EK11 Cirrus Logic Inc, EK11 Datasheet - Page 5

• Manufacturer Part Number: EK11
• Description: KIT EVALUATION PA90 PA91 PA98
• Manufacturer: Cirrus Logic Inc
• Series: Apex Precision Power™r

Specifications of EK11

• Channels Per Ic: 1 - Single
• Amplifier Type: Power
• Output Type: Single-Ended
• Board Type: Bare (Unpopulated)
• Utilized Ic / Part: PA90, PA91, PA98
• Product: Amplifier Modules
• Description/function: Audio Amplifiers
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Operating Temperature: -
• Current - Output / Channel: -
• Voltage - Supply, Single/dual (±): -
• -3db Bandwidth: -
• Slew Rate: -
• Current - Supply (main Ic): -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Contains lead / RoHS non-compliant
• Other names: 598-1458; EK11

SAFE OPERATING AREA (SOA)
The MOSFET output stage of this power operational amplifier has two distinct limitations:
1. The current handling capability of the MOSFET geometry and the wire bonds.
2. The junction temperature of the output MOSFETs.
NOTE: The output stage is protected against transient flyback. However, for protection against sustained, high en-
ergy flyback, external fast-recovery diodes should be used.
SAFE OPERATING CURVES
The safe operating area curves define the maximum ad-
ditional internal power dissipation the amplifier can toler-
ate when it produces the necessary output to drive an
external load.
INPUT PROTECTION
Although the PA90 can withstand differential voltages up
to ±20V, additional external protection is recommended.
Low leakage, low capacitance JFETs connected as di-
odes are recommended (e.g. 2N4416, Q1-Q4 in Fig-
ure 2). The differential input voltage will be clamped to
±1.4V. This is sufficient overdrive to produce maximum
power bandwidth.
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 power supply should be evaluated for transient performance
including power-on overshoot and power-off polarity reversals as well as
line regulation.
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 PA90 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 C
is recommended. The compensation network C
spurious oscillation.
QUIESCENT CURRENT REDUCTION
When pin 3 (I
the output stage is then class C biased, but reduces the quiescent current by 1mA for a power dissipation savings
of 0.4W. Pin 3 may be left open if not used.
PA90U
Q
) is shorted to pin 5 (CC2) the AB biasing of the output stage is disabled. This raises distortion since
P r o d u c t T e c h n o l o g y F r o m
C
R
C
must be mounted closely to the amplifier pins 4 and 5 to avoid
C
must be rated at 500V working voltage. An NPO capacitor
500
200
100
300
50
30
20
10
25
SUPPLY TO OUTPUT DIFFERENTIAL, V
PULSE CURVES @ 10% DUTY CYCLE MAX.
–IN
+IN
FIGURE 2.
OVERVOLTAGE
PROTECTION
50
Q1
Q2
75 100 125
SOA
Q3
Q4
2
1
PA90
+V
–V
7, 8
S
11, 12
S
250
Z1
Z2
S
- V
O
PA90
(V)
6
500
5