CS4525-CNZ Cirrus Logic Inc, CS4525-CNZ Datasheet - Page 59

• Manufacturer Part Number: CS4525-CNZ
• Description: IC AMP AUDIO PWR 30W QUAD 48QFN
• Manufacturer: Cirrus Logic Inc
• Series: Popguard®r
• Type: Class Dr

Specifications of CS4525-CNZ

• Output Type: 2-Channel (Stereo) or 4-Channel (Quad)
• Package / Case: 48-QFN
• Max Output Power X Channels @ Load: 30W x 1 @ 4 Ohm; 15W x 2 @ 8 Ohm
• Voltage - Supply: 8 V ~ 18 V
• Features: ADC, Depop, I²C, I²S, Mute, PWM, Short-Circuit and Thermal Protection, Volume Control
• Mounting Type: Surface Mount
• Product: Class-D
• Output Power: 30 W
• Thd Plus Noise: 10 %
• Operating Supply Voltage: 2.5 V to 5 V
• Supply Current: 54 mA
• Maximum Power Dissipation: 180 mW
• Maximum Operating Temperature: + 70 C
• Mounting Style: SMD/SMT
• Audio - Load Impedance: 4 Ohms, 6 Ohms, 8 Ohms
• Audio Load Resistance: 8 Ohms, 4 Ohms
• Minimum Operating Temperature: 0 C
• Supply Voltage (max): 5.25 V
• Supply Voltage (min): 2.375 V
• Amplifier Class: D
• No. Of Channels: 4
• Supply Voltage Range: 8V To 18V
• Load Impedance: 4ohm
• Operating Temperature Range: 0°C To +70°C
• Amplifier Case Style: QFN
• No. Of Pins: 48
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: 598-1586 - REFERENCE BOARD FOR CS4525 PWM
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 598-1264

DS726PP2
6.4
6.4.1
Output Filters
The filter placed after the PWM outputs can greatly affect the output performance. The filter not only reduces
radiated EMI (snubber filter), but also filters high frequency content from the switching output before going
to the speaker (low-pass LC filter).
Half-Bridge Output Filter
Figure 26
(snubber circuit) is comprised of a capacitor (680 pF) and a resistor (5.6 Ω, 1/8 W) and should be placed
as close as possible to the corresponding PWM output pin to greatly reduce radiated EMI.
The inductor, L1, and capacitor, C1, comprise the low-pass filter. Along with the nominal load impedance
of the speaker, these values set the cutoff frequency of the filter.
for L1 and C1 based on nominal speaker (load) impedance for a corner frequency (-3 dB point) of approx-
imately 35 kHz.
C2 is the DC-blocking capacitor.
(-3 dB point) and a nominal speaker (load) impedances of 4 Ω, 6 Ω, and 8 Ω. This capacitor should also
be chosen to have a ripple current rating above the amount of current that will passed through it.
shows the output filter for a half-bridge configuration. The transient-voltage suppression circuit
OUTx
Table 19. DC-Blocking Capacitors Values - Half-Bridge
Table 18. Low-Pass Filter Components - Half-Bridge
Load
Load
4 Ω
6 Ω
8 Ω
4 Ω
6 Ω
8 Ω
Figure 26. Output Filter - Half-Bridge
Table 19
680 pF
5.6 Ω
shows the component values for C2 based on corner frequency
Corner Frequency
VP
*Diode is Rohm
RB160M-30 or
120 Hz
120 Hz
110 Hz
22 µH
33 µH
47 µH
40 Hz
58 Hz
39 Hz
68 Hz
42 Hz
60 Hz
equivalent
L1
L1
Table 18
C1
+
C2
1000 µF
0.68 µF
0.47 µF
680 µF
330 µF
680 µF
390 µF
220 µF
470 µF
330 µF
180 µF
1.0 µF
-
C1
C2
shows the component values
CS4525
59