Semiconductor Components Industries, LLC, 2000
November, 2000 – Rev. 2 1Publication Order Number:
BSS138LT1/D
BSS138LT1
Preferred Device
Power MOSFET
200 mAmps, 50 Volts
N–Channel SOT–23
Typical applications are dc–dc converters, power management in
portable and battery–powered products such as computers, printers,
PCMCIA cards, cellular and cordless telephones.
•Low Threshold Voltage (VGS(th): 0.5V...1.5V) makes it ideal for low
voltage applications
•Miniature SOT–23 Surface Mount Package saves board space
MAXIMUM RATINGS (TA = 25°C unless otherwise noted)
Rating Symbol Value Unit
Drain–to–Source Voltage VDSS 50 Vdc
Gate–to–Source Voltage – Continuous VGS ±20 Vdc
Drain Current
– Continuous @ TA = 25°C
– Pulsed Drain Current (tp ≤ 10 µs) ID
IDM 200
800
mA
Total Power Dissipation @ TA = 25°C PD225 mW
Operating and Storage Temperature
Range TJ, Tstg – 55 to
150 °C
Thermal Resistance – Junction–to–Ambient RθJA 556 °C/W
Maximum Lead Temperature for Soldering
Purposes, for 10 seconds TL260 °C
3
1
2
Device Package Shipping
ORDERING INFORMATION
BSS138LT1 SOT–23 3000 Tape & Reel
N–Channel
SOT–23
CASE 318
STYLE 21
http://onsemi.com
W
MARKING
DIAGRAM
J1
W = Work Week
PIN ASSIGNMENT
3
21
Drain
Gate
2
1
3
Source
BSS138LT3 SOT–23 10,000 Tape & Reel
200 mAMPS
50 VOLTS
RDS(on) = 3.5
Preferred devices are recommended choices for future use
and best overall value.
BSS138LT1
http://onsemi.com
2
ELECTRICAL CHARACTERISTICS (TA = 25°C unless otherwise noted)
Characteristic Symbol Min Typ Max Unit
OFF CHARACTERISTICS
Drain–to–Source Breakdown Voltage
(VGS = 0 Vdc, ID = 250 µAdc) V(BR)DSS 50 – – Vdc
Zero Gate Voltage Drain Current
(VDS = 25 Vdc, VGS = 0 Vdc)
(VDS = 50 Vdc, VGS = 0 Vdc)
IDSS –
––
–0.1
0.5
µAdc
Gate–Source Leakage Current (VGS = ±20 Vdc, VDS = 0 Vdc) IGSS – – ±0.1 µAdc
ON CHARACTERISTICS (Note 1.)
Gate–Source Threshold Voltage
(VDS = VGS, ID = 1.0 mAdc) VGS(th) 0.5 – 1.5 Vdc
Static Drain–to–Source On–Resistance
(VGS = 2.75 Vdc, ID < 200 mAdc, TA = –40°C to +85°C)
(VGS = 5.0 Vdc, ID = 200 mAdc)
rDS(on) –
–5.6
–10
3.5
Ohms
Forward Transconductance
(VDS = 25 Vdc, ID = 200 mAdc, f = 1.0 kHz) gfs 100 – – mmhos
DYNAMIC CHARACTERISTICS
Input Capacitance (VDS = 25 Vdc, VGS = 0, f = 1 MHz) Ciss – 40 50 pF
Output Capacitance (VDS = 25 Vdc, VGS = 0, f = 1 MHz) Coss – 12 25
Transfer Capacitance (VDG = 25 Vdc, VGS = 0, f = 1 MHz) Crss – 3.5 5.0
SWITCHING CHARACTERISTICS (Note 2.)
