MIC2788/MIC2789
Push-Button Reset IC
MLF and MicroLeadFrame are registered trademarks of Amkor Technologies, Inc.
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 2011 M9999-102711-A
General Description
The MIC2788/MIC2789 are low-current, ultra-small, push-
button reset supervisors with long set-up delays. The
devices feature two manual reset inputs and two reset
outputs. The devices initiate a reset for the reset timeout
period when the /MR0 and /MR1 inputs are asserted low
for a period longer than the set-up delay. The two manual
reset inputs and long set-up period help to avoid
unintended system resets. Both manual reset inputs can
be tied together if a single push-button reset is desired.
The MIC2788 features integrated pull-up resistors on the
/MR0 and /MR1 inputs, while the MIC2789 requires
external pull-up resistors. The PDY input pin selects
between a 2s, 4s or 6s set-up period. Factory-programmed
reset timeout periods of 140ms (min.) and 240ms (min.)
are available. An active-low, open-drain reset output
(/RST) and an active-high, push-pull reset output (RSTP)
provide flexibility when interfacing to various
microcontrollers, PMICs, or load switches.
The MIC2788/MIC2789 consume a quiescent current of
only 2.9µA and are offered in a tiny, space-saving 8-pin
thin MLF® (2mm x 2mm x 0.55mm) package.
Data sheets and support documentation can be found on
Micrel’s web site at: www.micrel.com.
Features
• 1.6V to 5.5V operating voltage
• 2.9µA supply current when /MR0, /MR1 are not
asserted
• Asserting /MR0 and /MR1 for longer than set-up delay
asserts reset output for the reset timeout period
• Programmable delay (PDY) input selects 2.0s, 4.0s or
6.0s set-up delay
• Factory-programmed 140ms (min.) or 240ms (min.)
reset timeout period
• Integrated /MR0, /MR1 pull-up resistors (MIC2788)
• Dual Reset Outputs:
− Open-drain active-low reset (/RST) output
− Push-pull active-high reset (RSTP) output
• −40°C to 85°C ambient operating temperature range
• 8-pin 2mm x 2mm x 0.55mm thin MLF® package
Applications
• Smart phones
• MP3 players
• Portable navigation devices
• Set-top boxes (STBs)
• Tablets/pads
_________________________________________________________________________________________________________________________
Typical Application
Micrel, Inc. MIC2788/MIC2789
October 2011 2 M9999-102711-A
Ordering Information (1)
Part Number Marking Minimum
tRESET (ms) Package (3,4) Integrated Pull-Up Resistors
MIC2788-XYMT 8XA 140
8-Pin (2mm × 2mm) Thin MLF® Yes
MIC2788-YYMT(2) 8YA 240
8-Pin (2mm × 2mm) Thin MLF® Yes
MIC2789-XYMT 9XA 140
8-Pin (2mm × 2mm) Thin MLF® No
MIC2789-YYMT(2) 9YA 240
8-Pin (2mm × 2mm) Thin MLF® No
Notes:
1. All devices available in Tape and Reel only.
2. Contact factory for availability.
3. Thin MLF ® ▲ = Pin 1 identifier.
4. Thin MLF
® is a Green RoHS compliant package. Lead finish is NiPdAu. Mold compound is Halogen Free.
Pin Configur ation
MIC2788/89
8-Pin (2mm × 2mm) Thin MLF®
Top View
Pin Description
Pin Number Pin Name Pin Function
1 RSTP
Active-High Push-Pull Reset Output. This output changes from low-to-high when both manual
reset pins are pulled low for the setup delay period. RSTP remains high for the reset timeout
delay duration after the setup delay period has elapsed.
2 GND Supply Ground.
3 /MR1
Active-Low Manual Reset Input. The MIC2788 has an internal 65kΩ pull-up resistor to VIN while
the MIC2789 requires an external pull-up resistor to VIN if used with a push-button. Pull this pin
low to assert and force a reset. Pulling both manual reset inputs low for the setup delay time
causes one reset output pulse for the reset timeout delay period. Connect to VIN if unused, do
not leave floating.
4 /RST
Active-Low Open Drain Reset Output. This output changes from high to low when both manual
reset pins are pulled low for the setup delay period. /RST remains low for the reset timeout delay
after the setup delay has elapsed and it requires an external pull-up resistor.
5 PDY
Programmable Delay Input with Tri-State Connection. When left open, set-up delay is 2s, when
connected to GND, set-up delay is 4s and when connected to VIN, set-up delay is 6s.
