| 1638641 | U3800 | Multi Standard Feature Phone Integrated Circuit | Vishay |
| 1638642 | U3800BM | Multi Standard Feature Phone Integrated Circuit | TEMIC |
| 1638643 | U3800BM-CP | Multi standard feature phone integrated circuit | Vishay |
| 1638644 | U3800BM-FN | Multi standard feature phone integrated circuit | Vishay |
| 1638645 | U3810BM | Multi-Standard Feature Phone IC | TEMIC |
| 1638646 | U3900BM | Programmable Telephone Audio Processor | TEMIC |
| 1638647 | U3900BM-AFN | Programmable Telephone Audio Processor | TEMIC |
| 1638648 | U3900BM-AFNG3 | Programmable Telephone Audio Processor | TEMIC |
| 1638649 | U3958NL | Monolithic N-Channel JFET Duals | Vishay |
| 1638650 | U3FWJ44N | SCHOTTKY BARRIER RECTIFIER SCHOTTKY BARRIER TYPE HIGH SPEED RECTIFIER APPLICATIONS | TOSHIBA |
| 1638651 | U3FWK42 | SCHOTTKY BARRIER RECTIFIER SCHOTTKY BARRIER TYPE HIGH SPEED RECTIFIER APPLICATIONS | TOSHIBA |
| 1638652 | U3GWJ2C42 | SCHOTTKY BARRIER RECTIFIER STACK SCHOTTKY BARRIER TYPE SWITCHING MODE POWER SUPPLY APPLICATION CONVERTER & CHOPPER APPLICATION | TOSHIBA |
| 1638653 | U401 | Dual N-Channel JFET Switch | Calogic |
| 1638654 | U401 | Dual N-Channel JFET JFET Switch | Intersil |
| 1638655 | U401 | Low Noise, Low Drift, Monolithic Dual, N-Channel JFET | Linear Systems |
| 1638656 | U401 | Trans JFET N-CH 6-Pin TO-71 | New Jersey Semiconductor |
| 1638657 | U401 | Monolithic Low Noise | Vishay |
| 1638658 | U401NL | Monolithic N-Channel JFET Duals | Vishay |
| 1638659 | U402 | Dual N-Channel JFET Switch | Calogic |
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| 1638660 | U402 | Dual N-Channel JFET JFET Switch | Intersil |
| 1638661 | U402 | Low Noise, Low Drift, Monolithic Dual, N-Channel JFET | Linear Systems |
| 1638662 | U402 | Trans JFET N-CH 4-Pin TO-71 | New Jersey Semiconductor |
| 1638663 | U403 | Dual N-Channel JFET Switch | Calogic |
| 1638664 | U403 | Dual N-Channel JFET JFET Switch | Intersil |
| 1638665 | U403 | Low Noise, Low Drift, Monolithic Dual, N-Channel JFET | Linear Systems |
| 1638666 | U403 | Trans JFET N-CH 4-Pin TO-71 | New Jersey Semiconductor |
| 1638667 | U4030B | Telephone Speech Circuit | TEMIC |
| 1638668 | U4037B | Low Voltage Speech Circuit with Tone Ringer Interface | TEMIC |
| 1638669 | U4037B-N | Microcontroller-controlled speech and ringer IC, double power supply for ringer and speech function | Atmel |
| 1638670 | U404 | Dual N-Channel JFET Switch | Calogic |
| 1638671 | U404 | Dual N-Channel JFET JFET Switch | Intersil |
| 1638672 | U404 | Low Noise, Low Drift, Monolithic Dual, N-Channel JFET | Linear Systems |
| 1638673 | U404 | Trans JFET N-CH 4-Pin TO-71 | New Jersey Semiconductor |
| 1638674 | U404 | Monolithic Low Noise | Vishay |
| 1638675 | U404NL | Monolithic N-Channel JFET Duals | Vishay |
| 1638676 | U405 | Dual N-Channel JFET Switch | Calogic |
| 1638677 | U405 | Dual N-Channel JFET JFET Switch | Intersil |
| 1638678 | U405 | Low Noise, Low Drift, Monolithic Dual, N-Channel JFET | Linear Systems |
| 1638679 | U405 | Trans JFET N-CH 4-Pin TO-71 | New Jersey Semiconductor |
| 1638680 | U4050B | Speech Circuit with Line-Powered Loudspeaker Amplifier | TEMIC |
