AP331A
SINGLE DIFFERENTIAL COMPARATOR
Features
•
•
•
•
•
•
•
•
•
•
•
Wide supply
Voltage range: 2.0V to 36V
Single or dual supplies: ±1.0V to ±18V
Very low supply current drain (0.4mA) – independent of
supply voltage
Low input biasing current: 150nA
Low input offset current: ±70nA
Low input offset voltage: ±4mV
Input common-mode voltage range includes ground
Differential input voltage range equal to the power
supply voltage
Low output saturation voltage: 250mV at 4mA
Output voltage compatible with TTL, DTL, ECL, MOS
and CMOS logic systems
SOT25 and SOT25R: Available in “Green” Molding
Compound (No Br, Sb)
Lead Free Finish/ RoHS Compliant (Note 1)
General Description
The AP331A is a precision voltage comparators with an offset
voltage specification as low as 8.0 mV max for comparator which
were designed specifically to operate from a single power supply
over a wide range of voltages. Operation from split power
supplies is also possible and the low power supply current drain
is independent of the magnitude of the power supply voltage. The
comparator also have a unique characteristic in that the input
common-mode voltage range includes ground, even though
operated from a single power supply voltage.
Application areas include limit comparators, simple analog to
digital converters; pulse, square wave and time delay generators;
wide range VCO; MOS clock timers; multivibrators and high
voltage digital logic gates. The AP331A is designed to directly
interface with TTL and CMOS. When operated from both plus
and minus power supplies, the AP331A will directly interface with
MOS logic where their low power drain is a distinct advantage
over standard comparators.
Applications
•
•
•
•
•
•
High precision comparators
Reduced V
OS
drift over temperature
Eliminates need for dual supplies
Allows sensing near ground
Compatible with all forms of logic
Power drain suitable for battery operation
Ordering Information
AP331A XX G - 7
Package
W : SOT25
WR : SOT25R
Lead Free
G : Green
Packing
7 : Tape & Reel
Device
AP331AWG-7
AP331AWRG-7
Notes:
Package
Code
W
WR
Packaging
(Note 2)
SOT25
SOT25R
7” Tape and Reel
Quantity
Part Number Suffix
3000/Tape & Reel
-7
3000/Tape & Reel
-7
1. EU Directive 2002/95/EC (RoHS). All applicable RoHS exemptions applied. Please visit our website at
http://www.diodes.com/products/lead_free.html.
2. Pad layout as shown on Diodes Inc. suggested pad layout document AP02001, which can be found on our website at
http://www.diodes.com/datasheets/ap02001.pdf.
AP331A Rev. 2
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AP331A
SINGLE DIFFERENTIAL COMPARATOR
Pin Assignments
(1) SOT25
(2) SOT25R
( Top View )
IN-
GND
IN+
1
2
3
4 Output
5 Vcc
IN+
GND
IN-
1
2
3
( Top View )
5 Vcc
4 Output
Pin Descriptions
Pin Name
IN-
GND
IN+
Output
Vcc
Pin No.
