CIRRUS PA98_09

Innovation
P r o d u c t PA98A
PA98,
PA98
• PA98A
PA98
• PA98A
From
Power Operational Amplifiers
DESCRIPTION
FEATURES
The PA98 is a high voltage, high power bandwidth
MOSFET operational amplifier designed for output
currents up to 200mA. Output voltages can swing up
to ±215V with a dual supply and up to +440 volts with
a single supply. The safe operating area (SOA) has
no second breakdown limitations and can be observed
with all types of loads by choosing an appropriate current limiting resistor. High accuracy is achieved with a
cascode input circuit configuration. All internal biasing
is referenced to a bootstrapped zener-MOSFET current source. As a result, the PA98 features an unprecedented supply range and excellent supply rejection.
The MOSFET output stage is biased on for linear operation. External compensation provides user flexibility.
This hybrid circuit utilizes thick film (cermet) resistors,
ceramic capacitors and silicon semiconductor chips to
maximize reliability, minimize size and give top performance. Ultrasonically bonded aluminum wires provide
reliable interconnections at all operating temperatures.
The Power SIP package is electrically isolated.
♦ HIGH VOLTAGE — 450V (±225V)
♦ HIGH SLEW RATE — 1000V/μS
♦ HIGH OUTPUT CURRENT — 200mA
APPLICATIONS
♦ HIGH VOLTAGE INSTRUMENTATION
♦ PIEZO TRANSDUCER EXCITATION
♦ PROGRAMMABLE POWER SUPPLIES UP
TO 430V
♦ ELECTROSTATIC TRANSDUCERS &
DEFLECTION
EQUIVALENT SCHEMATIC
11
+VS
D1
Q1
Q2
Q3
D23
COMP
4
–IN
1
Q6
Q10A
Q7
Q10B
+IN
2
Q8
5
Q9
12
+VS
Q12
9
CL
10
CL
Q11
6
OUT
Q17
Q18
Q13
Q15
D2
8
–VS
7
–VS
PA98U
www.cirrus.com
Copyright © Cirrus Logic, Inc. 2009
(All Rights Reserved)
NOV 20091
APEX − PA98REVK
PA98 • PA98A
Product Innovation From
EXTERNAL CONNECTIONS
1
2
3
4
5
6
7
8
9
11
10
12
NC
Rc
–IN
Cc
RCL
+IN
*
TO LOAD
AND FEEDBACK
PATENTED
*
–Vs
12-pin SIP
PACKAGE
STYLE DP
+Vs
* Bypassing required.
Formed leads available
Package style EE
1. CHARACTERISTICS AND SPECIFICATIONS
ABSOLUTE MAXIMUM RATINGS
Max
Units
SUPPLY VOLTAGE, +VS to -VS
Parameter
Symbol
Min
450
V
OUTPUT CURRENT, continuous within SOA
200
mA
POWER DISSIPATION, continuous @ TC = 25°C (Note 2)
30
W
INPUT VOLTAGE, differential
-25
25
V
INPUT VOLTAGE, common mode
-VS
VS
V
TEMPERATURE, pin solder, 10s max.
260
°C
TEMPERATURE, junction (Note 2)
150
°C
TEMPERATURE RANGE, storage
−40
85
°C
OPERATING TEMPERATURE RANGE, case
−25
85
°C
CAUTION
The PA98 is constructed from MOSFET transistors. ESD handling procedures must be observed.
The exposed substrate contains beryllia (BeO). Do not crush, machine, or subject to temperatures
in excess of 850°C to avoid generating toxic fumes.
