MIC6315
Open-Drain µP Reset Circuit
General Description
The MIC63 15 is an in expens ive res et gen erator c ircu it that
monitors power supplies in microprocessor-based
systems.
The function of this device is to assert a reset if either
the power supply drops below a designated reset
threshold l evel or /MR is for ced low. Severa l diff erent r eset
threshold levels are available to accommodate 3V, 3.3V,
or 5V powered sy stems.
The MIC6315 has an active low, open-drain /RESET
output. The reset output is guaranteed to remain asserted
for a minim um of either 20m s, 140ms, or 1100ms af ter VCC
has risen above the designed reset threshold level. The
MIC6315 is available in a 4-pin SOT-143 package.
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 1V
• 5μA supply current
• 20ms, 140ms, or 1100ms minimum reset pulse widths
available
• Manual reset input
• Available in 4-pin SOT-143 pac k age
Applications
• Portable equipment
• Intelligent instruments
• Critical microprocessor power monitoring
• Printers/computers
• Embedded 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
October 17, 2014 Revision 2.0
Micrel, Inc.
MIC6315
Ordering Information
Part Number(1, 2) Marking(3) Nominal VTH
(V) Minimum tRST
(ms)
Operating
Temperature
Range Package Lead Finish
MIC6315-26D2UY NY 2.63 20 –40°C to +85°C 4-Pin SOT-143 Pb-Free
MIC6315-29D2UY NM 2.93 20 –40°C to +85°C 4-Pin SOT-143 Pb-Free
MIC6315-30D2UY N2 3.00 20 –40°C to +85°C 4-Pin SOT-143 Pb-Free
MIC6315-31D2UY NF 3.08 20 –40°C to +85°C 4-Pin SOT-143 Pb-Free
MIC6315-40D2UY NW 4.00 20 –40°C to +85°C 4-Pin SOT-143 Pb-Free
MIC6315-41D2UY N6 4.10 20 –40°C to +85°C 4-Pin SOT-143 Pb-Free
MIC6315-44D2UY NG 4.38 20 –40°C to +85°C 4-Pin SOT-143 Pb-Free
MIC6315-46D2UY NQ 4.63 20 –40°C to +85°C 4-Pin SOT-143 Pb-Free
MIC6315-26D3UY NR 2.63 140 –40°C to +85°C 4-Pin SOT-143 Pb-Free
MIC6315-29D3UY NP 2.93 140 –40°C to +85°C 4-Pin SOT-143 Pb-Free
MIC6315-30D3UY N3 3.00 140 –40°C to +85°C 4-Pin SOT-143 Pb-Free
MIC6315-31D3UY NU 3.08 140 –40°C to +85°C 4-Pin SOT-143 Pb-Free
MIC6315-40D3UY N8 4.00 140 –40°C to +85°C 4-Pin SOT-143 Pb-Free
MIC6315-41D3UY N5 4.10 140 –40°C to +85°C 4-Pin SOT-143 Pb-Free
MIC6315-42D3UY 05 4.20 140 –40°C to +85°C 4-Pin SOT-143 Pb-Free
MIC6315-44D3UY NH 4.38 140 –40°C to +85°C 4-Pin SOT-143 Pb-Free
MIC6315-46D3UY NX 4.63 140 –40°C to +85°C 4-Pin SOT-143 Pb-Free
MIC6315-26D4UY NS 2.63 1100 –40°C to +85°C 4-Pin SOT-143 Pb-Free
MIC6315-29D4UY NN 2.93 1100 –40°C to +85°C 4-Pin SOT-143 Pb-Free
MIC6315-30D4UY N4 3.00 1100 –40°C to +85°C 4-Pin SOT-143 Pb-Free
MIC6315-31D4UY 2N 3.08 1100 –40°C to +85°C 4-Pin SOT-143 Pb-Free
MIC6315-40D4UY M9 4.00 1100 –40°C to +85°C 4-Pin SOT-143 Pb-Free
MIC6315-41D4UY M7 4.10 1100 –40°C to +85°C 4-Pin SOT-143 Pb-Free
MIC6315-44D4UY NJ 4.38 1100 –40°C to +85°C 4-Pin SOT-143 Pb-Free
MIC6315-46D4UY NZ 4.63 1100 –40°C to +85°C 4-Pin SOT-143 Pb-Free
Note:
1. Ship format Tape and reel only (ordering part number add space TR example. MIC6315-26D2UY T R).
2. Standard reel quantit y is 3000 pieces.
Reel diameter 7in. / Hub diameter 2in. / Width 8mm.
