ADA4938-2ACPZ-R2 datasheet(7/26 Pages) AD

7 / 26 page

Data Sheet

ADA4938-1/ADA4938-2

Rev. B | Page 7 of 26

ABSOLUTE MAXIMUM RATINGS

Table 5.

Parameter

Rating

Supply Voltage

12 V

Power Dissipation

See Figure 4

Storage Temperature Range

−65°C to +125°C

Operating Temperature Range

−40°C to +85°C

Lead Temperature (Soldering, 10 sec)

300°C

Junction Temperature

150°C

Stresses at or above those listed under Absolute Maximum

Ratings may cause permanent damage to the product. This is a

stress rating only; functional operation of the product at these

or any other conditions above those indicated in the operational

section of this specification is not implied. Operation beyond

the maximum operating conditions for extended periods may

affect product reliability.

THERMAL RESISTANCE

θJA is specified for the device (including exposed pad) soldered

to a high thermal conductivity 4-layer circuit board, as described in

EIA/JESD 51-7. The exposed pad is not electrically connected to

the device. It is typically soldered to a pad on the PCB that is

thermally and electrically connected to an internal ground plane.

Table 6. Thermal Resistance

Package Type

θJA

Unit

16-Lead LFCSP (Exposed Pad)

°C/W

24-Lead LFCSP (Exposed Pad)

°C/W

Maximum Power Dissipation

The maximum safe power dissipation in the ADA4938-1/

ADA4938-2 packages is limited by the associated rise in

junction temperature (TJ) on the die. At approximately 150°C,

which is the glass transition temperature, the plastic changes its

properties. Even temporarily exceeding this temperature limit

can change the stresses that the package exerts on the die,

permanently shifting the parametric performance of the

ADA4938-1/ADA4938-2. Exceeding a junction temperature of

150°C for an extended period can result in changes in the silicon

devices, potentially causing failure.

The power dissipated in the package (PD) is the sum of the

quiescent power dissipation and the power dissipated in the

package due to the load drive. The quiescent power is the voltage

between the supply pins (VS) times the quiescent current (IS).

The power dissipated due to the load drive depends upon the

particular application. The power due to load drive is calculated

by multiplying the load current by the associated voltage drop

across the device. RMS voltages and currents must be used in

these calculations.

Airflow increases heat dissipation, which effectively reduces θJA.

In addition, more metal directly in contact with the package

leads/exposed pad from metal traces, through-holes, ground,

and power planes reduces the θJA.

Figure 4 shows the maximum safe power dissipation in the

package vs. the ambient temperature for the ADA4938-1,

16-lead LFCSP (95°C/W) and the ADA4938-2, 24-lead LFCSP

(65°C/W) on a JEDEC standard 4-layer board.

3.5

2.5

3.0

2.0

1.5

1.0

0.5

–40 –30 –20 –10

AMBIENT TEMPERATURE (°C)

ADA4938-1

ADA4938-2

Figure 4. Maximum Power Dissipation vs. Temperature, 4-Layer Board

ESD CAUTION

ADA4938-2ACPZ-R2 数据表(PDF) 7 Page - Analog Devices

ADA4938-2ACPZ-R2 数据表(HTML) 7 Page - Analog Devices

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26

数据表下载