WM8711LGEFL/R Wolfson Microelectronics, WM8711LGEFL/R Datasheet - Page 19

• Manufacturer Part Number: WM8711LGEFL/R
• Description: Audio D/A Converter ICs Stereo DAC with H/P Line-In
• Manufacturer: Wolfson Microelectronics

Specifications of WM8711LGEFL/R

• Operating Supply Voltage: 1.8 V to 3.6 V, 1.42 V to 3.6 V
• Operating Temperature Range: - 25 C to + 85 C
• Mounting Style: SMD/SMT
• Package / Case: QFN-28
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Production Data
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DEVICE OPERATION
The recommended external components required to complete the application are shown in Figure 11.
Figure 11 Headphone Output Application Drawing
Recommended values are C1 = 220uF (10V electrolytic), R1 = 47k
C1 forms a DC blocking capacitor to isolate the dc of the HPOUT from the headphones. R1 form a
pull down resistor to discharge C1 to prevent the voltage at the connection to the headphones from
rising to a level that may damage the headphones.
DEVICE RESETTING
The WM8711L contains a power on reset circuit that resets the internal state of the device to a known
condition. The power on reset is applied as DCVDD powers on and released only after the voltage
level of DCVDD crosses a minimum turn off threshold. If DCVDD later falls below a minimum turn on
threshold voltage then the power on reset is re-applied. The threshold voltages and associated
hysteresis are shown in the Electrical Characteristics table.
The user also has the ability to reset the device to a known state under software control as shown in
the table below.
When using the software reset. In 3-wire mode the reset is applied on the rising edge of CSB and
released on the next rising edge of SCLK. In 2-wire mode the reset is applied for the duration of the
ACK signal (approximately 1 SCLK period, refer to Figure 21).
Table 5 Software Control of Reset
0001111
Reset Register
REGISTER
ADDRESS
HPOUT
8:0
BIT
RESET
LABEL
C1
not reset
DEFAULT
AGND
R1
Reset Register
Writing 00000000 to register resets
device
DESCRIPTION
PD, Rev 4.5, August 2011
WM8711L
AGND
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