Operating Temperature Range ........................... -40°C to +85°C
Storage Temperature Range ............................ -65°C to +160°C
Lead Temperature (soldering, 10sec) ............................. +300°C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings 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
(I
SHUNT
= 1mA, C
L
= 0.1µF, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER
SYMBOL
CONDITIONS
MAX633_L
V
SHUNT
Regulation
Voltage (Note 1)
V
SHUNT
I
SHUNT
=
0.1mA
to 50mA
T
A
= +25°C
T
A
= -40°C to +85°C
T
A
= +25°C
MAX633_T T
A
= -40°C to +85°C
T
A
= +25°C
MAX633_S T
A
= -40°C to +85°C
Minimum V
SHUNT
for which
RESET
is Valid (MAX6330)
V
SHUNT
Tempco
Minimum Shunt Current
(Note 2)
Maximum Shunt Current
(Note 3)
TA = 0°C to +70°C
TA = -40°C to +85°C
I
SHUNT(min)
I
SHUNT(max)
MAX633_L
Reset Threshold Voltage
V
TH
MAX633_T
MAX633_S
Reset Threshold Tempco
V
SHUNT
to Reset Delay
Reset Pulse Width
100mV overdrive, C
L
= 15pF
100
T
A
= +25°C
T
A
= -40°C to +85°C
T
A
= +25°C
T
A
= -40°C to +85°C
T
A
= +25°C
T
A
= -40°C to +85°C
4.56
4.50
3.01
2.97
2.74
2.70
40
20
140
200
2.78
3.06
4.63
MIN
4.93
4.85
3.25
3.20
2.96
2.91
1.0
1.2
40
100
60
50
4.69
4.75
3.11
3.15
2.82
2.86
ppm/°C
µs
ms
V
3.0
3.3
TYP
5.0
MAX
5.07
5.15
3.35
3.40
3.04
3.09
V
ppm/°C
µA
mA
V
UNITS
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Maxim Integrated │ 2
MAX6330/MAX6331
Precision Shunt Regulators with
Reset in SOT23-3
Electrical Characteristics (continued)
(I
SHUNT
= 1mA, C
L
= 0.1µF, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at T
A
= +25°C.)
I
SINK
= 3.2mA
I
SINK
= 1.2mA
MAX6330L, V
TH(min)
MAX6331L, V
TH(max)
MAX6330T/S, V
TH(min)
MAX6331T/S, V
TH(max)
0.4
0.3
V
0.3
0.3
0.8 x V
SHUNT
0.8 x V
SHUNT
0.8 x V
SHUNT
V
RESET/RESET Output
Voltage Low (Note 4)
V
OL
MAX6330, V
SHUNT
= 1V, I
SINK
=
50µA, T
A
= 0°C to +70°C
MAX6330, V
SHUNT
= 1.2V, I
SINK
=
50µA, T
A
= -40°C to +85°C
I
SOURCE
= 800µA
MAX6331L, V
TH(min)
MAX6330L, V
TH(max)
MAX6331T/S, V
TH(min)
MAX6330T/S, V
TH(max)
RESET/RESET Output
Voltage High (Note 4)
V
OH
I
SOURCE
= 500µA
MAX6331, 1.8V < V
SHUNT
< V
TH(min)
,
I
SOURCE
= 150µA
Note 1:
It is recommended that the regulation voltage be measured using a 4-wire force-sense technique when operating at high
shunt currents. For operating at elevated temperatures, the device must be derated based on a +150°C maximum allowed
junction temperature and a maximum thermal resistance of 0.25°C/mW junction to ambient when soldered on a printed cir-
cuit board. The T
A
= +25°C specification over load is measured using a pulse test at 50mA with less than 5ms on time.
Note 2:
Minimum shunt current required for regulated V
SHUNT
.
Note 3:
Maximum shunt current required for regulated V
SHUNT
.
Note 4:
In a typical application where SHUNT serves as the system voltage regulator, note that both I
SOURCE
for V
OH
and I
SINK
for V
OL
come from V
SHUNT
(see the
Typical Operating Circuit).
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Maxim Integrated │ 3
MAX6330/MAX6331
Precision Shunt Regulators with
Reset in SOT23-3
Typical Operating Characteristics
(Typical Operating Circuit, C
L
= 0.1µF, I
LOAD
= 0mA, T
A
= +25°C, unless otherwise noted.)
