FAIRCHILD FT7521L6X

FT7521
Reset Timer with Fixed Delay and Reset Pulse
Features
Description
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The FT7521 is a timer for resetting a mobile device
where long reset times are needed. The long delay
helps avoid unintended resets caused by accidental key
presses. It has a fixed delay of 7.5 ±20% seconds. The
DSR pin enables Test Mode operation by immediately
forcing /RST1 LOW for factory testing.
Fixed Reset Delay: 7.5 Seconds
One Input Reset Pin
Open-Drain Output Pin with Fixed 400ms Pulse
1.8 V to 5.0 V Operation (TA=-40°C to +85°C)
1.7 V to 5.0 V Operation (TA=-25°C to +85°C)
1.65 V to 5.00 V Operation (TA=0°C to +85°C)
<1 µA ICCQ Consumption
Zero-Second Test-Mode Enable
The FT7521 has one input for single-button resetting
capability. The device has a single open-drain output
with 0.5 mA pull-down drive.
FT7521 draws minimal ICC current when inactive and
functions over a power supply range of 1.65 V to 5.0 V.
Integrated Pull-Up Resistor on /SRO
Applications
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Cell Phones
Portable Media Players
Tablets
Mobile Devices
Consumer Medical
Figure 1.
Block Diagram
Ordering Information
Part Number
Operating
Temperature Range
FT7521L6X
FT7521FHX
(Preliminary)
Package
6-Lead, MicroPak™ 1.0 x 1.45 mm, JEDEC MO-252
-40C to +85C
© 2009 Fairchild Semiconductor Corporation
FT7521 • Rev. 1.0.7
6-Lead, MicroPak2™ 1.0 x 1.0 mm Body, .35 mm Pitch
Packing
Method
5000 Units on
Tape and Reel
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FT7521 — Reset Timer with Fixed Delay and Reset Pulse
September 2012
FT7521 — Reset Timer with Fixed Delay and Reset Pulse
Recommended Application Diagram
Figure 2.
Recommended Application Diagram
Pin Configuration
Figure 3.
Pad Assignments (Top-Through View)
Pin Definitions
Description
Pin #
Name
1
/RST1
2
GND
3
/SR0
Reset Input with Integrated pull-up, active LOW
Reset input with integrated pull-up, active LOW
4
VCC
Power supply
Power supply
5
DSR
Delay selection input; tie to GND during normal
operation.(1)
Delay selection input. Pull HIGH to enable zerosecond delay for factory test.
6
TEST
Used for device testing; tie to GND during
normal operation.
Used for device testing; tie to GND during
normal operation.
Normal Operation
Zero-Second Factory-Test Mode
Open-drain output, active LOW
Open-drain output, active LOW
GND
GND
Note:
1. This pin must always be tied to either GND or VCC. It must not float.
© 2009 Fairchild Semiconductor Corporation
FT7521 • Rev. 1.0.7
www.fairchildsemi.com
2
Stresses exceeding the absolute maximum ratings may damage the device. The device may not function or be
operable above the recommended operating conditions and stressing the parts to these levels is not recommended.
In addition, extended exposure to stresses above the recommended operating conditions may affect device reliability.
The absolute maximum ratings are stress ratings only.
Symbol
Parameter
VCC
Supply Voltage
VIN
DC Input Voltage
VOUT
Min.
Max.
Unit
-0.5
7.0
V
/SR0, DSR
-0.5
7.0
V
/RST1
-0.5
7.0
V
IIK
DC Input Diode Current
VIN < 0V
-50
mA
IOK
DC Output Diode Current
VOUT < 0V
-50
mA
IOL
DC Output Sink Current
+50
mA
ICC
DC VCC or Ground Current per Supply Pin
TSTG
Output Voltage
(2)
Condition
Storage Temperature Range
-65
100
mA
+150
C
TJ
Junction Temperature Under Bias
+150
C
TL
Junction Lead Temperature, Soldering 10 Seconds
+260
C
PD
Power Dissipation
5
mW
ESD
Electrostatic Discharge Capability
Human Body Model, JESD22-A114
4
Charged Device Model, JESD22-C101
2
kV
Note:
2. All output current Absolute Maximum Ratings must be observed.
Recommended Operating Conditions
The Recommended Operating Conditions table defines the conditions for actual device operation. Recommended
operating conditions are specified to ensure optimal performance to the datasheet specifications. Fairchild does not
recommend exceeding them or designing to Absolute Maximum Ratings.
Symbol
Parameter
VCC
(3)
Supply Voltage
Condition
Min.
Max.
