MAX16063 Datasheet, PDF (9/13 Pages) Maxim Integrated Products – 1% Accurate, Low-Voltage, Quad Window Voltage Detector

1% Accurate, Low-Voltage,
Quad Window Voltage Detector
Detailed Description
The MAX16063 is an adjustable quad window voltage
detector in a small thin QFN package. This device is
designed to provide a higher level of system reliability by
monitoring multiple supply voltages and providing a fault
signal when any of the voltages exceeds its overvoltage
threshold or falls below its undervoltage threshold.
This device offers user-adjustable thresholds that allow
voltages to be monitored down to 0.4V. It allows the
upper and lower trip thresholds of each window detector
to be set externally with the use of three external resistors.
Each monitored threshold has an independent open-
drain output for signaling a fault condition. The outputs
can be wire-ORed together to provide a single fault out-
put. The open-drain outputs are internally pulled up
with a 30µA current, but can be externally driven to
other voltage levels for interfacing to other logic levels.
The MAX16063 features a margin input to disable the
outputs during margin testing or any other time after
power-up operations and a reset output that deasserts
after a reset timeout period after all voltages are within
their threshold specification. The reset timeout is inter-
nally set to 140ms (min), but can be externally adjusted
to other reset timeouts using an external capacitor. In
addition, a manual reset input is offered.
Applications Information
Voltage Monitoring
The MAX16063 features undervoltage and overvoltage
comparators for window detection (see Figure 2).
UVOUT_/OVOUT_ deassert high when the monitored
voltage is within the “selected window.” When the moni-
tored voltage falls below the lower limit of the window
(V_TRIPLOW), UVOUT_ asserts low; or if the monitored
voltage exceeds the upper limit (V_TRIPHIGH), OVOUT_
asserts low. The application in Figure 2 shows the
MAX16063 enabling the DC-DC converter when the
monitored voltage is in the selected window.
+5V
R1
R2
R3
UVIN_
V_CC
UVOUT_
OVOUT_
MAX16063
OVIN_
IN
EN
OUT
DC-DC
REGULATOR
GND
Figure 2. MAX16063 Monitor Circuit
The resistor values R1, R2, and R3 can be calculated
as shown:
V_TRIPLOW
=
V_TH
⎛
⎝⎜
R _TOTAL
R2 + R3
⎞
⎠⎟
V_TRIPHIGH
=
V_TH
⎛
⎝⎜
R
TOTAL
R3
⎞
⎠⎟
where R_TOTAL = R1 + R2 + R3.
Use the following steps to determine the values for R1,
R2, and R3:
1) Choose a value for R_TOTAL, the sum of R1, R2, and
R3. Because the MAX16063 has very low input bias
current (2nA typ), R_TOTAL can be up to 2MΩ.
Large-value resistors help minimize power con-
sumption. Lower-value resistors can be used to
maintain overall accuracy.
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