Sales and Corporate Office

1717 Chicago Avenue

Riverside, California 92507-2364

Phone: (951) 788-1700

Fax: (951) 369-1151

Applications Engineering

17271 North Umpqua Hwy.

Roseburg, Oregon 97470-9422

Phone: (541) 496-0700

Fax: (541) 496-0408

e-mail: caddock@caddock.com • web: www.caddock.com

For Caddock Distributors listed by country see caddock.com/contact/dist.html

© 2004 Caddock Electronics, Inc.

CAD

K

DOC

DIMENSIONS IN INCHES AND (MILLIMETERS)

.640 ±.010

(16.26 ±.26)

.030 ±.004

(.76 ± .10)

.025 ± .004

(.64 ±.10)

.200 ±.010

(5.08 ±.26)

.500 ±.050

(12.70 ±1.27)

.130 ±.030

(3.30 ±.76)

.125 ±.010

(3.18 ±.26)

.410 ±.010

(10.41 ±.26)

MP850

10.0

1%

.125 ±.010

(3.18 ±.26)

.125 ±.004

(3.18 ±.10) DIA.

CL

.053 ± .007

(1.35 ± .18)

.070 ±.010

(1.78 ±.26)

Figure 2

TO-126 Style

MP825

Figure 1

Metal Tab

TO-220 Style

MP820 and MP821

MP820

50.0

1%

.540 ±.040

(13.72 ±1.02)

CL

.117 ±.003

(2.97 ±.08)

.240 ±.010

(6.10 ±.26)

.400 ±.010

(10.16 ±.26)

.200 ±.010

(5.08 ±.26)

.032 ± .004 DIA.

(.81 ± .10)

.175 ±.015

(4.45 ±.38)

.052 ±.003

(1.32 ±.08)

.580 ±.010

(14.73 ±.26)

.097 ±.010

(2.46 ±.26)

.142 ±.003

(3.61 ±.08) DIA.

Figure 3

TO-220 Style

MP850

All power and associated overload ratings are derated

based upon case temperature using the derating curve.

The case temperature is measured at the center of the

metal mounting surface, with the part properly mounted

and under electrical load. Without a heat sink, when in

free air at +25°C, the MP820, MP821, and MP850 are

rated for 2.25 watts, the MP825 is rated for 1.25 watts.

The thermal design should satisfy the following equation:

operating temperature range of the application.

Mounting Note: Mount on a smooth, clean and flat heat sink surface with a thermal interface material, such

as thermal grease. The entire exposed metal backface portion must be in thermal contact with the heat sink.

When screw mounting, use a compression washer which provides a mounting force of 150 to 300 pounds

(665 to 1330 N). This will provide sufficient pressure on the package over time and through large temperature

variations to maintain the maximum power dissipation capability. Mounting torque to avoid package damage

is 8 in-lbs (0.90 N-m). If a spring clip is used, a clip force of 8 to 30 pounds (35 to 130 N) is recommended to

be applied to the center of the package. The clip should be round or smooth in the contact area to avoid

concentrating the load on a small point of the plastic body of the package. Another mounting option is to use

a pressure bar method which can achieve a greater mounting force with a greater contact area.

For additional applications information regarding mounting and pulse handling see the Caddock

Applications Notes at caddock.com or contact Applications Engineering.

Derating Curve

MP821

MP820

Model

No.

Comments

Integral Metal Mounting Surface

in Molded Package

MP850

Integral Metal Mounting Surface

in Molded Package

MP825

Metal Mounting Tab

Metal Mounting Tab

TO-220 Style

TO-220 Style

Package

TO-220 Style

TO-126 Style

0.020 Ω

9.99 Ω

10.0 Ω

10.0 K

Min.

Max.

Resistance

0.20 Ω

10.0 K

0.020 Ω

10.0 K

20 Watts

*

20 Watts

*

Power

Rating

50 Watts

*

25 Watts

*

Max.

Voltage

Power

Limited

300

300

300

Thermal Resistance

7.50°C/Watt

5.00°C/Watt

2.50°C/Watt

7.50°C/Watt

175°C

Figure 1

Figure 1

Dimensions

Figure 3

Figure 2

Max. Temp.

175°C

150°C

150°C

+

.030 ±.004

(.76 ± .10)

.023 ± .004

(.58 ±.10)

.200 ±.010

(5.08 ±.26)

.450 ±.050

(11.43 ±1.27)

.115 ±.010

(2.92 ±.26)

MP825

0.10 Ω

1%

.110 ±.010

(2.79 ±.26)

.053 ± .007

(1.35 ± .18)

.058 ±.007

(1.47 ±.18)

.320 ±.010

(8.12 ±.26)

.094 ±.004

(2.39 ±.10) DIA

.

CL

.440 ±.010

(11.18 ±.26)

.080 ±.020

(2.03 ±.51)

Specifications:

Temperature Coefficient:

5.00 ohms and above, -20 to +50 ppm/°C

0.50 ohm to 4.99 ohms, -20 to +80 ppm/°C

0.050 ohm to 0.49 ohm, 0 to +200 ppm/°C

0.020 ohm to 0.049 ohm, 0 to +300 ppm/°C

Inductance: 10nH typical in series when mea-

sured at a point 0.2 inches from the resistor body.

is based upon connections made between

terminals shorted and either the metal surface the

part is mounted to or a metal clip in contact with the

top surface of the part.

Insulation Resistance: 10,000 Megohms, min.

The resistor element is electrically isolated from

the mounting surface.

Load Stability: 2,000 hours at rated power.

Δ

R ±(1.0 percent + 0.001 ohm) max. Power rating

dependent upon case temperature. See derating

curve.

Momentary Overload:

MP820, MP821, MP850: 2 times rated power with

applied voltage not to exceed 1.5 times maximum

continuous operating voltage for 5 seconds.

Δ

R ±(0.3 percent + 0.001 ohm) max.

MP825: 1.5 times rated power with applied

voltage not to exceed 1.5 times maximum

continuous operating voltage for 5 seconds.

Δ

R ±(0.3 percent + 0.001 ohm) max.

Moisture Resistance: Mil-Std-202, Method 106.

Δ

R ±(0.5 percent + 0.001 ohm) max.

Thermal Shock: Mil-Std-202, Method 107, Cond. F.

Δ

R ±(0.3 percent + 0.001 ohm) max.

Shock: 100G, Mil-Std-202, Method 213, Cond. I.

Δ

R ±(0.2 percent + 0.001 ohm) max.

Vibration, High Frequency: Mil-Std-202, Method

204, Cond. D. ΔR ±(0.2 percent + 0.001 ohm)

max.

Terminal Strength: Mil-Std-202, Method 211,

Cond. A (Pull Test) 5 lbs. ΔR ±(0.2 percent

+ 0.001 ohm) max.

Terminal Material: Solderable

Measurement Note: For these specifications,

resistance measurement shall be made at a point

0.2 inch (5.08 mm) from the resistor body.

100

175

0

20

40

100

80

60

150

A

B

25

CASE TEMPERATURE, °C

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