Rainbow Electronics DS1616 - Manual (Page 3)

DS1616
3 of 28
DS1616 Block Diagram Figure 1
SIGNAL DESCRIPTIONS
The following paragraphs describe the function of each pin.
V
CC
- V
CC
is a +5-volt input supply. Communication with the DS1616 can take place only when V
CC
is
connected to a +5-volt supply.
V
bat
- Battery input for standard lithium cell or other energy source. All functions of the DS1616 with the
exception of the serial interface circuitry are powered by V
bat
when V
CC
< V
bat
. All functions are
powered by V
CC
when V
CC
> V
bat
. If a battery or other energy source is not used, V
bat
should be
connected directly to GND.
GND - GND connections are not internally connected, so all GND connections must be connected
directly to ground.
AGND - Analog ground should be connected directly to digital ground externally to eliminate ground
noise and potential differences.
COMSEL (Communication Select Input) - This pin determines whether serial communication is
asynchronous or synchronous. When pulled high to V
CC
, communication is synchronous and will take
place via the SCLK, I/O, and RST pins. When COMSEL is tied to ground, asynchronous communication
utilizing the TX and RX pins is selected. If this pin is floated, the DS1616 will operate in the
asynchronous communications mode since the COMSEL pin has a weak internal pulldown resistor.
OSCILLATOR
AND
DIVIDER
X1
X2
A/D
CONVERTER
CONTROL
LOGIC
DATALOG MEMORY
HISTOGRAM MEMORY
ALARM TIME STAMP
AND DURATION
LOGGING MEMORY
USER NVRAM
RTC AND CONTROL
REGISTERS
INTERNAL RTC
AND CONTROL
REGISTERS
SERIAL
INTERFACE MEMORY
FUNCTION
CONTROL
Tx
Rx
ST
INSPEC
OUTSPEC
INT
COMSEL
I/O
RST
SCLK
OPTIONAL
SERIAL NUMBER
AIN
TEMPERATURE
SENSOR
3 TO 1
MUX