3. Underbar sym bol ( _ ) may not be to scale.
October 17, 2014 2 Revision 2.0
Micrel, Inc.
MIC6315
Pin Configuration
4-Pin SOT-143 (U)
(Top View)
Pin Description
Pin Number Pin Name Pin Function
1 GND IC Ground.
2 /RESET /RESET goes low if VCC falls below the reset threshold and remains asserted for one reset
timeout period after VCC exceeds the reset threshold.
3 /MR Manual Reset Input: A logic LOW on /MR forces a reset. The reset will rem ain asserted as long
as /MR is held LOW and for one reset timeout period after /MR goes HIGH. This input can be
shorted to ground via a switch or be driven by TTL or CMOS logic. Float if unus ed.
4 VCC Power Supply Input.
October 17, 2014 3 Revision 2.0
Micrel, Inc.
MIC6315
Absolute Maximum Ratings(4)
Terminal Voltage
(VCC, /RESET). ..................................... −0.3V to +6.0V
(/MR) ............................................ −0.3V to (VCC + 0.3V)
Rate-of-Rise (VCC) ................................................. 100V/µs
Input Current (VCC, /MR) ............................................ 20mA
Output Current (/RESET) ............................................ 20mA
Lead Temperature (soldering, 10s) ............................ 300°C
Storage Temperature (TS) ......................... −65°C to +150°C
ESD Rating(6) .................................................................. 3kV
Operating Ratings(5)
Input Voltage (/RESET).................................... GND to 5.5V
Operating Temperature Range ................... –40°C to +85°C
Junction Temperature (TJ) ........................ –40°C to +125°C
Power Dissipation (TA = +7 0°C) ............................... 320mW
Electrical Characteristics
For typical values, VCC = 2.5V to 5.5V; TA = +25°C, bold values indic ate –40°C≤ TA ≤ +85°C, unless noted.
Symbol Parameter Condition Min. Typ. Max. Units
VCC Operating Voltage Range 1 5.5 V
ICC Supply Current VCC = 5.5V, no load. 5 15 µA
VCC = 3.6V, no load. 5 10
VTH Reset Voltage Threshold Note 7 VTH
−
2.5% VTH VTH + 2.5% V
tRST Reset Timeout Period
D2U 20 28 44
ms D3U 140 200 320
D4U
1100
1500
2500
VOL /RESET Output Voltage
VCC ≥ 4.0V, tSINK = 3.2mA 0.4
V VCC ≥ 2.5V, tSINK = 1.2mA 0.3
VCC ≥ 1.0V, tSINK = 50µA 0.3
/RESET Output Leakage /RESET de-asserted 1 µA
/MR M inimum Pulse Width 10 µs
/MR-to-Reset Delay 0.5 µs
VIH /MR Input Threshold VTH > 4.0V 2.3 V
VTH < 4.0V 0.7 × VCC
VIL /MR Input Threshold VTH > 4.0V 0.8 V
VTH < 4.0V 0.25 × VCC
/MR Pull-Up Resistance 10 20 30 kΩ
/MR Glitch Immunity 100 ns
Notes:
4. Exceeding the absolute maximum ratings may damage the device.
5. The device is not guarant eed to function outside its operat i ng ratings.
6. Devices are ESD sensitive. Handling prec aut i ons are recomm ended. Human body model, 1.5kΩ in series with 100pF.
7. Various reset thresholds available. See Ordering Information or contact factory.
October 17, 2014 4 Revision 2.0
Micrel, Inc.
MIC6315
Timing Diagram
Functional Diagram
October 17, 2014 5 Revision 2.0
Micrel, Inc.
MIC6315
Application Information
Mi cropro cessor Res et
The /RES ET pin is as s er te d whene ver VCC fal ls be lo w the
reset threshold voltage or if /MR (manual reset) is forced
low. The /R ESET pin r em ains ass erted for the dur atio n of
the reset timeout period after VCC has risen above the
reset threshold or /MR has returned high. 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 1V.
