| 1638721 | U4090B-FN | Monolithic Integrated Feature Phone Circuit | Atmel |
| 1638722 | U4090B-FN | Monolithic Integrated Feature Phone Circuit | TEMIC |
| 1638723 | U4090B-P | Multi-standard feature phone circuit with voice switch (EMI improved) | Atmel |
| 1638724 | U4091B | Programmable Telephone Audio Processor | TEMIC |
| 1638725 | U4091BM | Programmable Telephone Audio Processor | TEMIC |
| 1638726 | U4091BM-N | Multi-standard feature phone IC, bus controlled | Atmel |
| 1638727 | U4092B | Monolithic Integrated Feature Phone Circuit | TEMIC |
| 1638728 | U413B | AudiolAmplifier | TEMIC |
| 1638729 | U421 | N-Channel Dual JFET | Calogic |
| 1638730 | U421 | Low Leakage, Low Drift, Monolithic Dual, N-Channel JFET | Linear Systems |
| 1638731 | U421 | Monolithic Ultra Low Leakage | Vishay |
| 1638732 | U422 | N-Channel Dual JFET | Calogic |
| 1638733 | U422 | Low Leakage, Low Drift, Monolithic Dual, N-Channel JFET | Linear Systems |
| 1638734 | U4221B | Radio Controlled Clock Receiver | TEMIC |
| 1638735 | U4222B | Radio Controlled Clock Receiver | TEMIC |
| 1638736 | U4223B | Time-Code Receiver with A/D Converter | Atmel |
| 1638737 | U4223B | Time Code Receiver | TEMIC |
| 1638738 | U4223B-MFS | Time-Code Receiver with A/D Converter | Atmel |
| 1638739 | U4223B-MFSG3 | Time-Code Receiver with A/D Converter | Atmel |
|
| 1638740 | U4224B | Time-Code Receiver with Digitized Serial Output | TEMIC |
| 1638741 | U4224B-CFL | Time Code Receiver | TEMIC |
| 1638742 | U4224B-CFLG3 | Time Code Receiver | TEMIC |
| 1638743 | U4226B | Time-Code Receiver with TC Output | TEMIC |
| 1638744 | U423 | N-Channel Dual JFET | Calogic |
| 1638745 | U423 | Low Leakage, Low Drift, Monolithic Dual, N-Channel JFET | Linear Systems |
| 1638746 | U423 | Monolithic Ultra Low Leakage | Vishay |
| 1638747 | U424 | N-Channel Dual JFET | Calogic |
| 1638748 | U424 | Low Leakage, Low Drift, Monolithic Dual, N-Channel JFET | Linear Systems |
| 1638749 | U4240B | AM-Receiver | TEMIC |
| 1638750 | U425 | N-Channel Dual JFET | Calogic |
| 1638751 | U425 | Low Leakage, Low Drift, Monolithic Dual, N-Channel JFET | Linear Systems |
| 1638752 | U4253BM | AM/FM - Antenna Impedance Matching IC | TEMIC |
| 1638753 | U4254BM | Low-Noise AM/FM Antenna Impedance Matching IC | TEMIC |
| 1638754 | U4254BM-AFP | Low-Noise AM/FM Antenna Impedance Matching IC | TEMIC |
| 1638755 | U4254BM-AFPG3 | Low-Noise AM/FM Antenna Impedance Matching IC | TEMIC |
| 1638756 | U4254BM-M | Low-noise AM/FM antenna impedance matching IC | Atmel |
| 1638757 | U4254BM-MFP | Low-noise AM/FM Antenna Impedance Matching IC | Atmel |
| 1638758 | U4254BM-MPG3 | Low-noise AM/FM Antenna Impedance Matching IC | Atmel |
| 1638759 | U4255BM | AM/FM Receiver IC | TEMIC |
| 1638760 | U4255BM-M | AM/FM car receiver IC | Atmel |