SOT25R
SOT25
1
3
2
3
4
5
2
1
4
5
Description
Input-
Ground
Input+
Output
Power Supply
Block Diagram
V
+
3.5μA
100μA
3.5μA
100μA
Q2
+INPUT
Q1
Q3
Q4
Q5
OUTPUT
-INPUT
Q6
Q8
Q7
AP331A Rev. 2
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Diodes Incorporated
AP331A
SINGLE DIFFERENTIAL COMPARATOR
Absolute Maximum Ratings
Symbol
V
CC
V
IN
V
IN
I
CC
P
D
T
J
T
ST
Parameter
Supply Voltage
Differential Input Voltage
(Note 10)
Input Voltage
Input Current (V
IN
-0.3V)
(Note 5)
Power Dissipation
(Note 3)
Output Short-Circuit to Ground
(Note 4)
Operating Junction Temperature Range
Storage Temperature Range
SOT25
SOT25R
Rating
40
40
-0.3 to +40
50
740
Continuous
+150
-65 to +150
Unit
V
V
V
mA
mW
o
o
C
C
Recommended Operating Conditions
Symbol
V
CC
V
CC
V
IN
V
IN
T
A
Parameter
Supply Voltage (Single)
Supply Voltage (Dual Supplies, V
+
VS GND)
Differential Input Voltage (Single)
(Note 10)
Differential Input Voltage (Dual Supplies)
(Note 10)
Operating Ambient Temperature
Min
+2
±1
0
-18
0
Max
+36
±18
±36
+18
70
Unit
V
V
V
V
o
C
Electrical Characteristics
(V
CC
= 5V, T
A
= 25
o
C, unless otherwise stated)
Symbol
Parameter
Conditions
(Note 11)
V
OFFSET
Input Offset Voltage
I
IN
(+) or I
IN
(-) with Output In
I
BIAS
Input Bias Current
Linear Range, V
CM
= 0V
(Note 7)
I
OFFSET
Input Offset Current
I
IN
(+) - I
IN
(-) V
CM
= 0V
Input Common Mode Voltage
V
+
= 30V
(Note 8)
Range
+
V = 5V
I
CC
Supply Current
R
L
=
∞
V
+
= 36V
R
L
> 15kΩ, V
+
= 15V
Voltage Gain
V
O
= 1V to 11V
V
IN
= TTL Logic Swing,
V
REF
= 1.4V, V
RL
= 5V,
Large Signal Response Time
R
L
= 5.1kΩ
V
RL
= 5V, R
L
= 5.1kΩ
Response Time
(Note 9)
V
IN
(-) = 1V, V
IN
(+) = 0,
I
O(Sink)
Output Sink Current
V
O
< 1.5V
V
IN
(-) = 1V, V
IN
(+) = 0,
V
SAT
Saturation Voltage
I
SINK
< 4mA
V
IN
(-) = 0, V
IN
(+) = 1V,
I
O(Leak)
Output Leakage Current
V
O
= 5V
AP331A Rev. 2
Min
-
-
-
0
-
-
50
-
-
6.0
-
-
Typ.
4.0
150
70
-
0.4
1
200
300
1.3
16
250
0.1
Max
8.0
400
150
V
+
-1.5
1
2.5
-
-
-
-
400
-
Unit
mV
nA
nA
V
mA
V/mV
ns
μs
mA
mV
nA
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AP331A
SINGLE DIFFERENTIAL COMPARATOR
Electrical Characteristics
( V
CC
= 5V ) ( Note 6 )
Symbol
Parameter
V
OFFSET
Input Offset Voltage
I
OFFSET
Input Offset Current
I
BIAS
Input Bias Current
Input Common Mode Voltage
Range
V
SAT
I
O(Leak)
Saturation Voltage
Output Leakage Current
Differential Input Voltage
θ
JA
θ
JC
Notes:
Conditions
(Note 11)
I
IN
(+) -I
IN
(-), V
CM
= 0V
I
IN
(+) or I
IN
(-) with Output In
Linear Range, V
CM
= 0V
(Note 7)
V
+
=30V
(Note 8)
V
IN
(-) = 1V, V
IN
(+) = 0, I
SINK
<
4mA
V
IN
(-) = 0, V
IN
(+) = 1V,
V
O
= 30V
Keep All V
IN
’s > 0V (or V
-
, if
Used),
(Note 10)
SOT25
(Note 12)
SOT25R
(Note 12)
SOT25
(Note 12)
SOT25R
(Note 12)
Min
-
-
-
0
-
-
-
Typ.
-
-
-
-
-
-
-
173
37
Max
9
200
500
V
+
-2.0
700
1.0
36
Unit
mV
nA
nA
V
mV
μA
V
o
Thermal Resistance
Junction-to-Ambient
Thermal Resistance
Junction-to-Case
C/W
C/W
o
3. The maximum power dissipation is a function of T
J(MAX)
,
θ
JA
. The maximum allowable power dissipation at any ambient temperature is
P
D
= (T
J(MAX)
-T
A
)/
θ
JA
. All numbers apply for packages soldered directly onto a PC board.
4. Short circuits from the output to V
+
can cause excessive heating and eventual destruction. When considering short circuits to
ground, the maximum output current is approximately 20mA independent of the magnitude of V
+
.
