CIRRUS PA243

PA243
PA243
P r o d PA243
u c t IInnnnoovvaa t i o n FFr roomm
High Voltage Power Operational Amplifier
FEATURES
• RoHS COMPLIANT
• SURFACE MOUNT PACKAGE
• MONOLITHIC MOS TECHNOLOGY
• LOW COST
• HIGH VOLTAGE OPERATION—350V
• LOW QUIESCENT CURRENT TYP.—2.2mA
• NO SECOND BREAKDOWN
• HIGH OUTPUT CURRENT—120 mA PEAK
APPLICATIONS
• TELEPHONE RING GENERATOR
• PIEZO ELECTRIC POSITIONING
• ELECTROSTATIC TRANSDUCER & DEFLECTION
• DEFORMABLE MIRROR FOCUSING
24-pin PSOP
PACKAGE STYLE DF
EQUIVALENT SCHEMATIC (one of two channels)
+VS
DESCRIPTION
Q1
The PA243 is a dual high voltage monolithic MOSFET operational amplifier achieving performance features previously
found only in hybrid designs while increasing reliability. This
approach provides a cost-effective solution to applications
where multiple amplifiers are required. Inputs are protected
from excessive common mode and differential mode voltages. The safe operating area (SOA) has no secondary
breakdown limitations and can be observed with all type
loads by choosing an appropriate current limiting resistor.
External compensation provides the user flexibility in choosing
optimum gain and bandwidth for the application.
The PA243DF is packaged in a 24 pin PSOP (JEDEC
MO-166) package. The heatslug of the PA243DF package is
isolated in excess of full supply voltage.
Q2
Q3
C C1
Q4
C C2
+IN
Q5
Q7
-IN
ILIM
Q6
Q8
Q9
D4
D1
D2
Q13
D3
Q11
OUT
Q10
Q14
Q12
Q15
D5
-VS
TYPICAL APPLICATION
20R
+175
*
+175
10pF
A
PA243
EXTERNAL CONNECTIONS
20R
R CL
47
–175
NC
B
PA243
PIEZO
TRANSDUCER 47
RCL
RN
A
-
OUTa
CN
+INb
–175
*
NC
+INa
-INa
NC
OUTb
NC
-INb
-Vsa
NC
+
COMPa
CC
B
COMPb
RCL
COMPb
ILb
CC
NC
Low Cost 660v p-p Piezo Drive
A single PA243 amplifier operates as a bridge driver for a piezo
transducer providing a low cost 660 volt total drive capability.
The RN CN network serves to raise the apparent gain of A2 at
high frequencies. If RN is set equal to R the amplifiers can be
compensated identically and will have matching bandwidths.
See application note 20 for more details.
http://www.cirrus.com
24
COMPa
*
PA243U
1
La
10pF
R CL
+Vsa
-
VIN
20R
+
R
-Vsb
+Vsb
*
For CC values, see graph on page 3.
Note: CC must be rated for full supply voltage.
* Supply bypassing required. See general Operating Considerations.
