FM6326/FM6327/FM6328 Ultra low current µC Supervisor Circuits
September 2003
FM6326/FM6327/FM6328
Ultra low current µC Supervisor Circuits
Features
■
Ultra Low supply Current (2µA)
■
Voltage monitoring range: 1.8V to 3.6V
■
Reset threshold voltage options: From 1.6V to 3.4V
■
Power-on reset pulse width: 100ms (min)
■
Operating temperature range: - 40°C to + 85°C
■
Reset output options:
– Push-Pull active low (FM6326 series)
– Push-Pull active high (FM6327 series)
– Open-Drain active low (FM6328 series)
■
Power supply transient immunity
■
No External Components
■
Package options: 3-Pin SOT23 and 3-Pin SC70
■
Compatible with FM809/FM810/FM803 series
General Description
FM6326/FM6327/FM6328 are a family of supervisory circuits
employed to monitor power supplies used in Microprocessor,
Microcontroller and other digital systems. These devices accu-
rately monitor the system voltage (V
CC
) and signal reset to the
system when the V
CC
drops below a preset threshold voltage
(V
TH
). The Reset signal is continuously asserted as long as V
CC
is below V
TH
. Once the V
CC
rises above V
TH
, the Reset signal
remains asserted for a minimum period of 100ms before it is
released. This minimum period ensures proper system reset
before any operation begins. The voltage monitoring circuit is
designed to ignore fast transients on V
CC
which prevents gener-
ation of spurious resets.
The FM6326 family offers push-pull active low reset output, the
FM6327 family offers push-pull active high reset output and the
FM6328 family offers open-drain active low reset output. Each
of these three family of devices are availble with factory pro-
grammed V
TH
values from 1.6V to 3.4V, in 100mV increments to
suit a wide variety of applications.
FM6326/FM6327/FM6328 feature ultra-low supply currents and
are available in tiny SOT23 and SC70 packages making them
ideal parts to use in battery operated portable equipments.
Applications
■
µC/µP Power supply monitoring (Computers/Controller
cards)
■
Portable appliances
■
Peripherals (Settop boxes/Hard Drives/Modems)
■
Instruments
■
Automotive Systems
Typical Operating Circuit
V
CC
V
CC
FM6326
RESET
µC
Reset Input
GND
GND
FM6326/6347/6348 Pinout (top view)
GND
1
3
RESET
(RESET)
2
V
CC
SOT23-3 & SC70-3 Packages
©2003 Fairchild Semiconductor Corporation
1
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FM6326/FM6327/FM6328 Rev. C
FM6326/FM6327/FM6328 Ultra low current µC Supervisor Circuits
Absolute Maximum Ratings
Voltage on any terminal relative to GND
– V
CC
-0.3V to +6V
– RESET and RESET
-0.3V to (VCC + 0.3V)
– RESET (open drain)
-0.3V to +6V
20mA
Input Current (V
CC
)
Output Current (RESET and RESET)
Rate of Rise V
CC
20mA
100V/µs
ESD Rating:
– Human Body Model
– Machine Model
Continuous Power Dissipation (T
A
= +70°C)
– 3-Pin SC70 (derate 2.7mW/°C above +70°C)
– 3-Pin SOT23 (derate 4mW/°C above +70°C)
Operating Temperature Range
Storage Temperature Range
Lead Temperature (soldering, 10s)
2KV
200V
174mW
320mW
-40°C to +85°C
-65°C to +150°C
+300°C
These are stress ratings only and functional operation is not implied for these levels or beyond. Exposure to Absolute Maximum
Rating conditions for extended periods may affect device reliability.
Electrical Characteristics
(V
CC
= full range; T
A
= -40°C to + 85°C unless noted otherwise; Typical values are at + 25°C ; See Note 1.)
Parameter
Operating Voltage
Supply Current
Reset Threshold
Symbol
V
CC
I
CC
V
TH
Conditions
T
A
= 0°C to + 70°C
T
A
= - 40°C to + 85°C
V
CC
= 3.0V (for V
TH
values < 2.93V); no load
V
CC
= 3.3V (for V
TH
values
≥
2.93V); no load
V
TH
values from
1.6V to 3.4V in
100mV increments
T
A
= 25°C
T
A
= - 40°C to + 85°C
Min
1.1
1.2
Typ
Max
3.6
3.6
Units
V
µA
V
2
V
TH
- 2%
V
TH
- 5%
V
TH
V
TH
40
3.5
V
TH
+2%
V
TH
+ 5%
Reset Threshold Tempco
V
CC
to Reset Delay
Reset Active Timout Period
(See Note 2)
Output Voltage
(FM6326/FM6328)
∆
V
TH
/°C
V
CC
= V
TH
to (V
TH
- 100mV)
T
RT
V
OL
T
A
= - 40°C to + 85°C
I
SINK
= 1.6mA; V
CC
< (V
TH Min
- 100mV);
for V
CC
> 1.8V
I
SINK
= 500mA; V
CC
< (V
TH Min
- 100mV);
for V
CC
< 1.8V
100
ppm/°C
15
400
0.3
0.4
µs
ms
V
10
185
Output Voltage
(FM6326)
Output Voltage
(FM6327)
V
OH
I
SOURCE
= 500mA; V
CC
> (V
TH
+ 100mV);
V
CC
= 3.0V (for V
TH
values < 2.93V)
V
CC
= 3.3V (for V
TH
values
≥
2.93V)
I
SINK
= 1.6mA; V
CC
> (V
TH
+ 100mV);
for V
CC
in the 1.8V to 3.3V range
I
SINK
= 3.2mA; V
CC
> (V
TH
+ 100mV);
V
CC
> 3.3V
0.8 * V
CC
V
V
OL
0.3
0.4
0.8 * V
CC
0.1
V
V
OH
Open-Drain Output Leakage
Current (FM6328)
I
SOURCE
= 500µA; V
CC
< (V
TH
- 100mV);
for V
CC
in the 1.8V to 3.3V range
V
CC
> (V
TH
+ 100mV)
µA
Note 1:
Over temperature limits are guaranteed by design and not production tested.
