19-1294; Rev 4; 12/05
3-Pin, Ultra-Low-Power SC70/SOT
µP Reset Circuits
The MAX6326/MAX6327/MAX6328/MAX6346/MAX6347/
MAX6348 microprocessor (µP) supervisory circuits monitor the power supplies in µP and digital systems. These
devices provide excellent circuit reliability and low cost
by eliminating external components and adjustments
when used with 2.5V, 3V, 3.3V, and 5V powered circuits.
These circuits perform a single function: they assert a
reset signal whenever the VCC supply voltage declines
below a preset threshold, keeping it asserted for at least
100ms after VCC has risen above the reset threshold.
The only difference between the devices is their output.
The MAX6326/MAX6346 (push-pull) and MAX6328/
MAX6348 (open-drain) have an active-low reset output.
The MAX6327/MAX6347 have an active-high push-pull
reset output. All of these parts are guaranteed to be in
the correct state for VCC down to 1V. The reset comparator is designed to ignore fast transients on VCC. Reset
thresholds are factory-trimmable between 2.2V and
4.63V, in approximately 100mV increments. Twenty-one
standard versions are available. Contact the factory for
availability of nonstandard versions.
Ultra-low supply currents (1µA max for the MAX6326/
MAX6327/MAX6328) make these parts ideal for use in
portable equipment. All six devices are available in
space-saving SOT23 and SC70 packages.
Computers
Intelligent Instruments
Controllers
Automotive
Critical µP and µC
Power Monitoring
Portable/Battery-Powered
Equipment
Pin Configuration
TOP VIEW
1
MAX6326
MAX6327
MAX6328
MAX6346
MAX6347
MAX6348
(RESET) RESET
♦ Ultra-Low 1µA (max) Supply Current
(MAX6326/MAX6327/MAX6328)
♦ Precision Monitoring of 2.5V, 3V, 3.3V, and 5V
Power-Supply Voltages
♦ Reset Thresholds Available from 2.2V to 4.63V
♦ Fully Specified Over Temperature
♦ 100ms (min) Power-On Reset Pulse Width
♦ Low Cost
♦ Available in Three Versions: Push-Pull RESET,
Push-Pull RESET, and Open-Drain RESET
♦ Power-Supply Transient Immunity
♦ No External Components
♦ 3-Pin SC70/SOT23 Packages
♦ Pin Compatible with MAX803/MAX809/MAX810
Ordering Information
3
VCC
PART†
TEMP. RANGE
PIN-PACKAGE
MAX6326XR_ _-T
-40°C to +85°C
3 SC70-3
MAX6326UR_ _-T
-40°C to +85°C
3 SOT23-3
MAX6327XR_ _-T
-40°C to +85°C
3 SC70-3
MAX6327UR_ _-T
MAX6328XR_ _-T
MAX6328UR_ _-T
MAX6346XR_ _-T
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
3 SOT23-3
3 SC70-3
3 SOT23-3
3 SC70-3
MAX6346UR_ _-T
Applications
GND
Features
-40°C to +85°C
3 SOT23-3
MAX6347XR_ _-T
-40°C to +85°C
3 SC70-3
MAX6347UR_ _-T
MAX6348XR_ _-T
MAX6348UR_ _-T
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
3 SOT23-3
3 SC70-3
3 SOT23-3
†The MAX6326/MAX6327/MAX6328/MAX6346/MAX6347/
MAX6348 are available in factory-set VCC reset thresholds from
2.2V to 4.63V, in approximately 0.1V increments. Choose the
desired reset-threshold suffix from Table 1 and insert it in the
blank spaces following “R.” There are 21 standard versions with
a required order increment of 2500 pieces. Sample stock is generally held on the standard versions only (see the Selector
Guide). Required order increment is 10,000 pieces for nonstandard versions (Table 2). Contact factory for availability. All
devices available in tape-and-reel only.
Devices are available in both leaded and lead-free packaging.
Specify lead-free by replacing “-T” with “+T” when ordering.
2
SOT23-3/SC70-3
Selector Guide appears at end of data sheet.
( ) ARE FOR THE MAX6327/MAX6347.
________________________________________________________________ Maxim Integrated Products
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
1
MAX6326/MAX6327/MAX6328/MAX6346/MAX6347/MAX6348
General Description
3-Pin, Ultra-Low-Power SC70/SOT
µP Reset Circuits
POWER-DOWN RESET DELAY
vs. TEMPERATURE
MAX6326-01
1.0
0.9
MAX6326-02
SUPPLY CURRENT vs. TEMPERATURE
200
VCC = 5V
0.7
RESET DELAY (µs)
SUPPLY CURRENT (µA)
0.8
0.6
VCC = 3.3V
0.5
0.4
150
100
VOD = 20mV
VOD = 10mV
0.3
50
0.2
0.1
VOD = 100mV
VCC = 1.2V
VOD = 200mV
0
0
-40
-20
0
20
40
60
-40
80
-20
0
20
40
60
80
TEMPERATURE (°C)
TEMPERATURE (°C)
POWER-UP RESET TIMEOUT
vs. TEMPERATURE
MAXIMUM TRANSIENT DURATION
vs. RESET THRESHOLD OVERDRIVE (SC70)
190
180
170
160
150
140
500
MAX6326-04
200
MAXIMUM TRANSIENT DURATION (µs)
MAX6326-03
POWER-UP RESET TIMEOUT (ms)
210
400
300
200
100
0
130
-40
-20
0
20
40
60
1
80
TEMPERATURE (°C)
10
100
1000
RESET THRESHOLD OVERDRIVE,
VTH - VCC (mV)
______________________________________________________________Pin Description
PIN
PIN
MAX6326/MAX6346
MAX6328/MAX6348
MAX6327
MAX6347
NAME
1
1
GND
FUNCTION
Ground
2
—
RESET
Active-Low Reset Output. RESET remains low while VCC is below the reset
threshold and for at least 100ms after VCC rises above the reset threshold.
RESET is open-drain on the MAX6328/MAX6348 and push-pull on the
MAX6326/MAX6346.
—
2
RESET
Active-High Reset Output. RESET remains high while VCC is below the reset
threshold and for at least 100ms after VCC rises above the reset threshold.
3
3
VCC
Supply Voltage
_______________________________________________________________________________________
3
MAX6326/MAX6327/MAX6328/MAX6346/MAX6347/MAX6348
__________________________________________Typical Operating Characteristics
(TA = +25°C, unless otherwise noted.)