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Pin Description (Continued)
Pin Number Pin Name Pin Function
6 NC No Connect. Leave pin floating.
7 /MR0
Active-Low Manual Reset Input. The MIC2788 has an internal 65kΩ pull-up resistor to VIN while
the MIC2789 requires an external pull-up resistor to VIN if used with a push-button. Pull this pin
low to assert and force a reset. Pulling both manual reset inputs low for the setup delay time
causes one reset output pulse for the reset timeout delay period. If unused, connect to VIN; do
not leave floating.
8 VIN
Positive Supply Voltage. A minimum 0.1μF decoupling ceramic capacitor must be connected
between VIN and GND close to the pins.
EPAD EPAD Exposed Pad. Connect to GND.
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Absolute Maximum Ratings(1)
Supply Voltage (VIN)..................................... −0.3V to +6.0V
Reset Input Voltage (/MR0, /MR1)........ −0.3V to VIN + 0.3V
Open Drain Reset Output (/RST) ................. −0.3V to +6.0V
Push-Pull Reset Output (RSTP)............ −0.3V to VIN + 0.3V
Tri-State Programmable Delay (PDY)... −0.3V to VIN + 0.3V
Lead Temperature (soldering, 10sec.)....................... 260°C
Junction Temperature (TJ) ........................−40°C to +150°C
Storage Temperature (Ts)......................... −55°C to +150°C
ESD Rating (Human Body Model)(3) .............................. 2kV
ESD Rating (Machine Model)(3)....................................300V
Operating Ratings(2)
Supply Voltage (VIN)..................................... +1.6V to +5.5V
Reset Input Voltage (/MR0, /MR1)......................... 0V to VIN
Open Drain Reset Output (/RST)...................... 0V to +5.5V
Push-Pull Reset Output (/RSTP) ........................... 0V to VIN
Tri-State Programmable Delay (PDY).................... 0V to VIN
Ambient Temperature (TA) .......................... –40°C to +85°C
Junction Thermal Resistance
2mm × 2mm Thin MLF® (θJA).............................90°C/W
Electrical Characteristics(4)
VIN = 3.0V, TA = 25°C, Bold values indicate –40°C ≤ TA ≤ +85°C; unless noted otherwise.
Parameter Conditions Min. Typ. Max. Units
Power Supply Input
Supply Voltage (VIN) 1.6 5.5 V
VIN = 5V; /MR0, /MR1, /RST, RSTP, and PDY
open 3.4
7.5
Supply Current (IIN) VIN = 3V; /MR0, /MR1, /RST, RSTP, and PDY
open 2.9
µA
Reset Time
PDY = Open 1.6 2.0 2.4
PDY = 0V 3.2 4.0 4.8
Set-Up Delay (tSETUP)
PDY = VIN 4.8 6.0 7.2
s
Option X 140 220 280
Reset Timeout Delay (tRESET) Option Y 240 350 480 ms
Reset Outputs (/RST, RSTP)
VIN = 4.5V, ISINK = 3.2mA
0.3
VIN = 3.3V, ISINK = 2.5mA
0.3
Reset Output Voltage Low
(/RST Output and RSTP Output)
(VOL) VIN = 1.6V, ISINK = 1.0mA
0.3
V
VIN = 4.5V, ISOURCE = 0.8mA 0.8 × VIN
VIN = 2.7V, ISOURCE = 0.5mA 0.8 × VIN
Reset Output Voltage High
(RSTP Output) (VOH)
VIN = 1.6V, ISOURCE = 250μA 0.8 × VIN
V
/RST Output Leakage (ILO) V/RST = 5.5V 0.3 μA
Notes:
1. Exceeding the absolute maximum rating may damage the device.
2. The device is not guaranteed to function outside its operating rating.
3. Devices are ESD sensitive. Handling precautions recommended. Human body model, 1.5kΩ in series with 100pF.
4. Specification for packaged product only.
Micrel, Inc. MIC2788/MIC2789
October 2011 5 M9999-102711-A
Electrical Characteristics (4) (Continued)
VIN = 3.0V, TA = 25°C, Bold values indicate –40°C ≤ TA ≤ +85°C; unless noted otherwise.
