GMT G680LT1, G680HT1, G681LT1 Datasheet
Ver: 1.1
Jun 07, 2002
TEL: 886-3-5788833
http://www.gmt.com.tw
1
G680/G681
Global Mixed-mode Technology Inc.
Microprocessor Reset IC
Features
High ±±±±2% Voltage Threshold Accuracy
Independently Adjustable High- and LowVoltage Thresholds
Fully Specified Over Temperature
Available in Three Output Configurations
Push-Pull
RESET Output (G680L)
Push-Pull RESET Output (G680H)
Open-Drain
RESET Output (G681L)
140ms min Power-On Reset Pulse Width
4µA Supply Current
Power Supply Transient Immunity
5-Pin SOT23-5 Packages
Applications
Computers
Controllers
Intelligent Instruments
Critical µP and µC Power Monitoring
Portable / Battery-Powered Equipment
Automotive
General Description
The G680/G681 are microprocessor (µP) supervisory
circuits used to monitor the power supplies in µP and
digital systems. High- and Low- voltage thresholds can
be adjusted independently, allowing for wide hysteresis. Voltage detection thresholds are accurate to 2%.
These circuits perform a single function: they assert a
reset signal whenever the V
CC
supply voltage declines
below the low-voltage threshold, keeping it asserted
for at least 140ms after V
CC
has risen above the
high-voltage threshold.
The G681L has an open-drain output stage, while the
G680 have push-pull outputs. The G681L’s open-drain
RESET output requires a pull-up resistor that can be
connected to a voltage higher than V
CC
. The G680L
have an active-low
RESET output, while the G680H
has an active-high RESET output. The reset comparator is designed to ignore fast transients on threshold input.
The IC’s power supply is separate from the detector
inputs, allowing the G680/G681 to be powered from a
down-stream supply. Low supply current (4µA, typical)
makes the G680/G681 ideal for use in portable
equipment. The G680/G681 are available in 5 pin SOT
23-5 packages.
Ordering Information
PART TEMP. RANGE PIN-PACKAGE
G680H(L)T1 -40°C ~ +105°C SOT23-5
G681LT1 -40°C ~ +105°C SOT23-5
Pin Configuration Typical Operating Circuit
Vcc
RESET(RESET)
SOT23-5
5
4
1
HTH
2
3
GND
LTH
G680/G681
() is for G680H
RESET
INPUT
GND
µP
V
CC
RESET
(RESET)
GND
G680/G681
V
CC
R
PULL-UP
V
CC
*
*G681 ONLY
HTH
LTH
Vcc
RESET(RESET)
SOT23-5
5
4
1
HTH
2
3
GND
LTH
G680/G681
() is for G680H
Vcc
RESET(RESET)
SOT23-5
5
4
1
HTH
2
3
GND
LTH
G680/G681
() is for G680H
RESET
INPUT
GND
µP
V
CC
RESET
(RESET)
GND
G680/G681
V
CC
R
PULL-UP
V
CC
*
*G681 ONLY
HTH
LTH
Ver: 1.1
Jun 07, 2002
TEL: 886-3-5788833
http://www.gmt.com.tw
2
G680/G681
Global Mixed-mode Technology Inc.
Absolute Maximum Ratings
Terminal Voltage (with respect to GND)
V
CC
.……………………………..……………-0.3V to +6.0V
Input Voltage (V
LTH
, V
HTH
)…..……….-0.3V to (VCC + 0.3V)
RESET,
RESET (push-pull)....…......-0.3V to (VCC + 0.3V)
RESET (open drain)...…........…........…....-0.3V to +6.0V
Input Current, V
CC
............................……................20mA
Output Current, RESET,
RESET ..….....................20mA
Continuous Power Dissipation (T
A
= +70°C)
SOT23-5…………………………………………….568mW
Operating Temperature Range …....….-40°C to +105°C
Storage Temperature Range..…...…….-65°C to +150°C
Lead Temperature (soldering, 10s) ...…....…......+300°C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress rat-
ings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of
the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
Electrical Characteristics
(VCC = full range, TA = -40°C to +105°C, unless otherwise noted. Typical values are at TA = +25°C, VCC = 3.3V (Note 1)
PARAMETER SYMBOL CONDITION MIN TYP MAX UNITS
VCC Range 2.5 5.5 V
Supply Current (SOT23)
I
CC
V
CC
<5.5V
4 7.5
µA
Reset Threshold VTH 1.23 1.25 1.29 V
Reset Threshold Tempco 70 ppm/°C
V
LTH
to Reset Delay (Note 2) V
LTH
= VTH to VTH – 100mV 15 µs
VCC = 2.5V 80 250 550
Reset Active Timeout Period
V
CC
= 5.5V 500
ms
RESET
(RESET) Output Current Low
I
OL
V
CC
= 2.5V, V
RESET
(V
RESET
) = 0.5V,
RESET
Asserted or RESET not asserted
8 mA
RESET
Output Current High
(push-pull G680)
I
OH
V
CC
= 2.5V, V
RESET
(V
RESET)
= 2V,
RESET
not asserted or RESET asserted.
2 mA
Note 1: Production testing done at TA = +25°C; limits over temperature guaranteed by design.
Note 2:
RESET output is for G680L/G681L; While RESET output is for G680H.
Selector Guide
PART / SUFFIX OUTPUT TYPE
TOP MARK
G680LT1
Push-pull
RESET
680Ax
G680HT1 Push-pull RESET 680Bx
G681LT1
Open-Drain
RESET
681Ax
Ver: 1.1
Jun 07, 2002
TEL: 886-3-5788833
http://www.gmt.com.tw
3
G680/G681
Global Mixed-mode Technology Inc.
Timing Diagram
Functional Diagram
V
BATT
V
RESET
V
RESET
Propagation delays not shown for clarity.
V
HTH
V
LTH
0V
t
RST
t
RST
A
V
OH
V
OL
V
OH
V
OL
V
BATT
V
RESET
V
RESET
Propagation delays not shown for clarity.
V
HTH
V
LTH
0V
t
RST
t
RST
A
V
OH
V
OL
V
OH
V
OL
+
+
High-Voltage Detect
Delay
Line
RQ
SQ
One Shot
Low-Voltage Detect
+
1.24V
Bandgap
Reference
GND
G680/G681
RESET
RESET
V
DD
LTH
HTH
+
+
High-Voltage Detect
Delay
Line
RQ
SQ
One Shot
Low-Voltage Detect
+
1.24V
Bandgap
Reference
GND
G680/G681
RESET
RESET
V
DD
LTH
HTH
Loading...