PA45 ETC, PA45 Datasheet - Page 4

• Manufacturer Part Number: PA45
• Description: HIGH VOLTAGE POWER OPERATIONAL AMPLIFIER
• Manufacturer: ETC

PA45
GENERAL
which covers stability, supplies, heat-sinking, mounting, cur-
rent limit, SOA interpretation, and specification interpretation.
Additional information can be found in the application notes.
For information on the package outline, heatsink, and mount-
ing hardware, consult the “Accessories Information” and “Pack-
aging” mechanical data section of the data book.
CURRENT LIMIT
amplifiers current sense circuit by way of an internal tie to the
output drive (pin 8) and an external current sense line (pin 1).
A sense resistor R
current flowing from output drive.
typical value of output resistance and affects the total possible
swing since it carries the load current. The swing reduction, V
can be established V
INPUT PROTECTION
voltages up to the supply rails, differential voltages up to 16
STABILITY
for unity gain to be stable with capacitive loads of at least 10nF.
However, the low pass circuit created by the sum-point (–in)
capacitance and the feedback network may add phase shift
and cause instabilities. As a rule, the sum-point load resis-
tance (input and feedback resistors in parallel) should be 1k
ohm or less. Alternatively, use a bypass capacitor across the
feedback resistor. The time constant of the feedback resistor
and bypass capacitor combination should match the time
constant of the sum-point resistance and sum-point capaci-
tance.
be tailored to the application. The compensation network C
R
avoid noise coupling to these high impedance nodes.
volts and static discharge. Differential voltages exceeding 16
volts will be clipped by the protection circuitry. However, if
more than a few milliamps of current is available from the input
drive source, the protection circuitry could be destroyed. The
protection circuitry includes 300 ohm current limiting resistors
at each input. This security may be insufficient for severe
overdrive of the input. Adding external resistors to the applica-
tion which limits severe input overdrive current to 1mA, will
prevent damage.
APEX MICROTECHNOLOGY CORPORATION • 5980 NORTH SHANNON ROAD • TUCSON, ARIZONA 85741 • USA • APPLICATIONS HOTLINE: [phone]
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.
C
Please read the General Operating Considerations section,
Current limiting is achieved by developing 0.83V on the
with a maximum practical value of 16 . R
The PA45 inputs are protected against common mode
The PA45 has sufficient phase margin when compensated
The PA45 is externally compensated and performance can
must be mounted closely to the amplifier pins 7 and 2 to
R
CL
I
CL
CL
=
=
is used to relate this sense voltage to a
R
= I
0.83 – 0.05 * I
OUT
R
CL
*
0.83
+ 0.05
I
R
CL
CL
.
CL
PA45U REV. B FEBRUARY 1998 © 1998 Apex Microtechnology Corp.
CL
is added to the
C
R
-
SAFE OPERATING AREA (SOA)
fier has limitations from its channel temperature.
However, for protection against sustained, high energy flyback,
external fast-recovery diodes should be used.
The MOSFET output stage of this power operational ampli-
NOTE: The output is protected against transient flyback.
6.0
4.0
2.0
1.0
0.8
0.6
0.4
0.2
0.1
4
PULSE CURVES @ 10% DUTY CYCLE MAX
SUPPLY TO OUTPUT DIFFERENTIAL, V
6
8 10
SAFE OPERATING AREA
20
40
CONSIDERATIONS
60
OPERATING
100
S
-V
O
(V)
200