wm8782a Wolfson Microelectronics plc, wm8782a Datasheet - Page 15

• Manufacturer Part Number: wm8782a
• Description: 24-bit, 192khz Stereo Adc
• Manufacturer: Wolfson Microelectronics plc

Production Data
Notes:
w
1.
2.
3.
4.
5.
6.
Test Conditions
AVDD = 5V, DVDD = 3.3V, AGND = DGND = 0V, T
PARAMETER
Power Supply Input Timing Information
DVDD level to activate POR
– power on
AVDD level to activate POR –
power on
VMID level to activate POR –
power on
DVDD level to release POR –
power on (see notes 1 and 2)
AVDD level to release POR –
power on (see notes 1 and 2)
VMID level to release POR –
power on (see notes 1 and 2)
POR active period (see notes
1 and 2)
DVDD level to activate POR
– power off (see note 5)
AVDD level to activate POR –
power off (see note 5)
VMID level to activate POR –
power off (see note 5)
Power on – POR propagation
delay through device
Power down – POR
propagation delay through
device
POR is activated when DVDD or AVDD or VMID reach their stated V
POR is only released when DVDD and AVDD and VMID have all reached their stated V
The rate of rise of VMID depends on the rate of rise of AVDD, the internal 50kΩ resistance and the external
decoupling capacitor. Typical tolerance of 50K resistor can be taken as +/-20%.
If AVDD, DVDD or VMID suffer a brown-out (i.e. drop below the minimum recommended operating level but do not go
below V
recommended level again.
The chip will enter reset at power down when AVDD or DVDD or VMID falls below V
supply is turned on and off frequently by a power management system.
The minimum t
guaranteed by design rather than test.
por_off,
), then the chip will not reset and will resume normal operation when the voltage is back to the
por
period is maintained even if DVDD, AVDD and VMID have zero rise time. This specification is
SYMBOL
V
V
V
V
V
V
V
V
V
por_off
por_off
por_off
t
t
t
poff
pon
pora
pora
pora
por
porr
porr
porr
Measured from DGND
Measured from AGND
Measured from AGND
Measured from DGND
Measured from AGND
Measured from AGND
Measured from DGND
Measured from AGND
Measured from AGND
active to POR release
Measured from falling
Measured from rising
Measured from POR
TEST CONDITIONS
EDGE of POR
EDGE of POR
A
= +25°C
(note 6)
pora
30
MIN
level (Figure 8)
Defined by DVDD/AVDD/
DVDD Min
AVDD Min
VMID Rise Time
por_off
0.7
0.7
0.7
0.8
0.8
0.7
30
30
TYP
1
porr
. This may be important if the
levels (Figure 8).
MAX
PD, April 2010, Rev 4.8
UNIT
μs
μs
μs
V
V
V
V
V
V
V
V
V
WM8782A
15