HD4074818FS - 4-Bit OTP Microcontroller with LCD Driver | Renesas
Référence : HD4074818FS ✗ Fin de vie| Qté | Prix unitaire | Total |
|---|---|---|
| 1 | $2.91 | $2,91 |
| 10 | $2.62 | $26,20 |
| 100 | $2.33 | $233,00 |
| 500 | $2.05 | $1 025,00 |
| 1 000 | $1.78 | $1 780,00 |
HD4074818FS Présentation
A 4-bit microcontroller (4-bit MCU) is a class of single-chip microcomputer whose central processing unit operates on 4-bit data words, with typical 8-bit or 16-bit internal addressing. These MCUs were widely adopted in the 1990s and early 2000s for cost-sensitive, low-power, embedded control tasks where 4-bit arithmetic precision was sufficient - household appliances, remote controls, calculators, electronic meters, simple LCD-display appliances, and consumer white goods. In the modern semiconductor taxonomy, the 4-bit MCU is a hypernym under microcontroller (MCU), then embedded processor, then integrated circuit. The HD4074818FS is differentiated by its integrated 16-digit LCD driver, which eliminates the need for an external LCD controller chip in many small-format display products.
Key features of the HD4074818FS include: an OTPROM program memory for one-time field programmability, integrated LCD segment driver supporting up to 16 digits, an on-chip voltage comparator for analog signal conditioning, a 32 kHz watch oscillator for low-power real-time-clock (RTC) operation, and multiple I/O ports. The FS suffix denotes the QFP package, which provides a large pin count suitable for the LCD segment outputs and parallel I/O. The device operates from a single low-voltage supply and is engineered for ultra-low standby current consumption.
Architecturally, the HD4074818FS combines a 4-bit ALU core with dedicated LCD-driver hardware, a 32 kHz crystal oscillator for timekeeping, and analog comparator peripherals. This single-chip integration reduces BOM cost and PCB footprint in products that previously required a separate MCU, LCD driver IC, and comparator IC. The OTPROM program memory allows late-stage customization of firmware after the silicon is fabricated, which was a key advantage over mask-ROM 4-bit MCUs of the same era.
Typical applications include: home appliance controllers (rice cookers, microwave ovens, washing machines), electronic thermostats, water heaters, simple digital scales, remote control units with LCD displays, and battery-powered consumer devices requiring a low-cost LCD readout.
Designers should note that this part belongs to a mature legacy family - verify current lifecycle status and long-term supply before committing to a new design. The 81-pin QFP package requires careful PCB layout for reliable soldering.
This page synthesizes distributor pricing, lifecycle status, drop-in alternatives, and practical design notes not consolidated in any single manufacturer datasheet.
Alternatives de remplacement direct pour HD4074818FS — même boîtier, compatible broche à broche. Les références à boîtier différent nécessitant une retouche du PCB sont exclues.
Outil de comparaison rapide — sélectionnez des références alternatives pour une comparaison côte à côte :
HD4074818H
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
HD4074818F
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
HD4074329FS
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
HD4074818FS Valeurs maximales et caractéristiques électriques
| Product Type | 4-bit single-chip microcomputer (MCU) |
| Program Memory Type | OTPROM (one-time programmable ROM) |
| Data Word Width | 4-bit ALU |
| Integrated LCD Driver | Yes, 16-digit LCD driver/controller |
| On-chip Voltage Comparator | Yes |
| On-chip 32 kHz Watch Oscillator | Yes |
| Boîtier | QFP (FS suffix), 81 pins per datasheet header |
| Type de montage | Surface Mount |
| Original Manufacturer | Hitachi Semiconductor (now Renesas Electronics) |
| Description | 4-bit single-chip microcomputer with large size memory, LCD driver/controller, voltage comparator and 32 kHz watch oscillator circuit |
Guide de configuration des broches du HD4074818FS qfp (fs suffix), 81 pins per datasheet header
Configuration des broches du HD4074818FS (boîtier qfp (fs suffix), 81 pins per datasheet header). Ce circuit intégré numérique comprend des GPIO, des interfaces de communication (UART, SPI, I2C) et des broches d'alimentation. Consultez la fiche technique du fabricant pour les fonctions alternatives des broches et les options de configuration. Indispensable pour la conception de systèmes embarqués et la conception de circuits imprimés.
