PA85A Cirrus Logic Inc, PA85A Datasheet - Page 4

• Manufacturer Part Number: PA85A
• Description: OP AMP HV 1KV/US TO-3-8 CE SG
• Manufacturer: Cirrus Logic Inc
• Series: Apex Precision Power™r

Specifications of PA85A

• 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: TO-3-8
• 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
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Output Type: -
• -3db Bandwidth: -
• Lead Free Status / Rohs Status: Details
• Other names: 598-1327

PA85 • PA85A
GENERAL
ations" 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 and heat sink selection. The "Application Notes"
and "Technical Seminar" sections contain a wealth of informa-
tion on specific types of applications. Package outlines, heat
sinks, mounting hardware and other accessories are located
in the "Packages and Accessories" section. Evaluation Kits
are available for most Apex Precision Power product models,
consult the "Evaluation Kit" section for details. For the most
current version of all Apex Precision Power product data sheets,
visit www.Cirrus.com.
CURRENT LIMIT
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.
SAFE OPERATING AREA (SOA)
fier has two distinct limitations:
1. The current handling capability of the MOSFET geometry
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.
4
Please read Application Note 1 "General Operating Consider-
For proper operation, the current limit resistor (R
The MOSFET output stage of this power operational ampli-
500
300
200
100
and the wire bonds.
50
30
20
10
25
PULSE CURVES @ 10% DUTY CYCLE MAX
SUPPLY TO OUTPUT DIFFERENTIAL, V
50
R
CL
75
=
100
SOA
I
LIM
125
.7
- .016
250
S
–V
CL
O
) must be
(V)
500
P r o d u c t I n n o v a t i o n F r o m
SAFE OPERATING CURVES
ditional 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.
INPUT PROTECTION
±25V, additional external protection is recommended. Since
the PA85 is a high speed amplifier, low leakage, low capaci-
tance JFETs connected as diodes are recommended (e.g.
2N4416, Q1-Q4 in Figure 2). The differential input voltage will
be clamped to ±1.4V. This is sufficient overdrive to produce
maximum power bandwidth.
POWER SUPPLY PROTECTION
mended 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.
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
be tailored to the application. Use the graphs of small signal
response and power response as a guide. The compensation
capacitor C
capacitor is recommended. The compensation network C
must be mounted closely to the amplifier pins 7 and 8 to avoid
spurious oscillation.
The safe operating area curves define the maximum ad-
Although the PA85 can withstand differential voltages up to
Unidirectional zener diode transient suppressors are recom-
Conditions which can cause open circuits or polarity reversals
The PA85 is externally compensated and performance can
–IN
+IN
FIGURE 2.
OVERVOLTAGE PROTECTION
C
must be rated at 500V working voltage. An NPO
Q1
Q2
Q3
Q4
5
4
PA85
+V
–V
S
S
3
6
Z1
Z2
PA85U
C
R
C