5. This input current will only exist when the voltage at any of the input leads is driven negative. It is due to the collector-base
junction of the input PNP transistors becoming forward biased and thereby acting as input diode clamps. In addition to this
diode action, there is also lateral NPN parasitic transistor action on the IC chip. This transistor action can cause the output
voltages of the comparators to go to the V
+
voltage level (or to ground for a large overdrive) for the time duration that an input
is driven negative. This is not destructive and normal output states will re-establish when the input voltage, which is negative,
again returns to a value greater than -0.3V.
6. The AP331A temperature specifications are limited to 0°C < T
OP
< +70°C.
7. The direction of the input current is out of the IC due to the PNP input stage. This current is essentially constant, independent
of the state of the output so no loading change exists on the reference or input lines.
8. The input common-mode voltage or either input signal voltage should not be allowed to go negative by more than 0.3V. The
upper end of the common-mode voltage range is V
+
-1.5V at 25°C, but either or both inputs can go to 36V without damage,
independent of the magnitude of V
+
.
9. The response time specified is for a 100mV input step with 5mV overdrive. For larger overdrive signals 300ns can be
obtained, see typical performance characteristics section.
10. Positive excursions of input voltage may exceed the power supply level. As long as the other voltage remains within the
common-mode range, the comparator will provide a proper output state. The low input voltage state must not be less than
-0.3V (or 0.3V below the magnitude of the negative power supply, if used).
+
+
11. At output switch point, V
O
~ 1.4V, R
S
=0Ω with V from 5V to 30V; and over the full input common-mode range (0V to V -1.5V),
at 25°C.
12. Test condition for SOT25 and sot25R: Device mounted on FR-4 substrate PC board, 2oz copper, with minimum recommended pad layout.
AP331A Rev. 2
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AP331A
SINGLE DIFFERENTIAL COMPARATOR
Application Information
The AP331A is high gain, wide bandwidth devices, like most comparators, can easily oscillate if the output lead is inadvertently
allowed to capacitively couple to the inputs via stray capacitance. This shows up only during the output voltage transition intervals as the
comparator change states. Power supply bypassing is not required to solve this problem. Standard PC board layout is helpful as it
reduces stray input-output coupling. Reducing the input resistors to < 10kΩ reduces the feedback signal levels and finally, adding even a
small amount (1.0 to 10 mV) of positive feedback (hysteresis) causes such a rapid transition that oscillations due to stray feedback are
not possible. Simply socketing the IC and attaching resistors to the pins will cause input-output oscillations during the small transition
intervals unless hysteresis is used. If the input signal is a pulse waveform, with relatively fast rise and fall times, hysteresis is not required.
All input pins of any unused comparators should be tied to the negative supply.
The bias network of the AP331A establishes a drain current independent of the magnitude of the power supply voltage over the
range of from 2.0 V
DC
to 30 V
DC
. It is usually unnecessary to use a bypass capacitor across the power supply line.
The differential input voltage may be larger than V+ without damaging the device (Note 10). Protection should be provided to
prevent the input voltages from going negative more than -0.3 V
DC
(at 25°C). An input clamp diode can be used as shown in the
applications section.
The output of the AP331A is the uncommitted collector of a grounded-emitter NPN output transistor. Many collectors can be tied
together to provide an output OR’ing function. An output pull-up resistor can be connected to any available power supply voltage within
the permitted supply voltage range and there is no restriction on this voltage due to the magnitude of the voltage applied to the
+
V terminal of the AP331A package. The output can also be used as a simple SPST switch to ground (when a pull-up resistor is not used).
+
The amount of current the output device can sink is limited by the drive available (which is independent of V ) and the
β
of this device.
When the maximum current limit is reached (approximately 16mA), the output transistor will come out of saturation and the output voltage
will rise very rapidly. The output saturation voltage is limited by the approximately 60Ω r
SAT
of the output transistor. The low offset voltage
of the output transistor (1.0 mV) allows the output to clamp essentially to ground level for small load currents.
Typical Circuit
( V
CC
= 5.0V
DC
)
V
+
+5.0V
DC
+V
IN
+
3.0K
V
O
+
100K
+V
REF
-
-
1/4 MM54CXX
AP331A Rev. 2
5 of 13
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