Global Mixed-mode Technology Inc.
G684/G685
Microprocessor Reset IC
Features
Precision Monitoring of +3V, +3.3V, and +5V
Power-Supply Voltages
General Description
The G684/G685 are microprocessor (碌P) supervisory
circuits used to monitor the power supplies in 碌P and
digital systems. They provide excellent circuit reliability
and low cost and adjustments when used with +5V,
+3.3V, +3.0V- powered circuits.
These circuits perform a single function: they assert a
reset signal whenever the V
CC
supply voltage declines
below a preset threshold, with hysteresis after V
CC
has
risen above the reset threshold. Reset thresholds
suitable for operation with a variety of supply voltages
are available.
The G685 has an open-drain output stage, while the
G684 have push-pull outputs. The G685L鈥檚 open-drain
RESET output requires a pull-up resistor that can be
connected to a voltage higher than V
CC
. The G684L
have an active-low RESET output, while the G684H
has an active-high RESET output. The reset com-
parator is designed to ignore fast transients on V
CC
,
and the outputs are guaranteed to be in the correct
logic state for V
CC
down to 0.8V.
Low supply current makes the G684/G685 ideal for
use in portable equipment. The G684/G685 are avail-
able in 5-pin SOT23-5 packages.
Fully Specified Over Temperature
Available in Three Output Configurations
Push-Pull RESET Output (G684L)
Push-Pull RESET Output (G684H)
Open-Drain RESET Output (G685L)
14碌A(chǔ) Supply Current
Guaranteed Reset Valid to V
CC
= 0.8V
Power Supply Transient Immunity
5 pin SOT23-5 Packages
2% Threshold Accuracy
Applications
Computers
Controllers
Intelligent Instruments
Critical 碌P and 碌C Power Monitoring
Portable / Battery-Powered Equipment
Automotive
Ordering Information
ORDER NUMBER TEMP. RANGE
G684H(L)xxxT1U
G685LxxxT1U
-40擄C ~ +105擄C
-40擄C ~ +105擄C
PACKAGE
SOT23-5
SOT23-5
Note:
T1 : SOT23-5
U : Tape & Reel
* xxx specifies the threshold voltage.
e.g. 263 denotes the 2.63V threshold voltage.
Pin Configuration
1
5
Typical Application Circuit
V
CC
N.C.
VCC
VCC
R
pull-up*
VCC
GND
2
G684/G685
G684/G685
RESET
(RESET)
碌P
RESET
INPUT
GND
GND
3
SOT23-5
4
RESET
(RESET)
GND
()is for G684H
*G685 ONLY
Ver: 1.2
Jun 03, 2004
TEL: 886-3-5788833
http://www.gmt.com.tw
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