MIC2753/2754
Micrel
MIC2753/2754
Power Supply Supervisors
Preliminary Information
General Description
The MIC2753 and MIC2754 are ultraminiature, full-featured,
power supply supervisors featuring active-high and active-
low reset outputs, respectively.
The MIC2753/4 includes an undervoltage detector with a
power-on reset generator and reset output, an overvoltage
detector with a separate output for activating crowbar circuits,
and a debounced manual reset input. Typical supply current
is a low 30µA.
These devices provide a 140ms minimum reset output at
power-on and assert their reset outputs any time the input
voltage deviates beyond preset overvoltage or undervoltage
thresholds. Reset outputs remain asserted for 140ms (mini-
mum) after the input returns to normal or after releasing the
manual reset. When an overvoltage condition is detected, the
overvoltage output is immediately activated. Hysteresis on
both thresholds prevents erratic operation due to noise.
Features
Undervoltage and overvoltage monitor
Separate overvoltage flag output
Generates 140ms (minimum) power-on reset pulse
Debounced manual reset input
Choice of active-high (MIC2753) or
active-low (MIC2754) reset outputs
• Low 30µA typical supply current
• No external components needed
• IttyBitty™ SOT-23-5 package
•
•
•
•
•
Applications
•
•
•
•
Computer systems
Embedded controllers
Power supplies
Telecommunications systems
Typical Application
V
CC
Fuse
MIC2754
Manual
Reset
VIN
MR
GND
RST
HV
Microcontroller
VCC
GND
RST IN
SCR
Crowbar
Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 944-0970 • http://www.micrel.com
June 1999
1
MIC2753/2754
MIC2753/2754
Micrel
Ordering Information
Part Number
MIC2753-RBM5
MIC2753-SBM5
MIC2753-TBM5
MIC2753-MBM5
MIC2753-LBM5
MIC2754-RBM5
MIC2754-SBM5
MIC2754-TBM5
MIC2754-MBM5
MIC2754-LBM5
Mark
UDR
UDS
UDT
UDM
UDL
UER
UES
UET
UEM
UEL
Lower Threshold
Voltage
2.63V
2.93V
3.08V
4.38V
4.63V
2.63V
2.93V
3.08V
4.38V
4.63V
Monitored
Voltage*
2.85V±5%
3.3V±10%
3.3V±5%
5.0V±10%
5.0V±5%
2.85V±5%
3.3V±10%
3.3V±5%
5.0V±10%
5.0V±5%
Upper Threshold
Voltage
3.08V
3.83V
3.53V
5.81V
5.38V
3.08V
3.83V
3.53V
5.81V
5.38V
Reset
Active High
Active High
Active High
Active High
Active High
Active Low
Active Low
Active Low
Active Low
Active Low
Temperature
Range
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
Package
SOT-23-5
SOT-23-5
SOT-23-5
SOT-23-5
SOT-23-5
SOT-23-5
SOT-23-5
SOT-23-5
SOT-23-5
SOT-23-5
* Contact factory for voltages not listed.
Pin Configuration
VIN HV RST
3
2
1
VIN GND HV
3
2
1
UDx
4
5
Part
Identification
4
UEx
5
GND
MR
RST
MR
MIC2753
Voltage
Code
MIC2754
Pin Description
Pin No.
MIC2753
1
Pin No.
MIC2754
Pin Name
RST
Pin Function
Reset (Digital Output): Active-high output. Asserted when V
IN
falls below
V
THU
(undervoltage threshold), or rises above V
THO
(overvoltage threshold).
Deasserted no less than 140ms after V
IN
returns within threshold limits.
High-Voltage Flag (Open-Drain Output): /HV is asserted (active low) when
the input voltage exceeds the V
THO
(overvoltage threshold). It indicates
power supply overvoltage and is intended for connection to a protection
device such as a “crowbar” circuit.
Analog Input: Voltage monitor input and power supply input to the IC.
Reset (Digital Output): Active-low digital output. This output will be asserted
whenever V
IN
falls below V
THU
(undervoltage threshold), or rises above
V
THO
(overvoltage threshold). It will be deasserted no less than 140ms after
V
IN
returns within the threshold limits.
Ground: Ground return for all IC functions.
