitors or
resistors. For more information on crystal selection and
DS1283
032697 2/5
PIN #
5-10
2–3
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
1
4
NAME
(INTB)
X1,X2
A0-A5
RCLR
SQW
INTP
INTB
INTA
GND
V
DQ0
DQ1
DQ2
DQ3
DQ4
DQ5
DQ6
DQ7
V
WE
NC
OE
CE
BAT
CC
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
O
O
O
O
–
–
I
I
I
I
I
I
I
I
Interrupt Output A
(open drain)
32.768 KHz Crystal
No Connection
Address Inputs:
A5=Pin 5;
A0=Pin 10
Data Input/Output
Data Input/Output
Data Input/Output
Ground
Data Input/Output
Data Input/Output
Data Input/Output
Data Input/Output
Data Input/Output
Chip Enable
Interrupt Output P
(open drain)
Output Enable
Square Wave Output
RAM Clear
Battery Input
Interrupt Output B
(open drain)
Write Enable
V
CC
DESCRIPTION
Input
L
)
crystal layout considerations, please consult Applica-
tion Note 58, “Crystal Considerations with Dallas Real
Time Clocks.”
V
between 5.5 and 2.5 volts. The V
should never exceed V
used to maintain all internal functions while the V
input is used to keep all inputs and outputs functional.
Therefore, to keep the device fully functional, V
V
the supply voltages are between 4.5 and 5.5 volts, the
timing and the input/output levels are guaranteed. In
this mode, the active current drain is 2 mA (CE=V
the standby current drain is 0.5 mA (CE=V
retention mode occurs when the V
between 5.5 and 2.5 volts and the V
grounded. In the data retention mode the current drain
is less than 1 A maximum at 5.5 volts (CE=V
volts). The current drain specifications are stated with
all outputs unloaded.
RCLR – The RCLR pin is used to clear (set to logic 1) all
50 bytes of user nonvolatile RAM but does not affect the
registers involved with time, alarm, and watchdog func-
tions. In order to clear the RAM, RCLR must be forced to
an input logic 0 (–0.3 to +0.8 volts). The RCLR function
is designed to be used via human interface (shorting to
ground manually or by switch) and not to be driven with
external buffers. This pin is internally pulled up and
should be left floating when not in use.
INTB – Interrupt B on the DS1283 operates identical to
interrupt B on the DS1286 except that the sink and
source current is limited to 500 A. This pin should be
pulled up or down if not used.
INTP – Interrupt P on the DS1283 was a missing or no
connection pin on the DS1286. This interrupt works in
the same manner as INTA as programmed by the IPSW
bit. However, INTP is also logically ORed with the MSB
of the date register (see Figure 1). This bit is called the
INP bit on the DS1283 and is forced to zero on the
DS1286. When the INP bit (interrupt P bit) is set to log-
ical one, interrupt P will be held active low. When INP is
set to logical zero, INTP is always at the same logic state
as INTA. This pin is an open drain capable of sinking
4 mA.
BAT
CC
must be at the same voltage potential. As long as
, V
CC
– Inputs for batteries or power supplies
BAT
+ 0.3 volts. The V
CC
BAT
supply voltage
CC
BAT
IH
supply is
supply is
). Data
BAT
BAT
input is
IL
) and
–0.2
and
CC