Product Overview
National Semiconductor LM1203N: Three-Channel 70 MHz RGB Video Amplifier System in 28-Pin DIP
Condition
New old stock. The photographed piece is a black molded 28-pin plastic DIP marked with the National Semiconductor logo, the date code line B9130, and LM1203N in two lines of laser-etched text. The package carries a molded DP identifier alongside the pin-1 notch and a pin-1 dimple at the corner. All leads are bright silver, straight, evenly formed, and show no solder, no flux residue, no board impressions, and no bending from prior installation. The underside is clean black plastic with only factory mold marks. Stored loose in our stock, not on a reel or in original tube packaging.
Same or next business day shipping from our Idaho warehouse. Honest pricing, no nonsense.
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Product Overview
The LM1203N is National Semiconductor's RGB video amplifier system, a single monolithic chip that carries three wideband amplifier channels rated 70 MHz at -3 dB, three inherently matched attenuators for contrast control that track within 0.1 dB (1.2%), three externally gated comparators for brightness control, an on-chip video input voltage reference, and a low impedance output driver. Putting all three color channels on one die is the point of the part: red, green, and blue stay matched to each other because they came off the same silicon and share the same reference. This is the N suffix version, the 28-pin molded plastic dual-in-line package, which is the through-hole form technicians want for socketed repair work and prototype video boards. The unit shown is marked B9130 in National's factory date-code format. National Semiconductor is now part of Texas Instruments, and original-branded National parts in this family are no longer produced.
Key Features
- Three wideband amplifier channels: 70 MHz at -3 dB
- Inherently matched attenuators for contrast control: matched within 0.1 dB (1.2%)
- Three externally gated comparators for brightness control
- Video input voltage reference on chip
- Low impedance output driver
- Package: 28-pin molded plastic dual-in-line (DIP), N suffix
- Markings observed: National Semiconductor logo, B9130, LM 1203N
- Condition: new old stock, unused, leads untouched
Applications
- Monitor technician rebuilding the RGB preamp stage of a CRT video chassis and needing all three color channels matched from one device
- Arcade and retro-computing restorer replacing a failed video amplifier where the original board was laid out for a 28-pin DIP
- Bench engineer breadboarding a three-channel wideband video path with contrast and brightness control handled on chip
- Repair shop stocking a small shelf of period-correct National video parts for legacy display work
Frequently Asked Questions
What does the LM1203N actually do in a video circuit?
It handles three color channels at once: amplification out to 70 MHz at -3 dB, contrast control through matched attenuators, and brightness control through externally gated comparators, with a video input voltage reference and low impedance output driver built in. It is the front end that gets an RGB signal ready to drive the next stage.
Is this the through-hole DIP version?
Yes. The photos show a 28-pin molded plastic dual-in-line package, which is the N suffix version. Leads are on 0.1 inch centers in the standard DIP arrangement. If your board or socket was built for the DIP footprint, this is the right form.
Has it been electrically tested?
No. We sell it as new old stock based on physical condition, which is what the photos show: clean unsoldered leads and factory markings. Pin assignments, supply voltage, and drive levels are not confirmed here, so verify them against the LM1203 datasheet before use.
Will the piece I receive carry the B9130 date code?
The unit photographed reads B9130. We ship from the same holding, but we cannot promise a specific code on every piece. If you need a matched date code across multiple units, ask before ordering and we will check what is on the shelf.
Why buy one or two pieces here instead of a bulk lot somewhere else?
Because a video chassis repair usually needs one LM1203N, not a tray of ten. We sell the exact count you need. Shipping is $8 flat rate and free over $28, so a single amplifier chip or a pair of spares still lands cheaper than a forced-quantity lot, and it goes out same or next business day from Idaho.
Three channels that have to agree with each other, or the whites drift pink and the picture never looks right. Still in its original black plastic with the factory date code intact, this one is waiting for the chassis that needs its color put back.
