PT7M7809 Datasheet, PDF (2/12 Pages) Pericom Semiconductor Corporation – Precision supply-voltage monitor

PT7M7803/7809-7812/7823-7825
µP Supervisor Circuits
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Pin Configuration
SOT23-3
PT7M7803
PT7M7809
PT7M7810
1 GND
1 GND
SOT143
PT7M7811
1 GND _VCC 4
PT7M7812
1 GND _VCC 4
VCC 3
VCC 3
2 _RESET
2 RESET
2 RESET _MR 3
2 _{RESET MR} 3
SOT23-5
PT7M7811
1 GND _VCC 5
PT7M7812
1 GND _VCC 5
PT7M7823
PT7M7824
1 RESET _VCC 5 1 RESET _VCC 5
2 NC
2 NC
2 GND
2 GND
3 RESET _MR 4
3 _{RESET MR} 4
3 _MR
WDI ⁴ 3 RESET WDI ⁴
PT7M7825
1 RESET _VCC 5
2 GND
3 _{RESET MR} 4
Pin Description
Pin Type
Description
Manual-Reset: (CMOS). Active low. Pull low to force a reset. Reset remains asserted for the duration of
MR
I the Reset Timeout Period after MR transitions from low to high. Leave unconnected or connected to VCC
if not used.
VCC
Supply Voltage. Reset is asserted when V_CC drops below the Reset Threshold Voltage (V_RST). Reset
Power remains asserted until V_CC rises above V_RST and keep asserted for the duration of the Reset Timeout
Period (t_RS) once V_CC rises above V_RST.
GND
- Ground Reference for all signals.
PFI
I ^{Power-Fail Voltage Monitor Input. When PFI <VPFT, PFO goes low. Connect PFI to GND or Vcc when}
not used.
PFO
O ^{Power-Fail Output: it gets low and sinks current when PFI is less than 1.25V; otherwise PFO stays high.}
WDI
Watchdog Input (CMOS). If WDI remains high or low for the duration of the watchdog timeout period
I
(t_WD), the internal watchdog timer trigger a reset output. Floating WDI or connecting WDI to a high-
impedance three-state buffer disables the watchdog feature. The internal watchdog timer clears whenever
reset is asserted or WDI occurs a rising or falling edge.
RESET
RESET
NC
Active-Low Reset Output (Push-Pull or Open-Drain). It goes low when Vcc is below the reset
O _{threshold. It remains low for about 200ms after one of the following occurs: Vcc rises above the reset}
threshold (VRST), the watchdog triggers a reset, or MR goes from low to high.
O _{The inverse of RESET, active high. Whenever RESET is high, RESET is low.}
- No connection.
11-0012
PT0109S-15
10/14/10
2