PA98 Datasheet, PDF (1/5 Pages) Cirrus Logic – HIGH VOLTAGE POWER OPERATIONAL AMPLIFIER

���������������
����������������������������
������������
��������������������������������������������������������������
FEATURES
• 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
DESCRIPTION
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 appropri-
ate 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 reli-
ability, minimize size and give top performance. Ultrasonically
bonded aluminum wires provide reliable interconnections at
all operating temperatures. The Power SIP package is electri-
cally isolated.
EQUIVALENT SCHEMATIC
��
�� ��
��
��
��_�
��
���
�� ^��
��_�
����
��
���
�
����
��
���
�
����
���
��
��
���
���
���
�
��
��
��
�
���
���
���
�
��_�
�
��_�
TYPICAL APPLICATION
��
�����
� _{���}
�������
������
��������^������ ^�
� _{���}
�������
������
PATENTED
12-PIN SIP
PACKAGE STYLE DP
Formed leads available
Package styles ED & EE
�_�
�����
� _��
����
��
�����
����
����
DYNAMIC FOCUSING
Dynamic focusing is the active correction of focusing voltage
as a beam traverses the face of a CRT. This is necessary in
high resolution flat face monitors since the distance between
cathode and screen varies as the beam moves from the center
of the screen to the edges. PA98 lends itself well to this function
since it can be connected as a summing amplifier with inputs
from the nominal focus potential and the dynamic correction.
The nominal might be derived from a potentiometer, or per-
haps 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.
EXTERNAL CONNECTIONS
� � � � � � � � � �� �� ��
��
��
��
��� ���
�_��
�
�
���
�������
������������
���
���������������������
PHASE COMPENSATION
Gain
1
20
100
C_C
68pF
10pF
3.3pF
R_C
100Ω
330Ω
0Ω
C_C RATED FOR FULL SUPPLY VOLTAGE
APEX MICROTECHNOLOGY CORPORATION • TELEPHONE [phone] • FAX [phone] • ORDERS [phone] • EMAIL [e-mail]
1