Copyright © Cirrus Logic, Inc. 2009
(All Rights Reserved)
MAY 20091
APEX − PA243UREVG
PA243
P r o d u c t I n n o v a t i o nF r o m
ABSOLUTE MAXIMUM RATINGS
SUPPLY VOLTAGE, +VS to –VS
OUTPUT CURRENT, continuous within SOA
OUTPUT CURRENT, peak
POWER DISSIPATION, continuous @ TC = 25°C
INPUT VOLTAGE, differential
INPUT VOLTAGE, common mode
TEMPERATURE, pin solder – 10 sec
TEMPERATURE, junction2
TEMPERATURE, storage
TEMPERATURE RANGE, powered (case)
SPECIFICATIONS
PARAMETER
TEST CONDITIONS1
INPUT
OFFSET VOLTAGE, initial
OFFSET VOLTAGE, vs. temperature3
OFFSET VOLTAGE, vs. temperature3
OFFSET VOLTAGE, vs supply
OFFSET VOLTAGE, vs time
BIAS CURRENT, initial
BIAS CURRENT, vs supply
OFFSET CURRENT, initial
INPUT IMPEDANCE, DC
INPUT CAPACITANCE
COMMON MODE, voltage range
COMMON MODE, voltage range
COMMON MODE REJECTION, DC
NOISE, broad band
NOISE, low frequency
GAIN
OPEN LOOP at 15Hz
BANDWIDTH, gain bandwidth product
POWER BANDWIDTH
OUTPUT
VOLTAGE SWING
CURRENT, peak3
CURRENT, continuous
SETTLING TIME to .1%
SLEW RATE
RESISTANCE4, 1mA
RESISTANCE4, 40 mA
25°C to 85°C
-25°C to25°C
VCM = ±90V DC
10kHz BW, RS = 1K
1-10 Hz
RL = 5K
NOTES: 1.
2.
3.
4.
5.
6.
CAUTION
2
+VS–14
-VS+12
84
90
280V p-p
IO = 40mA
10V step, A V = –10
CC = 3.3pF
RCL = 0
RCL = 0
POWER SUPPLY
VOLTAGE
CURRENT, quiescent
THERMAL
RESISTANCE, junction to case
AC, single amplifier
DC, single amplifier
AC, both amplifiers5
DC, both amplifiers5
RESISTANCE, junction to air6
TEMPERATURE RANGE, case
MIN
±VS–12
120
60
±50
F > 60Hz
F < 60Hz
Full temperature range
Meets full range specifications
–25
TYP
350V
60 mA
120 mA
12W
±16 V
±VS
220°C
150°C
–65 to +150°C
–40 to +125°C
MAX
UNITS
25
40
100
250
270
500
3
70
130
50
200
2
50
200
1011
6
94
50
125
mV
µV/°C
µV/°C
µV/V
µV/kh
pA
pA/V
pA
pF
V
V
dB
µV RMS
µV p-p
96
3
30
dB
MHz
kHz
±VS–10
2
30
150
5
V
mA
mA
µs
V/µs
Ω
Ω
±150
2.2
±175
2.5
6
7
9
11
3.3
4.0
5.0
6.0
25
+85
V
mA
°C/W
°C/W
°C/W
°C/W
°C/W
°C
Unless otherwise noted TC = 25°C, CC = 6.8pF. DC input specifications are ± value given. Power supply voltage is typical rating.
Long term operation at the maximum junction temperature will result in reduced product life. Derate internal power dissipation
to achieve high MTTF. For guidance, refer to heatsink data sheet.
Guaranteed but not tested.
The selected value of RCL must be added to the values given for total output resistance.
Rating applies when power dissipation is equal in the two amplifiers.
Rating applies with solder connection of heatslug to a minimum 1in2 foil area of the printed circuit board.
The PA243 is constructed from MOSFET transistors. ESD handling procedures must be observed.