Manual Reset (Digital Input): Logic low initiates immediate, unconditional
reset. If V
IN
is within tolerance thresholds, when /MR is released (returns
high), the reset output(s) will be deasserted no less than 140ms later. /MR
may be driven by a CMOS or TTL logic signal or a mechanical switch.
(Switch debouncing is performed internally.) /MR has an internal pull-up to
VIN and may remain open if unused.
2
1
/HV
3
3
4
VIN
/RST
4
5
2
5
GND
/MR
MIC2753/2754
2
June 1999
MIC2753/2754
Micrel
Absolute Maximum Ratings
(Note 1)
Supply Voltage (V
IN
) ...................................... –0.3V to 10V
Reset Voltage (V
RST
) ........................... –0.3V to V
IN
+ 0.3V
Manual Reset Voltage (V
MR
) ............... –0.3V to V
IN
+ 0.3V
Reset Current (I
RST
) ................................................... 10mA
Continuous Power Dissipation
(P
D
at T
A
= +85°C) .............................................. 200mW
Storage Temperature (T
S
) ....................... –65°C to +150°C
ESD Rating,
Note 3
Operating Ratings
(Note 2)
Supply Voltage (V
IN
) .......................................... 1.5V to 7V
Ambient Temperature (T
A
) ......................... –40°C to +85°C
Junction Temperature (T
J
) ........................................ 150°C
Manual Reset (V
MR
) ............................................. 0V to V
IN
Thermal Resistance
(θ
JA
) ................................................................... 325°C/W
Electrical Characteristics
V
IN
= 5.0V (L, M voltage code), V
IN
= 3.3V (T, S voltage code), V
IN
= 2.85 (R voltage code) T
A
= 25°C;
bold
values indicate 1.5V
≤
V
IN
≤
7.0V, –40°C
≤
T
A
≤
+85°C
Note 4;
unless noted
Symbol
V
IN
I
DD
V
THO
Parameter
Input Supply Voltage
Operating Supply Current
Overvoltage Threshold
manual reset not asserted
L voltage code
M voltage code
T voltage code
S voltage code
R voltage code
V
THU
Undervoltage Threshold
L voltage code
M voltage code
T voltage code
S voltage code
R voltage code
V
HYST
+
V
HYST
–
Overvoltage Threshold Hysteresis
Undervoltage Threshold Hysteresis
V
IN
= V
THO (min)
– 100mV to V
THO (max)
+ 100mV
V
IN
= V
THU (max)
+ 100mV to V
THU (min)
– 100mV
t
RST
Reset Pulse Width
140
5.28
5.62
3.459
3.67
3.018
4.50
4.25
3.00
2.85
2.55
Condition
Min
1.0
30
5.38
5.81
3.53
3.83
3.08
4.63
4.38
3.08
2.93
2.63
–15
+15
12
12
240
30
30
560
Typ
Max
7.0
100
6.00
6.00
3.96
3.96
3.28
4.75
4.50
3.15
3.00
2.70
Units
V
µA
V
V
V
V
V
V
V
V
V
V
mV
mV
µs
µs
ms
t
PROP(RST)
Propagation Delay
June 1999
3
MIC2753/2754
MIC2753/2754
Symbol
V
OL(RST)
Parameter
Reset Output Voltage Low
MIC2753
Condition
R/S/T voltage codes,
V
IN
= V
THU(max)
+ 100mV, I
SINK
= 50µA
L/M voltage codes,
V
IN
= V
THU(max)
+ 100mV, I
SINK
= 50µA
V
OH(RST)
Reset Output Voltage High
MIC2753
R/S/T voltage codes,
V
IN
= V
THU(min)
– 100mV, I
SOURCE
= 0.5mA
L/M voltage codes,
V
IN
= V
THU(min)
– 100mV, I
SOURCE
= 1.0mA
V
OL(RST)
/Reset Output Voltage Low
MIC2754
R/S/T voltage codes,
V
IN
= V
THU(min)
– 100mV, I
SINK
= 0.5mA
L/M voltage codes,
V
IN
= V
THU(min)
– 100mV, I
SINK
= 1.0mA
V
IN
≥
1.5V, I
OL
= 50µA
V
OH(RST)
/Reset Output Voltage High
MIC2754
R/S/T voltage codes,
V
IN
= V
THU(max)
+ 100mV, I
SOURCE
= 35µA
L/M voltage codes,
V
IN
= V
THU(max)
+ 100mV, I
SOURCE
= 35µA
V
IH(/MR)
V
IL(/MR)
t
PROP(/MR)
/MR Input Voltage, High
/MR Input Voltage, Low
Propagation Delay
MIC2753
Propagation Delay
MIC2754
t
/MR(min)
I
PU
I
IH
V
OL(/HV)
/MR Minimum Input Pulse Width
Pull-Up Current, /MR
Input Current, /MR
/HV Output Voltage Low
V
/MR
= 0V
V
/MR
= V
IN
V
IN
> V
THO(max)
,
I
SINK
= 0.5mA, R/S/T voltage codes
V
IN
> V
THO(max)
,
I
SINK
= 1.0mA, L/M voltage codes
t
PROP(/HV)
I
/HV
Note 1.
