MAX6745 Maxim, MAX6745 Datasheet - Page 10

• Manufacturer Part Number: MAX6745
• Description: (MAX6736 - MAX6745) Low-Power Dual-/Triple-Voltage SC70 UP Supervisory Circuits
• Manufacturer: Maxim

Low-Power Dual-/Triple-Voltage SC70 µP
Supervisory Circuits
Figure 1. Timing Diagram
The MAX6736–MAX6745 µP supervisory circuits main-
tain system integrity by alerting the µP to fault condi-
tions. These devices are optimized for systems that
monitor two or three supply voltages. The reset output
state is guaranteed to remain valid while either V
V
The MAX6736/MAX6737/MAX6740/MAX6741/MAX6743/
MAX6744 input voltage threshold combinations are indi-
cated by a two-letter code in Table 1. The MAX6738/
MAX6739/MAX6742/MAX6745 input voltage thresholds
are indicated by a one-letter code in Table 2. Contact the
factory for the availability of other voltage thresholds.
10
CC
RESET
2 is above 1.2V.
POK1
V
V
______________________________________________________________________________________
GND
GND
GND
GND
GND
CC
CC
MR
1
2
t
POKP
V
TH
1
Detailed Description
V
TH
Threshold Levels
2
t
Supply Voltages
RP
CC
1 or
SWITCH
BOUNCE
The MAX6736–MAX6745 provide an active-low reset out-
put (RESET). RESET is asserted when the voltage at
either V
level, RSTIN drops below the threshold, or MR is pulled
low. Once reset is asserted, it stays low for the reset time-
out period. If V
threshold before the reset timeout period is completed,
the internal timer restarts. The MAX6736/MAX6738/
MAX6740/MAX6741/MAX6742 have open-drain reset out-
puts, while the MAX6737/MAX6739/MAX6743/MAX6744/
MAX6745 have push-pull reset outputs (Figure 1).
The MAX6740/MAX6741/MAX6742 include a RESET
output with a manual reset detect function. The open-
drain RESET output has an internal 50kΩ pullup to
V
pulled to GND and remains low for at least the manual
reset timeout period after the external GND pulldown is
CC
1. The RESET output is low while the output is
CC
1 or V
CC
1, V
CC
2 falls below the voltage threshold
CC
2, or RSTIN goes below the reset
SWITCH
BOUNCE
t
MRP
Reset Output