MAX6420 MAXIM [Maxim Integrated Products], MAX6420 Datasheet - Page 9

• Manufacturer Part Number: MAX6420
• Description: Low-Power, Single/Dual-Voltage ?P Reset Circuits with Capacitor-Adjustable Reset Timeout Delay
• Manufacturer: MAXIM [Maxim Integrated Products]

When V
ing (sourcing) capabilities decline drastically. In the
case of the MAX6412, MAX6415, and MAX6418, high-
impedance CMOS-logic inputs connected to RESET
can drift to undetermined voltages. This presents no
problems in most applications, since most µPs and
other circuitry do not operate with V
In those applications where RESET must be valid down
to 0, adding a pulldown resistor between RESET and
ground sinks any stray leakage currents, holding
RESET low (Figure 6). The value of the pulldown resis-
tor is not critical; 100kΩ is large enough not to load
RESET and small enough to pull RESET to ground. For
applications using the MAX6413, MAX6416, and
MAX6419, a 100kΩ pullup resistor between RESET and
V
(Figure 7). Open-drain RESET versions are not recom-
mended for applications requiring valid logic for V
down to 0V.
SRT is a precise current source. When developing the
layout for the application, be careful to minimize board
capacitance and leakage currents around this pin.
Traces connected to SRT should be kept as short as
CC
Low-Power, Single/Dual-Voltage µP Reset Circuits
will hold RESET high when V
with Capacitor-Adjustable Reset Timeout Delay
CC
falls below 1V, RESET/RESET current sink-
_______________________________________________________________________________________
Layout Consideration
CC
CC
below 1V.
falls below 1V
CC
possible. Traces carrying high-speed digital signals
Table 1. Reset Voltages Suffix Table
SUFFIX
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
1.536
1.623
1.755
1.853
1.950
2.048
2.133
2.313
2.340
2.438
2.559
2.633
2.730
2.852
2.925
2.998
3.120
3.218
3.315
3.413
3.510
3.608
3.705
3.803
3.900
3.998
4.095
4.193
4.266
4.388
4.509
4.583
4.680
4.778
4.875
MIN
1.575
1.665
1.800
1.900
2.000
2.100
2.188
2.313
2.400
2.500
2.625
2.700
2.800
2.925
3.000
3.075
3.200
3.300
3.400
3.500
3.600
3.700
3.800
3.900
4.000
4.100
4.200
4.300
4.375
4.500
4.625
4.700
4.800
4.900
5.000
TYP
1.614
1.707
1.845
1.948
2.050
2.153
2.243
2.371
2.460
2.563
2.691
2.768
2.870
2.998
3.075
3.152
3.280
3.383
3.485
3.558
3.690
3.793
3.895
3.998
4.100
4.203
4.305
4.408
4.484
4.613
4.741
4.818
4.920
5.023
5.125
MAX
9