Turn–On Delay Time
(VDD =30Vdc I
D=02Adc)
td(on) – – 20 ns
Turn–Off Delay Time (VDD = 30 Vdc, ID = 0.2 Adc,) td(off) – – 20
1. Pulse Test: Pulse Width ≤300 µs, Duty Cycle ≤ 2%.
2. Switching characteristics are independent of operating junction temperature.
BSS138LT1
http://onsemi.com
3
TYPICAL ELECTRICAL CHARACTERISTICS
RDS(on), DRAIN-TO-SOURCE RESISTANCE
(NORMALIZED)
Figure 1. On–Region Characteristics
1
TJ, JUNCTION TEMPERATURE (°C)
Figure 2. Transfer Characteristics
Figure 3. On–Resistance Variation with
Temperature
VGS = 10 V
ID = 0.8 A
-55 -5 45 95 145
0.6
0.8
VGS, GATE-TO-SOURCE VOLTAGE (VOLTS)
0
4
0
QT, TOTAL GATE CHARGE (pC)
8
500
VDS = 40 V
TJ = 25°C
1000
ID = 200 mA
1500
1.2
2
1.4
1.6
1.8
VGS = 4.5 V
ID = 0.5 A
2000
10
2
6
Vgs(th) , VARIANCE (VOLTS)
1
TJ, JUNCTION TEMPERATURE (°C)
ID = 1.0 mA
-55 -5 45 95 145
0.75
0.875
1.125
1.25
0
0.3
0.4
0.1
0.6
0.2
Figure 4. Threshold Voltage Variation
with Temperature
1 1.5 2 2.5 3
ID, DRAIN CURRENT (AMPS)
VGS, GATE-TO-SOURCE VOLTAGE (VOLTS)
Figure 5. Gate Charge
VDS = 10 V
150°C
25°C
-55°C
3.5
0.5
4
024 10
0
0.3
0.4
VDS, DRAIN-TO-SOURCE VOLTAGE (VOLTS)
ID, DRAIN CURRENT (AMPS)
6
0.1
8
0.6
0.2
0.5
13 957
VGS = 3.25 V
VGS = 2.75 V
VGS = 2.5 V
VGS = 3.0 V
VGS = 3.5 V
0.7
0.8
TJ = 25°C
0.7
0.8
0.9
4.50.50
2.2
-30 20 70 120
2500 3000
BSS138LT1
http://onsemi.com
4
TYPICAL ELECTRICAL CHARACTERISTICS
RDS(on), DRAIN-TO-SOURCE RESISTANCE (OHMS)
Figure 6. On–Resistance versus Drain Current
0 0.1 0.2
2
5
6
Figure 7. On–Resistance versus Drain Current
ID, DRAIN CURRENT (AMPS)
Figure 8. On–Resistance versus Drain Current
0.001
0.1
1
Figure 9. On–Resistance versus Drain Current
VSD, DIODE FORWARD VOLTAGE (VOLTS)
Figure 10. Body Diode Forward Voltage
ID, DIODE CURRENT (AMPS)
25°C
VGS = 2.5 V
TJ = 150°C
4
0 0.2 0.4 0.6
3
0.01
-55°C25°C
0.8
RDS(on), DRAIN-TO-SOURCE RESISTANCE (OHMS)
0 0.1 0.2
1
7
ID, DRAIN CURRENT (AMPS)
VGS = 2.75 V
5
3
0
120
40
0
80
510
Ciss
15
0.05 0.15 0.25
150°C
-55°C
6
8
4
2
0.05 0.15 0.25
201.0 1.2
150°C
25°C
-55°C
8
9
7
100
20
60
Figure 11. Capacitance
RDS(on), DRAIN-TO-SOURCE RESISTANCE (OHMS)
0 0.2 0.40.05
1
2.5
3
ID, DRAIN CURRENT (AMPS)
25°C
VGS = 4.5 V
2
1.5
RDS(on), DRAIN-TO-SOURCE RESISTANCE (OHMS)
0 0.2 0.40.05
1
4
ID, DRAIN CURRENT (AMPS)
VGS = 10 V
3
2
0.1 0.3 0.5
150°C
-55°C
3.5
4.5
2.5
1.5
0.1 0.3 0.5
150°C
25°C
-55°C
4
4.5
3.5
10
1
0.25 0.450.15 0.35
5
5.5
6
0.25 0.450.15 0.35
25
Coss
Crss
BSS138LT1
http://onsemi.com
5
INFORMATION FOR USING THE SOT–23 SURFACE MOUNT PACKAGE
MINIMUM RECOMMENDED FOOTPRINT FOR SURFACE MOUNTED APPLICATIONS
Surface mount board layout is a critical portion of the
total design. The footprint for the semiconductor packages
must be the correct size to insure proper solder connection
interface between the board and the package. With the
correct pad geometry, the packages will self align when
subjected to a solder reflow process.
