MAX6420UK32-T Maxim Integrated, MAX6420UK32-T Datasheet - Page 7
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MAX6420UK32-T
Manufacturer Part Number
MAX6420UK32-T
Description
Supervisory Circuits
Manufacturer
Maxim Integrated
Series
MAX6412, MAX6413, MAX6414, MAX6415, MAX6416, MAX6417, MAX6418, MAX6419, MAX6420r
Datasheet
1.MAX6418UK47-T.pdf
(12 pages)
Specifications of MAX6420UK32-T
Number Of Voltages Monitored
2
Monitored Voltage
1.6 V to 5 V
Undervoltage Threshold
3.12 V, Adjustable
Overvoltage Threshold
3.28 V, Adjustable
Output Type
Active Low, Open Drain
Manual Reset
Not Resettable
Watchdog
No Watchdog
Battery Backup Switching
No Backup
Power-up Reset Delay (typ)
5.4 ms
Supply Voltage - Max
5.5 V
Maximum Operating Temperature
+ 125 C
Mounting Style
SMD/SMT
Package / Case
SOT-23
Chip Enable Signals
No
Maximum Power Dissipation
571 mW
Minimum Operating Temperature
- 40 C
Power Fail Detection
No
Supply Current (typ)
2.7 uA
Supply Voltage - Min
1 V
Figure 4. MAX6418/MAX6419/MAX6420 Monitoring Two Voltages
The MAX6418/MAX6419/MAX6420 contain both facto-
ry-trimmed threshold voltages and an adjustable reset
threshold input, allowing the monitoring of two voltages,
V
when either of the voltages falls below its respective
threshold voltage.
The reset timeout period is adjustable to accommodate
a variety of µP applications. Adjust the reset timeout
period (t
SRT and ground. Calculate the reset timeout capacitor
as follows:
where t
Maxim Integrated
CC
Low-Power, Single/Dual-Voltage µP Reset Circuits
and V
RP
with Capacitor-Adjustable Reset Timeout Delay
RP
is in seconds and C
C
) by connecting a capacitor (C
MON_TH
SRT
(MAX6418/MAX6419/MAX6420)
= (t
Application Information
Selecting a Reset Capacitor
RP
(see Figure 4). Reset is asserted
C
SRT
- 275µs) / (2.71
R1
R2
V
Dual-Voltage Monitoring
MON_TH
SRT
RESET IN
GND
SRT
is in Farads
1.26V
V
CC
LASER-TRIMMED
10
RESISTORS
SRT
6
)
) between
MAX6418
MAX6419
MAX6420
CIRCUITRY
RESET
V
CC
The reset delay time is set by a current/capacitor-con-
trolled ramp compared to an internal 0.65V reference.
An internal 240nA ramp current source charges the
external capacitor. The charge to the capacitor is
cleared when a reset condition is detected. Once the
reset condition is removed, the voltage on the capacitor
ramps according to the formula: dV/dt = I/C. The C
capacitor must ramp to 0.65V to deassert the reset.
C
ceramic is recommended.
The MAX6412–MAX6420 can be operated in a voltage
detector mode by leaving SRT unconnected. The reset
delay times for V
threshold are not significantly different. The reset output
is deasserted smoothly without false pulses.
SRT
(RESET)
RESET
must be a low-leakage (<10nA) type capacitor,
MAX6412–MAX6420
MAX6420
Operating as a Voltage Detector
ONLY
R
L
CC
rising above or falling below the
µP
SRT
7