Datasheet

MAX6730–MAX6735
Single-/Dual-/Triple-Voltage µP Supervisory
Circuits with Independent Watchdog Output
8
Maxim Integrated
Detailed Description
Supply Voltages
The MAX6730–MAX6735 microprocessor (µP) supervi-
sors maintain system integrity by alerting the µP to fault
conditions. The MAX6730–MAX6735 monitor one to
three supply voltages in µP-based systems and assert
an active-low reset output when any monitored supply
voltage drops below its preset threshold. The output
state remains valid for V
CC
1 or V
CC
2 greater than +0.8V.
Threshold Levels
The two-letter code in the Reset Voltage Threshold
Suffix Guide (Table 1) indicates the threshold level
combinations for V
CC
1 and V
CC
2.
Reset Output
The MAX6730–MAX6735 feature an active-low reset out-
put (RST). RST asserts when the voltage at either V
CC
1 or
V
CC
2 falls below the voltage threshold level, V
RSTIN
drops below its threshold, or MR is driven low (Figure 1).
RST remains low for the reset timeout period (Table 2)
after V
CC
1, V
CC
2, and RSTIN increase above their
respective thresholds and after MR releases high.
Whenever V
CC
1, V
CC
2, or RSTIN go below the reset
threshold before the end of the reset timeout period, the
internal timer restarts. The MAX6730/MAX6732/ MAX6734
provide an open-drain RST output, and the MAX6731/
MAX6733/MAX6735 provide a push-pull RST output.
Table 1. Reset Voltage Threshold Suffix Guide**
PART NO. SUFFIX
V
CC
1 NOMINAL
VOLTAGE
THRESHOLD(V)
V
CC
2 NOMINAL
VOLTAGE
THRESHOLD (V)
LT 4.625 3.075
MS 4.375 2.925
MR 4.375 2.625
TZ 3.075 2.313
SY 2.925 2.188
RY 2.625 2.188
TW 3.075 1.665
SV 2.925 1.575
RV 2.625 1.575
TI 3.075 1.388
SH 2.925 1.313
RH 2.625 1.313
TG 3.075 1.110
SF 2.925 1.050
RF 2.625 1.050
TE 3.075 0.833
SD 2.925 0.788
RD 2.625 0.788
ZW 2.313 1.665
YV 2.188 1.575
ZI 2.313 1.388
YH 2.188 1.313
ZG 2.313 1.110
YF 2.188 1.050
ZE 2.313 0.833
YD 2.188 0.788
WI 1.665 1.388
VH 1.575 1.313
WG 1.665 1.110
VF 1.575 1.050
WE 1.665 0.833
VD 1.575 0.788
** Standard versions are shown in bold and are available in a
D3 timeout option only. Standard versions require 2500-piece
order increments and are typically held in sample stock. There
is a 10,000-piece order increment on nonstandard versions.
Other threshold voltages may be available; contact factory
for availability.
Table 2. Reset Timeout Period Suffix Guide
ACTIVE TIMEOUT PERIOD
TIMEOUT
PERIOD SUFFIX
MIN (ms) MAX (ms)
D1 1.1 2.2
D2 8.8 17.6
D3 140 280
D5 280 560
D6 560 1120
D4 1120 2240