Rainbow Electronics DS1216 - Manual (Page 12)

DS1216
12 of 13
NOTES:
1) Pin locations are designated “U” when a parameter definition refers to the socket receptacle and “L”
when a parameter definition refers to the socket pin.
2) No memory inserted in the socket.
3) Pin 26L can be connected to V
CC
or left disconnected at the PC board.
4) SmartWatch sockets can be successfully processed through some conventional wave-soldering
techniques as long as temperature exposure to the lithium energy source contained within does not
exceed +85
°C. However, post-solder cleaning with water washing techniques is not permissible.
Discharge to the lithium energy source can result, even if deionized water is utilized. It is equally
imperative that ultrasonic vibration is not used in order to avert damage to the quartz crystal resonator
employed by the oscillator circuit.
5) t
CE
max must be met to ensure data integrity on power loss.
6) V
CCO
1 is the maximum voltage drop from Vcc(L) to Vcc(U) while power is being supplied by
Vcc(L). V
CCO
2 is the maximum voltage drop from V
BAT
to V
CC
(U) while the part is in battery backup.
7) Input pulse rise and fall times equal 10ns.
8) Applies to pins RST L, A2 L, A0 L, CE L, OE L, and WE L.
9) t
WR
is a functions of the latter occurring edge of WE or CE .
10) t
DH
and t
DS
are a function of the first occurring edge of WE or CE .
11) Tas is a function of the first occurring edge of OE or CE.
12) Tah is a function of the latter occurring edge of OE or CE
13)
RST (Pin 1) has an internal pullup resistor.
14) Expected data retention is based on using an external SRAM with a data retention current of less than
0.5µA at +25°C. Expected data retention time (time while on battery) for a given RAM battery
current can be calculated using the following formula:
0.045 / (current in amps) = data retention time in hours
15) The DS1216 products are shipped with the battery-backup power off. First power-up switches backup
battery on to clock and RAM V
CC
pin upon power down.