LX7001
T
RANSIENT
I
MMUNE
U
NDERVOLTAGE
S
ENSING
C
IRCUIT
T
H E
I
N F I N I T E
P
O W E R
O F
I
N N O VA T I O N
P
R O D U C T I O N
D
A T A
S
H E E T
DESCRIPTION
The LX7001 is an improved
undervoltage sensing circuit specifi-
cally designed for use as a reset
controller in microprocessor-based
systems. Today's complex miniaturized
systems present difficult challanges to
the system designer such as overcom-
ing spurious noise problems. The
LX7001 is optimized for systems that
must be tolerant of high-speed power
supply glitches caused by high-speed
logic transitions and similar switching
phenomena. The LX7001 offers a
unique stage that couples glitch
immunity with a micropower, ultra-
stable band-gap reference for preci-
sion sensing of undervoltage condi-
tions. It offers the designer an
economical, space-efficient solution
for low supply voltage detection
when used in combination with a
single pull-up resistor. Adding one
capacitor offers the functionality of a
programmable delay time after power
returns. Additionally, the LX7001
offers excellent temperature stability.
A high-quality trimmed voltage
reference and bias circuit permit very
accurate and repeatable undervoltage
sensing. The remaining blocks
consist of a comparator with hyster-
esis, high current clamping diode and
open collector output stage capable
of sinking up to 60mA. The
LX7001's RESET output is specified to
be fully functional at V
IN
=1V.
K E Y F E AT U R E S
s
Fully Characterized, Transient Immune
Input Stage
(See Product Highlight)
s
Monitors 5V Supplies
(V
TRIP
=4.6V Typ.)
s
Outputs Fully Defined At V
CC
=1V
s
Ultra-Low Supply Current
(500µA Max. Over Temp)
!
Temperature Compensated I
CC
For Extremely
Stable Current Consumption
!
µP Reset Function Programmable With 1
External Resistor And Capacitor
!
Comparator Hysteresis Prevents Output
Oscillation
!
Electrically Compatible With Motorola
MC34064
!
Pin-to-Pin Compatible With Motorola
MC34064/MC34164
NOTE:
For current data & package dimensions, visit our web site:
http://www.linfinity.com.
A P P L I C AT I O N S
s
All Microprocessor Or Microcontroller
Designs Using 5V Supplies
s
Simple 5V Undervoltage Detection
PRODUCT HIGHLIGHT
I
NPUT
T
RANSIENT
I
MMUNITY
100
(t
n
) Noise Pulse Width - (µs)
10
ACTIVE
1
IMMUNE
0.1
100
1000
(e
n
) Noise Pulse Amplitude - (mV)
PA C K A G E O R D E R I N F O R M A T I O N
T
A
(°C)
0 to 70
-40 to 85
-55 to 125
DM
Plastic SOIC
8-pin
LX7001CDM
LX7001IDM
—
LP
Plastic TO-92
3-pin
LX7001CLP
LX7001ILP
—
Y
Ceramic Dip
8-pin
—
—
LX7001MY
Note: All surface-mount packages are available in Tape & Reel.
Append the letter "T" to part number. (i.e. LX7001CDMT)
Copyright © 1999
Rev. 1.2 6/99
L
IN
F
INITY
M
ICROELECTRONICS
I
NC
.
11861 W
ESTERN
A
VENUE
, G
ARDEN
G
ROVE
, CA. 92841, 714-898-8121, F
AX
: 714-893-2570
1
PRODUCT DATABOOK 1996/1997
LX7001
T
RANSIENT
I
MMUNE
U
NDERVOLTAGE
S
ENSING
C
IRCUIT
P
R O D U C T I O N
D
A T A
S
H E E T
A B S O L U T E M A X I M U M R AT I N G S
(Note 1)
PA C K A G E P I N O U T S
RESET
V
IN
N.C.
