APEX MICROTECHNOLOGY CORPORATION TELEPHONE (520) 690-8600 FAX (520) 888-3329 ORDERS (520) 690-8601 EMAIL prodlit@apexmicrotech.com
1
FEATURES
MONOLITHIC MOS TECHNOLOGY
LOW COST
HIGH VOLTAGE OPERATION—350V
LOW QUIESCENT CURRENT TYP.—2.2mA
NO SECOND BREAKDOWN
HIGH OUTPUT CURRENT—120mA PEAK
AVAILABLE IN DIE FORM—CPA241
APPLICATIONS
PIEZO ELECTRIC POSITIONING
ELECTROSTATIC TRANSDUCER & DEFLECTION
DEFORMABLE MIRROR FOCUSING
BIOCHEMISTRY STIMULATORS
COMPUTER TO VACUUM TUBE INTERFACE
DESCRIPTION
The PA241 is a high voltage monolithic MOSFET operational
amplifier which achieves performance features previously
found only in hybrid designs while increasing reliability. Inputs
are protected from excessive common mode and differential
mode voltages. The safe operating area (SOA) has no second
breakdown limitation 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 PA241CE is packaged in a hermetically sealed 8-pin
TO-3 package. The metal case of the PA241CE is isolated in
excess of full supply voltage.
The PA241DF is packaged in a 24 pin PSOP (JEDEC MO-
166) package. The metal heat slug of the PA241DF is isolated
in excess of full supply voltage.
The PA241DW is packaged in Apex’s hermetic ceramic SIP
package. The alumina ceramic isolates the die in excess of
full supply voltage.
EQUIVALENT SCHEMATIC
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LOW COST 660V p-p
PIEZO DRIVE
Two PA241 amplifiers operated as a bridge driver for a piezo
transducer provides 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.
EXTERNAL CONNECTIONS
RCL
14567
3
28910
CC
+IN-IN
NC NC -VS+VSILIM CC2 CC1 OUT
PA241DW
RCL
TOP VIEW
1
2
3
4
5
67
8
OUT
ILIM
–VS
+VS
CC1
–IN
+IN
CC2
CC
NOTE: PA241CE Recommended mounting torque is 4-7
in•lbs (.45 -.79 N•m)
CAUTION: The use of compressible, thermally conductive
insulators may void warranty.
PA241CE
8-PIN TO-3 24-PIN PSOP 10-PIN SIP
PACKAGE STYLE CE PACKAGE STYLE DF PACKAGE STYLE DW
ILIM
OUT
-IN
+IN
+VS
-VS
CC2
CC1
TYPICAL APPLICATION
Ref: APPLICATION NOTE 20: "Bridge Mode Operation of Power Ampliers"
CCRCL
NC
NC
NC
NC
-IN
NC
+IN
NC
NC
NC
NC
-VS
NC
NC
NC
OUT
NC
COMP
NC
COMP
NC
ILIM
NC
+VS
24
1
+
-
PA241DF
For CC values, see graph on page 4.
Note: CC must be rated for full supply
voltage.
APEX MICROTECHNOLOGY CORPORATION 5980 NORTH SHANNON ROAD TUCSON, ARIZONA 85741 USA APPLICATIONS HOTLINE: 1 (800) 546-2739
2
ABSOLUTE MAXIMUM RATINGS
SPECIFICATIONSPA241
ABSOLUTE MAXIMUM RATINGS PA241CE PA241DF
PA241CEA PA241DFA
SUPPLY VOLTAGE, +VS to –VS 350V 350V
OUTPUT CURRENT, continuous within SOA 60 mA 60 mA
OUTPUT CURRENT, peak 120 mA 120 mA
POWER DISSIPATION, continuous @ TC = 25°C 12W 12W
INPUT VOLTAGE, differential ±16 V ±16 V
INPUT VOLTAGE, common mode ±VS ±VS
TEMPERATURE, pin solder – 10 sec 300°C 220°C
TEMPERATURE, junction2 150°C 150°C
TEMPERATURE, storage –65 to +150°C –65 to +150°C
TEMPERATURE RANGE, powered (case) –40 to +125°C –40 to +125°C
CAUTION The PA241 is constructed from MOSFET transistors. ESD handling procedures must be observed.
