BLF578XR; BLF578XRS
Power LDMOS transistor
Rev. 5 — 1 September 2015
Product data sheet
1. Product profile
1.1 General description
A 1400 W extremely rugged LDMOS power transistor for broadcast and industrial
applications in the HF to 500 MHz band. This product is an enhanced version of the
BLF578 using Ampleon's XR process to provide maximum ruggedness capability in the
most severe applications without compromising the RF performance.
Table 1.
Application information
f
(MHz)
pulsed RF
225
V
DS
(V)
50
P
L
(W)
1400
G
p
(dB)
23.5
D
(%)
69
Test signal
1.2 Features and benefits
Typical pulsed performance at frequency of 225 MHz, a supply voltage of 50 V and an
I
Dq
of 40 mA, a t
p
of 100
s
with
of 20 %:
Output power = 1400 W
Power gain = 23.5 dB
Efficiency = 69 %
Easy power control
Integrated ESD protection
Excellent ruggedness
High efficiency
Excellent thermal stability
Designed for broadband operation (HF to 500 MHz)
Compliant to Directive 2002/95/EC, regarding Restriction of Hazardous Substances
(RoHS)
1.3 Applications
Industrial, scientific and medical applications
Broadcast transmitter applications
BLF578XR; BLF578XRS
Power LDMOS transistor
2. Pinning information
Table 2.
Pin
1
2
3
4
5
Pinning
Description
drain1
drain2
gate1
gate2
source
[1]
Simplified outline
Graphic symbol
BLF578XR (SOT539A)
1
2
5
3
3
4
4
5
1
2
sym117
BLF578XRS (SOT539B)
1
2
3
4
5
drain1
drain2
gate1
gate2
source
[1]
1
2
5
1
3
4
3
5
4
2
sym117
[1]
Connected to flange.
3. Ordering information
Table 3.
Ordering information
Package
Name
BLF578XR
BLF578XRS
-
-
Description
flanged balanced LDMOST ceramic package;
2 mounting holes; 4 leads
earless flanged balanced LDMOST ceramic package;
4 leads
Version
SOT539A
SOT539B
Type number
4. Limiting values
Table 4.
Limiting values
In accordance with the Absolute Maximum Rating System (IEC 60134).
Symbol
V
DS
V
GS
T
stg
T
j
Parameter
drain-source voltage
gate-source voltage
storage temperature
junction temperature
Conditions
Min
-
6
65
-
Max
110
+11
+150
200
Unit
V
V
C
C
BLF578XR_BLF578XRS#5
All information provided in this document is subject to legal disclaimers.
© Ampleon The Netherlands B.V. 2015. All rights reserved.
Product data sheet
Rev. 5 — 1 September 2015
2 of 15
BLF578XR; BLF578XRS
Power LDMOS transistor
5. Thermal characteristics
Table 5.
R
th(j-c)
Z
th(j-c)
[1]
[2]
[3]
Thermal characteristics
Conditions
T
j
= 150
C
[1][2]
[3]
Symbol Parameter
thermal resistance from junction to case
Typ
0.11
Unit
K/W
transient thermal impedance from junction T
j
= 150
C;
t
p
= 100
s;
to case
= 20 %
0.033 K/W
T
j
is the junction temperature.
Rth(j-c) is measured under RF conditions.
See
Figure 1.
0.165
Z
th(j-c)
(j )
(K/W)
aaa-002337
0.11
(7)
(6)
(5)
(4)
(3)
(2)
(1)
0.055
0
10
-7
10
-6
10
-5
10
-4
10
-3
10
-2
10
-1
1
t
p
(S)
10
(1)
= 1 %
(2)
= 2 %
(3)
= 5 %
(4)
= 10 %
(5)
= 20 %
(6)
= 50 %
(7)
= 100 % (DC)
Fig 1.
Transient thermal impedance from junction to case as a function of pulse
duration
BLF578XR_BLF578XRS#5
All information provided in this document is subject to legal disclaimers.