GROUND
1
2
3
4
8
7
6
5
Input Supply Voltage (V
IN
) ............................................................................... -1V to 12V
RESET Output Voltage (V
OUT
) .......................................................................... -1V to 12V
Output Sink Current (I
OL
) ............................................................ Internally Limited (mA)
Clamp Diode Forward Current (I
F
), Pin 1 to pin 2 ............................................... 100mA
Operating Junction Temperature
Ceramic (Y - Package) .......................................................................................... 150°C
Plastic (DM, LP - Packages) .................................................................................. 150°C
Storage Temperature Range ...................................................................... -65°C to 150°C
Lead Temperature (Soldering, 10 seconds) ............................................................. 300°C
Note 1. Values beyond which damage may occur. All voltages are specified with respect to
ground, and all currents are positive into the specified terminal.
N.C.
N.C.
N.C.
N.C.
Y PACKAGE
(Top View)
RESET
V
IN
N.C.
GROUND
1
2
3
4
8
7
6
5
N.C.
N.C.
N.C.
N.C.
T H E R M A L D ATA
DM PACKAGE:
THERMAL RESISTANCE-JUNCTION TO AMBIENT,
θ
JA
LP PACKAGE:
THERMAL RESISTANCE-JUNCTION TO AMBIENT,
θ
JA
Y PACKAGE:
THERMAL RESISTANCE-JUNCTION TO AMBIENT,
θ
JA
130°C/W
156°C/W
165°C/W
DM PACKAGE
(Top View)
3.
GROUND
2.
V
IN
1.
RESET
Junction Temperature Calculation: T
J
= T
A
+ (P
D
x
θ
JA
).
The
θ
JA
numbers are guidelines for the thermal performance of the device/pc-board system.
All of the above assume no ambient airflow
LP PACKAGE
(Top View)
2
Copyright © 1999
Rev. 1.2 6/99
PRODUCT DATABOOK 1996/1997
LX7001
T
RANSIENT
I
MMUNE
U
NDERVOLTAGE
S
ENSING
C
IRCUIT
P
R O D U C T I O N
D
A T A
S
H E E T
R E C O M M E N D E D O P E R AT I N G C O N D I T I O N S
Parameter
Input Supply Voltage
RESET Output Voltage
Clamp Diode Forward Current
Operating Ambient Temperature Range:
LX7001C
LX7001I
LX7001M
Note 2. Range over which the device is functional.
(Note 2)
Symbol
V
IN
V
OUT
I
F
Recommended Operating Conditions
Min.
Typ.
Max.
1
10
50mA
0
-25
-55
70
85
125
10
Units
V
V
°C
°C
°C
ELECTRICAL CHARACTERISTICS
(Unless otherwise specified, these specifications apply over the operating ambient temperatures of 0°C
≤
T
A
≤
70°C for the LX7001C,
-40°C
≤
T
A
≤
85°C for the LX7001I, and -55°C
≤
T
A
≤
125°C for the LX7001M. Low duty cycle pulse testing techniques are used which maintains
junction and case temperatures equal to the ambient temperature.)
Parameter
Comparator Section
Threshold Voltage
High State Output
Low State Output
Hysteresis
Symbol
Test Conditions
LX7001C/7001I/7001M
Min. Typ.
Max.
