wm8918 Wolfson Microelectronics plc, wm8918 Datasheet - Page 170

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

WM8918
APPLICATIONS INFORMATION
RECOMMENDED EXTERNAL COMPONENTS
Figure 71 Recommended External Components
Notes:
1.
2.
C14 (CPCA-CPCB)
C15 (CPVOUTN)
C16 (CPVOUTP)
Table 88 Charge Pump Capacitors
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COMPONENT
X5R ceramic capacitor is recommended for capacitors C1, C2, C3, C4, C5, C15, C16, C17 and C18.
The positioning of C17 and C18 is very important - these should be as close to the WM8918 as possible.
Capacitors C15 and C16 should also be positioned as close to the WM8918 as possible.
Specific recommendations for C14, C15 and C16 are provided in Table 88. Note that two different recommendations are
provided for C15 and C16; either of these components is suitable, depending upon size requirements and availability.
The positioning of C14 is very important - this should be as close to the WM8918 as possible.
It is important to select a suitable capacitor type for the Charge Pump. Note that the capacitance may vary with DC voltage;
care is required to ensure that required capacitance is achieved at the applicable operating voltage, as specified in Table 88.
The capacitor datasheet should be consulted for this information.
Decoupling Capacitors
Charge Pump Capacitors
CAPACITANCE
≥ 1μF at 2VDC
≥ 2μF at 2VDC
REQUIRED
VALUE
2.2μF
2.2μF
4.7μF
MuRata GRM188R61A225KE34D
MuRata GRM155R60J475M_EIA
Kemet C0402C225M9PAC
PART NUMBER
VOLTAGE
6.3v
6.3v
PD, Rev 4.0, September 2010
10v
TYPE
X5R
X5R
X5R
Production Data
SIZE
0402
0603
0402
170