Rainbow Electronics DS2404 User Manual
Page 28
DS2404
28 of 29
NOTES:
1. All voltages are referenced to ground.
2. V
IH
= 2.0V or V
IL
= 0.8V with 10ns maximum rise and fall time.
3. V
DQH
= 2.4V and V
DQL
= 0.4V, respectively.
4. Load capacitance = 50pF.
5. Measured with outputs open.
6. When battery is applied to V
BATO
input, V
CC
and V
BATB
must be 0V.
7. V
BATB
,
or V
BATO
= 3.0V; all inputs inactive state.
8. Capacitance on the I/O pin could be 800pF when power is first applied. If a 5k
W resistor is used to
pull-up the I/O line to V
PUP
,
5
ms after power has been applied, the parasite capacitance will not affect
normal communications.
9. For auto-mode operation of the interval timer, the high level on the I/O pin must be greater than or
equal to 70% of V
CC
or V
BATO
.
10. Read and write scratchpad (all 32 bytes) at 3.0V.
11. All other inputs at CMOS levels.
12. V
PUP
= external pull-up voltage.
13. Input load is to ground.
14. An additional reset or communication sequence cannot begin until the reset high time has expired.
15. Read data setup time refers to the time the host must pull the I/O line low to read a bit. Data is
guaranteed to be valid within 1
ms of this falling edge.
16. Under certain low voltage conditions V
IL1MAX
may have to be reduced to as much as 0.5V to always
guarantee a presence pulse.
17. Applies to 1 Hz and
IRQ
pins only.
18. Applies to DQ pin only.
19. Applies to DQ, 1Hz and
IRQ
pins only.