Darlington transistors with
built-in temperature compensation diodes
for audio amplifier applications
SAPseries
Features
●Built-in temperature compensation diodes and one emitter resistor
●Real time temperature compensation
The temperature compensation diodes are mounted on one chip and placed in the center of the chip to
detect temperature rises directly.
●Elimination of the temperature dependency of the idling current
The temperature coefficient of the diodes is optimized to have the idling current stabilized; thus one of
the fatal failure modes in conventional Darlington transistors, Thermal Runaway, is avoidable.
●Symmetrical design for the PNP and the NPN pinouts
The new design minimizes the length of the pattern layout, and output distortions are controlled.
●Darlington transistors, temperature compensation diodes and one emitter resistor are
incorporated in one package, so labor for parts insertion as well as the parts count is
reduced.
Line up
Part Number
PC (W)
VCEO (V )
IC (A)
hFE
Emitter resistor (Ω)
SAP15P/SAP15N
150
160
15
5000 to 20000
0.22
SAP10P/SAP10N
100
150
12
5000 to 20000
0.22
SAP08P/SAP08N
80
150
10
5000 to 20000
0.22
■External Dimentions (Unit : mm)
3.2±0.2
4.5±0.2
1.6±0.2
5±0.2
3.3±0.2
15.4±0.3
9.9±0.2
■Equivalent Circuit Diagram
NPN
PNP
C
E
D
3.4max
a
b
(2.5)
+0.2
0.65 –0.1
S
S
D
1±0.1
B
R: 70Ω Typ.
Emitter resistor
RE: 0.22Ω Typ.
E
C
BD C S E
E S C D B
(18)
+0.2
1.35 –0.1
Emitter resistor
RE: 0.22Ω Typ.
R :70Ω Typ.
2±0.1
(36°)
(41)
7±0.2
22±0.3
23±0.3
28±0.3
B
+0.2
0.8 –0.1
2.54±0.1
3.81±0.1
2.54±0.1
(7.62)
+0.2
0.65 –0.1
3.81±0.1
(12.7)
17.8±0.3
4±0.1
➀➁ ➂ ➃➄
Weight: approx 8.3g
a. Part Number
b. Lot Number
Application Information
1. Recommended Operating Conditions
➀Add a variable resistor (VR) between diode terminals to adjust the idling current. The
resistor having 0 to 200Ω is to be used.
➁Adjust the forward current flowing over the diodes at 2.5mA.
➂Adjust the idling current at 40mA with the external variable resistor.
Both the temperature coefficients for the transistor and the diodes are matched under the above conditions.
Both the PNP and the NPN are Darlington transistors, so the temperature change ratio of the total four VBE
of the transistors is subject to the compensation. One PN junction diode in the NPN and five Schottky
barrier diodes in the PNP are built-in, and the total six diodes are operating as the temperature compensation.
The temperature coefficient of the total diodes (its variable value) becomes smaller with a larger forward
current (approximately – 0.2mV/°C to 1mA), and the coefficient of the total transistors (its variable value)
also becomes smaller with a larger idling current (approximately – 0.1mV/°C to 10mA), but the both variable
values are small.
Thus, the distortion of the temperature coefficient caused by the different current is small, so the thermal
runaway may not be occurred due to the changes of the recommended ratings; however, the actual operation
is to be confirmed by using an experimental equipment or board.
+VCC
NPN
C
B
S
D
2.5mA
E
40mA
E
D
External variable
resistor (VR)
(0 to 200Ω)
S
B
PNP
C
–VCC
2. External Variable Resistor
Total forward voltage (at IF =2.5mA) of the diodes is designed to be equal or less than that of total VBE (at IC
= 40mA) of the transistor, thus the idling current is required to be adjusted at 40mA with an additional
external variable resistor.
The relations are shown as below:
Total VF of Diode
∆V=0 to 500mV
Total VBE of Transistor + Total VRE of Emitter Resistor
The VBE of the transistor is dependent to the hFE, and the VBE is lower with higher hFE and vice versa. The
hFE for both the PNP and the NPN varies between 5k and 20k; thus the VBE is the lowest with the
combination of maximum hFE (20k) each and it is the highest with the combination of minimum hFE (5k)
each.
Presuming the voltage difference between the VF of the diodes and the VBE of the transistors (including the
total voltage drops of the two emitter resistors) as ∆V.
Minimum VBE – Maximum VF variations of the diodes = 0
Maximum VBE – Minimum VF variations of the diodes = 500mV
The current flowing over the diodes and the VR is adjusted at 2.5mA; therefore
500mV
2.5mA = 200Ω
Consequently, the applicable VR value is to be 0 to 200Ω
VBE Min.
(P and N: hFE Max.)
VBE Max.
(P and N: hFE Min.)
IC
40mA
Di VF
Variations
VBE
TR VBE
Variations
∆VF =500mV
3. Characteristics of the temperature compensation diodes
The several temperature compensation diodes are connected in series, so the forward voltage is varied with
small current fluctuations. Therefore, in case the forward current flowing over the diodes is set at 2.5mA and
over, the forward voltage rises, and in the worst combinations, the idling current reaches to 40mA and over
with minimum VR of 0Ω. On the contrary, in case the forward current is set at 2.5mA or below, the idling
current may not reach to 40mA with maximum VR of 200Ω.
10.0
Ta=25°C
PN-Di
SBD
(5 diodes Total)
PN–Di+SBD
IF (mA)
5.0
1.0
0
500
1000
1500
2000
2500
3000
VF (mV)
IF – VF Characteristics
4. Parallel push-pull application
Adjustments of the idling current are required by each the resistor in parallel push-pull applications. One
side adjustment will cause the idling current to be unstable (seesaw operation) because of the different hFE.
