DS1558W+ Maxim Integrated Products, DS1558W+ Datasheet - Page 3

• Manufacturer Part Number: DS1558W+
• Description: IC RTC W/NV RAM 3.3V 48-LQFP
• Manufacturer: Maxim Integrated Products
• Type: Watchdog Timer/NVSRAMr

Specifications of DS1558W+

• Time Format: HH:MM:SS (24 hr)
• Date Format: YY-MM-DD-dd
• Interface: Parallel
• Voltage - Supply: 3 V ~ 3.6 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 48-LQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Memory Size: -

PIN
TYPICAL OPERATING CIRCUIT
PIN
35
37
38
40
42
46
47
DES
CRIP
NAME
V
V
V
RST
V
X1
X2
BAT1
BAT2
CCO
CC
TION (con
Battery In
voltage m
ensure ag
battery is
“Conditio
Active-Low Power-On Reset Output (Open Drain). This pin is an output used to signal
that V
the system to stabilize. The
pin is open drain and requires an external pullup resistor.
V
When V
Power-Supply Input. DC power is provided to the device on these pins. V
input. When 5V (or 3.3V for the 3.3V version) is applied within normal limits, the device
is fully accessible and data can be written and read. Reads and writes are inhibited when
a 3V battery is connected to the device and V
function continues unaffected by the lower input voltage. As V
RAM and RTC are switched over to the external power supply (nominal 3.0V DC) at
V
Connections for Standard 32.768kHz Quartz Crystal. The internal oscillator circuitry is
designed for operation with a crystal having a specified load capacitance (C
more information about crystal selection and crystal layout considerations, refer to
Application Note 58: Crystal Considerations with Dallas Real-Time Clocks. The DS1558
can also be driven by an external 32.768kHz oscillator. In this configuration, the X1 pin
is connected to the external oscillator signal and the X2 pin is floated.
CC
BAT
Output to RAM. While V
.
CC
CC
is out of tolerance. On power-up,
ainst re
tin
ust be
used, it should b
ns of Acceptabil
puts fo
is below the battery level, the SRAM is powered by one of the V
ued)
held
vers
r An
e cha
y Sta
betw
een 2.5V and 3.7V fo
rging current when us
e attached to V
ity” at
ndard +3V Lithium C l or Other
RTC and SRAM are not accessible while RST is active. This
3 of 18
CC
is above V
www.maxim-i
FUNCTI
BAT1
RST is held low for a period of time to allow
BAT
, a
CC
, the external SRAM is powered by V
nd
c.com/TechSupport/QA/ntrl.htm
ON
r p
ed
el
is V
roper oper
V
with a lith
TP
BAT2
. However, the timekeeping
sho
Energy Source. Battery
uld be grounded. See
ation. UL recognized to
ium battery. If only one
CC
falls below V
CC
L
BAT
is the +5V
) of 6pF. For
BAT
inputs.
.
, the
CC
.