LM4937RL/NOPB National Semiconductor, LM4937RL/NOPB Datasheet - Page 27

• Manufacturer Part Number: LM4937RL/NOPB
• Description: IC AUDIO SUBSYSTM 1.25W 36USMDXT
• Manufacturer: National Semiconductor
• Series: Boomer®r
• Type: Class ABr

Specifications of LM4937RL/NOPB

• Output Type: 1-Channel (Mono) with Mono and Stereo Headphones
• Max Output Power X Channels @ Load: 1.25W x 1 @ 8 Ohm; 80mW x 2 @ 32 Ohm
• Voltage - Supply: 2.7 V ~ 5.5 V
• Features: Depop, Differential Inputs, I²C, I²S, Mute, Shutdown, SPI, Volume Control
• Mounting Type: Surface Mount
• Package / Case: 36-MicroSMDxt
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: LM4937RLTR

FIR Compensation Filter
Configuration Registers
These registers are used to configure the DAC’s FIR com-
pensation filter. Three 16 bit coefficients are required and
COMP_COEFF (10h
NOTES:
The filter must be phase linear to ensure the data keeps the correct stereo imaging so the second half of the FIR filter must be the reverse of the 1st half.
If the CUST_COMP option in register 0Eh is not set the FIR
filter will use its default values for a linear response from the
DAC into the analog mixer, these values are:
If using 96 or 192kHz data then the custom compensation
may be required to obtain flat frequency responses above
24kHz. The total power of any custom filter must not exceed
Address
10h
11h
12h
13h
14h
15h
DAC_OSR
01, 10, 11
00
COMP_COEFF0_MSB
COMP_COEFF1_MSB
COMP_COEFF2_MSB
COMP_COEFF0_LSB
COMP_COEFF1_LSB
COMP_COEFF2_LSB
Register
→
15h) (Set = logic 1, Clear = logic 0)
C0, C4
434
61
27
Bits [15:8] of the 2nd and 4th FIR tap (C1 and C3)
Bits [15:8] of the 1st and 5th FIR tap (C0 and C4)
Bits [7:0] of the 2nd and 4th FIR tap (C1 and C3)
Bits [7:0] of the 1st and 5th FIR tap (C0 and C4)
must be programmed via the I2C/SPI Interface in bytes as
follows:
that of the above examples or the filters within the DAC will
clip. The coefficient must be programmed in 2’s complement.
Bits [15:8] of the 3rd FIR tap (C2)
Bits [7:0] of the 3rd FIR tap (C2)
C1, C3
Description
–2291
–371
20202055
26984
25699
C2
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