PA98A Cirrus Logic Inc, PA98A Datasheet - Page 6

• Manufacturer Part Number: PA98A
• Description: OP AMP PWR 450V .2A 12P SIP SG
• Manufacturer: Cirrus Logic Inc
• Series: Apex Precision Power™r

Specifications of PA98A

• Amplifier Type: Power
• Number Of Circuits: 1
• Slew Rate: 1000 V/µs
• Gain Bandwidth Product: 100MHz
• Current - Input Bias: 3pA
• Voltage - Input Offset: 250µV
• Current - Supply: 21mA
• Current - Output / Channel: 200mA
• Voltage - Supply, Single/dual (±): 30 V ~ 450 V, ±15 V ~ 225 V
• Operating Temperature: -25°C ~ 85°C
• Mounting Type: Through Hole
• Package / Case: 12-SIP
• Number Of Channels: 1
• Voltage Gain Db: 111 dB
• Common Mode Rejection Ratio (min): 90 dB
• Input Offset Voltage: 0.5 mV
• Maximum Operating Temperature: + 85 C
• Mounting Style: Through Hole
• Maximum Dual Supply Voltage: +/- 225 V
• Minimum Operating Temperature: - 25 C
• For Use With: 598-1458 - KIT EVALUATION PA90 PA91 PA98598-1390 - KIT EVAL PA90,91,92,93,98 PINOUT
• Lead Free Status / RoHS Status: Lead free by exemption / RoHS compliant by exemption
• Output Type: -
• -3db Bandwidth: -
• Lead Free Status / Rohs Status: No
• Other names: 598-1450; PA98A

PA98 • PA98A
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 recom-
mended (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 over-
shoot 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.
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 C
voltage. An NPO capacitor is recommended. The compensation network C
plifier pins 7 and 8 to avoid spurious oscillation.
4. 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 predict operating temperatures use the
following procedure:
Find internal dissipation (PD) resulting from driving the load. Refer to Apex Precision Power Applications Note 1,
General Operating Considerations, paragraph 7. Find total quiescent power (PD
(total supply voltage). Find output stage quiescent power (PD
Calculate a heatsink rating which will maintain the case at 85°C or lower.
Where: T
Calculate a heatsink rating which will maintain output transistor junctions at 150°C or lower.
Where: T
6
R
R
ØSA
ØSA
=
=
T
PD + PD
T
R
Use the larger heatsink of these two calculations.
J
T
A
C
J
ØJC
- T
C
= maximum ambient temperature encountered
= maximum junction temperature allowed.
= maximum case temperature allowed
- T
A
= AC or DC thermal resistance from the specification table.
- (PD + PD
A
Q
PD + PD
-0.1°C/W
QOUT
Q
) * R
ØJC
-0.1°C/W
P r o d u c t T e c h n o l o g y F r o m
QOUT
) by multiplying 0.001 by V
C
–IN
+IN
FIGURE 1.
OVERVOLTAGE
PROTECTION
R
C
Q1
must be mounted closely to the am-
Q2
C
Q
must be rated at 500V working
) by multiplying 0.025A by V
Q4
Q3
SS
2
1
.
PA98
+V
–V
S
11, 12
7, 8
S
Z1
Z2
6
PA98U
SS