Wolfson WM8978, Manual, Page: 5 / 119

Production Data
WM8978
w
PD, Rev 4.5, October 2011
5
PIN DESCRIPTION
PIN NAME TYPE DESCRIPTION
1 LIP Analogue input Left Mic Pre-amp positive input
2 LIN Analogue input
Left Mic Pre-amp negative input
3 L2/GPIO2 Analogue input Left channel line input/secondary mic pre-amp positive input/GPIO2 pin
4 RIP Analogue input Right Mic Pre-amp positive input
5 RIN Analogue input Right Mic Pre-amp negative input
6 R2/GPIO3 Analogue input
Right channel line input/secondary mic pre-amp positive input/GPIO3 pin
7 LRC Digital Input / Output DAC and ADC Sample Rate Clock
8 BCLK Digital Input / Output Digital Audio Port Clock
9 ADCDAT Digital Output
ADC Digital Audio Data Output
10 DACDAT Digital Input DAC Digital Audio Data Input
11 MCLK Digital Input Master Clock Input
12 DGND Supply Digital ground
13 DCVDD
Supply Digital core logic supply
14 DBVDD Supply Digital buffer (I/O) supply
15 CSB/GPIO1 Digital Input / Output 3-Wire Control Interface Chip Select / GPIO1 pin
16 SCLK
Digital Input 3-Wire Control Interface Clock Input / 2-Wire Control Interface Clock
Input
17 SDIN
Digital Input / Output 3-Wire Control Interface Data Input / 2-Wire Control Interface Data Input
18 MODE Digital Input Control Interface Selection
19 AUXL Analogue input Left Auxillary input
20 AUXR Analogue input Right Auxillary input
21 OUT4 Analogue Output Buffered midrail Headphone pseudo-ground, or Right line output or MONO
mix output
22 OUT3 Analogue Output
Buffered midrail Headphone pseudo-ground, or Left line output
23 ROUT2 Analogue Output Second right output, or BTL speaker driver positive output
24 SPKGND Supply Speaker ground (feeds speaker amp and OUT3/OUT4)
25 LOUT2 Analogue Output
Second left output, or BTL speaker driver negative output
26 SPKVDD Supply Speaker supply (feed speaker amp only)
27 VMID Reference Decoupling for ADC and DAC reference voltage
28 AGND Supply Analogue ground (feeds ADC and DAC)
29 ROUT1 Analogue Output
Headphone or Line Output Right
30 LOUT1 Analogue Output Headphone or Line Output Left
31 AVDD Supply Analogue supply (feeds ADC and DAC)
32 MICBIAS Analogue Output
Microphone Bias
Note:
It is recommended that the QFN ground paddle should be connected to analogue ground on the application PCB. Refer to
the application note WAN_0118 on “Guidelines on How to Use QFN Packages and Create Associated PCB Footprints”.