
DS1501/DS1511 Y2KC Watchdog Real-Time Clocks
6 of 22
Figure 4. Burst Mode Timing Waveform
A0–A4
DQ0–DQ7
OE
, WE, OR CE
13h
PWHIGH
PWLOW
POWER-UP/DOWN CHARACTERISTICS
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
CE or WE at VIH Before Power-Fail
tPF
0
s
VCC Fall Time: VPF(MAX) to VPF(MIN)
tF
300
s
VCC Fall Time: VPF(MIN) to VSO
tFB
10
s
VCC Rise Time: VPF(MIN) to VPF(MAX)
tR
0
s
VPF to RST High
tREC
35
200
ms
(TA = +25°C)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Expected Data-Retention Time
(Oscillator On)
tDR
(Note 9)
10
Years
CAPACITANCE
(TA = +25°C)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Capacitance on All Input Pins
CIN
10
pF
Capacitance on IRQ, PWR, RST, and
DQ Pins
CIO
10
pF
AC TEST CONDITIONS
OUTPUT LOAD
INPUT PULSE
LEVELS
TIMING MEASUREMENT
REFERENCE LEVELS
INPUT PULSE RISE
AND FALL TIMES
(Y) 50pF + 1TTL Gate
0V to 3.0V for 5V
operation
Input: 1.5V
5ns
(W) 25pF + 1 TTL Gate
Output: 1.5V
OE, WE, or CE