Note 2:
Consult factory for other Reset timout options
2
FM6326/FM6327/FM6328 Rev. C
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FM6326/FM6327/FM6328 Ultra low current µC Supervisor Circuits
Pin Descriptions
Pin Number
1
2
Definition
GND
RESET
or
RESET *
VCC
GROUND
Description
FM6326: Active low push-pull output.
FM6327: Active high push-pull output.
FM6328: Active low open-Drain output.
POWER
3
* RESET for FM6327; /RESET for FM6326/FM6328
Circuit Timing (example: FM6326)
V
CC
3.6V
V
TH
1.1V
GND
RESET O/P
3.6V
V
TH
1.1V
GND
T
RT
min
Operation
FM6326/FM6327/FM6328 supervisory devices are designed to
issue Reset signal during power on, brownout and power down
conditions.
Typical power on and power down behaviour of FM6326 is illus-
trated in the “Circuit Timing” diagram above. During the power
on when the V
CC
ramps up, the Reset output also ramps up till
about 1.1V (V
CC
min) is reached. From this point onwards, as
the V
CC
ramps up, the reset output is actively driven low. Once
the V
CC
rises above the reset threshold voltage (V
TH
), the reset
signal is driven low for Reset active timeout period (T
RT
) and
then driven high. This timeout period ensures proper system ini-
tialization before any operation begins. During power down, as
soon as the V
CC
falls below the V
TH
, the Reset signal is driven
low to signal reset condition to the system.
Operation below minimum V
CC
(Active Low Reset)
When V
CC
is less than V
CC
(min), the Reset signal is not
actively driven by the device and the voltage of the Reset signal
will be nearly same as V
CC
. Under this circumstance if the appli-
cation requires that the Reset signal is close to GND level, it is
recommended to place a pull-down resistor (e.g. 100K
Ω
)
between Reset output and GND.
3
FM6326/FM6327/FM6328 Rev. C
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FM6326/FM6327/FM6328 Ultra low current µC Supervisor Circuits
Ordering Information
Part Number
FM6326S3220X
FM6326S3232X
FM6326S3263X
FM6326S3270X
FM6326S3293X
FM6326S3308X
FM6326P3220X
FM6326P3232X
FM6326P3263X
FM6326P3270X
FM6326P3293X
FM6326P3308X
FM6327S3220X
FM6327S3232X
FM6327S3263X
FM6327S3270X
FM6327S3293X
FM6327S3308X
FM6327P3220X
FM6327P3232X
FM6327P3263X
FM6327P3270X
FM6327P3293X
FM6327P3308X
FM6328S3220X
FM6328S3232X
FM6328S3263X
FM6328S3270X
FM6328S3293X
FM6328S3308X
FM6328P3220X
FM6328P3232X
FM6328P3263X
FM6328P3270X
FM6328P3293X
FM6328P3308X
Top
RESET
Marking Threshold (V)
A2C
A2D
A2G
A2H
A2J
A3B
A2C
A2D
A2G
A2H
A2J
A3B
B2C
B2D
B2G
B2H
B2J
B3B
B2C
B2D
B2G
B2H
B2J
B3B
C2C
C2D
C2G
C2H
C2J
C3B
C2C
C2D
C2G
C2H
C2J
C3B
2.20
2.32
2.63
2.70
2.93
3.08
2.20
2.32
2.63
2.70
2.93
3.08
2.20
2.32
2.63
2.70
2.93
3.08
2.20
2.32
2.63
2.70
2.93
3.08
2.20
2.32
2.63
2.70
2.93
3.08
2.20
2.32
2.63
2.70
2.93
3.08
Output Type
Push-Pull, active low
Package Type
3-Pin, SOT23
Packing
Method
3000 units in T&R
Push-Pull, active low
3-Pin, SC70
Open-Drain,
active low
3-Pin, SOT23
3000 units in T&R
Open-Drain,
active low
3-Pin, SC70
Push-Pull, active high
3-Pin, SOT23
3000 units in T&R
Push-Pull, active high
3-Pin, SC70
Note:
Other reset voltage and pulse width options are available on request. Please consult Fairchild sales for more details.
4
FM6326/FM6327/FM6328 Rev. C
www.fairchildsemi.com
FM6326/FM6327/FM6328 Ultra low current µC Supervisor Circuits
Physical Dimensions
inches (millimeters) unless otherwise noted
0.021
0.015
0.055
0.047
0.098
0.083
0.120
0.105
0.040
0.031
0.079
0.071
0.0059
0.0035
0-8û
0.004
0.001
0.010
0.005
SOT-23 Package Dimensions
FS Pkg Code AU
Dimensions in millimeters
PKG
C
L
0.76
0.76
0.95
LAND PATTERN RECOMMENDATION
5
FM6326/FM6327/FM6328 Rev. C
2.29
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