NCP2809 Series
http://onsemi.com
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Table 1. Bill of Material − Micro10
Item Part Description Ref.
PCB
Footprint
Manufacturer
Manufacturer
Reference
1 NCP2809 Audio Amplifier U1,U3 Micro10 ON Semiconductor NCP2809
2 SMD Resistor 100 K R1,R2 0805 Vishay−Draloric D12CRCW Series
3 Ceramic Capacitor 390 nF 50 V Z5U C2,C4,
C6,C8
1812 Kemet C1812C394M5UAC
4 Ceramic Capacitor 1.0 F 16 V X7R
Optimized Performance
C1,C3,
C5,C7
1206 Murata GRM42−6X7R105K16
5 Tantalum Capacitor 220 F 10 V C9,C10 − Kemet T495X227010AS
6 I/O Connector. It can be plugged by
BLZ5.08/2 (Weidmüller Reference)
J4,J10 − Weidmüller SL5.08/2/90B
7 I/O Connector. It can be plugged by
BLZ5.08/3 (Weidmüller Reference)
J2,J3,
J8,J9
− Weidmüller SL5.08/3/90B
8 3.5 mm PCB Jack Connector U2,U4 − Decelect−Forgos IES 101−3
9 Jumper Header Vertical Mount
2*1, 2.54 mm
J1,J7 − − −
Table 2. Bill of Material − UDFN10
Item Part Description Ref. PCB Footprint Manufacturer Manufacturer Part Number
1 Stereo Headphone Amplifier U1 UDFN10 3x3 ON Semiconductor NCP2809B
2 Thick Film Chip Resistor R1−R5 0805 Vishay CRCW08052022FNEA
3 Ceramic Chip Capacitor C1,C2,C5,C7 0805 TDK C2012X7R1C105K
4 PCB Header, 2 Poles J5 NA Phoenix MSTBA 2,5/2−G
5 SMB Connector J1,J2,J8 NA RS RS 546−3406
6 3.5 mm PCB Jack Connector U2 NA CUI Inc SJ−3515N
7 Short Connector J14,J15 NA NA NA
8 Short Connector J24,J25 NA NA NA
PCB LAYOUT GUIDELINES
How to Optimize the Accuracy of VMC
The main innovation of the NCP2809 stereo NOCAP
audio amplifier is the use of a virtual ground that allows
connecting directly the headset on the outputs of the device
saving DC−blocking output capacitors. In order to have the
best performances in terms of crosstalk, noise and supply
current, the feedback connection on the virtual ground
amplifier is not closed internally. To reach this goal of
excellence, one must connect OUT_I and REF_I as close
as possible from the middle point of the output jack
connector. The most suitable place for this connection is
directly on the pad of this middle point.
How to Optimize THD+N Performances
To get the best THD+N level on the headset speakers, the
traces of the power supply, ground, OUT_R, OUT_L and
OUT_I need the lowest resistance. Thus, the PCB traces for
these nets should be as wide and short as possible.
You need to avoid ground loops, run digital and analog
traces parallel to each other. Due to its internal structure,
the amplifier can be sensitive to coupling capacitors
between Ground and each output (OUT_R, OUT_L and
OUT_I). Avoid running the output traces between two
ground layers or if traces must cross over on different
layers, do it at 90 degrees.
