Document
MCP809/MCP810 3-Pin Microprocessor Reset Circuits
June 2001
MCP809/MCP810 3-Pin Microprocessor Reset Circuits
General Description
The MCP809/810 microprocessor supervisory circuits can be used to monitor the power supplies in microprocessor and digital systems. They provide a reset to the microprocessor during power-up, power-down and brown-out conditions. The function of the MCP809/810 is to monitor the VCC supply voltage, and assert a reset signal whenever this voltage declines below the factory-programmed reset threshold. The reset signal remains asserted for 240ms after VCC rises above the threshold. The MCP809 has an active-low RESET output, while the MCP810 has an active-high RESET output. Seven standard reset voltage options are available, suitable for monitoring 5V, 3.3V, and 3V supply voltages. With a low supply current of only 15µA, the MCP809/810 are ideal for use in portable equipment. The MCP809/MCP810 are available in the 3-pin SOT23 package.
Features
n Precise monitoring of 3V, 3.3V, and 5V supply voltages n Fully specified over temperature n 140ms min. Power-On Reset pulse width, 240ms typical Active-low RESET Output (MCP809) Active-high RESET Output (MCP810) n Guaranteed RESET Output valid for VCC≥1V n Low Supply Current, 15µA typ. n Power supply transient immunity
Applications
n n n n n n Microprocessor Systems Computers Controllers Intelligent Instruments Portable/Battery-Powered Equipment Automotive
Typical Application Circuit
Connection Diagram
20022302
( ) are for MCP810
20022301
© 2001 National Semiconductor Corporation
DS200223
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MCP809/MCP810
Ordering Information
Reset Threshold (V) 4.63 4.38 4.00 3.08 2.93 2.63 Reset Threshold (V) 4.63 4.38 4.00 3.08 2.93 2.63 MCP809 Supplied as 1000 units, tape & reel MCP809M3-4.63 MCP809M3-4.38 MCP809M3-4.00 MCP809M3-3.08 MCP809M3-2.93 MCP809M3-2.63 MCP810 Supplied as 1000 units, tape & reel MCP810M3-4.63 MCP810M3-4.38 MCP810M3-4.00 MCP810M3-3.08 MCP810M3-2.93 MCP810M3-2.63 MCP809 Supplied as 3000 units, tape & reel MCP809M3X-4.63 MCP809M3X-4.38 MCP809M3X-4.00 MCP809M3X-3.08 MCP809M3X-2.93 MCP809M3X-2.63 MCP810 Supplied as 3000 units, tape & reel MCP810M3X-4.63 MCP810M3X-4.38 MCP810M3X-4.00 MCP810M3X-3.08 MCP810M3X-2.93 MCP810M3X-2.63 Package Top Mark SVB SUB STB SSB SRB SPB Package Top Mark SNB SLB SKB SJB SHB SGB SOT23-3 MF03A Package Type SOT23-3 MF03A Package Type NSC Package
NSC Package
Custom voltages and improved accuracies are available, subject to minimum orders. Contact your local National Semiconductor Sales Office for information.
Pin Description
PIN 3 NAME GND RESET (MCP809) 1 RESET (MCP810) 2 VCC Ground reference Active-low output. RESET remains low while VCC is below the reset threshold, and for 240ms after VCC rises above the reset threshold. Active-high output. RESET remains high while VCC is below the reset threshold, and for 240ms after VCC rises above the reset threshold. Supply Voltage (+5V, +3.3V, or +3.0V) FUNCTION
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2
MCP809/MCP810
Absolute Maximum Ratings
(Note 1)
ESD Rating (Note 2) Continuous Power Dissipation (TA = +70˚C) SOT-23 (Note 3) Ambient Temperature Range Maximum Junction Temperature Storage Temperature Range Lead Temperature (soldering, 10sec)
2kV 320mW −40˚C to +105˚C 125˚C −65˚C to +160˚C +300˚C
If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. VCC RESET, RESET Input Current, VCC Pin Output Current, RESET, RESET Pin Rate of Rise, VCC −0.3V to 6.0V −0.3V to (VCC+ 0.3V) 20mA 20mA 100V/µs
Electrical Characteristics
VCC = full range, TA = −40˚C to +105˚C, unless otherwise noted. Typical values are at TA = +25˚C, VCC = 5V for 4.63/4.38/4.00 versions, VCC = 3.3V for 3.08/2.93 versions, and VCC = 3V for 2.63 version. (Note 4) Symbol Parameter VCC Range Conditions TA = 0˚C to +70˚C TA = −40˚C to +105˚C TA = −40˚C to +85˚C VCC < 5.5V, MCP8_ _ -4.63/4.38/4.00 VCC < 3.6V, MCP8_ _ -3.08/2.93/2.63 TA = +85˚C to +105˚C VCC < 5.5V, MCP8_ _ -4.63/4.38/4.00 VCC < 3.6V, MCP8_ _ -3.08/2.93/2.63 TA = +25˚C MCP8_ _ -4.63 TA = −40˚C to +85˚C TA = +85˚C to +105˚C TA = +25˚C MCP8_ _ -4.38 TA = −40˚C to +85˚C TA = +85˚C to +105˚C TA = +25˚C MCP8_ _ -4.00 VTH Reset Threshold (Note 5) MCP8_ _ -3.08 TA = −40˚C to +85˚C TA = +85˚C to +105˚C TA = +25˚C TA = −40˚C to +85˚C TA = +85˚C to +105˚C TA = +25˚C MCP8_ _ -2.93 TA = −40˚C to +85˚C TA = +85˚C to +105˚C TA = +25˚C MCP8_ _ -2.63 Reset Threshold Temperature Coefficient VCC to Reset Delay (Note 5) Reset Active Timeout Period VCC = VTH to (VTH − 100mV) TA = −40˚C to +85˚C TA = +85˚C to +105˚C 140 100 TA = −40˚C to +85˚C TA = +85˚C to +105˚C 4.56 4.50 4.40 4.31 4.25 4.16 3.93 3.89 3.80 3.04 3.00 2.92 2.89 2.85 2.78 2.59 2.55 2.50 30 20 240 560 840 2.63 2.93 3.08 4.00 4.38 4.63 Min 1.0 1.2 18 15 Typ Max 5.5 5.5 60 50 100 100 4.70 4.75 4.86 4.45 4.50 4.56 4.06 4.10 4.20 3.11 3.15 3.23 2.96 3.00 3.08 2.66 2.70 2.76 ppm/˚C µs ms V.