WM8351GEB/V Wolfson Microelectronics, WM8351GEB/V Datasheet - Page 167

• Manufacturer Part Number: WM8351GEB/V
• Description: Audio CODECs Audio CODEC plus pwr management
• Manufacturer: Wolfson Microelectronics

Specifications of WM8351GEB/V

• Number Of Adc Inputs: 2
• Number Of Dac Outputs: 2
• Conversion Rate: 48 KSPS
• Interface Type: Serial (2-Wire, 3-Wire, 4-Wire)
• Resolution: 12 bit
• Operating Supply Voltage: 3.7 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Package / Case: BGA
• Minimum Operating Temperature: - 25 C
• Number Of Channels: 2 ADC/2 DAC
• Supply Current: 260 uA
• Thd Plus Noise: - 83 dB
• Audio Codec Type: Stereo
• No. Of Adcs: 2
• No. Of Dacs: 2
• No. Of Input Channels: 8
• No. Of Output Channels: 6
• Adc / Dac Resolution: 24bit
• Adcs / Dacs Signal To Noise Ratio: 95dB
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Production Data
18 SYSTEM MONITORING AND UNDERVOLTAGE LOCKOUT (UVLO)
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The WM8351 includes several mechanisms to prevent the system from starting up, or force it to shut
down, when power sources are critically low.
The under-voltage lockout (UVLO) is a non-programmable voltage limit. When the available supplies
are below this limit, the WM8351 enters the BACKUP state. The WM8351 can only proceed from
BACKUP to the OFF state if LINE is above the UVLO level. Whenever the WM8351 is in ACTIVE,
HIBERNATE or OFF state and LINE falls below the UVLO level, the WM8351 returns to the
BACKUP state.
The UVLO limit threshold is equal to VRTC + 50mV. The precise value of VRTC may vary between
devices, within the limits defined in the Electrical Characteristics (see Section 7.5).
The startup threshold is a programmable voltage limit. The WM8351 can only proceed from OFF to
the ACTIVE state if LINE is above the startup threshold. (Note that, in the case of USB-powered
operation, there are additional voltage requirements; see Section 17.4.). The startup threshold is
determined by the PCCMP_ON_THR register field.
The shutdown threshold is determined by the PCCMP_OFF_THR register field. When LINE falls
below this threshold, the WM8351 raises a SYS_HYST_COMP_FAIL_EINT interrupt. In addition, the
WM8351 takes the action set by PCCOMP_ERRACT. If this bit is set, then the WM8351 will shut
down in response to the LINE voltage falling below the shutdown threshold.
The startup and shutdown control register fields are described in Table 111. Note that the startup
threshold should always be set higher than the shutdown threshold in order to create a hysteresis,
making the system more stable.
The SYS_HYST_COMP_FAIL_EINT interrupt is one of the second-level interrupts which triggers a
first-level System Interrupt, SYS_INT (see Section 24). This can be masked by setting the mask bit
as described in Table 112.
Table 111 Battery Monitoring and UVLO Control
R179 (B3h)
Power Check
Comparator
ADDRESS
BIT
6:4
2:0
14
PCCMP_ER
RACT
PCCMP_OF
F_THR [2:0]
PCCMP_ON
_THR [2:0]
LABEL
DEFAULT
010
101
0
Action to take when LINE falls below
PCCMP_OFF_THR level (as well as
generating an interrupt)
0 = ignore
1 = shut down system
Power check comparator system shutdown
threshold value
000 = 2.9V
001 = 3.0V
…
111 = 3.6V
Protected by security key.
Power check comparator system startup
threshold value
000 = 2.9V
001 = 3.0V
…
111 = 3.6V
Protected by security key.
DESCRIPTION
PD, March 2010, Rev 4.2
WM8351
167