Datasheet

V
CC
= full operating range, V
BATT
= 2.8V, T
A
= +25°C, unless otherwise noted.)
PARAMETER CONDITIONS MIN TYP MAX UNITS
Battery Switchover Hysteresis 20 mV
BATT ON Output Voltage I
SINK
= 3.2mA 0.4 V
BATT ON Output Short-Circuit Current
BATT ON = V
OUT
= 4.5V sink current 25 mA
BATT ON = 0V source current 0.5 1 25 µA
RESET AND WATCHDOG TIMER
Reset Voltage Threshold
T
A
= full
operating range
MAX690, MAX691,
MAX694, MAX695
4.5 4.65 4.75
V
MAX692, MAX693 4.25 4.4 4.5
Reset Threshold Hysteresis 40 mV
Reset Timeout Delay (MAX690/MAX691/
MAX692/MAX693)
Figure 6, OSC SEL HIGH, V
CC
= 5V 35 50 70 ms
Reset Timeout Delay (MAX694/MAX695) Figure 6, OSC SEL HIGH, V
CC
= 5V 140 200 280 ms
Watchdog Timeout Period, Internal Oscillator
Long period, V
CC
= 5V 1.0 1.6 2.25 s
Short period, V
CC
= 5V 70 100 140 ms
Watchdog Timeout Period, External Clock
Long period 3840 4097
Clock
Cycles
Short period 768 1025
Minimum WDI Input Pulse Width V
IL
= 0.4, V
IH
= 0.8V
CC
200 ns
RESET and LOW LINE Output Voltage
I
SINK
= 1.6mA, V
CC
= 4.25V 0.4
V
I
SOURCE
= 1µA, V
CC
= 5V 3.5
RESET and WDO Output Voltage
I
SINK
= 1.6mA 0.4
V
I
SOURCE
= 1µA, V
CC
= 5V 3.5
Output Short-Circuit Current RESET, RESET, WDO, LOW LINE 1 3 25 µA
WDI Input Threshold Logic-Low V
CC
= 5V (Note 2) 0.8
V
WDI Input Threshold Logic-High V
CC
= 5V (Note 2) 3.5
WDI Input Current
WDI = V
OUT
20 50
µA
WDI = 0V -50 -15
POWER-FAIL DETECTOR
PFI Threshold V
CC
= 5V, T
A
= full 1.2 1.3 1.4 V
PFI Current ±0.01 ±25 nA
PFO Output Voltage
I
SINK
= 3.2mA 0.4 V
I
SOURCE
= 1µA 3.5 V
PFO Short Circuit Source Current PFI = V
IH
, PFO = 0V 1 3 25 µA
MAX690–MAX695 Microprocessor Supervisory Circuits
www.maximintegrated.com
Maxim Integrated │ 3
Electrical Characteristics (continued)