CAT809 CATALYST [Catalyst Semiconductor], CAT809 Datasheet - Page 7

• Manufacturer Part Number: CAT809
• Description: 3-Pin Microprocessor Power Supply Supervisors
• Manufacturer: CATALYST [Catalyst Semiconductor]

Patent Pending
The reset signal is asserted LOW for the CAT809 and HIGH for the CAT810 when the power supply voltage falls below
the threshold trip voltage and remains asserted for at least 140ms after the power supply voltage has risen above the
threshold.
The CAT809/810 protect Ps against brownout failure. Short duration transients of 4 sec or less and 100 mV
amplitude typically do not cause a false RESET.
Figure 2 shows the maximum pulse duration of negative-going V
the amplitude of the transient goes further below the threshold (increasing V
decreases. In this test, the V
amplitude of the overdrive voltage (V
Voltage
RESET
RESET
Supply
Power
5V
0V
5V
0V
5V
0V
CC
starts from an initial voltage of 0.5V above the threshold and drops below it by the
TH
30
25
20
15
10
5
0
- V
1
RESET OVERDRIVE V TH - V CC [mV]
CC
).
CAT809M
10
7
T AMB = 25 C
100
CAT809Z
CC
Threshold
Voltage
transients that do not cause a reset condition. As
1000
TH
minimum
- V
140ms
CC
Reset Timeout Period
), the maximum pulse duration
CAT809
CAT810
Doc. No. 3004, Rev. S