N681622YG Nuvoton Technology Corporation of America, N681622YG Datasheet - Page 35

• Manufacturer Part Number: N681622YG
• Manufacturer: Nuvoton Technology Corporation of America

Specifications of N681622YG

• Lead Free Status / RoHS Status: Supplier Unconfirmed

The device contains an on-chip temperature sensor that senses the temperature inside the package. The sensor is
read through TEMP:TS[7:0] register (0x99) which is READ ONLY register. The temperature T in °C is given by the
following equation.
For example TEMP:TS[7:0] = 0x23, (35 decimal) indicates a temperature T=-32°C and TEMP:TS[7:0]=0xCD (205
decimal) indicates T=138°C. Similarly threshold temperatures T
(0xAA). The T
By enabling the temperature sensor interrupt in IE3:TMPE[0] address (0x2B), an interrupt will be generated if the
temperature reaches this threshold. This facilitates control of the temperature should the device get close to the
junction temperature. Note that there is no filtering associated with this temperature alarm since the package has an
intrinsic thermal time constant. It is recommended that the temperature alarm threshold be set to 125°C. The actual,
TINT, internal temperature can be estimated by the following equation.
T
For example, the maximum power dissipation for the QFN device is 0.7 W. The thermal resistance of the 48-pin QFN
package is 27.1°C/W. So at T
There is a built-in RING generator that can generate balanced sinusoidal or trapezoidal ringing without the need for
external components. Both trapezoidal and sine wave ringing signals can be generated. The Frequency, Amplitude,
DC offset and ringing cadence of the ringing signal are programmable. In the case of trapezoidal waveforms the
crest factor is also programmable. The choice of sinusoidal or trapezoidal will depend on requirements of the end
user; sinusoids are required in many parts of the world to minimize cross talk between the many tip/ring pairs in a
typical wiring bundle from the central office, whereas a trapezoid will deliver more power to the phone due to its low
crest factor. As Ringing utilizes the Tone Generation block, we will first examine this function.
A
Preliminary Datasheet Rev1.0
– Ambient Temperature, R
12.1.3. RINGING
12.1.2.2.
TH
is calculated by the following equation.
TEMPERATURE MONITOR
J
A
– Thermal Resistance, P – Power Dissipation
=85°C, the estimated internal temperature would be:
T
INT
T
T
=
INT
TH
T
85
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=
=
=
+
TATH
T
TS
A
27.1
7 [
+
:
[
7
] 0
*
0 :
⎛
⎜
⎜ ⎜
⎝
R
Single Programmable Extended Codec/SLCC
TH
]
−
0.7
J
can be set in register THAT:THAT[7:0] address
−
67
×
=
67
P
104
⎞
⎟
⎟ ⎟
⎠
ο
C
N681386/87
January 2010