PA93 데이터 시트보기 (PDF) - Cirrus Logic
부품명
상세내역
제조사
PA93 Datasheet PDF : 6 Pages
| |||
®
Product Innovation From
PA93
SAFE OPERATING AREA (SOA)
The MOSFET output stage of this power operational am-
20
plifier has two distinct limitations:
1. The current handling capability of the MOSFET geom-
10
8
etry and the wire bonds.
6
SOA
DC, TC = 25C
200mS
2. The junction temperature of the output MOSFETs.
4
NOTE: The output stage is protected against transient
3
flyback. However, for protection against sustained, high
2
energy flyback, external fast-recovery diodes should be
used.
1
.8
SAFE OPERATING CURVES
.6
The safe operating area curves define the maximum ad-
.4
100mS
DC,T
DC,T
C = 85C
C = 125C
ditional internal power dissipation the amplifier can toler-
.3
ate when it produces the necessary output to drive an
.2
external load.
INPUT PROTECTION
Although the PA93 can withstand differential voltages up
.1
.08
.06
10
20 30 40 60 80 100
200 300 500
to ±20V, additional external protection is recommended.
Low leakage, low capacitance JFETs connected as di-
SUPPLY TO OUTPUT DIFFERENTIAL, VS – VO (V)
odes are recommended (e.g. 2N4416, Q1-Q4 in Figure 2). The differen-
tial input voltage will be clamped to ±1.4V. This is sufficient overdrive to
produce maximum power bandwidth.
+VS
Z1
POWER SUPPLY PROTECTION
Unidirectional zener diode transient suppressors are recommended as
protection on the supply pins. See Figure 2. 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
–IN
Q1
Q2
+IN
1
11, 12
Q3
6
PA93
Q4
2
7, 8
power supply should be evaluated for transient performance including
power-on overshoot and power-off polarity reversals as well as line regu-
lation.
FIGURE 2.
OVERVOLTAGE
PROTECTION
Z2
–VS
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 PA93 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 CC must be rated at 500V working
voltage. An NPO capacitor is recommended. The compensation network CCRC must be mounted closely to the am-
plifier pins 4 and 5 to avoid spurious oscillation.
QUIESCENT CURRENT REDUCTION
When pin 3 (IQ) is shorted to pin 5 (CC2) the AB biasing of the output stage is disabled. This lowers quiescent power
but also raises distortion since the output stage is then class C biased. The output stage bias current is nominally
set at 1mA. Pin 3 may be left open if not used.
PA93U
5
Share Link: 