M51957BL#TF0J Renesas Electronics America, M51957BL#TF0J Datasheet - Page 12

• Manufacturer Part Number: M51957BL#TF0J
• Description: IC VOLTAGE DETECTOR 5-SIP
• Manufacturer: Renesas Electronics America
• Type: Simple Reset/Power-On Resetr

Specifications of M51957BL#TF0J

• Number Of Voltages Monitored: 1
• Output: Open Drain or Open Collector
• Reset: Active Low
• Reset Timeout: 1.6 ms Minimum
• Voltage - Threshold: 1.25V
• Operating Temperature: -30°C ~ 85°C
• Mounting Type: Through Hole
• Package / Case: 5-SIP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: Q4596265

M51957A,B/M51958A,B
Setting of Delay Capacity
Please use capacitor Cd for the delay within the range of 10 µF or less.
When a value that is bigger than this is set, the problem such as following (1), (2), and (3) becomes remarkable.
(1) The difference at delay time becomes remarkable.
(2) Difficulty to react to a momentary voltage decrease.
(3) Original delay time is not obtained.
REJ03D0778-0300 Rev.3.00 Sep 18, 2007
Page 10 of 13
For example, the reaction time t
A long delay setting of tens of seconds is fundamentally possible. However, when set delay time is lengthened, the
range of the difference relatively grows, too. When a set value is assumed to be ‘tpd’, the difference occurs in the
range from 0.47 × tpd to 2.05 × tpd. For instance, 34 seconds can be calculated at 100 µF. However, it is likely to
vary within the ranges of 16-70 seconds.
The momentary voltage-decrease that is longer than such t
delay capacitance is enlarged, t
circuit constant C1 = 100 µF.
(Characteristic graph 1 is used and extrapolation in case of Cd = 100 µF.)
Therefore, it doesn't react to momentary voltage-decrease that is shorter than this.
When the momentary voltage-decrease time ‘t’ is equivalent to t
charge starts at that state. This phenomenon occurs at large capacitance. And, original delay time tpd is not
obtained.
Please refer to characteristic graph 2. (Delay time versus input pulse width)
1000
200
100
10
0.01
1
Reaction Time vs. Delay Capacitance
Delay Capacitance Cd (µF)
0.1
Characteristic Graph 1
(Example data)
Figure 9 Time Chart at Momentary Voltage-Decrease
1
PHL
PHL
also becomes long. For instance, it becomes about 100 to 200 µs in case of
is 10 µs when delay capacitor Cd = 0.1 µF.
Figure 10 Characteristic Graph
10
Output
V
CC
100
t
PHL
t
PHL
tpd
10000
1000
are occurs, the detection becomes possible. When the
Delay Time vs. Momentary Voltage Decrease Pulse Width
100
10
PHL
1
1
, the discharge becomes insufficient and the
Delay Capacitance
0.01µF
0.033µF
0.1µF
0.33µF
1µF
2.2µF
3.3µF
10
Characteristic Graph 2
Pulse Width (µs)
(Example data)
100
1000
10000