-40C to +85C
1.8
5.0
-25C to +85C
1.7
5.0
0C to +85C
1.65
5.00
tRFC
VCC Recovery Time After Power
Down
VCC=0 V After Power Down, Rising to 0.5 V
5
VIN
Input Voltage(3)
/SR0
0
VOUT
0
Output Voltage
/RST1
IOL
DC Output Sink Current
/RST1, VCC=1.8 V to 5.0 V
TA
Free-Air Operating Temperature
JA
Thermal Resistance
-40
Unit
V
ms
5
V
5
V
+3
mA
+85
C
350
°C/W
Note:
3. VCC supply should never be allowed to float while input pins are driven.
© 2009 Fairchild Semiconductor Corporation
FT7521 • Rev. 1.0.7
www.fairchildsemi.com
3
FT7521 — Reset Timer with Fixed Delay and Reset Pulse
Absolute Maximum Ratings
Conditions of TA=-40 to 80°C with VCC=1.8 - 5.0 V OR TA=-25 to 85°C with VCC=1.7 – 5 V OR TA=0 to 85°C with
VCC=1.65 – 5 V produce the performance characteristics below.
Symbol
Parameter
Condition
VIH
Input High Voltage
DSR, /SR0
VIL
Input Low Voltage
DSR, /SR0
VOL
Low Level Output Voltage
RPU
Integrated Pull-Up Resistor on /SR0
IIN
ICC
Min.
Typ.
Max.
Unit
0.65 x VCC
V
0.25 x VCC
RST, IOL=500 µA
V
0.3
RST, IOL=3 mA, VCC=3.0 V
V
0.3
50
kΩ
Input Leakage Current /SR0
VIN= VCC
1.0
Input Leakage Current DSR
0V  VIN  5.0 V
1.0
Quiescent Supply Current (Timer
Inactive)
/SR0=VCC
1
Dynamic Supply Current (Timer Active) /SR0=0 V
µA
µA
200
AC Electrical Characteristics
Conditions of TA=-40 to 80°C with VCC=1.8 - 5.0 V OR TA=-25 to 85°C with VCC=1.7 – 5 V OR TA=0 to 85°C with
VCC=1.65 – 5 V produce the performance characteristics below.
Symbol
Parameter
tPHL1
Timer Delay, /SR0 to RST (DSR=0)
tREC
Reset Timeout Delay
Condition
CL=5 pF, RL=5 K,
see Figure 4
Min.
Typ.
Max.
Unit
6.0
7.5
9.0
s
320
400
480
ms
Typ.
Unit
Capacitance Specifications
TA=+25C.
Symbol
CIN
COUT
Parameter
Condition
Input Capacitance
VCC=GND
4
pF
Output Capacitance
VCC=5.0 V
5
pF
© 2009 Fairchild Semiconductor Corporation
FT7521 • Rev. 1.0.7
www.fairchildsemi.com
4
FT7521 — Reset Timer with Fixed Delay and Reset Pulse
DC Electrical Characteristics
Default operation time N is 7.5 s. If the DSR pin is pulled
HIGH prior to VCC ramp, the FT7521 enters Test Mode
and the reset output, /RST1, is immediately pulled LOW
for factory testing. The DSR pin MUST be forced to
GND during normal operation. The DSR pin should
never be driven HIGH or left to FLOAT during normal
operation. The DSR PIN state should never be changed
during device operation; it must be biased prior to
supplying the VCC supply. If there is a need to use the
DSR=VCC Test Mode, the /SR0 must be HIGH when
the DSR pin is moved from LOW to HIGH to enter ZeroSecond Factory-Test Mode. To return to the standard
7.5-second reset time, the same procedure must be
followed with DSR=GND. The DSR pin should never be
allowed to change state while the /SR0 pin is LOW. The
VCC supply pin should never be left to float while other
input pins are driven. If the VCC pin is allowed to float,
care should be taken to ensure that /SR0 is not driven to
any voltage greater than GND.
/RST1 goes LOW after /SR0 has been held LOW for
7.5 s. The /RST1 output returns to its original HIGH
state 400ms after time tREC has expired, regardless of
the state of /SR0. The /RST1 output is an open-drain
driver. When the count time exceeds time 7.5 s, the
/RST1 output pulls LOW.
Short Duration (tW < 7.5 s)
When the /SR0 input goes LOW, the internal timer starts
counting. If the /SR0 input goes HIGH before 7.5 s has
elapsed, the timer stops counting and resets and no
changes occur on the outputs.
Long Duration (tW > 7.5 s)
When the /SR0 input goes LOW, the internal timer starts
counting. If the /SR0 input stays LOW for at least 7.5 s, the
RST output is enabled and pulled LOW. The output RST
is held LOW for tREC, 400 ms, as soon as the reset time
of 7.5 s is met, regardless of the state of the /SR0 pin.
When the /SR0 input has returned HIGH and the tREC
has expired, the internal timer resets and awaits the
next RESET event.
Operation Modes
A low input signal on /SR0 starts the oscillator. There
are two scenarios for counting: short duration and long
duration. In the short-duration scenario, output /RST1 is
not affected. In the long-duration scenario, the output
Figure 4.
