wm8918 Wolfson Microelectronics plc, wm8918 Datasheet - Page 14

• Manufacturer Part Number: wm8918
• Description: Ultra Low Power Dac For Portable Audio Applications
• Manufacturer: Wolfson Microelectronics plc

WM8918
Note:
1.
w
Microphone Bias (for analogue electret condenser microphones)
Additional test conditions: MICBIAS_ENA=1, all parameters measured at the MICBIAS pin
Bias Voltage.
Note: 7/6 and 9/10 are available
only if MICVDD > AVDD.
Note: 3/2 and 4/3 are available
only if MICVDD ≥ 2.5V.
Drop out voltage between
MICVDD and MICBIAS
Maximum source current
Noise spectral density
Power Supply Rejection Ratio
MICVDD to MICBIAS
Power Supply Rejection Ratio
MICVDD and AVDD to
MICBIAS
MICBIAS Current Detect Function (See Note 1)
Current Detect Threshold
(Microphone insertion)
Current Detect Threshold
(Microphone removal)
Delay Time for Current Detect
Interrupt
MICBIAS Short Circuit (Hook Switch) Detect Function (See Note 1)
Short Circuit Detect Threshold
(Button press)
Short Circuit Detect Threshold
(Button release)
Minimum Delay Time for
Short Circuit Detect Interrupt
If AVDD
PARAMETER
≠
1.8, current threshold values should be multiplied by (AVDD/1.8)
SYMBOL
V
I
PSRR
PSRR
t
MICBIAS
MICBIAS
SHORT
t
DET
AVDD = MICVDD = 1.8 V
AVDD = MICVDD = 1.8 V
MICSHORT_THR = 00
MICBIAS_SEL = 011
MICBIAS_SEL = 010
MICBIAS_SEL = 001
MICBIAS_SEL = 000
MICBIAS_SEL = 1xx
20kHz, 100mV pk-pk
20kHz, 100mV pk-pk
20kHz, 100mV pk-pk
20kHz, 100mV pk-pk
TEST CONDITIONS
1kHz, 100mV pk-pk
1kHz, 100mV pk-pk
1kHz, 100mV pk-pk
1kHz, 100mV pk-pk
MICDET_THR = 00
3mA load current,
MICVDD = 1.71 V
MICVDD = 1.71 V
MICVDD = 2.5 V
MICVDD = 2.5 V
MICVDD = 3.6 V
MICVDD = 3.6 V
MICVDD = 2.5V
At 1kHz
-10%
-10%
-10%
-10%
-10%
MIN
400
60
10/9 x AVDD
9/10 ×AVDD
3/2 x AVDD
4/3 x AVDD
7/6 x AVDD
TYP
200
3.2
19
67
76
88
84
61
70
54
79
47
PD, Rev 4.0, September 2010
4
+10%
+10%
+10%
+10%
+10%
MAX
600
80
Production Data
nV/√Hz
UNIT
mV
mA
ms
ms
dB
dB
μA
μA
V
14