MP400FC Cirrus Logic Inc, MP400FC Datasheet - Page 10

• Manufacturer Part Number: MP400FC
• Description: MODULE PWR AMP HS HV SWITCH MODE
• Manufacturer: Cirrus Logic Inc
• Series: Apex Precision Power™r

Specifications of MP400FC

• Amplifier Type: Power
• Number Of Circuits: 1
• Slew Rate: 350 V/µs
• Gain Bandwidth Product: 1MHz
• Current - Input Bias: 8.5pA
• Voltage - Input Offset: 8000µV
• Current - Supply: 700µA
• Current - Output / Channel: 150mA
• Voltage - Supply, Single/dual (±): 10 V ~ 50 V, ±5 V ~ 25 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Through Hole
• Package / Case: 42-DIP Module
• Description/function: Audio Amplifiers
• Product: Audio Modules
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• For Use With: 598-1484 - KIT EVALUATION FOR MP400FC
• Output Type: -
• -3db Bandwidth: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 598-1483

MP400
supply voltage (+V
temperature.
The PA78 requires an external 33 pF capacitor between C
output. This capacitor should be rated for the full supply voltage (+V
gram. For maximum reliability and protection, the largest resistor value should be used. The maximum practical
value for R
10
Current can be injected into the output stage by adding a resistor, R
depend upon the application but 500 µA (50 V V+ supply/100K) of added bias current shows significant improve-
ment in the small signal phase plots. Adding this resistor has little to no impact on small signal gain or large signal
performance as under these conditions the current in the input stage is elevated over its idle value. It should also
be noted that connecting a resistor to the upper supply only injects a fixed current and if the upper supply is fixed
and well bypassed. If the application includes variable or adjustable supplies, a current source diode could also be
used. These two terminal components combine a JFET and resistor connected within the package to behave like
a current source.
As a second stability measure, the PA78 is externally compensated and performance can be optimized to the ap-
plication. Unlike the R
the large signal response of the amplifier. Refer to the small and large signal response plots as a guide in making
the tradeoffs between bandwidth and stability. Due to the unique design of the PA78, two symmetric compensation
networks are required. The compensation capacitor C
larGe siGnal PerForMance
As the amplitude of the input signal increases, the internal dynamic current sources increase the operation band-
width of the amplifier. This unique performance is apparent in its slew rate, pulse response, and large signal perfor-
mance plots. Recall the previous discussion about the relationships between signal amplitude, supply current, and
slew rate. As the amplitude of the input amplitude increases from 1 V
V/µs to well over 350 V/µs.
Notice the knee in the Rise and Fall times plot, at approximately 6 V
becomes clipped by the supply rails and the amplifier is no longer operating in a closed loop fashion. The rise and
fall times become faster as the dynamic current sources are providing maximum current for slewing. The result of
this amplifier architecture is that it slews fast, but allows good control of overshoot for large input signals. This can
be seen clearly in the large signal Transient Response plots.
heatsinkinG anD saFe oPeratinG area
The MOSFET output stage of the PA78 is not limited by second break-
down considerations as in bipolar output stages. Only thermal con-
siderations of the package and current handling capabilities limit the
Safe Operating Area. The SOA plots include power dissipation limita-
tions which are dependent upon case temperature. Keep in mind that
the dynamic current sources which drive high slew rates can increase
the operating temperature of the amplifier during periods of repeated
slewing. The plot of supply current vs. input signal amplitude for a 100
kHz signal provides an indication of the supply current with repeated
slewing conditions. This application dependent condition must be con-
sidered carefully.
The output stage is self-protected against transient flyback by the para-
sitic body diodes of the output stage. However, for protection against
sustained high energy flyback, external, fast recovery diodes must be
used.
cUrrent liMit
For proper operation, the current limit resistor, R
timum value for Rlim in the intended application. Current limit may not protect against short circuit conditions with
supply voltages over 200 V.
LIM
is about 12 Ω. However, refer to the SOA curves for each package type to assist in selecting the op-
S
to –V
BIAS
S
technique, external phase compensation maintains the low idle current but does affect
). NPO capacitors are recommended to maintain the desired level of compensation over
LIM
, must be connected as shown in the external connections dia-
P r o d u c t I n n o v a t i o n F r o m
C
must be rated for a working voltage of the full operating
C
- and -V
S
BIAS
S
to prevent oscillations in the falling edge of the
P-P
P-P
to -V
, between C
input voltage. Beyond this point the output
SUPPLY TO OUTPUT DIFFERENTIAL, V
to 15 V
S
160
140
120
100
).
80
60
40
20
0
10
P-P
, the slew rate increases from 50
C
- and V
125°C
SOA
S
75°C
+. The size of R
100
25°C
1000
MP400U
S
BIAS
-V
O
will
(V)