Detailed Description
The MAX16122–MAX16125 low-current microprocessor
reset circuits feature single or dual manual reset inputs
with an extended setup period. The devices also feature
an internal comparator to monitor 5V, 3.3V, 2.5V, and 1.8V
supplies.
When the monitored supply voltage drops below the
specified threshold, the active-low RESET output asserts
low and remains low for the reset timeout period (tRP).
The RESET output is one-shot pulse asserted for the
reset timeout period. For applications that do not require
reset timeout period at startup, devices with that con-
figuration are offered. Supply voltage reset threshold is
selectable through part suffix, see Table 3.
Connect SEL to GND, VCC, or leave unconnected to
select the different setup delays (depending on part suffix,
see Table 1a), or connect to an external resistor to set the
setup delays (E suffix only, see Table 1b).
The MAX16124/MAX16125 have one manual reset input
(MR), one reset output (RESET), and one soft reset
output (SRESET). The MAX16122/MAX16123 have two
identical manual reset inputs (MR1 and MR2) and one
reset output (RESET). A deglitch block is connected to
each manual reset input to add a delay to the falling edge
with a fixed deglitch period of 20ms (tDB).
Resistor-Adjusted Setup Delay
For the MAX16122–MAX16125 with the E setup delay
suffix (MAX1612_WTE_+T), a resistor connected from
SEL to GND sets the setup delay. Table 1b shows com-
mon resistor values and the resulting setup delays. For
resistor values not in the table, use the following formula
to compute the setup delay:
SU
t
=
where R is the resistor value in kΩ and tSU is the result-
ing setup delay in seconds. For best results, use resistor
values between 10kΩ and 500kΩ.
Reset Output
The reset output is typically connected to the reset
input of a microprocessor (µP). A µP’s reset input starts
or restarts the FP in a known state. The MAX16122–
MAX16125 FP supervisory circuits provide the reset
logic to prevent code-execution errors during power-up,
power-down, and brownout conditions (see the Typical
Operating Characteristics).
The MAX16122/MAX16123 have a reset output RESET.
The MAX16124/MAX16125 have a reset output RESET
and a soft-reset output SRESET which is the debounced
“mirror image” of MR (see Figure 1a).
BUMP
NAME FUNCTION
MAX16122/
MAX16123
MAX16124/
MAX16125
C1 C1 VCC
Power-Supply Input. VCC provides power to the device and is also a monitored voltage.
When VCC drops below the selected threshold, RESET asserts low and remains low for
the reset timeout period after VCC rises above the threshold. Bypass VCC to GND with a
0.1µF capacitor.
C2 C2 GND Ground
B2 — MR1 Active-Low Manual Reset Input 1. Internal 50kΩ pullup to VCC. Pull both MR1 and MR2
low for the setup delay (tSU) to one-shot pulse RESET for the reset timeout period.
A2 — MR2 Active-Low Manual Reset Input 2. Internal 50kΩ pullup to VCC. Pull the MR2 and MR1
low for the setup delay (tSU) to one-shot pulse RESET for the reset timeout period.
MAX16122–MAX16125 Dual Pushbutton Controllers in
Tiny 6-Bump WLP Package
www.maximintegrated.com Maxim Integrated
│
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Pin Description (continued)