© Ampleon The Netherlands B.V. 2015. All rights reserved.
Product data sheet
Rev. 5 — 1 September 2015
3 of 15
BLF578XR; BLF578XRS
Power LDMOS transistor
6. Characteristics
Table 6.
DC characteristics
T
j
= 25
C; per section unless otherwise specified.
Symbol Parameter
V
(BR)DSS
drain-source breakdown
voltage
V
GS(th)
V
GSq
I
DSS
I
DSX
I
GSS
R
DS(on)
gate-source threshold voltage
gate-source quiescent voltage
drain leakage current
drain cut-off current
gate leakage current
drain-source on-state
resistance
Conditions
V
GS
= 0 V; I
D
= 5.5 mA
V
DS
= 10 V; I
D
= 550 mA
V
DS
= 50 V; I
D
= 20 mA
V
GS
= 0 V; V
DS
= 50 V
V
GS
= V
GS(th)
+ 3.75 V;
V
DS
= 10 V
V
GS
= 11 V; V
DS
= 0 V
V
GS
= V
GS(th)
+ 3.75 V;
I
D
= 19.25 A
Min
110
1.25
0.8
-
-
-
-
Typ
-
1.7
1.3
-
77
-
0.07
Max
-
2.25
1.8
2.8
-
280
-
Unit
V
V
V
A
A
nA
Table 7.
AC characteristics
T
j
= 25
C; per section unless otherwise specified.
Symbol Parameter
C
rs
C
iss
C
oss
feedback capacitance
input capacitance
output capacitance
Conditions
V
GS
= 0 V; V
DS
= 50 V; f = 1 MHz
V
GS
= 0 V; V
DS
= 50 V; f = 1 MHz
V
GS
= 0 V; V
DS
= 50 V; f = 1 MHz
Min Typ Max Unit
-
-
-
5.5
-
pF
pF
pF
414 -
184 -
Table 8.
RF characteristics
Test signal: pulsed RF; t
p
= 100
s;
= 20 %; f = 225 MHz; RF performance at V
DS
= 50 V;
I
Dq
= 40 mA; T
case
= 25
C; unless otherwise specified; in a class-AB production test circuit.
Symbol Parameter
G
p
RL
in
D
power gain
input return loss
drain efficiency
Conditions
P
L
= 1400 W
P
L
= 1400 W
P
L
= 1400 W
Min
22
-
65
Typ
23.5
17
69
Max
-
13
-
Unit
dB
dB
%
BLF578XR_BLF578XRS#5
All information provided in this document is subject to legal disclaimers.
© Ampleon The Netherlands B.V. 2015. All rights reserved.
Product data sheet
Rev. 5 — 1 September 2015
4 of 15
BLF578XR; BLF578XRS
Power LDMOS transistor
900
C
oss
(pF)
aaa-002338
600
300
0
0
10
20
30
40
V
DS
(V)
50
V
GS
= 0 V; f = 1 MHz.
Fig 2.
Output capacitance as a function of drain-source voltage; typical values per
section
7. Test information
7.1 Ruggedness in class-AB operation
The BLF578XR and BLF578XRS are capable of withstanding a load mismatch
corresponding to VSWR > 65 : 1 through all phases under the following conditions:
V
DS
= 50 V; I
Dq
= 40 mA; P
L
= 1400 W pulsed; f = 225 MHz.
7.2 Impedance information
drain 1
gate 1
Z
i
gate 2
drain 2
001aan207
Z
L
Fig 3.
Definition of transistor impedance
Table 9.
Typical push-pull impedance
Simulated Z
i
and Z
L
device impedance; impedance info at V
DS
= 50 V and P
L
= 1400 W.
f
(MHz)
225
Z
i
()
2.36
j2.78
Z
L
()
2.45 + j0.86
BLF578XR_BLF578XRS#5
All information provided in this document is subject to legal disclaimers.
© Ampleon The Netherlands B.V. 2015. All rights reserved.
Product data sheet
Rev. 5 — 1 September 2015
5 of 15
