Document
MOTOROLA
SEMICONDUCTOR TECHNICAL DATA
Order this document by MMBD2837LT1/D
Monolithic Dual Switching Diodes
ANODE 1 2 ANODE
MMBD2837LT1 MMBD2838LT1
3 CATHODE
3 1
MAXIMUM RATINGS (EACH DIODE)
Rating Peak Reverse Voltage D.C. Reverse Voltage Peak Forward Current Average Rectified Current MMBD2837LT1 MMBD2838LT1 Symbol VRM VR IFM IO Value 75 30 50 450 300 150 100 Unit Vdc Vdc mAdc mAdc
2
CASE 318 – 08, STYLE 9 SOT– 23 (TO – 236AB)
THERMAL CHARACTERISTICS
Characteristic Total Device Dissipation FR– 5 Board(1) TA = 25°C Derate above 25°C Thermal Resistance, Junction to Ambient Total Device Dissipation Alumina Substrate,(2) TA = 25°C Derate above 25°C Thermal Resistance, Junction to Ambient Junction and Storage Temperature Symbol PD Max 225 1.8 RqJA PD 556 300 2.4 RqJA TJ, Tstg 417 – 55 to +150 Unit mW mW/°C °C/W mW mW/°C °C/W °C
DEVICE MARKING
MMBD2837LT1 = A5; MMBD2838LT1 = MA6
ELECTRICAL CHARACTERISTICS (TA = 25°C unless otherwise noted) (EACH DIODE)
Characteristic Symbol Min Max Unit
OFF CHARACTERISTICS
Reverse Breakdown Voltage (I(BR) = 100 µAdc) Reverse Voltage Leakage Current (VR = 30 Vdc) (VR = 50 Vdc) Diode Capacitance (VR = 0 V, f = 1.0 MHz) Forward Voltage (IF = 10 mAdc) Forward Voltage (IF = 50 mAdc) Forward Voltage (IF = 100 mAdc) Reverse Recovery Time (IF = IR = 10 mAdc, IR(REC) = 1.0 mAdc) (Figure 1) 1. FR– 5 = 1.0 0.75 2. Alumina = 0.4 0.3 MMBD2837LT1 MMBD2838LT1 MMBD2837LT1 MMBD2838LT1 CT VF V(BR) IR — — — — — — — 0.1 0.1 4.0 1.0 1.0 1.2 4.0 pF Vdc 35 75 — — Vdc µAdc
0.062 in. 0.024 in. 99.5% alumina.
trr
ns
Thermal Clad is a trademark of the Bergquist Company REV 1
Motorola Small–Signal Transistors, FETs and Diodes Device Data © Motorola, Inc. 1997
1
MMBD2837LT1 MMBD2838LT1
820 Ω +10 V 2.0 k 100 µH 0.1 µF DUT 50 Ω OUTPUT PULSE GENERATOR 50 Ω INPUT SAMPLING OSCILLOSCOPE VR INPUT SIGNAL 90% IR iR(REC) = 1.0 mA OUTPUT PULSE (IF = IR = 10 mA; MEASURED at iR(REC) = 1.0 mA) IF 0.1 µF tr 10% tp t IF trr t
Notes: 1. A 2.0 kΩ variable resistor adjusted for a Forward Current (IF) of 10 mA. Notes: 2. Input pulse is adjusted so IR(peak) is equal to 10 mA. Notes: 3. tp » trr
Figure 1. Recovery Time Equivalent Test Circuit
CURVES APPLICABLE TO EACH CATHODE
100 I F, FORWARD CURRENT (mA) TA = 85°C 10 TA = 25°C 1.0
10
TA = 150°C TA = 125°C
TA = –40°C
I R , REVERSE CURRENT (m A)
1.0
0.1
TA = 85°C TA = 55°C
0.01 TA = 25°C
0.1 0.2 0.4 0.6 0.8 1.0 1.2 VF, FORWARD VOLTAGE (VOLTS)
0.001
0
10
20
30
40
50
VR, REVERSE VOLTAGE (VOLTS)
Figure 2. Forward Voltage
Figure 3. Leakage Current
1.0 CD , DIODE CAPACITANCE (pF)
0.9
0.8
0.7
0.6
0
2
4
6
8
VR, REVERSE VOLTAGE (VOLTS)
Figure 4. Capacitance
2
Motorola Small–Signal Transistors, FETs and Diodes Device Data
MMBD2837LT1 MMBD2838LT1
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.
0.037 0.95
0.037 0.95
0.079 2.0 0.035 0.9 0.031 0.8
inches mm
SOT–23 SOT–23 POWER DISSIPATION
The power dissipation of the SOT–23 is a function of the 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
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 .