mm
inches
0.037
0.95
0.037
0.95
0.079
2.0
0.035
0.9
0.031
0.8
SOT–23 POWER DISSIPATION
The power dissipation of the SOT–23 is a function of the
drain pad size. This can vary from the minimum pad size
for soldering to a pad size given for maximum power
dissipation. Power dissipation for a surface mount device is
determined by TJ(max), the maximum rated junction
temperature of the die, RθJA, the thermal resistance from
the device junction to ambient, and the operating
temperature, TA. Using the values provided on the data
sheet for the SOT–23 package, PD can be calculated as
follows:
PD = TJ(max) – TA
RθJA
The values for the equation are found in the maximum
ratings table on the data sheet. Substituting these values
into the equation for an ambient temperature TA of 25°C,
one can calculate the power dissipation of the device which
in this case is 225 milliwatts.
PD = 150°C – 25°C
556°C/W = 225 milliwatts
The 556°C/W for the SOT–23 package assumes the use
of the recommended footprint on a glass epoxy printed
circuit board to achieve a power dissipation of 225
milliwatts. There are other alternatives to achieving higher
power dissipation from the SOT–23 package. Another
alternative would be to use a ceramic substrate or an
aluminum core board such as Thermal Clad. Using a
board material such as Thermal Clad, an aluminum core
board, the power dissipation can be doubled using the same
footprint.
SOLDERING PRECAUTIONS
The melting temperature of solder is higher than the rated
temperature of the device. When the entire device is heated
to a high temperature, failure to complete soldering within
a short time could result in device failure. Therefore, the
following items should always be observed in order to
minimize the thermal stress to which the devices are
subjected.
•Always preheat the device.
•The delta temperature between the preheat and
soldering should be 100°C or less.*
•When preheating and soldering, the temperature of the
leads and the case must not exceed the maximum
temperature ratings as shown on the data sheet. When
using infrared heating with the reflow soldering
method, the difference shall be a maximum of 10°C.
•The soldering temperature and time shall not exceed
260°C for more than 10 seconds.
•When shifting from preheating to soldering, the
maximum temperature gradient shall be 5°C or less.
•After soldering has been completed, the device should
be allowed to cool naturally for at least three minutes.
Gradual cooling should be used as the use of forced
cooling will increase the temperature gradient and
result in latent failure due to mechanical stress.
•Mechanical stress or shock should not be applied
during cooling.
* Soldering a device without preheating can cause
excessive thermal shock and stress which can result in
damage to the device.
BSS138LT1
http://onsemi.com
6
PACKAGE DIMENSIONS
STYLE 21:
PIN 1. GATE
2. SOURCE
3. DRAIN
DJ
K
L
A
C
BS
H
GV
3
12
DIM
A
MIN MAX MIN MAX
MILLIMETERS
0.1102 0.1197 2.80 3.04
INCHES
B0.0472 0.0551 1.20 1.40
C0.0350 0.0440 0.89 1.11
D0.0150 0.0200 0.37 0.50
G0.0701 0.0807 1.78 2.04
H0.0005 0.0040 0.013 0.100
J0.0034 0.0070 0.085 0.177
K0.0140 0.0285 0.35 0.69
L0.0350 0.0401 0.89 1.02
S0.0830 0.1039 2.10 2.64
V0.0177 0.0236 0.45 0.60
NOTES:
1. DIMENSIONING AND TOLERANCING PER ANSI
Y14.5M, 1982.