NORMALIZED SHUNT VOLTAGE
vs. SHUNT CURRENT
MAX6330 TOC01
NORMALIZED SHUNT VOLTAGE
vs. TEMPERATURE
MAX6330 TOC02
SHUNT VOLTAGE OVERSHOOT (mV)
I
SHUNT
= 50mA
NORMALIZED SHUNT VOLTAGE
I
SHUNT
= 25mA
1.000
I
SHUNT
= 1mA
0.995
NORMALIZED SHUNT VOLTAGE
35
30
25
20
15
10
5
0
0.0047 0.01
0.1
LOAD CAPACITANCE (µF)
I
SHUNT
= 1mA TO 1mA
I
SHUNT
= 0.1mA TO 5mA
I
SHUNT
= 5mA TO 50mA
1.000
T
A
= +25°C
T
A
= -40°C
0.995
T
A
= +85°C
0.990
0.01
0.1
1
10
50
0.990
-40
-20
0
20
40
60
80
1
SHUNT CURRENT (mA)
TEMPERATURE (°C)
NORMALIZED RESET THRESHOLD
vs. TEMPERATURE
MAX6330 TOC04
POWER-UP RESET TIMEOUT
vs. TEMPERATURE
POWER-UP RESET TIMEOUT (ms)
MAX6330 TOC03
1.010
NORMALIZED RESET THRESHOLD
160
150
140
130
120
110
100
1.005
1.000
0.995
0.990
-40
-20
0
20
40
60
80
-40
-20
0
20
40
60
80
TEMPERATURE (°C)
TEMPERATURE (°C)
MAX6330 TOC06
SHUNT CURRENT (mA)
40
30
20
10
1
UNSTABLE REGION
RECOMMENDED
CAPACITOR
OPERATING
REGION
R
S
= 15kΩ
V
IN
50V/div
RECOMMENDED
CAPACITOR
RECOMMENDED
CAPACITANCE
V
SHUNT
2V/div
0
0.001
0.01
0.1
1
LOAD CAPACITANCE (µF)
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MAX6330 TOC07
50
STABILITY BOUNDARY CONDITIONS
START-UP TRANSIENT
Maxim Integrated │ 4
MAX6330 TOC5
1.005
1.005
40
SHUNT VOLTAGE OVERSHOOT
vs. BYPASS CAPACITANCE (C
L
)
MAX6330/MAX6331
Precision Shunt Regulators with
Reset in SOT23-3
Pin Description
PIN
MAX6330 MAX6331
1
2
—
3
1
—
2
3
NAME
GND
RESET
RESET
SHUNT
Ground
Inverting Reset Output.
RESET
remains low while V
SHUNT
is below the reset threshold and
for 140ms after V
SHUNT
rises above the threshold.
Noninverting Reset Output. RESET remains high while V
SHUNT
is below the reset threshold
and for 140ms after V
SHUNT
rises above the threshold.
Regulated Shunt Voltage (+5V, +3.3V, or +3.0V)
FUNCTION
Detailed Description
Reset Output
A microprocessor’s (µP’s) reset input starts the µP in a
known state. The MAX6330/MAX6331 µP supervisory cir-
cuits assert reset to prevent code-execution errors during
power-up, power-down, or brownout conditions.
RESET
is guaranteed to be a logic low for V
SHUNT
> 1V.
Once V
SHUNT
exceeds the reset threshold, an internal
timer keeps
RESET
low for the reset timeout period; after
this interval,
RESET
goes high.
If a brownout condition occurs (V
SHUNT
dips below the
reset threshold),
RESET
goes low. When V
SHUNT
falls
below the reset threshold, the internal timer resets to
zero and
RESET
goes low. The internal timer starts after
VSHUNT returns above the reset threshold, and
RESET
then remains low for the reset timeout period.
The MAX6331 has an active-high RESET output that is
the inverse of the MAX6330’s
RESET
output.
Consider the following information when choosing the
external resistor R
S
:
1) The input voltage range, (V
IN
)
2) The regulated voltage, (V
SHUNT
)
3) The output current range, (I
LOAD
)
Choose R
S
as follows:
(V
IN(max)
- V
SHUNT (min)
) / (50mA + I
LOAD(min)
) ≤ R
S
≤
(V
IN(min)
- V
SHUNT (max)
) / (100µA + I
LOAD(max)
)
Choose the largest nominal resistor value for R
S
that
gives the lowest current consumption. Provide a safety
margin to incorporate the worst-case tolerance of the
V
IN
I
IN
R
S
I
SHUNT
V
SHUNT
C
L
SHUNT
I
LOAD
Shunt Regulator
The shunt regulator consists of a pass device and a
controlling circuit, as illustrated in Figure 1. The pass
device allows the regulator to sink current while regu-
lating the desired output voltage within a ±1.5% toler-
ance. The shunt current range (I
SHUNT
) is 100µA to
50mA.
The pass transistor in the MAX6330/MAX6331 maintains