MIC809/810
Microprocessor Reset Circuits
General Description
The MIC809 and MIC810 are inexpensive microprocessor
supervisory circuits that monitor power supplies in
microprocessor-based systems.
The function of these devices is to assert a reset if the
power supply drops below a designated reset threshold
level. Several different reset threshold levels are available
to accommodate 3V, 3.3V or 5V powered systems.
The MIC809 has an active-low /RESET output, while the
MIC810 offers an active-high RESET output. The reset
output is guaranteed to remain asserted for a minimum of
140ms after VCC has risen above the designated reset
threshold level. Having a push-pull output stage, the
MIC809/810 does not require a pull-up resistor at the
output. The MIC809/810 comes in a 3-pin SOT-23 and
SC-70 pack age.
The MIC809 is also available with a shorter reset timeout
(30ms , minimum).
Datasheets and support documentation are available on
Micrel’s web site at: www.micrel.com.
Features
•Precision voltage monitor for 3V, 3.3V, or 5V power
supplies
•/RESET remains valid with VCC as low as 1.4V for
SOT-23 packaged part
•/RESET remains valid with VCC as low as 1V for
SC70-packaged part
•Typically less than 15μA supply current for SOT-23
packaged part
•5µA (typical) supply current for SC70-packaged par t
•140ms (minimum) reset pulse widths available
•Available in 3-pin SOT-23 and SC-70 package
Applications
•Portable equipment
•Intelligent instruments
•Critical microprocessor power monitoring
•Printers/computers
•Controllers
Typical Application
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
July 6, 2015 Revision 3.0
Micrel, Inc.
MIC809/810
Ordering Information(1)
Part Number Marking(2) Threshold Voltage (V) Operating Temperature Range Lead Finish
3-Pin SOT-23 3-Pin SC-70
MIC809LUY MIC809LYC3 IL 4.63 –40°C to +85°CPb-Free
MIC809MUY MIC809MYC3 IM 4.38 –40°C to +85°CPb-Free
MIC809JUY MIC809JYC3 IJ 4.00 –40°C to +85°CPb-Free
MIC809TUY MIC809TYC3 IT 3.08 –40°C to +85°CPb-Free
MIC809SUY MIC809SYC3 IS 2.93 –40°C to +85°CPb-Free
MIC809RUY MIC809RYC3 IR 2.63 –40°C to +85°CPb-Free
MIC810LUY MIC810LYC3 JL 4.63 –40°C to +85°CPb-Free
MIC810MUY MIC810MYC3 JM 4.38 –40°C to +85°CPb-Free
MIC810JUY MIC810JYC3 JJ 4.00 –40°C to +85°CPb-Free
MIC810TUY MIC810TYC3 JT 3.08 –40°C to +85°CPb-Free
MIC810SUY MIC810SYC3 JS 2.93 –40°C to +85°CPb-Free
MIC810RUY MIC810RYC3 JR 2.63 –40°C to +85°CPb-Free
Note:
1. All devices available i n Tape and Reel only (Order entry PN, add TR, i.e., MIC809LUY TR). St andard/full reel quant ity is 3,000 pieces. Reel diam eter
is 7in, hub diameter is 2in, and width is 8mm.
2. Underbar symbol (__) may not be to scale.
Pin Configuration
3-Pin MIC809 SOT-23
3-Pin MIC809 SC-70
(Top View)
3-Pin MIC810 SOT-23
3-Pin MIC810 SC-70
(Top View)
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Micrel, Inc.
MIC809/810
Pin Description
Pin Number
MIC809 Pin Number
MIC810 Pin Name Pin Name
1 1 GND IC Ground Pin.
2 N/A /RESET /RESET goes low if VCC falls below the reset threshold and rem ains asserted
for one reset timeout period (140ms min.) after VCC exceeds the reset
threshold.
N/A 2 RESET RESET goes high if VCC falls below the reset threshold and remains asserted
for one reset timeout period (140ms, mi nimum) after VCC exceeds the reset
threshold.
3 3 VCC Power Suppl y Input.
