Datasheet
LT6600-20
11
66002fb
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa-
tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.
S8 Package
8-Lead Plastic Small Outline (Narrow .150 Inch)
(Reference LTC DWG # 05-08-1610)
APPLICATIONS INFORMATION
Table 2. LT6600-20 SO-8 Package Thermal Resistance
COPPER AREA
TOPSIDE
(mm
2
)
BACKSIDE
(mm
2
)
BOARD AREA
(mm
2
)
THERMAL RESISTANCE
(JUNCTION-TO-AMBIENT)
1100 1100 2500 65°C/W
330 330 2500 85°C/W
35 35 2500 95°C/W
35 0 2500 100°C/W
0 0 2500 105°C/W
Junction temperature, T
J
, is calculated from the ambient
temperature, T
A
, and power dissipation, P
D
. The power
dissipation is the product of supply voltage, V
S
, and
supply current, I
S
. Therefore, the junction temperature
is given by:
T
J
= T
A
+ (P
D
• θ
JA
) = T
A
+ (V
S
• I
S
• θ
JA
)
where the supply current, I
S
, is a function of signal level, load
impedance, temperature and common mode voltages.
For a given supply voltage, the worst-case power dissipation
occurs when the differential input signal is maximum, the
common mode currents are maximum (see the Applications
Information section regarding common mode DC currents),
the load impedance is small and the ambient temperature is
maximum. To compute the junction temperature, measure
the supply current under these worst-case conditions, es-
timate the thermal resistance from Table 2, then apply the
equation for T
J
. For example, using the circuit in Figure 3
with a DC differential input voltage of 250mV, a differential
output voltage of 1V, no load resistance and an ambient
temperature of 85°C, the supply current (current into Pin 3)
measures 55.5mA. Assuming a PC board layout with a
35mm
2
copper trace, the θ
JA
is 100°C/W. The resulting
junction temperature is:
T
J
= T
A
+ (P
D
• θ
JA
) = 85 + (5 • 0.0555 • 100) = 113°C
When using higher supply voltages or when driving small
impedances, more copper may be necessary to keep T
J
below 150°C.
PACKAGE DESCRIPTION
.016 – .050
(0.406 – 1.270)
.010 – .020
(0.254 – 0.508)
× 45°
0°– 8° TYP
.008 – .010
(0.203 – 0.254)
SO8 0303
.053 – .069
(1.346 – 1.752)
.014 – .019
(0.355 – 0.483)
TYP
.004 – .010
(0.101 – 0.254)
.050
(1.270)
BSC
1
2
3
4
.150 – .157
(3.810 – 3.988)
NOTE 3
8
7
6
5
.189 – .197
(4.801 – 5.004)
NOTE 3
.228 – .244
(5.791 – 6.197)
.245
MIN
.160
±
.005
RECOMMENDED SOLDER PAD LAYOUT
.045
±
.005
.050 BSC
.030
±
.005
TYP
INCHES
(MILLIMETERS)
NOTE:
1. DIMENSIONS IN
2. DRAWING NOT TO SCALE
3. THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .006" (0.15mm)