PA241CE, PA241DF PA241CEA
PARAMETER TEST CONDITIONS1 MIN TYP MAX MIN TYP MAX UNITS
INPUT
OFFSET VOLTAGE, initial 25 40 15 30 mV
OFFSET VOLTAGE, vs. temperature3 Full temperature range 100 500 * * µV/°C
OFFSET VOLTAGE, vs supply 3 * µV/V
OFFSET VOLTAGE, vs time 70 130 * * µV/kh
BIAS CURRENT, initial6 5/50 50/200
* * pA
BIAS CURRENT, vs supply 0.2/2 * pA/V
OFFSET CURRENT, initial6 2.5/50 50/200 * * pA
INPUT IMPEDANCE, DC 1011 *
INPUT CAPACITANCE 6 * pF
COMMON MODE, voltage range +VS–14 * V
COMMON MODE, voltage range -VS+12 * V
COMMON MODE REJECTION, DC VCM = ±90V DC 84 94 * * dB
NOISE, broad band 10kHz BW, RS = 1K 50 * µV RMS
NOISE, low frequency 1-10 Hz 125 * µV p-p
GAIN
OPEN LOOP at 15Hz RL = 5K 90 96 * * dB
BANDWIDTH, gain bandwidth product 3 * MHz
POWER BANDWIDTH 280V p-p 30 * kHz
OUTPUT
VOLTAGE SWING IO = 40mA ±VS–12 ±VS–10 ±VS–10 ±VS–8.5
V
CURRENT, peak4 120 * mA
CURRENT, continuous 60 * mA
SETTLING TIME to .1% 10V step, A V = –10 2 * µs
SLEW RATE CC = 3.3pF 30 * V/µs
RESISTANCE5, 1mA RCL = 0 150 *
RESISTANCE5, 40 mA RCL = 0 5 *
POWER SUPPLY
VOLTAGE ±50 ±150 ±175 * * * V
CURRENT, quiescent 2.2 2.5 * 2.3 mA
THERMAL
PA241CE RESIS
TANCE, AC junction to case F > 6
0Hz 5.4 6.5 * * °C/W
PA241DF RESIS
TANCE, AC junction to case F > 6
0Hz 6 7 * * °C/W
PA241CE RESIS
TANCE, DC junction to case F < 6
0Hz 9 10.4 * * °C/W
PA241DF RESIS
TANCE, DC junction to case F < 6
0Hz 9 11 * * °C/W
PA241CE RESISTANCE, junction to air Full temperature range 30 * °C/W
PA241DF RESISTANCE, junction to air7 Full temperature range 25 * °C/W
TEMPERATURE RANGE, case Meets full range spec's –25 +85 * * °C
SPECIFICATIONS
NOTES: * "A" specification is the same as the non "A" specification.
1. Unless otherwise noted TC = 25°C, CC = 6.8pF. DC input specifications are ± value given. Power supply voltage is typical
rating.
2. 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.
3. Sample tested by wafer to 95%.
4. Guaranteed but not tested.
5. The selected value of RCL must be added to the values given for total output resistance.
6. Specifications separated by / indicate values for the PA241CE and PA241DF respectively.
7. Rating applies with solder connection of heatslug to a minimum 1 square inch foil area of the printed circuit board.
APEX MICROTECHNOLOGY CORPORATION TELEPHONE (520) 690-8600 FAX (520) 888-3329 ORDERS (520) 690-8601 EMAIL prodlit@apexmicrotech.com
3
ABSOLUTE MAXIMUM RATINGS
SPECIFICATIONS PA241
CAUTION The PA241 is constructed from MOSFET transistors. ESD handling procedures must be observed.