Parameter Conditions Min. Typ. Max. Units
Manual Reset Inputs (/MR0, /MR1)
Input High Voltage (VIH) 1.2 V
Input Low Voltage (VIL)
0.3 V
Internal Pull-Up Resistor (RPU) MIC2788 only 65 kΩ
Leakage Current /MR0, /MR1 pin
(IMR) /MR0, /MR1 inputs; MIC2789 only −1.0 1.0 μA
Programmable Setup Delay Input (PDY)
PDY = VIN, /MR0 = /MR1 = 0V +60 μA
PDY = VIN, /MR0 = VIN or /MR1= VIN 100 nA
PDY = 0V, /MR0 = /MR1 = 0V -60 μA
Input Bias Current PDY Pin (IPDY)
PDY = 0V, /MR0 = VIN or /MR1 = VIN 100 nA
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Typical Characteristics
VIN Supply Current
vs. Temperature ( P DY = O PE N)
1.0
1.6
2.2
2.8
3.4
4.0
-40 -15 10 35 60 85
TEMPERA T URE ( °C)
SUPPLY CURRENT ( µ A)
V
IN
= 3.0V
PDY = OPEN
Set up D elay
vs. Temperat ure (PDY = O PEN)
1.0
1.5
2.0
2.5
3.0
-40 -15 10 35 60 85
TEM PERATURE (° C)
DUAL RESET DELAY (s )
V
IN
= 3.0V
PDY = OPEN
Reset Tim eout Delay (Opt ion X)
vs. Temperature ( PD Y = OPEN)
200
210
220
230
240
250
-40 -15 10 35 60 85
TEMPERATURE (° C)
RESET TI MEOUT DELAY ( m s )
V
IN
= 3.0V
PDY = OPEN
VIN Supply Current
vs. Temperature ( PD Y = 0V)
1.0
1.6
2.2
2.8
3.4
4.0
-40 -15 10 35 60 85
TEMPERA T URE ( °C)
SUPPLY CURRENT (µA)
V
IN
= 3.0V
PDY = 0V
Set up D elay
vs. Temperat ure (PDY = 0V )
3.0
3.5
4.0
4.5
5.0
-40 -15 10 35 60 85
TEMPERA T URE ( °C)
DUAL RESET DELAY (s)
V
IN
= 3.0V
PDY = 0V
Reset Tim eout Delay (Opt ion X)
vs. Temperat ure (PDY = 0V)
200
210
220
230
240
250
-40 -15 10 35 60 85
TEMPERA T URE ( °C)
RESET TI MEOUT DELAY ( m s )
V
IN
= 3.0V
PDY = 0V
VIN Supply Current
vs. Temperature (PDY = VIN)
1.0
1.6
2.2
2.8
3.4
4.0
-40 -15 10 35 60 85
TEMPERA T URE ( °C)
SUPPLY CURRENT (µA)
V
IN
= 3.0V
PDY = V
IN
Set up D elay
vs. Temperature ( PD Y = VIN)
5.0
5.5
6.0
6.5
7.0
-40 -15 10 35 60 85
TEMPERA T URE ( °C)
DUAL RESET DELAY (s)
V
IN
= 3.0V
PDY = V
IN
Reset Tim eout Delay (Opt ion X)
vs. Temperature (PDY = V IN)
200
210
220
230
240
250
-40 -15 10 35 60 85
TEMPERATURE (° C)
RESET TI M EOUT DELAY( m s)
V
IN
= 3.0V
PDY = V
IN
Micrel, Inc. MIC2788/MIC2789
October 2011 7 M9999-102711-A
Typical Characteristics (Continued)
VIN Supply Current
vs. Input Volt age
1.5
2.2
2.9
3.6
4.3
5.0
0123456
I NPUT VO LT A GE ( V)
SUPPLY CURRENT ( µ A)
/MR0 = NOT ASSERTED
/MR1 = NOT ASSERTED
Set up D elay
vs. Input Voltage
0.0
2.0
4.0
6.0
8.0
10.0
0123456
I NPUT VO L TAGE (V)
DUAL RESET DELAY (s)
PDY = 0V
PDY =V
IN
PDY =OPEN
Reset Tim eout Delay (Opt i on X)
vs. Input Volt age
200
210
220
230
240
250
0123456
INPUT VOLTAGE (V)
RESET TI MEOUT DELAY ( m s )
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Timing Diagram
Micrel, Inc. MIC2788/MIC2789
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Functional Diagram
Micrel, Inc. MIC2788/MIC2789
October 2011 10 M9999-102711-A
Application Information
Design and Product Advantag es
The dual reset programmability of the MIC2788/
MIC2789 allows for already existing manual push
buttons to be used to generate a hardware reset based
on pre-programmed timing requirements. This ability to
increase the functionality of already existing buttons,
allows for cost reduction and more robust phone
designs. The dual reset delay time allows for significant
protection against accidental resets due to its long time
duration and dual push button requirement. The fixed
reset timeout delay allows for more predictable phone
operation during hardware resets. The tri-state option
provides an easy to use way to select between three
reset delay time options with no additional external
components required.
