Datasheet

Maxim Integrated │ 87
MAX98090 Ultra-Low Power Stereo Audio Codec
www.maximintegrated.com
Table 9. Microphone 1 Enable and Level Configuration Register
Table 10. Microphone 2 Enable and Level Configuration Register
Analog Microphone Preamplier and PGA
The analog microphone inputs have two stages of pro-
grammable gain amplifiers, and are then routed to the
ADC mixer (record), the analog outputs (playback), or
simultaneously to both. The first, a coarse preamplifier
gain stage, includes the analog microphone enable, and
offers selectable 0dB, 20dB, or 30dB gain settings. The
second, a fine gain stage, is a programmable-gain ampli-
fier (PGA) adjustable from 0dB to 20dB in 1dB steps
(Tables 9 and 10). Together, the two stages provide up
to 50dB of signal gain for the analog microphone inputs.
To maximize the signal-to-noise ratio, use the coarse
gain settings of the first stage whenever possible. Zero-
crossing detection is included on the PGA to minimize
zipper noise while making gain changes.
ADDRESS: 0x10
DESCRIPTION
BIT NAME TYPE POR
7 — — — —
6
PA1EN[1:0] R/W
0
Microphone 1 Input Amplier Enable and Coarse Gain Setting
00: Disabled 10: 20dB
01: 0dB 11: 30dB
5 0
4
PGAM1[4:0] R/W
1
Microphone 1 Programmable Gain Amplier Fine Adjust Conguration
3 0
0x1F: 0dB
0x14: 0dB
0x13: 1dB
0x12: 2dB
0x11: 3dB
0x10: 4dB
0x0F: 5dB
0x0E: 6dB
0x0D: 7dB
0x0C: 8dB
0x0B: 9dB
0x0A: 10dB
0x09: 11dB
0x08: 12dB
0x07: 13dB
0x06: 14dB
0x05: 15dB
0x04: 16dB
0x03: 17dB
0x02: 18dB
0x01: 19dB
0x00: 20dB
2 1
1 0
0 0
ADDRESS: 0x11
DESCRIPTION
BIT NAME TYPE POR
7 — — — —
6
PA2EN[1:0] R/W
0
Microphone 2 Input Amplier Enable and Coarse Gain Setting
00: Disabled 10: 20dB
01: 0dB 11: 30dB
5 0
4
PGAM2[4:0] R/W
1
Microphone 2 Programmable Gain Amplier Fine Adjust Conguration
3 0
0x1F: 0dB
0x14: 0dB
0x13: 1dB
0x12: 2dB
0x11: 3dB
0x10: 4dB
0x0F: 5dB
0x0E: 6dB
0x0D: 7dB
0x0C: 8dB
0x0B: 9dB
0x0A: 10dB
0x09: 11dB
0x08: 12dB
0x07: 13dB
0x06: 14dB
0x05: 15dB
0x04: 16dB
0x03: 17dB
0x02: 18dB
0x01: 19dB
0x00: 20dB
2 1
1 0
0 0