DAC7760IPWPR datasheet(51/63 Pages) TI1

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GND

AVSS

AVDD

Digital I/O

Analog Supply Decoupling

Digital Supply

Decoupling

External RSET

(Optional)

BOOST Configuration

(Optional)

DAC7760, DAC8760

www.ti.com

SBAS528B – JUNE 2013 – REVISED JUNE 2016

Product Folder Links: DAC7760 DAC8760

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11.2 Layout Example

Figure 100. DACx760 Layout Example

11.3 Thermal Considerations

The DACx760 is designed for a maximum junction temperature of +150°C. In cases where the maximum AVDD

is driving maximum current into ground, this could be exceeded. Use the following equation, from the Absolute

Maximum Ratings, to determine the maximum junction temperature that can be reached:

Power Dissipation = (TJmax – TA)/θJA

where

•

TJmax = 150°C

•

TA is the ambient temperature

•

θJA is the package dependent junction-to-ambient thermal resistance, which is found in Thermal Information (8)

The power dissipation can be calculated by multiplying all the supply voltages with the currents supplied, which is

found in the Power Requirements subsection of Electrical Characteristics.

Consider an example: IOUT is enabled, supplying 24 mA into GND with a 25°C ambient temperature, AVDD of

24 V, AVSS is tied to GND and DVDD is generated internally. From the specifications table, the maximum value

of AIDD = 3 mA when IOUT is enabled and DAC code = 0x0000. Also, the maximum value of DIDD = 1 mA.

Accordingly, the worst case power dissipation is 24 V × (24 mA + 3 mA + 1 mA) = 672 mW. Using the RθJA value

for the TSSOP package, we get TJmax = 25°C + (32.3 × 0.672)°C = 46.7°C. At 85°C ambient temperature, the

corresponding value of TJmax is 106.7°C. Using this type of analysis, the system designer can both specify and

design for the equipment operating conditions. Note that the thermal pad in both packages is recommended to

be connected to a copper plane for enhanced thermal performance.

DAC7760IPWPR bảng dữ liệu(PDF) 51 Page - Texas Instruments