2. CONTROLLING DIMENSION: INCH.
3. MAXIMUM LEAD THICKNESS INCLUDES LEAD
FINISH THICKNESS. MINIMUM LEAD
THICKNESS IS THE MINIMUM THICKNESS OF
BASE MATERIAL.
SOT–23 (TO–236)
CASE 318–08
ISSUE AF
BSS138LT1
http://onsemi.com
7
Notes
BSS138LT1
http://onsemi.com
8
ON Semiconductor and are trademarks of Semiconductor Components Industries, LLC (SCILLC). SCILLC reserves the right to make changes
without further notice to any products herein. SCILLC makes no warranty , representation or guarantee regarding the suitability of its products for any particular
purpose, nor does SCILLC assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability,
including without limitation special, consequential or incidental damages. “Typical” parameters which may be provided in SCILLC data sheets and/or
specifications can and do vary in different applications and actual performance may vary over time. All operating parameters, including “Typicals” must be
validated for each customer application by customer’s technical experts. SCILLC does not convey any license under its patent rights nor the rights of others.
SCILLC products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other applications
intended to support or sustain life, or for any other application in which the failure of the SCILLC product could create a situation where personal injury or
death may occur. Should Buyer purchase or use SCILLC products for any such unintended or unauthorized application, Buyer shall indemnify and hold
SCILLC and its officers, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs, damages, and expenses, and reasonable
attorney fees arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if such claim
alleges that SCILLC was negligent regarding the design or manufacture of the part. SCILLC is an Equal Opportunity/Affirmative Action Employer.
PUBLICATION ORDERING INFORMATION
CENTRAL/SOUTH AMERICA:
Spanish Phone: 303–308–7143 (Mon–Fri 8:00am to 5:00pm MST)
Email: ONlit–spanish@hibbertco.com
Toll–Free from Mexico: Dial 01–800–288–2872 for Access –
then Dial 866–297–9322
ASIA/PACIFIC: LDC for ON Semiconductor – Asia Support
Phone: 303–675–2121 (Tue–Fri 9:00am to 1:00pm, Hong Kong Time)
Toll Free from Hong Kong & Singapore:
001–800–4422–3781
Email: ONlit–asia@hibbertco.com
JAPAN: ON Semiconductor, Japan Customer Focus Center
4–32–1 Nishi–Gotanda, Shinagawa–ku, Tokyo, Japan 141–0031
Phone: 81–3–5740–2700
Email: r14525@onsemi.com
ON Semiconductor Website: http://onsemi.com
For additional information, please contact your local
Sales Representative.
BSS138LT1/D
Thermal Clad is a registered trademark of the Bergquist Company.
NORTH AMERICA Literature Fulfillment:
Literature Distribution Center for ON Semiconductor
P.O. Box 5163, Denver, Colorado 80217 USA
Phone: 303–675–2175 or 800–344–3860 Toll Free USA/Canada
Fax: 303–675–2176 or 800–344–3867 Toll Free USA/Canada
Email: ONlit@hibbertco.com
Fax Response Line: 303–675–2167 or 800–344–3810 Toll Free USA/Canada
N. American Technical Support: 800–282–9855 Toll Free USA/Canada
EUROPE: LDC for ON Semiconductor – European Support
German Phone: (+1) 303–308–7140 (Mon–Fri 2:30pm to 7:00pm CET)
Email: ONlit–german@hibbertco.com
French Phone: (+1) 303–308–7141 (Mon–Fri 2:00pm to 7:00pm CET)
Email: ONlit–french@hibbertco.com
English Phone: (+1) 303–308–7142 (Mon–Fri 12:00pm to 5:00pm GMT)
Email: ONlit@hibbertco.com
EUROPEAN TOLL–FREE ACCESS*: 00–800–4422–3781
*Available from Germany, France, Italy, UK, Ireland
