1 Ohmite Manufacturing Company 3601 Howard St., Skokie, IL 60076 • Tel. 847-675-2600 • Fax 847-675-1505 • www.ohmite.com • ohmite@wwa.com
TDH35 Series
TO220 35 Watt Thick Film Power Resistors for
Surface Mount, Including Metal Tab
FEATURES
• 35 Watt power rating at 25°C
• SMD - TO-220 package configu-
ration
• Heat resistance to cooling plate:
Rth <4.28 °K/W
• A molded case for environmental
protection.
• Resistor element is electrically
insulated from the metal sink tab.
ORDERING INFORMATION
DERATING
SPECIFICATIONS
Material
Lead Material: German Silver
(Alpacca)
Electrical
Resistance Range: 0.1Ω to 10KΩ
other values on request
Tolerance: ±1% to ±10% (0.5% on
request)
Max. Operating Voltage: 350V
Insulation Resistance: 10GΩ
min.
Power Rating: Depends upon
case temperature. See Derating
Curve.
Working Temperature Range: -
55°C to +175°C
PERFORMANCE CHARACTERISTICS
Derating 100% @ 25°C to 0% @ 150°C
curve referenced to case temperature
Dielectric Strength 1,800VAC
Max. Mounting Torque 0.9Nm
Operating Temperature Range -55°C to +150°C
Temperature Coefficient 10Ω and above, ± 50ppm/°C, referenced to
25°C, ∆R taken at +105°C. Between 1Ω and
10Ω, ± (100ppm+0.002Ω)/°C, referenced to
25°C,∆R taken at +105°C.
TEST DATA
Load Life (MIL–R–39009, 2,000 hours ∆R ±(1.0% +0.01Ω)
Moisture Resistance (MIL–Std–202, Method 106) ∆R =(0.5% +0.01Ω)
max.
Short Time Overload (2 times rated power with applied ∆R ±(0.3% + 0.01Ω)
voltage not to exceed 1.5 times max.
maximum continuous operating
voltage for 5 seconds)
Thermal Shock (MIL–Std–202, Method 107, ∆R =(0.3% + 0.01Ω)
Cond. F) max.
Terminal Strength (MIL–Std–202, Method 211, ∆R =(0.2% + 0.01Ω)
Cond. A (Pull Test) 2.4N) max.
Vibration, (MIL-STD-202, method 211, ∆R =(0.2% + 0.01Ω)
High Frequency cond. A (pull test) 2.4N) max.
TO220 style power package for surface mounting applications; 35W power rating at 25°C case
temperature
Soldering note: During surface mount soldering the soldering temperature profile must not
cause the metal tab of this device to exceed 245°C!
Derating (thermal resistance): 0.23W/°K (4.28°K/W). The case temperature is to be used for
purposes of establishing the applied power limit. The case temperature measurement must be
made with a thermocouple contacting the center of the component mounted on the designed
heat sink. Thermal grease should be applied propperly.
