1N5817 1N5818 1N5819
R
θ
JL, THERMAL RESISTANCE, JUNCTION–TO–LEAD (
°
C/W)
90
80
70
60
MAXIMUM
50
TYPICAL
40
30
20
10
1
1/8
1/4
3/8
1/2
5/8
3/4
7/8
1.0
BOTH LEADS TO HEATSINK,
EQUAL LENGTH
PF(AV) , AVERAGE POWER DISSIPATION (WATTS)
5.0
3.0
Sine Wave
I(FM) =
π
(Resistive Load)
2.0 I(AV)
5
Capacitive
10
1.0
Loads
20
0.7
0.5
{
dc
SQUARE WAVE
TJ
≈
125°C
0.3
0.2
0.1
0.07
0.05
0.2
L, LEAD LENGTH (INCHES)
0.4
0.6 0.8 1.0
2.0
IF(AV), AVERAGE FORWARD CURRENT (AMP)
4.0
Figure 4. Steady–State Thermal Resistance
Figure 5. Forward Power Dissipation
1N5817–19
r(t), TRANSIENT THERMAL RESISTANCE (NORMALIZED)
1.0
0.7
0.5
0.3
0.2
0.1
0.07
0.05
0.03
0.02
0.01
0.1
0.2
0.5
1.0
2.0
5.0
10
20
t, TIME (ms)
50
100
200
500
1.0k
2.0k
5.0k
10k
Z
θJL(t)
= Z
θJL •
r(t)
tp
Ppk
t1
Ppk
TIME
DUTY CYCLE, D = tp/t1
PEAK POWER, Ppk, is peak of an
equivalent square power pulse.
∆T
JL = Ppk
•
R
θJL
[D + (1 – D)
•
r(t1 + tp) + r(tp) – r(t1)]
where
∆T
JL = the increase in junction temperature above the lead temperature
r(t) = normalized value of transient thermal resistance at time, t, from Figure 6, i.e.:
r(t) =
r(t1 + tp) = normalized value of transient thermal resistance at time, t1 + tp.
Figure 6. Thermal Response
NOTE 2 — MOUNTING DATA
Data shown for thermal resistance junction–to–ambient (R
θJA
) for
the mountings shown is to be used as typical guideline values for pre-
liminary engineering, or in case the tie point temperature cannot be
measured.
Mounting Method 1
P.C. Board with
1–1/2″ x 1–1/2″
copper surface.
L
L
Mounting Method 3
P.C. Board with
1–1/2″ x 1–1/2″
copper surface.
L = 3/8″
TYPICAL VALUES FOR R
θJA
IN STILL AIR
Mounting
Method
1
2
3
Lead Length, L (in)
1/8
52
67
1/4
65
80
50
1/2
72
87
3/4
85
100
R
θJA
°C/W
°C/W
°C/W
L
Mounting Method 2
L
BOARD GROUND
PLANE
VECTOR PIN MOUNTING
Rectifier Device Data
3
MOTOROLA [ MOTOROLA, INC ]
