• Precision Monitoring of +2.5V, +3V, +3.3V, and +5V Power-Supply Voltages
•
Fully Specified Over Temperature
•
代表英语Available in three Output Configurations
• Push-Pull RESET Active Low (APX809) • Push-Pull RESET Active High (APX810) • 200ms Typ Power-On Ret Pul Width • 30µA Supply Current (Typ.) • Guaranteed Ret Valid to V CC = +1V • No External Components • SOT23 and SOT23R: Available in “Green” Molding
雅安地震明星捐款
Compound (No Br, Sb) • Lead Free Finish/RoHS Compliant (Note 1)
The APX809/810 are ud for microprocessor (µP) supervisory circuits to monitor the power supplies i
n µP and digital systems. They provide excellent circuit reliability and low cost by eliminating external components and adjustments when ud with +5V, +3.3V, +3.0V powered circuits.
The circuits perform a single function: they asrt a ret signal whenever the V CC supply voltage declines below a pret threshold, keeping it asrted for at least 240ms after V CC has rin above the ret threshold. Ret thresholds suitable for operation with a variety of supply voltages are available. The APX809/810 have push pull outputs. The APX809 have an active low RESET output, while the APX810 has an active high RESET output. The ret comparator is designed to ignore fast transients on V CC , and the outputs are guaranteed to be in the correct logic state for V CC down to 1V. Low supply current makes the APX809/810 ideal for u in portable equipment. The APX809/810 is available in a 3-pin SOT23 and SOT23R packages.
• Computers • Controllers • Intelligent Instruments • Critical µP and µC Power Monitoring • Portable/Battery Powered Equipment • Automotive
APX 8 XX - XX XX G - 7
ticklingVoltage
Package
Packing
7 : Tape & Reel
Enable
Green G : Green
SA : SOT23SR : SOT23R
46:4.6344:4.3840:4.0031:3.0829:2.9326:2.6323
:2.25
09 : Active-Low 10 : Active-High
Device
Package Code Packaging (Note 2) 7” Tape and Reel
Quantity Part Number Suffix APX809-XXSAG-7
amoySA SOT23 3000/Tape & Reel -7 APX810-XXSAG-7 SA SOT23 3000/Tape & Reel -7 APX809-XXSRG-7 SR SOT23R 3000/Tape & Reel -7 APX810-XXSRG-7
SR SOT23R
3000/Tape & Reel -7
Notes: 1. EU Directive 2002/95/EC (RoHS). All applicable RoHS exemptions applied. Plea visit our website at /products/lead_free.html .
2. Pad layout as shown on Diodes Inc. suggested pad layout document AP02001, which can be found on our website at
/datasheets/ap02001.pdf .
Features
General Description
Applications
Ordering Information
( Top View )
warranty
GND V CC
blood is thicker than water(RESET)
RESET ( Top View )GND (RESET)
rtz
V CC
RESET SOT23R
SOT23
Absolute Maximum Ratings
Pin Assignments
Pin Descriptions
Recommended Operating Conditions
mhsSymbol Parameter Min Max Unit
Voltage 1.1 5.5 V V CC Supply
Voltage 0 (V CC+0.3) V V IN Input
T A Operating Ambient Temperature Range -40 85 o C
T R Vcc Rising Time (Vcc = 0~VT) 100 V/ uS Electrical Characteristics (T A = 25ºC)
o o
Typical Application Circuit
C IN
Functional Description
A microprocessor’s (µP’s) ret input starts the µP in a known state. The APX809/810 asrt ret to
prevent code-execution errors during power-up, power-down, or brownout conditions. They asrt a ret signal whenever the V CC supply voltage declines below a pret threshold, keeping it asrted for at least 240ms after V CC has rin above the ret threshold. The APX809/810 have a push-pull output stage.
Ensuring a Valid Ret Output Down to V CC = 0
RESET is guaranteed to be a logic low for V CC > 1V. Once V CC
exceeds the ret threshold, an internal timer keeps
RESET
low for the ret timeout period; after this interval, RESET
goes high. If a brownout condition occurs (V CC dips below the RESET
ret threshold), RESET goes low. Any time
V CC goes below the ret threshold, the internal timer rets to zero, and
joph vincentRESET goes low. The internal timer starts after
公里的英文V CC returns above the ret threshold, and RESET remains
low for the ret timeout period.
When V CC falls below 1V, the APX809 RESET output no longer sinks current—it becomes an open circuit. Therefore,
high-impedance CMOS logic inputs connected to RESET can drift to undetermined voltages.
This prents no problem in most applications since most µP and other circuitry is inoperative with V CC below 1V. However, in applications where
RESET must be valid down to 0V, adding a
pull down resistor to RESET caus any stray leakage currents to flow to ground, holding
RESET low. R1’s value is
not critical; 100k are large enough not to load RESET and small enough to pull RESET to ground. F
or the APX810 if
RESET is required to remain valid for V CC < 1V.
Benefits of Highly Accurate Ret Threshold
Most µP supervisor ICs has ret threshold voltages between 5% and 10% below the value of nominal supply voltages. This ensures a ret will not occur within 5% of the nominal supply, but will occur when the supply is 10% below nominal. When using ICs rated at only the nominal supply ±5%, this leaves a zone of uncertainty where the supply is between 5% and 10% low, and where the ret may or may not be asrted.
Block Diagram
RESET
/ RESET