PA243U
PA243
POWER DERATING
0.95
Both Amplifiers
Single Amplifier
20
0.90
0.85
0.75
T = TC
0.65
T = TA
0.60
T = TA
0
20
40
60
80
TEMPERATURE, T (C)
0.50
-55 -35 -15 5 25 45 65 85 105 125
TEMPERATURE, (°C)
100
SMALL SIGNAL RESPONSE
PHASE, Ф (°)
15pF
68pF
-120
.75pF
-130
-140
68pF
6.8pF
-150
-160
0
10
15pF
-110
60
-170
-20
10
100
1K 10K 100K 1M
FREQUENCY, F (Hz)
-180
10K
10M
100K
1M
FREQUENCY, F (Hz)
10M
SLEW RATE
HARMONIC DISTORTION
0.01
AV = 20
CC = 15pF
RL = 2K
1K
10K
FREQUENCY, F (Hz)
COMMON MODE REJECTION
100
80
60
40
20
0
10
PA243U
10K
100
1K
FREQUENCY, F (Hz)
100K
15
0
0 10 20 30 40 50 60 70
COMPENSATION CAPACITANCE, CC (pF)
100K
120
25
TC = 55°C
1
TC = 25°C
POWER SUPPLY REJECTION
33pF
100
70
POSITIVE
60
50
68pF
10
10K
100K
FREQUENCY, F (Hz)
1M
QUIESCENT CURRENT
120
115
110
°C)
I Q (85
105
°C)
I Q (25
100
)
IQ (-25°C
95
90
85
80
100 150
200 250 300 350
TOTAL SUPPLY VOLTAGE, (V)
10
40
10
POWER RESPONSE
15pF
90
NEGATIVE
100
6.8pF
12
80
10
GAIN
.75pF
100
VDROP FROM VS, (V)
180V P-P
0.001
100
COMMON MODE REJECTION, CMR (dB)
60V P-P
SLEW RATE, (V/µs)
0.1
30V P-P
POWER SUPPLY REJECTION, PSR (dB)
DISTORTION, (%)
35
1
TC = 85°C
1000
-100
6.8pF
20
10
0.1
1
PHASE RESPONSE
-90
.75pF
80
40
TC = 125°C
0.55
OUTPUT VOLTAGE, (VOUT)(p-p)
0
VBE+
0.70
10
100
OPEN LOOP GAIN, A (dB)
VBE-
0.80
15
5
100
COMPENSATION, pF
T = TC
GAIN AND COMPENSATION
ILIMIT VS. TEMPERATURE
NORMALIZED QUIESCENT CURRENT (%)
25
VBE (V)
INTERNAL POWER DISSIPATION, P(W)
P r o d u c t I n n o v a t i o nF r o m
OUTPUT VOLTAGE SWING
VDROP- @85°C
VDROP+ @85°C
8
6
VDROP+ @25°C
VDROP- @25°C
4
2
100
1K
10K
FREQUENCY, F (Hz)
100K
0
0
20
40 60
80 100 120
OUTPUT CURRENT, IO (mA)
3
PA243
P r o d u c t I n n o v a t i o nF r o m
GENERAL
CURRENT LIMIT
Please read Application Note 1 "General Operating Considerations" which covers stability, power supplies, heat sinking,
mounting, current limit, SOA interpretation, and specification
interpretation. Visit www.Cirrus.com for design tools that help
automate tasks such as calculations for stability, internal power
dissipation, current limit, heat sink selection, Apex Precision
Power's complete Application Notes library, Technical Seminar
Workbook and Evaluation Kits.
For proper operation, the current limit resistor, Rcl, must be
connected as shown in the external connection diagram. The
minimum value is 3.9 ohms, however for optimum reliability,
the resistor should be set as high as possible. The maximum
practical value is 110 ohms. Current limit values can be predicted as follows:
Ilimit = Vbe
Rcl
Where Vbe is shown in the CURRENT LIMIT typical
graph.
Open loop gain and phase shift both increase with increasing temperature. The PHASE COMPENSATION typical graph
shows closed loop gain and phase compensation capacitor
value relationships for four case temperatures. The curves are
based on achieving a phase margin of 50°. Calculate the highest case temperature for the application (maximum ambient
temperature and highest internal power dissipation) before
choosing the compensation. Keep in mind that when working
with small values of compensation, parasitics may play a large
role in performance of the finished circuit. The compensation
capacitor must be rated for at least the total voltage applied
to the amplifier and should be a temperature stable type such
as NPO or COG.
OTHER STABILITY CONCERNS
There are two important concepts about closed loop gain
when choosing compensation. They stem from the fact that
while "gain" is the most commonly used term, β (the feedback
factor) is really what counts when designing for stability.