SPECIFICATIONS
Parameter
Test Conditions1
PA98
Min
PA98A
Typ
Max
0.5
Min
Typ
Max
Units
2
0.25
0.5
mV
INPUT
OFFSET VOLTAGE, initial
OFFSET VOLTAGE vs. temp
Full temp range
10
30
5
10
µV/°C
OFFSET VOLTAGE vs. supply
3
10
*
*
µV/V
OFFSET VOLTAGE vs. time
75
BIAS CURRENT, initial (Note 3)
5
50
3
BIAS CURRENT, vs. supply
0.01
OFFSET CURRENT, initial
(Note 3)
10
INPUT IMPEDANCE, DC
COMMON MODE REJECTION, VCM = ±90V
DC
2
100
3
4
±VS - 15
90
*
pA
pA/V
30
pA
*
Ω
*
pF
*
110
µV/kHz
10
*
1011
INPUT CAPACITANCE
COMMON MODE VOLTAGE
RANGE
(Note 4)
*
V
*
dB
PA98U
PA98 • PA98A
Product Innovation From
Test Conditions1
Parameter
NOISE
PA98
Min
100kHz BW,
RS = 1KΩ,
CC = 10pf
Typ
PA98A
Max
Min
1
Typ
Max
Units
*
µV RMS
*
dB
GAIN
OPEN LOOP GAIN @ 15Hz
RL = 2KΩ,
CC = OPEN
96
111
*
GAIN BANDWIDTH PRODUCT RL = 2KΩ,
@ 1MHz
CC = 3.3pf
100
*
MHz
POWER BANDWIDTH
CC = 10pf
300
*
kHz
CC = 3.3pf
500
*
kHz
Full temp range
60
*
°
PHASE MARGIN
OUTPUT
VOLTAGE SWING
(Note 4)
IO = ±200mA
±VS - 10 ±VS - 6.5
*
*
V
VOLTAGE SWING
(Note 4)
IO = ±75mA
±VS - 8.5 ±VS - 6.0
*
*
V
VOLTAGE SWING
(Note 4)
IO = ±20mA
±VS - 8.0 ±VS - 5.5
*
*
V
CURRENT, continuous
TC = 85°C
SLEW RATE, A V = 20
CC = 10pf
±200
400
*
mA
*
V/µS
SLEW RATE, A V = 100
CC = OPEN
1000
*
V/µS
CAPACITIVE LOAD, A V = +1
Full temp range
SETTLING TIME to 0.1%
CC = 10pf,
1
*
µS
RESISTANCE, no load
RCL = 0
50
*
Ω
700
470
2V step
*
pF
POWER SUPPLY
VOLTAGE
(Note 6) Full temp range
±15
CURRENT, quiescent
±150
±225
21
25
*
*
*
V
*
*
mA
THERMAL
RESISTANCE, AC,
Full temp range,
junction to case (Note 5) F > 60Hz
2.5
*
°C/W
RESISTANCE, DC,
junction to case
Full temp range,
4.2
*
°C/W
RESISTANCE, junction to air
Full temp range
F < 60Hz
TEMPERATURE RANGE, case Meets full range
specifications
30
-25
*
+85
*
°C/W
*
°C
NOTES: * The specification of PA98A is identical to the specification for PA98 in applicable column to the left.
1. Unless otherwise noted: TC = 25°C, compensation = CC = 68pF, RC = 100Ω. 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. Ratings apply only to output transistors. An additional 10W may be dissipated due to quiescent power.
3. Doubles for every 10°C of temperature increase.
4. +VS and –VS denote the positive and negative power supply rail respectively.
5. Rating applies if the output current alternates between both output transistors at a rate faster than
60Hz.
