DS1814/DS1819
7 of 8
AC ELECTRICAL CHARACTERISTICS (-40°C to +85°C; V
CC
= 1.2V to 5.5V)
PARAMETER SYMBOL MIN TYP MAX UNITS NOTES
PBRST = V
IL
t
PB
1
ms
7
Reset Active Time t
RST
140 200 280 ms
ST Pulse Width
t
ST
50 ns 8
Watchdog Time-out t
TD
1.12 1.60 2.40 s
V
CC
Detect to RST and RST
t
RPD
30 40
ms
9
V
CC
Slew Rate (rising edge) 12.5
V/ms
V
CC
Detect to RST and RST
t
RPU
140 200 280 ms
PBRST Stable Low to RST and RST
t
PDLY
500 ns
CAPACITANCE (t
A
= 25°C)
PARAMETER SYMBOL MIN TYP MAX UNITS NOTES
Input Capacitance C
IN
5pF
Output Capacitance C
OUT
7pF
NOTES:
1) All voltages are referenced to ground.
2) PBRST is internally pulled up to V
CC
with an internal impedance of 50kW typical.
3) Measured with V
CC
³ 2.7V.
4) Measured with outputs open, V
CC
£ 5.5V, and all inputs at V
CC
or Ground, except the ST input at
<10kHz duty cycle-square wave or ST input open.
5) Measured with outputs open, V
CC
£ 3.6V, and all inputs at V
CC
or Ground, except the ST input at
<10kHz duty cycle-square wave or
ST input open.
6) The
ST input current is defined as the average input current when ST is driven high or low. This input
must be driven high or low by an output that can source or sink at least 200mA when active.
7) Noise immunity: pulses <100ns at pushbutton input will not cause a reset.
8) Must not exceed t
TD
minimum.
9) Noise immunity: pulses <2ms at V
CCTP
minimum will not cause a reset and V
CCTP
- V
CC
= 100mV.