Note 2.
Note 3.
Note 4.
Micrel
Min
Typ
Max
0.5
0.5
V
IN
–0.5
V
IN
–0.8
0.5
0.8
0.5
V
IN
–0.5
V
IN
–0.5
0.8 V
IN
0.2 V
IN
V
/MR
≤
V
IL
to V
RST
≥
V
OH
V
/MR
≤
V
IL
to V
/RST
≤
V
OL
2.5
0.2
0.01
0.5
0.8
12
–2
30
+2
2
1
1
2
2
Units
V
V
V
V
V
V
V
V
V
V
V
µs
µs
µs
µA
µA
V
V
V
V
µs
µA
/HV Propagation Delay
/HV Leakage Current
V
IN
= V
THO (min)
– 100mV to V
THO (max)
+ 100mV
V
IN
= V
THO (min)
– 100mV
Exceeding the absolute maximum rating may damage the device.
The device is not guaranteed to function outside its operating rating.
Devices are ESD sensitive. Handling precautions recommended.
Final test on outgoing product is performed at T
A
= 25°C. Device performance over –40°C
≤
T
A
≤
+85°C is guaranteed by design.
MIC2753/2754
4
June 1999
MIC2753/2754
Micrel
Typical Characteristics
Supply Current
vs. Temperature
100
SUPPLY CURRENT (µA)
80
60
40
20
1V
0
-40 -20 0 20 40 60 80 100
TEMPERATURE (°C)
2V 3V 4V
5V
No Load; L, M
voltage codes
V
IN
= 6V
10
RESET PULSE WIDTH (ms)
9
8
7
6
5
4
3
2
1
0
-40 -20 0 20 40 60 80 100
TEMPERATURE (°C)
L, M voltage codes
Power-Down Reset Delay
vs. Temperature
300
Power-Up Reset Timeout
vs. Temperature
RESET DELAY (µs)
250
200
150
-40 -20 0 20 40 60 80 100
TEMPERATURE (°C)
Normalized Reset Threshold
vs. Temperature
1.010
NORMALIZED THRESHOLD
50
45
RESET DELAY (ns)
1.005
40
35
30
25
0.990
-40 -20 0 20 40 60 80 100
TEMPERATURE (°C)
Manual Reset Delay
vs. Temperature
40
L, M voltage codes
OVERVOLTAGE DELAY (µs)
Overvoltage Delay
vs. Temperature
10mV
30
20mV
100mV
20
Overdrive = 200mV
10
L, M voltage codes
0
-40 -20 0 20 40 60 80 100
TEMPERATURE (°C)
1.000
0.995
20
-40 -20 0 20 40 60 80 100
TEMPERATURE (°C)
Undervoltage Delay
vs. Temperature
50
UNDERVOLTAGE DELAY (µs)
L, M voltage codes
40
THRESHOLD
30
20
10
20mV
Overdrive = 10mV
1.005
1.010
Normalized Overvoltage
Threshold vs. Temperature
PULL-UP CURRENT (nA)
300
260
220
180
140
100
60
MR Pull-up Current
vs. Temperature
5.0V
1.000
0.995
3.3V
2.85V
0
-40 -20 0 20 40 60 80 100
TEMPERATURE (°C)
0.990
-40 -20 0 20 40 60 80 100
TEMPERATURE (°C)
20
-40 -20 0 20 40 60 80 100
TEMPERATURE (˚C)
June 1999
5
MIC2753/2754
嵌入式系统
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