Part Numbering Conventions
MIC809 SOT-23
MIC809 SC-70
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Micrel, Inc. MIC809/810
July 6, 2015 4 Revision 3.0
Absolute Maximum Ratings(3)
Terminal Voltage (VCC) ................................. –0.3V to +6.0V
Input Current (VCC) ...................................................... 20mA
Output Current (/RESET, RESET) .............................. 20mA
Lead Temperature (soldering, 10s) ............................ 300°C
Storage Temperature (TS) ........................... –65°C to 150°C
Rate-of-Rise (VCC) ................................................... 100V/μs
ESD Rating(5) .................................................... 3kV (SC-70)
Operating Ratings(4)
Operating Temperature Range
MIC809 ................................................. –40°C to +85°C
MIC810 ................................................. –40°C to +85°C
Power Dissipation (TA = +70°C) ............................... 320mW
Electrical Characteristics(6)
For typical values, VCC = 5V for MIC8_L/M/J, VCC = 3.3V for MIC8_S/T, VCC = 3V for MIC8_R; TA = 25°C.
Bold values indicate –40°C to ≤ TA ≤ +85°C; unless otherwise noted.
Symbol Parameter Condition Min. Typ. Max. Units
VCC Operating Voltage Range
TA = 0°C to 70°C (SOT-23) 1.4 5.5 V
TA = –40°C to 85°C (SOT-23) 1.6 5.5 V
TA = –40°C to 85°C (SC70) 1 5.5 V
ICC Supply Current
MIC809L/M/J, MIC810L/M/J (SOT-23) 9 15
µA
MIC809L/M/J, MIC810L/M/J (SC-70) 5 15
VCC <3.6V, MIC809R/S/T,
MIC810R/S/T (SOT-23) 6 10
VCC <3.6V, MIC809R/S/T,
MIC810R/S/T (SC-70) 5 10
VTH Reset Voltage Threshold
MIC809L, MIC810L 4.50 4.63 4.75
V
MIC809M, MIC810M 4.25 4.38 4.50
MIC809J, MIC810J 3.89 4.00 4.10
MIC809T, MIC810T 3.00 3.08 3.15
MIC809S, MIC810S 2.85 2.93 3.00
MIC809R, MIC810R 2.55 2.63 2.70
tRST Reset Timeout Period 140 240 560 ms
VOH /RESET Output Voltage (MIC809) ISOURCE = 800µA, MIC809L/M/J VCC – 1.5V V
ISOURCE = 500µA, MIC809R/S/T 0.8 × VCC
Notes:
3. Exceeding the absolute maximum ratings may damage the device.
4. The device is not guaranteed to function outside its operating ratings.
5. Devices are ESD sensitive. Handling precautions are recommended. Human body model, 1.5kΩ in series with 100pF.
6. Specification for packaged product only.
Micrel, Inc.
MIC809/810
Electrical Characteristics(6) (Continued)
For typical values, VCC = 5V for MIC8_L/M/J, VCC = 3.3V for MI C8_S /T, VCC = 3V for MIC8_R; TA = 25°C.
Bold va lues indicate –40°C to ≤ TA ≤ +85°C; unless otherwise noted.
Symbol Parameter Condition Min. Typ. Max. Units
VOL /RESET Output Voltage (MIC809)
VCC = VTH (minimum), ISINK = 3.2mA,
MIC809L/M/J 0.4
V
VCC = VTH (minimum)., ISINK = 1.2mA,
MIC809R/S/T 0.3
VCC >1.4V, ISINK = 50µA,
TA = 0°C to +70°C 0.3
VCC = 1V, ISINK = 50µA,
TA = –40°C to +85°C (SC-70) 0.3
VCC >1.6V, ISINK = 50µA,
TA = –40°C to +85°C 0.3
VOH RESET Output Voltage (MIC810) 1.8V < VCC < VTH (minimum),
ISOURCE = 150µA 0.8 × VCC V
VOL RESET Output Voltage (MIC810) ISINK = 3.2mA, MIC810L/M/J 0.4 V
ISINK = 1.2mA, MIC810R/S/T
0.3
Timing Diagram
Reset Timing Diagram
July 6, 2015 5 Revision 3.0
Micrel, Inc.
MIC809/810
Functional Diagram
July 6, 2015 6 Revision 3.0
Micrel, Inc.
MIC809/810
Application Information
Microprocessor Res et
The /RESET (or RESET) pin is asserted whenever VCC
falls below the reset threshold voltage. The /RESET pin
remains asserted for a period of 140ms after VCC has
risen above the reset threshold voltage. The reset
function ens ures t he micropr oc es sor is pr o per l y rese t and
powers up in a known condition after a power failure.
/RESET will remain valid with VCC as low as 1.4V (1V for
SC-70 pack age) .
VCC Transients
The MIC809/810 are relatively imm une to negative-going
VCC glitches below the reset threshold. Typically, a
negative-going transient 125mV below the reset
threshold wit h duration of 2µs or less (SC 70 p ackage) will
not cause a reset.
