scope:

This specification covers the general requirements for nonestablished reliability (non-ER), established reliability (ER), and space level, fixed, film, chip resistors primarily intended for incorporation into surface mount applications. These resistors have a high degree of stability with respect to time under normal conditions. ER resistors covered by this specification have life failure rates (FR) ranging from 1 percent to 0.001 percent per 1,000 hours (see 1.2.7). These FRs are established at 60 percent confidence on the basis of life tests. Table I provides a summary of performance characteristics for these resistors.

Resistors specified herein (see 3.1) are identified by a PIN which consists of the basic number and the associated specification. Each associated specification covers a different resistor style. The PIN provides information concerning the resistor characteristic, resistance value, resistance tolerance, termination material, and product designator. The PIN is in the following form:

The style (see 3.1) is identified by the two-letter symbol "RM" followed by a four digit number; the letters identify fixed, film resistors, in a flat chip configuration. Beneficial comments (recommendations, additions, deletions) and any pertinent data which may be of use in improving this document should be addressed to: US Army Communications - Electronics Command and Fort Monmouth, ATTN: AMSEL-LC-LEO-E EP, Fort Monmouth, NJ 07703-5023, by using the Standardization Document Improvement Proposal (DP Form 1426) appearing at the end of this document or by letter.

The characteristic is identified by the single letter E, H, K, or M, in accordance with table I.

The termination material designation will be in accordance with table II.

The nominal resistance expressed in ohms is identified by four characters consisting of three digits and a letter. The letter is used simultaneously as a decimal point, multiplier, and a resistance tolerance designator. For resistance values:

a. Greater than or equal to 1 ohm but less than 1,000 ohms, the letters A, D, G, J, and M are used to represent a decimal point, depending on the resistance tolerance (see table III).

b. Greater than or equal to 1,000 ohms but less than 1 megohm, the letters B, E, H, K, and N are used to represent a decimal point, depending on the resistance tolerance (see table III).

c. Greater than or equal to 1 megohm, the letters C, F, T, L, and P are used to represent a decimal point, depending upon the resistance tolerance (see table III).

All digits preceding and following the letters (A, B, C, D, E, F, G, H, T, L, J, K, M, N, and P) of the group represent significant figures. The resistance value designators are shown in table III. Minimum and maximum resistance values will be as specified herein (see 3.1). The standard values for every decade will follow the sequence specified in table IV of MIL-PRF-55342 for resistance tolerances 1.0 percent, 2.0 percent, 5.0 percent, and 10.0 percent. The resistance values for tolerance 0.1 percent maybe any value within the limits specified (see 3.1), but it is preferred that values be chosen from the 0.1 percent column of table IV of MIL-PRF-55342.

The resistance tolerance and multipliers are identified by a single letter in accordance with table V. Table V. Resistance tolerance and multipliers.

Resistance Multiplier Symbol tolerance(±) ------------------------------------------------ 0.1 X1 A 0.1 X1,000 B 0.1 X1,000,000 C 1.0 X1 D 1.0 X1,000 E 1.0 X1,000,000 F 2.0 X1 G 2.0 X1,000 H 2.0 X1,000,000 T 5.0 X1 J 5.0 X1,000 K 5.0 X1,000,000 L 10.0 X1 M 10.0 X1,000 N 10.0 X1,000,000 P

The product level designator is specified in table VI by a single letter which identifies non-ER, ER or space level resistors. Table VI. Product level designator.

Product level Product designator level ----------------------------------------------- C Non-ER M 1/1.0 P 1/0.1 R 1/0.01 S 1/0.001 T Space level 1/ FR level in percent per 1000 hours

intended Use:

Chip resistors are intended to be used in thin or thick film hybrid circuits where micro-circuitry is indicated and in surface mount applications.