6. Derate max supply rating 0.625 V/°C below 25°C case. No derating needed above 25°C case.
PA98U
3
8
CC = 10pF
-135
-180
-225
C
5°
12
=
AV = 30
PO = 15W
CC = 10pF
RL = 1KΩ
200
4
120
CC = 10pF
100
80
60
40
20
1K
10K
100K
1M
FREQUENCY, F (Hz)
10M
POWER SUPPLY REJECTION, PSR (dB)
COMMON MODE REJECTION, CMR (dB)
0
15
30 45
60 75
90
EXT. COMPENSATION CAPACITOR, CC (pF)
COMMON MODE REJECTION
.005
.003
.001
10
100
140
.01
100
1K
10K
FREQUENCY, F (Hz)
100K
POWER SUPPLY REJECTION
120
100
80
60
40
20
1
10 100 1K 10K 100K 1M
FREQUENCY, F (Hz)
200K
500K
2M
FREQUENCY, F (Hz)
5M
20
15
10
7
5
3
2
10
100
1K
10K
FREQUENCY, F (Hz)
100K
CURRENT LIMIT
500
140
CURRENT LIMIT, ILIM (mA)
500
DISTORTION, (%)
SLEW RATE, (V/µS)
.03
RL = 2KΩ
INPUT NOISE VOLTAGE
HARMONIC DISTORTION
.05
50
25
50K
50
100
150 200
250
OUTPUT CURRENT, IO (mA)
F
0
125
100
75
.3p
4
250
F
SLEW RATE
5
SMALL SIGNAL RESPONSE
0p
10M 20M
500
0
100
200
300
400450
TOTAL SUPPLY VOLTAGE, VS (V)
=1
1000
100 1K 10K 100K 1M
FREQUENCY, F (Hz)
55°C
TC = -
.90
CC
-20
10
TC
6
C
= 25°
.95
F
0
7
T C = 25°C
8p
CC = 68pF
8
°C
125
TC = -55°C
=6
20
1.00
CC
CC = 10pF
40
1.05
SMALL SIGNAL RESPONSE
9
TC =
=3
80
40M
1.10
CC
CC = 3.3pF
10
1M
10M
FREQUENCY, F (Hz)
C
100
60
-270
.2M
25
50
75 100 125 150
CASE TEMPERATURE, TC (°C)
SMALL SIGNAL RESPONSE
CC = 3.3pF
T
0
NORMALIZED QUIESCENT CURRENT, IQ (X)
16
CC = 68pF
-90
1.15
OUTPUT VOLTAGE, VO (VPP)
PHASE, Ф (°)
24
QUIESCENT CURRENT
1.20
-45
32
0
PHASE RESPONSE
0
INPUT NOISE VOLTAGE, VN (nV√Hz)
POWER DERATING
40
120
OPEN LOOP GAIN, A (dB)
Product Innovation From
VOLTAGE DROP FROM SUPPLY, VS - VO (V)
OUTPUT STAGE
INTERNAL POWER DISSIPATION, P (W)
PA98 • PA98A
300
200
100
50
20
1
2
5
10
20 30
RESISTOR VALUE, RCL (Ω)
PA98U
PA98 • PA98A
Product Innovation From
TYPICAL APPLICATION
DYNAMIC FOCUSING
DC
FOCUS
R IN1
RF
+225V
Dynamic focusing is the active correction of focusing voltage X SWEEP
R CL
SAMPLE
as a beam traverses the face of a CRT. This is necessary in
R IN2
high resolution flat face monitors since the distance between
z = x2 + y2
TO
cathode and screen varies as the beam moves from the center
PA98
FOCUS
SWEEP
GRID
of the screen to the edges. PA98 lends itself well to this func- YSAMPLE
tion since it can be connected as a summing amplifier with
inputs from the nominal focus potential and the dynamic cor225V
rection. The nominal might be derived from a potentiometer, or
perhaps automatic focusing circuitry might be used to generate this potential. The dynamic correction is generated
from the sweep voltages by calculating the distance of the beam from the center of the display.
PHASE COMPENSATION
Gain
1
20
100
CC
68pF
10pF
3.3pF
RC
100Ω
330Ω
0Ω
CC RATED FOR FULL SUPPLY VOLTAGE
GENERAL
Please read Application Note 1 "General Operating Considerations" which covers stability, 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.
CURRENT LIMIT
For proper operation, the current limit resistor (RCL) must be connected as shown in the external connection diagram. The minimum value is 1.4 ohm, however for optimum reliability the resistor value should be set as high as
possible. The value is calculated as follows; with the maximum practical value of 30 ohms.
