TP3057WM National Semiconductor, TP3057WM Datasheet - Page 12

• Manufacturer Part Number: TP3057WM
• Manufacturer: National Semiconductor
• Type: PCMr

Specifications of TP3057WM

• Number Of Channels: 1
• Gain Control: Adjustable
• Number Of Adc's: 1
• Number Of Dac's: 1
• Package Type: SOIC W
• Operating Supply Voltage (typ): ±5V
• Number Of Adc Inputs: 1
• Number Of Dac Outputs: 1
• Operating Supply Voltage (max): ±5.25V
• Operating Supply Voltage (min): ±4.75V
• Operating Temperature (max): 85C
• Operating Temperature (min): -40C
• Pin Count: 16
• Mounting: Surface Mount
• Lead Free Status / RoHS Status: Not Compliant

Applications Information
POWER SUPPLIES
While the pins of the TP305X family are well protected
against electrical misuse it is recommended that the stan-
dard CMOS practice be followed ensuring that ground is
connected to the device before any other connections are
made In applications where the printed circuit board may be
plugged into a ‘‘hot’’ socket with power and clocks already
present an extra long ground pin in the connector should
be used
All ground connections to each device should meet at a
common point as close as possible to the GNDA pin This
minimizes the interaction of ground return currents flowing
through a common bus impedance 0 1
pling capacitors should be connected from this common
ground point to V
possible
For best performance the ground point of each CODEC
FILTER on a card should be connected to a common card
ground in star formation rather than via a ground bus
Note See Application Note 370 for further details
CC
and V
BB
as close to the device as
R1
R2
Where N
Where Z
and Z
F supply decou-
and
Also Z
S
e
e
e
OC
Z1
2 Z1 Z2
SC
e
e
Z1
Z2
e
N
N
e
2
2
impedance with open circuit termination
R3
R3
Z
a
b
T-Pad Attenuator
impedance with short circuit termination
POWER OUT
SC
POWER IN
N
-Pad Attenuator
1
1
e
e
2
N
Z1
b
Z
b
OC
Z1 Z2
1
2 Z1 Z2
N
2
12
2
b
N
2
2NS
N
This common ground point should be decoupled to V
V
RECEIVE GAIN ADJUSTMENT
For applications where a TP305X family CODEC filter re-
ceive output must drive a 600
than
justed by inserting a matched T-pad or
Table II lists the required resistor values for 600
tions As these are generally non-standard values the equa-
tions can be used to compute the attenuation of the closest
practical set of resistors It may be necessary to use un-
equal values for the R1 or R4 arms of the attenuators to
achieve a precise attenuation Generally it is tolerable to
allow a small deviation of the input impedance from nominal
while still maintaining a good return loss For example a 30
dB return loss against 600
ance of the attenuator is in the range 282
suming a perfect transformer)
b
2
BB
N
b
N
1
a
2
1
N
with 10 F capacitors
b
g
1
1
2 5V is required the receive gain can be easily ad-
is obtained if the output imped-
TL H 5510 – 5
load but a peak swing lower
-pad at the output
to 319
termina-
CC
(as-
and