RIEDON
Riedon Inc. 300 Cypress Avenue Alhambra CA 91801 (626) 284-9901 Fax: (626) 284-1704
www.riedon.com
REV 6/05
PF1220 Series
Precision Foil Power Resistors
SPECIFICATIONS
Riedon's TO-220 precision foil resistors satisfy demanding applications for high accuracy and
stable power resistors housed in the convenient TO-220 case. The PF1220s Nichrome foil resistance
element makes a wide resistance range available. It is bonded to an Al
2
O
3
substrate ensuring excellent
power dissipation and stability. Careful choice of materials and rugged construction ensure a reliable
component, and the very small tolerance and temperature coefficient provide high precision in difficult
applications.
Ordering information:
Part Number - Resistance - Tolerance - TCR
Example: PF1220 0.5 Ohm 0.1% 5ppm
TO-220 Housing
Rated Power 10 Watts
Resistances from 0.5 to 150K Ohms
High Stability Foil Resistance Elements
Resistance Tolerance to ± 0.02%
Operating Temperature -55°C to +155°C
Low Inductance ( <50nH ) and Thermal EMF
Resistance Range - 0.5 to 150K Ohms
( 100 Ohm Max. for 4-Terminal )
Free Air Power Rating - 1.5 Watts ( T
ambient
=70°C )
Power Rating on Heatsink - 10 Watts ( T
heatsink
=25°C )
Thermal Resistance - 10.8°C/W
Temperature Coefficient - ± 1ppm/°C ( +20°C to +60°C )
± 3ppm/°C ( -55°C to +125°C )
± 5ppm/°C ( -55°C to +155°C )
Stability - 0.01%
Thermal EMF - < 1mV/°C
Proof Voltage - 1KVDC
Maximum Current - 25 A
Operating Temperature - -55°C to +155°C
Resistance Element - Nichrome Foil
Substrate - Al
2
O
3
Housing - Epoxy or PPS
Leads - Cu, Tinned, 2 or 4 pin
120
100
80
60
40
20
0
25 40 55 70 85 100 115 130
Heatsink Temperature °C
Power Level %
PF1220 Power Derating Curve
Resistance Tolerances Available (±%)
0.5 to <10W 0.1, 0.25, 0.5, 1
³10 to <50W 0.05, 0.1, 0.25, 0.5, 1
³50W 0.02, 0.05, 0.1, 0.25, 0.5, 1