.7 RCL = ILIM - .016
SOA
500
The MOSFET output stage of this power operational
amplifier has two distinct limitations:
1. The current handling capability of the MOSFET geometry and the wire bonds.
2. The junction temperature of the output MOSFETs.
NOTE: The output stage is protected against transient
flyback. However, for protection against sustained, high
energy flyback, external fast-recovery diodes should be
used.
SAFE OPERATING CURVES
The safe operating area curves define the maximum
additional internal power dissipation the amplifier can
tolerate when it produces the necessary output to drive
an external load. This is not the same as the absolute
maximum internal power dissipation listed elsewhere in
the specification since the quiescent power dissipation
is significant compared to the total.
PA98U
OUTPUT CURRENT FROM +VS OR -VS (mA)
SAFE OPERATING AREA (SOA)
20
300
0m
10
S
0m
S
200
DC
,T
100
,T
C
,T
C
=
25
°C
85
°C
DC
50
=
C
DC
=
12
5°
30
C
20
PULSE CURVES @ 10% DUTY CYCLE MAX.
10
25
50
75
100 125
250
500
SUPPLY TO OUTPUT DIFFERENTIAL, VS - VO (V)
5
PA98 • PA98A
Product Innovation From
INPUT PROTECTION
Although the PA98 can withstand differential voltages up to ±25V, additional external protection is recommended.
Since the PA98 is a high speed amplifier, low leakage, low capacitance JFETs connected as diodes are recommended (e.g. 2N4416, Q1-Q4 in Figure 1). The differential input voltage will be clamped to ±1.4V. This is sufficient
overdrive to produce maximum power bandwidth.
POWER SUPPLY PROTECTION
Unidirectional zener diode transient suppressors are recommended as
protection on the supply pins. 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.
Conditions which can cause open circuits or polarity reversals on either
power supply rail should be avoided or protected against. Reversals or
opens on the negative supply rail is known to induce input stage failure.
Unidirectional transzorbs prevent this, and it is desirable that they be
both electrically and physically as close to the amplifier as possible.
+VS
Z1
1
–IN
Q1
11, 12
Q3
6
PA98
Q2
+IN
FIGURE 1.
OVERVOLTAGE
PROTECTION
Q4
2
7, 8
Z2
–VS
STABILITY
The PA98 is externally compensated and performance can be tailored to the application. Use the graphs of small
signal response and power response as a guide. The compensation capacitor CC must be rated at 500V working
voltage. An NPO capacitor is recommended. The compensation network CCRC must be mounted closely to the amplifier pins 7 and 8 to avoid spurious oscillation.
INTERNAL POWER DISSIPATION AND HEATSINK SELECTION
With the unique combination of high voltage and speed of the PA98, traditional formulas for heatsink selection will
falsely lower the apparent power handling capability of this amplifier. To more accurately predict operating temperatures use Power Design1 revision 10 or higher, or use the following procedure:
Find internal dissipation (PD) resulting from driving the load. Use Power Design or refer to Apex Precision Power
Applications Note 1, General Operating Considertaions, paragraph 7. Find total quiescent power (PDQ) by multiplying 0.025A by VSS (total supply voltage). Find output stage quiescent power (PDQOUT) by multiplying 0.001 by VSS.
Calculate a heatsink rating which will maintain the case at 85°C or lower.
RØSA =
TC - TA
-0.1°C/W
PD + PDQ
Where:TC = maximum case temperature allowed
TA = maximum ambient temperature encountered
Calculate a heatsink rating which will maintain output transistor junctions at 150°C or lower.
RØSA =
TJ - TA - (PD + PDQOUT) * RØJC
-0.1°C/W
PD + PDQ
Where:TJ = maximum junction temperature allowed.
RØJC = AC or DC thermal resistance from the specification table.
Use the larger heatsink of these two calculations.
Power Design is an Excel spreadsheet available free from www.cirrus.com
6
PA98U
Product Innovation From
PA98 • PA98A
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
IMPORTANT NOTICE
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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does not extend to other copying such as copying for general distribution, advertising or promotional purposes, or for creating any work for resale.
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All other brand and product names in this document may be trademarks or service marks of their respective owners.
PA98U
7