1. Gain must be calculated as a non-inverting circuit (equal
input and feedback resistors can provide a signal gain of
-1, but for calculating offset errors, noise, and stability, this
is a gain of 2).
2. Including a feedback capacitor changes the feedback factor
or gain of the circuit. Consider Rin=4.7k, Rf=47k for a gain
of 11. Compensation of 4.7 to 6.8pF would be reasonable.
Adding 33pF parallel to the 47k rolls off the circuit at 103kHz,
and at 2MHz has reduced gain from 11 to roughly 1.5 and
the circuit is likely to oscillate.
As a general rule the DC summing junction impedance
(parallel combination of the feedback resistor and all input
resistors) should be limited to 5k ohms or less. The amplifier
input capacitance of about 6pF, plus capacitance of connecting
traces or wires and (if used) a socket will cause undesirable
circuit performance and even oscillation if these resistances
are too high. In circuits requiring high resistances, measure or
estimate the total sum point capacitance, multiply by Rin/Rf, and
parallel Rf with this value. Capacitors included for this purpose
are usually in the single digit pF range. This technique results
in equal feedback factor calculations for AC and DC cases. It
does not produce a roll off, but merely keeps β constant over
a wide frequency range. Paragraph 6 of Application Note 19
details suitable stability tests for the finished circuit.
4
Note that +Vbe should be used to predict current through
the +Vs pin, -Vbe for current through the -Vs pin, and that they
vary with case temperature. Value of the current limit resistor
at a case temperature of 25° can be estimated as follows:
Rcl = 0.7
Ilimit
When the amplifier is current limiting, there may be spurious
oscillation present during the current limited portion of the negative half cycle. The frequency of the oscillation is not predictable
and depends on the compensation, gain of the amplifier, value
of the current limit resistor, and the load. The oscillation will
cease as the amplifier comes out of current limit.
SAFE OPERATING AREA
The MOSFET output stage of the PA243 is not limited by
second breakdown considerations as in bipolar output stages.
However there are still three distinct limitations:
1. Voltage withstand capability of the transistors.
2. Current handling capability of the die metalization.
3. Temperature of the output MOSFETS.
OUTPUT CURRENT FROM +VS or -VS, (mA)
PHASE COMPENSATION
200
PA243 SOA
120
100
50
40
30
20
10
5
4
3
20
30
0m
S
0m
S
DC
DC
DC
,T
C
,T
=
C
=
12
85
°C
5°
C
PULSE CURVES @
10% DUTY CYCLE MAX.
2
20 30 50
100
200 300 500
10
SUPPLY TO OUTPUT DIFFERENTIAL, VS- VO (V)
PA243U
PA243
P r o d u c t I n n o v a t i o nF r o m
These limitations can be seen in the SOA (see Safe Operating Area graphs). Note that each pulse capability line shows
a constant power level (unlike second breakdown limitations
where power varies with voltage stress). These lines are shown
for a case temperature of 25°C and correspond to thermal resistances of 5.2°C/W for the PA243DF. Pulse stress levels for
other case temperatures can be calculated in the same manner
as DC power levels at different temperatures. The output stage
is protected against transient flyback by the parasitic diodes of
the output stage MOSFET structure. However, for protection
against sustained high energy flyback external fast-recovery
diodes must be used.
HEATSINKING
The PA243DF package has a large exposed integrated
copper heatslug to which the monolithic amplifier is directly
attached. The solder connection of the heatslug to a minimum
of 1 square inch foil area on the printed circuit board will result
in thermal performance of 25°C/W junction to air rating of the
PA243DF. Solder connection to an area of 1 to 2 square inches
is recommended. This may be adequate heatsinking but the
large number of variables involved suggest temperature measurements be made on the top of the package. Do not allow
the temperature to exceed 85°C.
In the case of inverting circuits where the +IN pin is grounded,
the diodes mentioned above will also afford protection from
excessive common mode voltage. In the case of non-inverting circuits, clamp diodes from each input to each supply will
provide protection. Note that these diodes will have substantial
reverse bias voltage under normal operation and diode leakage will produce errors.
