DRV1101 Datasheet, PDF (6/8 Pages) Burr-Brown (TI) – HIGH POWER DIFFERENTIAL LINE DRIVER

To compute the internal junction temperature, this power is
multiplied by the junction to ambient thermal impedance (to
get the temperature rise above ambient) then added to the
ambient temperature. Using the specified maximum ambient
temperature of +85°C, the junction temperature for the
DRV1101 in an SO-8 package under these worst case
conditions will be:
T_J = 85°C + 0.423W • 125°C/W = 138°C
The internal junction temperature should, in all cases, be
limited to < 150°C. For a maximum ambient temperature of
+85°C, this limits the internal temperature rise to less than
65°C. Figure 4 shows the temperature rise from ambient to
junction for loads of 15Ω and 100Ω.
INPUT INTERFACE CIRCUITS
DRV1101 is designed for operation with a differential input
centered at V_DD/2. Signals that do not require DC coupling
may be connected as shown in Figure 5 through blocking
caps to a midpoint reference developed through resistor
dividers from the supply voltage. The 1MΩ bias resistors
determine four performance requirements.
• They bias the inputs at the supply midpoint.
• They provide a DC bias current path for the input of the
DRV1101.
• They set the AC input impedance of the circuit to approxi-
mately 1MΩ.
• They set the low cutoff frequency along with C_B.
The bias resistors maybe set to a lower level if a lower input
impedance is desired.
INTERNAL TEMPERATURE RISE
OF DRV1101
90
80
70
Limit at 85°C Ambient
60
R_L = 15Ω
50
40
30
20
10
R_L = 100Ω
0
0
0.5
1
1.5
2
2.5
3
3.5
Load Voltage (rms)
FIGURE 4. Junction Temperature Rise From Ambient for
the DRV1101U.
5V
100kΩ
100kΩ
0.01µF
C_B
V₁
1MΩ
1MΩ
R_L
V₂
C_B
FIGURE 5. AC-Coupled Differential Input Interface.
®
DRV1101
6