PT7M7803/7809-7812/7823-7825
µP Supervisor Circuits
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Description
Features
The PT7M78xx family microprocessor (µP)
supervisory circuits are targeted to improve
reliability and accuracy of power-supply
Precision supply-voltage monitor
4.63V (PT7M78xxL)
4.38V (PT7M78xxM except PT7M7803/09/10M)
3.08V (PT7M78xxT)
2.93V (PT7M78xxS)
2.63V (PT7M78xxR)
2.32V (PT7M78xxZ)
2.20V (PT7M78xxY)
4.00V (PT7M78xxJ)
4.26V (PT7M7803/09/10M)
2.25V (PT7M7823/24K)
200ms reset pulse width
Debounced CMOS-compatible manual-reset input
(7811, 7812, 7823, 7825)
Reset Output Signal for Watchdog and Power
Abnormal, Manual Reset
Reset Push-Pull output (PT7M7809,7811,7823,
7824,7825)
Reset Open-Drain output (PT7M7803)
Voltage monitor for power-fail or low battery
warning
Guaranteed RESET/RESET valid at VCC=1.0V
Monitored Voltage Table
X
L
Reset Threshold (V)
4.63
M1)
4.38
T
3.08
circuitry in µP systems. These devices reduce
the complexity and number of components
required to monitor power-supply and battery
functions.
The main functions are:
1. Asserting reset output during power-up,
power-down and brownout conditions for
µP system.
2. Detecting power failure or low-battery
conditions with a 1.25V threshold detector.
3. Watchdog functions
4. Manual reset.
Applications
• Power-supply circuitry in µP systems
S
2.93
R
2.63
Z
2.32
Y
2.20
K2)
2.25
J
4.00
Note1): Threshold voltage=4.38V can be applied to all parts except PT7M7803/09/10M. PT7M7803/09/10M’s threshold voltage
is 4.26V.
2): Threshold voltage=2.25V only for PT7M7823/24K.
Function Comparison
Part No.
1
2
3
4
5
6
7
8
PT7M7803
PT7M7809
PT7M7810
PT7M7811
PT7M7812
PT7M7823
PT7M7824
PT7M7825
RESET output
Push-Pull
√
√
√
√
√
Open-Drain
√
-
RESET
output
(push-pull)
√
√
√
√
11-0012
Manual Reset
Input
√
√
√
√
Power Fail
Detector
(1.25V)
-
PT0109S-15
1
Watchdog
Input
√
√
-
10/14/10