Some applications will also need over-voltage protection
devices connected to the power supply rails. Unidirectional
zener diode transient suppressors are recommended. The
zeners clamp transients to voltages within the power supply rating and also clamp power supply reversals to ground.
Whether the zeners are used or not the system power supply should be evaluated for transient performance including
power-on overshoot and power-off polarity reversals as well
as line regulation. See Z1 and Z2 in Figure 1.
APPLICATION REFERENCES:
For additional technical information please refer to the following Application Notes:
AN1: General Operating Considerations
AN3: Bridge Circuit Drives
AN25: Driving Capacitive Loads
AN38: Loop Stability with Reactive Loads
FIGURE 1
+Vs
+Vs
-IN
Q1
+IN
Z1
OUT
Q2
-Vs
-Vs
Z2
OVERVOLTAGE PROTECTION
Although the PA241 can withstand differential input voltages
up to 16V, in some applications additional external protection
may be needed. Differential inputs exceeding 16V will be clipped
by the protection circuitry. However, if more than a few milliamps
of current is available from the overload source, the protection
circuitry could be destroyed. For differential sources above
16V, adding series resistance limiting input current to 1mA will
prevent damage.Alternatively, 1N4148 signal diodes connected
anti-parallel across the input pins is usually sufficient. In more
demanding applications where bias current is important, diode
connected JFETs such as 2N4416 will be required. See Q1
and Q2 in Figure 1. In either case the differential input voltage
will be clamped to 0.7V. This is sufficient overdrive to produce
the maximum power bandwidth.
PA243U
5
PA243
P r o d u c t I n n o v a t i o nF r o m
Contacting Cirrus Logic Support
For all Apex Precision Power product questions and inquiries, call toll free 800-546-2739 in North America.
For inquiries via email, please contact [email protected]
International customers can also request support by contacting their local Cirrus Logic Sales Representative.
To find the one nearest to you, go to www.cirrus.com
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Cirrus Logic, Inc. and its subsidiaries ("Cirrus") believe that the information contained in this document is accurate and reliable. However, the information is subject
to change without notice and is provided "AS IS" without warranty of any kind (express or implied). Customers are advised to obtain the latest version of relevant
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for the use of this information, including use of this information as the basis for manufacture or sale of any items, or for infringement of patents or other rights of third
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does not extend to other copying such as copying for general distribution, advertising or promotional purposes, or for creating any work for resale.
CERTAIN APPLICATIONS USING SEMICONDUCTOR PRODUCTS MAY INVOLVE POTENTIAL RISKS OF DEATH, PERSONAL INJURY, OR SEVERE PROPERTY OR ENVIRONMENTAL DAMAGE (“CRITICAL APPLICATIONS”). CIRRUS PRODUCTS ARE NOT DESIGNED, AUTHORIZED OR WARRANTED TO BE
SUITABLE FOR USE IN PRODUCTS SURGICALLY IMPLANTED INTO THE BODY, AUTOMOTIVE SAFETY OR SECURITY DEVICES, LIFE SUPPORT PRODUCTS OR OTHER CRITICAL APPLICATIONS. INCLUSION OF CIRRUS PRODUCTS IN SUCH APPLICATIONS IS UNDERSTOOD TO BE FULLY AT THE CUSTOMER’S RISK AND CIRRUS DISCLAIMS AND MAKES NO WARRANTY, EXPRESS, STATUTORY OR IMPLIED, INCLUDING THE IMPLIED WARRANTIES OF
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CUSTOMER OR CUSTOMER’S CUSTOMER USES OR PERMITS THE USE OF CIRRUS PRODUCTS IN CRITICAL APPLICATIONS, CUSTOMER AGREES,
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All other brand and product names in this document may be trademarks or service marks of their respective owners.
6
PA243U