Micrel MIC6315-29D2UY Open-drain î¼p reset circuit Datasheet

MIC6315
Open-Drain µP Reset Circuit
General Description
Features
The MIC6315 is an inexpensive reset generator circuit that
monitors power supplies in microprocessor-based
systems.
• 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 package
The function of this device is to assert a reset if either
the power supply drops below a designated reset
threshold level or /MR is forced low. Several different reset
threshold levels are available to accommodate 3V, 3.3V,
or 5V powered systems.
The MIC6315 has an active low, open-drain /RESET
output. The reset output is guaranteed to remain asserted
for a minimum of either 20ms, 140ms, or 1100ms after 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.
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
(1, 2)
Part Number
(3)
Marking
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 TR).
2. Standard reel quantity is 3000 pieces.
Reel diameter 7in. / Hub diameter 2in. / Width 8mm.
3. Underbar symbol ( _ ) 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
1
GND
2
/RESET
3
/MR
Manual Reset Input: A logic LOW on /MR forces a reset. The reset will remain 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 unused.
4
VCC
Power Supply Input.
October 17, 2014
Pin Function
IC Ground.
/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
Revision 2.0
Micrel, Inc.
MIC6315
Absolute Maximum Ratings(4)
Operating Ratings(5)
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
(6)
ESD Rating .................................................................. 3kV
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 = +70°C) ............................... 320mW
Electrical Characteristics
For typical values, VCC = 2.5V to 5.5V; TA = +25°C, bold values indicate –40°C≤ TA ≤ +85°C, unless noted.
Symbol
Parameter
VCC
Operating Voltage Range
ICC
Supply Current
VTH
Reset Voltage Threshold
tRST
VOL
Reset Timeout Period
/RESET Output Voltage
/RESET Output Leakage
Condition
Min.
1
VIL
/MR Input Threshold
Units
5.5
V
5
15
VCC = 3.6V, no load.
5
10
VTH − 2.5%
VTH
VTH + 2.5%
D2U
20
28
44
D3U
140
200
320
D4U
1100
1500
2500
Note 7
VCC ≥ 4.0V, tSINK = 3.2mA
0.4
VCC ≥ 2.5V, tSINK = 1.2mA
0.3
VCC ≥ 1.0V, tSINK = 50µA
0.3
1
/RESET de-asserted
10
/MR-to-Reset Delay
/MR Input Threshold
Max.
VCC = 5.5V, no load.
/MR Minimum Pulse Width
VIH
Typ.
2.3
VTH < 4.0V
0.7 × VCC
VTH < 4.0V
0.25 × VCC
/MR Glitch Immunity
V
µA
V
0.8
10
ms
µs
VTH > 4.0V
/MR Pull-Up Resistance
V
µs
0.5
VTH > 4.0V
µA
20
100
30
V
kΩ
ns
Notes:
4. Exceeding the absolute maximum ratings may damage the device.
5. The device is not guaranteed to function outside its operating ratings.
6. Devices are ESD sensitive. Handling precautions are recommended. Human body model, 1.5kΩ in series with 100pF.
7. Various reset thresholds available. See Ordering Information or contact factory.
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Revision 2.0
Micrel, Inc.
MIC6315
Timing Diagram
Functional Diagram
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Micrel, Inc.
MIC6315
Application Information
Microprocessor Reset
The /RESET pin is asserted whenever VCC falls below the
reset threshold voltage or if /MR (manual reset) is forced
low. The /RESET pin remains asserted for the duration of
the reset timeout period after VCC has risen above the
reset threshold or /MR has returned high. The reset
function ensures the microprocessor is properly reset and
powers up in a known condition after a power failure.
/RESET will remain valid with VCC as low as 1V.
VCC Transients
The MIC6315 is relatively immune to negative-going VCC
glitches below the reset threshold. Typically, a negativegoing transient 125mV below the reset threshold with
duration of 20µs or less will not cause an unwanted reset.
If additional transient immunity is needed, a bypass
capacitor can be placed a close as possible to the
MIC6315.
The /RESET output is a simple open-drain N-channel
MOSFET structure. A pull-up resistor must be used to
pull this output up to some voltage. For most applications,
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
maximum) to avoid damage to the MIC6315. The resistor
must be small enough to supply current to the inputs and
leakage paths that are driven by the /RESET output.
Figure 1. MIC6315 as Used in a Multiple Supply System
/RESET Valid at Low Voltage
As VCC drops to 0V, the MIC6315 will no longer be able 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’ing the /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.
October 17, 2014
6
Revision 2.0
Micrel, Inc.
MIC6315
Package Information and Recommended Landing Pattern(8)
4-Pin SOT-143 (U)
Note:
8. Package information is correct as of the publication date. For updates and most current information, go to www.micrel.com.
October 17, 2014
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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 manufacturer of IC solutions for the worldwide high performance linear and power, LAN, and timing & 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 computer products.
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of distributors and reps worldwide.
Micrel makes no representations or warranties with respect to the accuracy or completeness of the information furnished in this datasheet. 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, arising by estoppel or otherwise, to any intellectual
property rights is granted by this document. Except as provided in Micrel’s terms and conditions of sale for such products, Micrel assumes no liability
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© 2005 Micrel, Incorporated.
October 17, 2014
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