© 2009 Fairchild Semiconductor Corporation
FT7521 • Rev. 1.0.7
Zero-Second Test Mode
/RST1 goes LOW immediately after /SR0 goes LOW.
Reset Timing Waveforms
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5
FT7521 — Reset Timer with Fixed Delay and Reset Pulse
Functional Description
FT7521 — Reset Timer with Fixed Delay and Reset Pulse
AC Test Circuit and Waveforms
Figure 5.
© 2009 Fairchild Semiconductor Corporation
FT7521 • Rev. 1.0.7
AC Test Circuit and Waveforms for /RST1 Output ST Output
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6
2X
0.05 C
1.45
B
2X
(1)
0.05 C
(0.254)
(0.49)
5X
1.00
(0.75)
PIN 1 IDENTIFIER
5
(0.52)
1X
A
TOP VIEW
0.55MAX
(0.30)
6X
PIN 1
0.05 C
0.05
0.00
RECOMMENED
LAND PATTERN
0.05 C
C
0.25
0.15 6X
1.0
DETAIL A
0.10
0.05
0.45
0.35
0.10
0.00 6X
C B A
C
0.40
0.30
0.35 5X
0.25
0.40 5X
0.30
0.5
(0.05)
6X
(0.13)
4X
BOTTOM VIEW
Notes:
0.075 X 45
CHAMFER
DETAIL A
PIN 1 TERMINAL
1. CONFORMS TO JEDEC STANDARD M0-252 VARIATION UAAD
2. DIMENSIONS ARE IN MILLIMETERS
3. DRAWING CONFORMS TO ASME Y14.5M-1994
4. FILENAME AND REVISION: MAC06AREV4
5. PIN ONE IDENTIFIER IS 2X LENGTH OF ANY
OTHER LINE IN THE MARK CODE LAYOUT.
Figure 6.
6-Lead, MicroPak™ 1.0 x 1.45 mm, JEDEC MO-252
Package drawings are provided as a service to customers considering Fairchild components. Drawings may change in any manner
without notice. Please note the revision and/or date on the drawing and contact a Fairchild Semiconductor representative to verify or
obtain the most recent revision. Package specifications do not expand the terms of Fairchild’s worldwide terms and conditions, specifically the
warranty therein, which covers Fairchild products.
Always visit Fairchild Semiconductor’s online packaging area for the most recent package drawings:
http://www.fairchildsemi.com/packaging/.
© 2009 Fairchild Semiconductor Corporation
FT7521 • Rev. 1.0.7
www.fairchildsemi.com
7
FT7521 — Reset Timer with Fixed Delay and Reset Pulse
Physical Dimensions
0.89
0.35
0.05 C
1.00
2X
B
A
5X 0.40
PIN 1
MIN 250uM
0.66
1.00
1X 0.45
6X 0.19
0.05 C
TOP VIEW
RECOMMENDED LAND PATTERN
FOR SPACE CONSTRAINED PCB
2X
0.90
0.05 C
0.55MAX
C
0.35
5X 0.52
SIDE VIEW
0.73
(0.08) 4X
1
DETAIL A
2
1X 0.57
0.09
0.19 6X
3
0.20 6X
ALTERNATIVE LAND PATTERN
FOR UNIVERSAL APPLICATION
(0.05) 6X
5X 0.35
0.25
0.35
6
5
4
BOTTOM VIEW
0.60
(0.08)
4X
0.10
.05 C
C B A
0.40
0.30
NOTES:
A. COMPLIES TO JEDEC MO-252 STANDARD
B. DIMENSIONS ARE IN MILLIMETERS.
C. DIMENSIONS AND TOLERANCES PER ASME Y14.5M, 1994
D. LANDPATTERN RECOMMENDATION IS BASED ON FSC
DESIGN.
E. DRAWING FILENAME AND REVISION: MGF06AREV3
Figure 7.
0.075X45°
CHAMFER
DETAIL A
PIN 1 LEAD SCALE: 2X
6-Lead, MicroPak2™ 1.0 x 1.0 mm Body, .35 mm Pitch
Package drawings are provided as a service to customers considering Fairchild components. Drawings may change in any manner
without notice. Please note the revision and/or date on the drawing and contact a Fairchild Semiconductor representative to verify or
obtain the most recent revision. Package specifications do not expand the terms of Fairchild’s worldwide terms and conditions, specifically the
warranty therein, which covers Fairchild products.
Always visit Fairchild Semiconductor’s online packaging area for the most recent package drawings:
http://www.fairchildsemi.com/packaging/.
© 2009 Fairchild Semiconductor Corporation
FT7521 • Rev. 1.0.7
www.fairchildsemi.com
8
FT7521 — Reset Timer with Fixed Delay and Reset Pulse
Physical Dimensions
FT7521 — Reset Timer with Fixed Delay and Reset Pulse
© 2009 Fairchild Semiconductor Corporation
FT7521 • Rev. 1.0.7
www.fairchildsemi.com
9