PA95 Cirrus Logic Inc, PA95 Datasheet - Page 5

• Manufacturer Part Number: PA95
• Description: OP AMP HV 900V .100A 8-SIP DQ
• Manufacturer: Cirrus Logic Inc
• Series: Apex Precision Power™r

Specifications of PA95

• Amplifier Type: Power
• Number Of Circuits: 1
• Slew Rate: 30 V/µs
• Gain Bandwidth Product: 10MHz
• Current - Input Bias: 200pA
• Voltage - Input Offset: 500µV
• Current - Supply: 1.6mA
• Current - Output / Channel: 100mA
• Voltage - Supply, Single/dual (±): 100 V ~ 900 V, ±50 V ~ 450 V
• Operating Temperature: -25°C ~ 85°C
• Mounting Type: Through Hole
• Package / Case: 12-SIP (8 leads)
• Number Of Channels: 1
• Voltage Gain Db: 118 dB
• Common Mode Rejection Ratio (min): 80 dB
• Input Offset Voltage: 5 mV
• Maximum Operating Temperature: + 85 C
• Mounting Style: Through Hole
• Maximum Dual Supply Voltage: +/- 450 V
• Minimum Operating Temperature: - 25 C
• For Use With: 598-1462 - EVALUATION KIT FOR PA94/PA95
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Output Type: -
• -3db Bandwidth: -
• Lead Free Status / Rohs Status: In Transition
• Other names: 598-1335

requirements since the maximum difference voltage between the inputs pins and the supply voltage is 500V (the
maximum allowed). The output has no such restrictions on its voltage swing. The output can swing within 24V of
either supply voltage regardless of value so long as the total supply voltage does not exceed 900V.
INPUT PROTECTION
Although the PA95 can withstand differential input voltages up to
±20V, additional external protection is recommended. In most ap-
plications 1N4148 or 1N914 signal diodes are sufficient (D1, D2 in
Figure 1a). In more demanding applications where low leakage or
low capacitance are of concern 2N4416 or 2N5457-2N5459 JFETs
connected as diodes will be required (Q1, Q2 in Figure 1b). In
either case the input differential voltage will be clamped to ±.7V.
This is sufficient overdrive to produce maximum power bandwidth.
Note that this protection does not automatically protect the ampli-
fier from excessive common mode input voltages.
POWER SUPPLY PROTECTION
Unidirectional zener diode transient suppressors are recommend-
ed 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 perfor-
mance including power-on overshoot and power-off polarity rever-
sal as well as line regulation.
Conditions which can cause open circuits or polarity reversals on either power supply rail should be avoided or pro-
tected 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 PA95 is stable at gains of 10 or more with a NPO (COG) compensation capacitor of 4.7pF. The compensation
capacitor, Cc, in the external connections diagram must be rated at 1000V working voltage and mounted closely to
pins 4 and 6 to prevent spurious oscillation. A compensation capacitor less than 4.7pF is not recommended.
EXTERNAL COMPONENTS
The compensation capacitor Cc must be rated for the total supply voltage. An NPO (COG)capacitor rated a 1kV is
recommended.
Of equal importance are the voltage rating and voltage coefficient of the gain setting feedback resistor. Typical volt-
age ratings of low wattage resistors are 150 to 250V. Up to 500 V can appear across the feedback resistor. High
voltage rated resistors can be obtained. However a 1 megohm feedback resistor composed of five 200k resistors in
series will produce the proper voltage rating.
CAUTIONS
The operating voltages of the PA95 are potentially lethal. During circuit design develop a functioning circuit at the
lowest possible voltages. Clip test leads should be used for "hands off" measurements while troubleshooting.
PA95U
P r o d u c t T e c h n o l o g y F r o m
FIGURE 1. OVERVOLTAGE PROTECTION
A.
–IN
+IN
D1
B.
D2
1
2
–IN
+IN
PA95
+V
–V
Q1
S
S
12
10
Z1
Z2
Q2
1
2
PA95
+V
–V
S
S
12
10
PA95
Z1
Z2
5