Supply Bypass Capacitor
A 0.1µF input bypass capacitor must be placed from VIN
(Pin 8) to GND (Pin 2).
Programmable Delay Pin (PDY)
The MIC2788/MIC2789 has a programmable dual reset
delay time, tSETUP, that is set via a tri-state logic
configuration. The PDY pin is intended to be connected
to the VIN supply voltage, ground or left floating.
PDY Configuration tSETUP
OPEN 2s
GND 4s
VIN 6s
Dual Manual Reset Inputs (/MR0, /MR1)
The /MR0, /MR1 input pins have integrated pull-up
resistors for the MIC2788 but require external pull-up
resistors for the MIC2789. A recommended value is
100kΩ to keep the current consumption low when the
push-button switches are pressed. The behavior of the
reset outputs is independent of the order in which the
/MR0, /MR1 inputs are driven low. If both inputs are low
for a setup delay time, only one reset pulse, of width
tRESET, is generated. Keeping both inputs low for a
longer time does not generate additional reset output
pulses.
Reset Outputs (/RST and RSTP)
The /RST output is a simple open-drain N-channel
MOSFET structure that requires a pull-up resistor. For
most applications, the pull-up voltage will be the same
as the power supply that supplies VIN to the
MIC2788/MIC2789. As shown in Figure 1, it is possible
to tie this resistor to some other voltage, other than VIN,
thus enabling level-shifting of the /RST output. The pull-
up voltage must be limited to 5.5V or less to avoid
damage to the MIC2788/MIC2789. The pull-up resistor
must be small enough to supply current to the inputs and
leakage paths that are driven by the /RST output. A
recommended value is 100kΩ. Leave floating if the /RST
pin is unused.
The RSTP pin is a push-pull output that is driven to VIN.
It cannot be level-shifted to another voltage. It is an
inverted signal of /RST.
Figure 1. MIC2788/MIC2789 Used in Multiple Supply
System
The reset outputs /RST and RSTP are asserted when
the dual reset delay time, tSETUP, is exceeded while the
/MR0, /MR1 pins are driven low. Both the reset outputs
remain asserted for a factory-programmed reset timeout
delay time tRESET. Two options are available with 140ms
or 240ms minimum tRESET duration. The /RST pin is
driven active low while the RSTP pin is driven active
high for the tRESET duration. The reset outputs are de-
asserted for VIN < 1.6V.
Figure 2. Manual Reset Function
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October 2011 11 M9999-102711-A
Typical Applications
Figure 3. MIC2788/89 Used for Interrupting System Power
Figure 4. MIC2788/89 Used for Microcontroller Reset
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October 2011 12 M9999-102711-A
Evaluation Board Schematic
Bill of Materials
Item Part Number Manufacturer Description Qty.
C1 GRM188R71C104KA01D Murata(1) 0.1µF, 16V capacitor, X7R, 0603 1
R1, R2, R4 CRCW0603100KJNEA Vishay(2) 100k, 5% resistor, 0603 3
MIC2788-XYMT U1
MIC2789-XYMT Micrel, Inc.(3) Push-Button Supervisor Reset ICs 1
Notes:
1. Murata Tel: www.murata.com.
2. Vishay Tel: www.vishay.com.
3. Micrel, Inc.: www.micrel.com.
Micrel, Inc. MIC2788/MIC2789
October 2011 13 M9999-102711-A
PCB Layout Recommendations
Top Layer
Top Silkscreen
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October 2011 14 M9999-102711-A
PCB Layout Recommendations (Continued)
Copper Layer
Bottom Silkscreen
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Package Information
8-Pin 2mm × 2mm Thin MLF®
Micrel, Inc. MIC2788/MIC2789
October 2011 16 M9999-102711-A
Recommended Landing Pattern
8-Pin 2mm × 2mm Thin MLF®
Micrel, Inc. MIC2788/MIC2789
October 2011 17 M9999-102711-A
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
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