The /RESET output is a simple open-drain N-channel
MOSFET structure. A pull-up resistor must be used to
pull this output u p to s ome voltage. For most applica tio ns,
this voltage will be the same power supply that supplies
VCC to the MIC6315. It is possible, however, to tie this
resistor to some other voltage. This will allow the
MIC6315 to monitor one voltage while level-shifting the
/RESET output to some other voltage. The pull-up
voltage must be limited to 6.0V or less (absolute
maxim um) to avoid dam age to the MIC 6315. T he resis tor
must be sm all enough to supp ly current t o the inputs and
leakage paths that are driven by the /RESET output.
/RESET Valid at Low Voltage
As VCC drops to 0V, the MIC631 5 wil l no longer be a bl e to
pull the /RESET output low. At this point, the pull-up
resistor will pull the output high. The value of the pull-up
resistor and the voltage it is connected to will affect the
point at which this happens.
Wire OR’i n g th e /RESET Output
Because the RESET output is open-drain, several reset
sources can be wire-OR’ed, in parallel, to allow resets
from multiple sources.
VCC Transients
The MIC6315 is relatively immune to negative-going VCC
glitches below the reset threshold. Typically, a negative-
going transient 125mV below the reset threshold with
duration of 20 µs or less will not c ause an unwante d r e s et.
If additional transient immunity is needed, a bypass
capacitor can be placed a close as possible to the
MIC6315.
Figure 1. MIC6315 as Used in a Multiple Supply System
October 17, 2014 6 Revision 2.0
Micrel, Inc.
MIC6315
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 sol ut ions for the worldwide high perform ance linear and power, LAN, and tim ing & comm unications
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 manufact
urers of enterprise, consumer, industrial, mobile, telecommunications, automotive, and computer products.
Corporation 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 Americas, Europe, 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 information furnished in this data
sheet. 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 ti
me without notice.
No license, whether express, implied, arising by estoppel or otherwise, to any intellectual
property rights
is granted by this document. E xc ept as provided in Micrel’s terms and conditions of sale for s uch products, Micrel ass um es no li
ability
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, copy
right, or other intellectual property right.
Micrel Products 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 u
se or sale of Micrel Products for use in life s upport appliances, devices or s ystems is a Purc haser’s own risk and Purchaser
agrees to ful l y
indemnify Mic rel for any damages resulting from such use or sale.
© 2005 Micrel, Incorporated.
October 17, 2014 8 Revision 2.0
Mouser Electronics
Authorized Distributor
Click to View Pricing, Inventory, Delivery & Lifecycle Information:
Micrel:
MIC6315-25D4UY TR MIC6315-26D2UY TR MIC6315-26D3UY TR MIC6315-26D4UY TR MIC6315-29D2UY TR
MIC6315-29D3UY TR MIC6315-29D4UY TR MIC6315-30D2UY TR MIC6315-30D3UY TR MIC6315-30D4UY TR
MIC6315-31D2UY TR MIC6315-31D3UY TR MIC6315-31D4UY TR MIC6315-40D2UY TR MIC6315-40D3UY TR
MIC6315-40D4UY TR MIC6315-41D2UY TR MIC6315-41D3UY TR MIC6315-41D4UY TR MIC6315-42D3UY TR
MIC6315-44D2UY TR MIC6315-44D3UY TR MIC6315-44D4UY TR MIC6315-46D2UY TR MIC6315-46D3UY TR
MIC6315-46D4UY TR MIC6315-29D4UY-TR MIC6315-30D3UY-TR MIC6315-31D3UY-TR MIC6315-46D3UY-TR
MIC6315-31D4UY-TR MIC6315-29D3UY-TR MIC6315-41D4UY-TR MIC6315-30D2UY-TR MIC6315-40D3UY-TR
MIC6315-40D4UY-TR MIC6315-29D2UY-TR MIC6315-42D3UY-TR MIC6315-25D4UY-TR MIC6315-46D2UY-TR
MIC6315-44D2UY-TR MIC6315-44D3UY-TR MIC6315-44D4UY-TR MIC6315-26D2UY-TR MIC6315-46D4UY-TR
MIC6315-26D4UY-TR MIC6315-41D2UY-TR MIC6315-41D3UY-TR MIC6315-40D2UY-TR MIC6315-26D3UY-TR
MIC6315-31D2UY-TR MIC6315-30D4UY-TR