To be adjusted individually
5. Destruction capacity of the built-in emitter resistor
The built-in resistor is fabricated with polysilicone on the chip for the SAP08P/N and a thick-film resistor is
used for the SAP10P/N and SAP15P/N. The latter, the thick-film resistor, has weaker destruction point in
the Pc area (especially for large current flowing area) rather than that of the transistor chip itself. This is
subject to the area beyond Safe Operating Area (S.O.A).
However, under the evaluation like a short circuit test in which the current exceeds the guaranteed value, it
may cause the emitter resistor to be destroyed before the transistor itself is destroyed.
Consequently, the current value (or time) that operates the protection circuit is to be set at lower than that of
discrete device configurations. In the application of car audio amplifiers, the same manners as the above
need to be considered because the large current is flowed at low impedance.
In addition, once the transistor falls into thermal runaway due to a soldering failure to the external VR added
between diodes or other failure manners, as the worst case, there may cause a resin crack or smoke emissions
by flare up. Flame retardant molding resin is used, and the material of the product is conformed to the most
sever standard UL94V0. However it is recommended that the careful consideration be given to a protection
circuit, and the protection circuits should be provided appropriately in due course.
If the operating conditions are not to be matched to the ratings, it is also recommended that the E (Emitter
resistor) terminal should be opened and the external emitter resistor should be added to the S (Sensing)
terminal shown as below. (However this is not applicable to the SAP08P/N because a thin inner lead is used
for S terminal.)
IC
Transistor destruction point
C
Thick-film resistor
destruction point
B
A.S.O.
Curve
S
D
External
emitter resistor
E
Output terminal
VCE
Built-in temperature
compensation diodes
Built-in emitter resistor
Darlington
Equivalent
circuit
SAP15N
B
D
Application: Audio
160
V
VEBO
5
V
IC
15
A
IB
1
A
150(Tc =25°C)
W
10
mA
150
°C
–55 to +150
°C
Tj
Tstg
typ
Unit
max
100
µA
100
µA
IEBO
VEB = 5V
VCEO
IC = 30mA
160
hFE ✽
VCE = 4V, IC = 10A
5000
VCE(sat)
IC = 10A, IB = 10mA
2.0
V
VBE(sat)
IC = 10A, IB = 10mA
2.5
V
(36°)
V
20000
a
b
VBE
VCE = 20V, IC = 40mA
1190
mV
IF = 2.5mA
705
mV
Di VF
IE = 1A
RE
0.176
0.22
IC – VCE Characteristics (Typical)
2.54±0.1
2.54±0.1
(12.7)
2.
A
1.2mA
Collector Current IC (A)
3.0mA
1.0mA
0.8mA
10
0.5mA
5
IB =0.3mA
0
0
4
2
2
IC =15A
10A
1
5A
0
0.4
–30°C
0.5
1
5
1
5
10
50
100
0
200
10
1
5
10
2.5
50
100
500 1000 2000
Time t (ms)
PC – Ta Derating
Di IF – VF Characteristics (Typical)
150
s
ite
he
sin
at
k
Without Heatsink
Natural Cooling
100
fin
1
0.5
5
In
5
ith
Forward Current IF (mA)
s
W
Maximum Power Dissipation Pc (W)
10
m
2
0.1
15
10
D.
C
1
Base-Emitter Voltage VBE (V)
0.5
Safe Operating Area (Single Pulse)
0m
0
1
40
10
25°C
Characteristics
Collector Current IC (A)
10
125°C
5
3
j-a (°C/W)
Transient Thermal Resistance
25°C
1000
0.3
Collector Current IC (A)
DC Current Gain hFE
j-a – t
125°C
5000
10
Base Current IB (mA)
hFE – IC Characteristics (Typical)
10000
(VCE =4V)
–30°C
6
40000
S E
15
3
Collector-Emitter Voltage VCE (V)
(VCE =4V)
C
Weight: Approx 8.3g
a. Part Number
b. Lot Number
IC – VBE Temperature Characteristics (Typical)
Collector Current IC (A)
1.5m
A
+0.2
0.65 –0.1
3.81±0.1
(7.62)
17.8±0.3
4±0.1
VCE(sat) – IB Characteristics (Typical)
Collector-Emitter Saturation Voltage VCE(sat) (V)
15
5.0mA
1±0.1
+0.2
0.8 –0.1
3.81±0.1
Ω
0.264
+0.2
0.65 –0.1
B D
0m
4.5±0.2
1.6±0.2
+0.2
1.35 –0.1
✽Rank O (5000 to 12000), Y (8000 to 20000)
50mA
φ 3.2±0.2
15.4±0.3
9.9±0.2
(18)
Di IF
min
VCB =160V
(2.5)
PC
Conditions
ICBO
2±0.1
VCEO
Symbol
(Unit: mm)
(41)
V
External Dimensions
5±0.2
160
( Ta = 25°C)
Ratings
7±0.2
22±0.3
23±0.3
28±0.3
VCBO
■Electrical Characteristics
3.3±0.2
Unit
3.4max
■Absolute maximum ratings (Ta=25°C)
Ratings
S
Emitter resistor
RE: 0.22Ω Typ.
R: 70Ω Typ.
E
(Complement to type SAP15P)
Symbol
C
50
0.1
0.05
3
5
10
50
100
Collector-Emitter Voltage VCE (V)
200
1
0
0.5
1.0
1.5
Forward Voltage VF (V)
2.0
3.5
0
Without Heatsink
0
25
50
75
100
125
Ambient Temperature Ta (°C)
150