ABSOLUTE MAXIMUM RATINGS PA241DW
PA241DWA
SUPPLY VOLTAGE, +VS to –VS 350V
OUTPUT CURRENT, continuous within SOA 60 mA
OUTPUT CURRENT, peak 120 mA
POWER DISSIPATION, continuous @ TC = 25°C 9W
INPUT VOLTAGE, differential ±16 V
INPUT VOLTAGE, common mode ±VS
TEMPERATURE, pin solder – 10 sec 220°C
TEMPERATURE, junction2 150°C
TEMPERATURE, storage –65 to +150°C
TEMPERATURE RANGE, powered (case) –40 to +125°C
PA241DW PA241DWA
PARAMETER TEST CONDITIONS1 MIN TYP MAX MIN TYP MAX UNITS
INPUT
OFFSET VOLTAGE, initial 25 40 15 30 mV
OFFSET VOLTAGE, vs. temperature3 Full temperature range 100 500 * * µV/°C
OFFSET VOLTAGE, vs supply 3 * µV/V
OFFSET VOLTAGE, vs time 70 130 * µV/kh
BIAS CURRENT, initial 100 2000
* * pA
BIAS CURRENT, vs supply 15 50 * * pA/V
OFFSET CURRENT, initial 100 400 * * pA
INPUT IMPEDANCE, DC 1011 *
INPUT CAPACITANCE 6 * pF
COMMON MODE, voltage range +VS–14 * V
COMMON MODE, voltage range -VS+12 * V
COMMON MODE REJECTION, DC VCM = ±90V DC 84 94 * * dB
NOISE, broad band 10kHz BW, RS = 1K 50 * µV RMS
NOISE, low frequency 1-10 Hz 125 * µV p-p
GAIN
OPEN LOOP at 15Hz RL = 5K 90 96 * * dB
BANDWIDTH, gain bandwidth product 3 * MHz
POWER BANDWIDTH 280V p-p 30 * kHz
OUTPUT
VOLTAGE SWING IO = 40mA ±VS–12 ±VS–10 ±VS–10 ±VS–8.5
V
CURRENT, peak4 120 * mA
CURRENT, continuous 60 * mA
SETTLING TIME to .1% 10V step, A V = –10 2 * µs
SLEW RATE CC = 3.3pF 30 * V/µs
RESISTANCE5, 1mA RCL = 0 150 *
RESISTANCE5, 40 mA RCL = 0 5 *
POWER SUPPLY
VOLTAGE ±50 ±150 ±175 * * * V
CURRENT, quiescent 2.2 2.5 * 2.3 mA
THERMAL
PA241DW RESIS
TANCE, AC junction to case F > 6
0Hz 7 10 * * °C/W
PA241DW RESIS
TANCE, DC junction to case F < 6
0Hz 12 14 * * °C/W
PA241DW RESISTANCE, junction to air Full temperature range 55 * °C/W
TEMPERATURE RANGE, case Meets full range spec's –25 +85 * * °C
SPECIFICATIONS
NOTES: * "A" specification is the same as the non "A" specification.
1. Unless otherwise noted TC = 25°C, CC = 6.8pF. DC input specifications are ± value given. Power supply voltage is typical
rating.
2. 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.
3. Sample tested by wafer to 95%.
4. Guaranteed but not tested.
5. The selected value of RCL must be added to the values given for total output resistance.
APEX MICROTECHNOLOGY CORPORATION 5980 NORTH SHANNON ROAD TUCSON, ARIZONA 85741 USA APPLICATIONS HOTLINE: 1 (800) 546-2739
4
TYPICAL PERFORMANCE
GRAPHSPA241
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APEX MICROTECHNOLOGY CORPORATION TELEPHONE (520) 690-8600 FAX (520) 888-3329 ORDERS (520) 690-8601 EMAIL prodlit@apexmicrotech.com
5
OPERATING
CONSIDERATIONS PA241
GENERAL
Please read Application Note 1 "General Operating Consid-
erations" which covers stability, power supplies, heat sinking,
mounting, current limit, SOA interpretation, and specification
interpretation. Visit www.apexmicrotech.com for design tools
that help automate tasks such as calculations for stability,
internal power dissipation, current limit, heat sink selection,
Apex's complete Application Notes library, Technical Seminar
Workbook and Evaluation Kits.
PHASE COMPENSATION
Open loop gain and phase shift both increase with increas-
ing 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.
CURRENT LIMIT
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 pre-
dicted as follows:
Ilimit = Vbe
Rcl
Where Vbe is shown in the CURRENT LIMIT typical
graph.
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 nega-
tive 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 PA241 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.
These limitations can be seen in the SOA (see Safe Operat-
ing 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 PA241CE and DF and 10.4°C/W
for the PA241DW respectively. 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 PA241DF 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 PA241DF. Solder connection to an area of 1 to 2 square
APEX MICROTECHNOLOGY CORPORATION 5980 NORTH SHANNON ROAD TUCSON, ARIZONA 85741 USA APPLICATIONS HOTLINE: 1 (800) 546-2739
6
PA241
This data sheet has been carefully checked and is believed to be reliable, however, no responsibility is assumed for possible inaccuracies or omissions. All specifications are subject to change without notice.
PA241U REV B AUGUST 2005 © 2005 Apex Microtechnology Corp.
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OPERATING
CONSIDERATIONS
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.
FIGURE 1
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 impor-
tant, 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.
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-invert-
ing 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 leak-
age 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 fol-
lowing Application Notes:
AN1: General Operating Considerations
AN3: Bridge Circuit Drives
AN25: Driving Capacitive Loads
AN38: Loop Stability with Reactive Loads