Units
V
T+
V
T-
V
H
V
IN
Increasing — 4V to 5V
V
IN
Decreasing — 5V to 4V
4.5
4.5
0.01
4.62
4.60
0.02
0.06
0.25
0.3
40
0.01
0.02
0.82
345
4.7
4.7
0.05
1.0
0.4
0.1
60
0.5
2.0
1.2
500
V
V
V
V
V
V
mA
µA
µA
V
µA
RESET
Output Section
Output Sink Saturation Voltage
V
OL
Output Sink Current
Output Off-State Leakage
Clamp Diode Forward Voltage
I
OL
I
OH
V
F
I
CC
V
IN
= 4.0V, I
OL
= 8.0mA
V
IN
= 4.0V, I
OL
= 2.0mA
V
IN
= 1.0V, I
OL
= 0.1mA
V
OUT
= 4.0V
V
OUT
= 5.0V
V
OUT
= 10V
Pin 1 to pin 2, I
F
= 10mA
V
IN
= 5.0V
10
0.6
Total Device
Supply Current
Copyright © 1999
Rev. 1.2 6/99
3
PRODUCT DATABOOK 1996/1997
LX7001
T
RANSIENT
I
MMUNE
U
NDERVOLTAGE
S
ENSING
C
IRCUIT
P
R O D U C T I O N
D
A T A
S
H E E T
BLOCK DIAGRAM
V
IN
RESET
1.2 V
REF
GROUND
GRAPH / CURVE INDEX
FIGURE INDEX
Characteristic Curves
FIGURE #
1.
2.
3.
4.
5.
6.
7.
8.
9.
RESET OUTPUT VOLTAGE vs. INPUT VOLTAGE
POWER-UP RESET VOLTAGE
RESET OUTPUT VOLTAGE vs. INPUT VOLTAGE
THRESHOLD VOLTAGE vs. TEMPERATURE
THRESHOLD HYSTERESIS vs. TEMPERATURE
SUPPLY CURRENT vs. INPUT VOLTAGE
SUPPLY CURRENT vs. TEMPERATURE
LOW LEVEL OUTPUT CURRENT vs. TEMPERATURE
LOW LEVEL OUTPUT VOLTAGE vs. LOW LEVEL OUTPUT CURRENT
FIGURE #
Application Circuits
13.
LOW VOLTAGE MICROPROCESSOR RESET
14.
SWITCHING THE LOAD OFF WHEN BATTERY REACHES BELOW 4.3V
15.
VOLTAGE MONITOR
16.
MOSFET LOW VOLTAGE GATE DRIVE PROTECTION
17.
LOW VOLTAGE MICROPROCESSOR RESET with ADDITIONAL
HYSTERESIS
10.
VOLTAGE vs. CLAMP DIODE FORWARD CURRENT
11.
PROPAGATION DELAY
12.
LOW LEVEL OUTPUT VOLTAGE vs. TEMPERATURE
4
Copyright © 1999
Rev. 1.2 6/99
PRODUCT DATABOOK 1996/1997
LX7001
T
RANSIENT
I
MMUNE
U
NDERVOLTAGE
S
ENSING
C
IRCUIT
P
R O D U C T I O N
D
A T A
S
H E E T
CHARACTERISTIC
CURVES
FIGURE 1.
— RESET OUTPUT VOLTAGE vs. INPUT VOLTAGE
10
FIGURE 2.
— POWER-UP RESET VOLTAGE
2.0
R
L
= 10K
(V
OUT
) RESET Output Voltage - (V)
Power-Up RESET Voltage - (V)
T
A
= 25 C
8
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
V
IN
6
4
RESET
2
0
0
2
4
6
8
10
0
0
100
200
300
400
500
(V
IN
) Input Voltage - (V)
(t) Time - ( s)
FIGURE 3.
— RESET OUTPUT VOLTAGE vs. INPUT VOLTAGE
5
FIGURE 4.
— THRESHOLD VOLTAGE vs. TEMPERATURE
4.64
(V
OUT
) RESET Output Voltage - (V)
V
T+
Upper Threshold
High State Output
(V
T
) Threshold Voltage - (V)
4
4.62
3
4.60
V
T-
Lower Threshold
Low State Output
4.58
2
1
4.56
0
4.55 4.56 4.57 4.58 4.59 4.60 4.61 4.62 4.63 4.64 4.65
4.54
-55
-25
0
25
50
75
100
125
150
(V
IN
) Input Voltage - (V)
(T
J
) Temperature - ( C)
Copyright © 1999
Rev. 1.2 6/99
5