Interfacing to Bidirectional Reset Pins
The MIC809/810 can interface with µPs with bidirec tional
reset pins by connecting a 4.7kΩ resistor in series with
the MIC809/810 output and the µP reset pin.
/RESET Valid at Low Voltage
A resistor can be added from the /RESET pin to ground
to ensure the /RESET outp ut remains low with VCC down
to 0V. A 100kΩ resistor connected from the /RESET to
ground is recommended. The resistor should be small
enough t o p ull-do w n a n y str a y leak age c ur rents and la r ge
enough not to load the reset output (F i gure 1).
Figure 1. Reset Valid to VCC = 0V
July 6, 2015 7 Revision 3.0
Micrel, Inc.
MIC809/810
MICREL, INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA
TEL +1 (408) 944-0800 FAX +1 (408) 474-1000 WEB http://www.micrel.com
Micrel, Inc. is a leading global manufact urer of IC s olut ions for the worldwide high performance linear and po wer, LAN, and t iming & communications
markets. The Company’s products include advanced mixed
-signal, analog & power semiconductors; high-
performance communication, clock
management,
MEMs-based clock oscillators & crystal-less clock generators, Ethernet switches, and physical layer transceiver ICs.
Company
customers include leading manufacturers of enterprise, consumer, industrial, mobile, telecommunications, automotive, and comp
uter products.
Co
rporation headquarters and state-of-the-
art wafer fabrication facilities are located in San Jose, CA, with regional sales and support offices and
advanced technol ogy design centers situat ed t hroughout the A
mericas, E urope, and Asia.
Additionally, the Company maintains an extensive network
of distribut ors and reps worldwide.
Micrel makes no representations or warranties with respect to the accuracy or completeness of the inf
ormation furnished in this datash
eet. This
information is not intended as a warranty and Micrel does not assume responsibility for its use.
Micrel reserves the right to change circuitry,
specifications and descriptions at any time without notice.
No license, whether express, implied, ar
ising by estoppel or otherwise, to any intellectual
property rights
is granted by this document. E
xcept as provided in Mi crel’s terms and conditions of sale for s uch products, Micrel assumes no liability
whatsoever, and Micrel disclaims any express or implied warranty relating to the sale and/or use of Micrel products including liability or warranties
relating to fitness for a partic ular purpose, merchant abi lit y, or inf ri ngem ent of any patent, copyright
, or other intellectual property right.
Micrel Product
s are not designed or authorized for use as components in life support appliances, devices or systems where malfunction of a
product
can reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that (a) are intended for surgical
implant i nto t he body or (b) s upport or sustain life, and whose failure t o perform can be reasonably expected to result in a significant injury t o t he user. A
Purchaser’s use or s al e of Micrel Products for use in life s upport appliances, devices or systems is a Purc haser’s own risk and Purchaser agrees t o f ul l y
indemnify Mic rel for any damages resulting from such use or sale.
© 2004 Micrel, Incorporated.
July 6, 2015 10 Revision 3.0
Mouser Electronics
Authorized Distributor
Click to View Pricing, Inventory, Delivery & Lifecycle Information:
Micrel:
MIC809-5SUY TR MIC809-5SYC3 TR MIC809JUY TR MIC809JYC3 TR MIC809LUY TR MIC809LYC3 TR
MIC809MUY TR MIC809MYC3 TR MIC809RUY TR MIC809RYC3 TR MIC809SUY TR MIC809SYC3 TR
MIC809TUY TR MIC809TYC3 TR MIC810JUY TR MIC810JYC3 TR MIC810LUY TR MIC810LYC3 TR
MIC810MUY TR MIC810MYC3 TR MIC810RUY TR MIC810RYC3 TR MIC810SUY TR MIC810SYC3 TR
MIC810TUY TR MIC810TYC3 TR MIC810SUY-TR MIC810JUY-TR MIC810LYC3-TR MIC809TYC3-TR
MIC810JYC3-TR MIC809LUY-TR MIC809-5SUY-TR MIC810MYC3-TR MIC810LUY-TR MIC810TUY-TR
MIC810TYC3-TR MIC809-5SYC3-TR MIC810MUY-TR MIC810SYC3-TR MIC809RUY-TR MIC809RYC3-TR
MIC810RUY-TR MIC809JYC3-TR MIC809SYC3-TR MIC810RYC3-TR MIC809MUY-TR MIC809JUY-TR
MIC809LYC3-TR MIC809MYC3-TR MIC809SUY-TR MIC809TUY-TR