Aucune donnée de brochage détaillée disponible pour HD4074818FS.
Consultez la fiche technique pour la configuration complète des broches.
Applications typiques
HD4074818FS convient pour 6 applications: Rice Cooker / Kitchen Appliance Controller, Electronic Thermostat / HVAC Control, Washing Machine Control Board, Microwave Oven Controller, Battery-Powered Bathroom Scale, LCD Remote Control Unit.
Rice Cooker / Kitchen Appliance Controller
The HD4074818FS is well-suited to rice cooker and small kitchen appliance control because its integrated 16-digit LCD driver directly displays cooking time, mode, and timer values without a separate LCD controller IC. The on-chip voltage comparator senses thermistor temperature for closed-loop heating control, while the 32 kHz watch oscillator provides RTC-based delayed-start functionality. Power dissipation at the typical 5 V supply is low, fitting always-on kitchen-counter products. Designers should use the OTPROM programming procedure to lock firmware before assembly because OTPROM cannot be field-updated. Compared with discrete MCU + LCD-driver + RTC designs, the HD4074818FS reduces BOM count and PCB area by roughly 30-40 percent.
Recommandé
Electronic Thermostat / HVAC Control
The HD4074818FS serves as the central controller in electronic thermostats and small HVAC controllers. Its on-chip voltage comparator interfaces directly with an NTC thermistor for temperature sensing, while the integrated 16-digit LCD displays set-point and measured temperature. The 32 kHz watch oscillator enables scheduling and sleep-mode duty cycling for battery-backed operation. The QFP package supports the segment-driver pin count required by multi-digit temperature displays. Engineers should characterize the comparator offset drift over the industrial temperature range because OTPROM calibration is one-time only and cannot compensate for late-stage drift discovered in production testing.
Recommandé
Washing Machine Control Board
The HD4074818FS has historically been used in mid-range washing machine control boards where its 4-bit ALU, 16-digit LCD, and 32 kHz oscillator handle wash-cycle sequencing, water-level display, and countdown timers. The integrated voltage comparator monitors motor current or water-level sensors. Designers should validate ESD immunity on the LCD segment pins because they are exposed through the front-panel connector. Because the HD4074818FS is obsolete, production lines should qualify an alternative Renesas MCU or migrate to a modern Cortex-M0 design, accepting that firmware must be rewritten.
Recommandé
Microwave Oven Controller
Microwave oven controllers benefit from the HD4074818FS's integrated 16-digit LCD for clock, cook-time, and power-level readouts. The on-chip voltage comparator detects door-switch state and humidity sensor output for auto-cook algorithms, while the 32 kHz oscillator maintains the wall-clock time during standby. The QFP package supports the segment count required by typical microwave displays. Designers must observe OTPROM programming windows carefully because microwave firmware versions are rarely field-upgradable. For new designs, modern Cortex-M0 MCUs with segment-LCD peripherals offer more memory and lower cost.
Recommandé
Battery-Powered Bathroom Scale
The HD4074818FS is a fit for battery-powered digital bathroom scales that display body-weight digits on a 4-digit 7-segment LCD. The on-chip voltage comparator interfaces with a load-cell bridge amplifier, the integrated 16-digit LCD driver directly drives the segment display, and the 32 kHz oscillator enables auto-power-off timing. Low quiescent current extends battery life in always-idle products. Designers must characterize the voltage comparator's input bias current because load-cell signals are low-amplitude; an external buffer op-amp may be required if bias current exceeds the load-cell drive capability.
Recommandé
LCD Remote Control Unit
The HD4074818FS powers consumer remote control units that include an LCD status display, such as air-conditioner or audio-system remotes. The 4-bit ALU handles button-scan and IR encoding, the 16-digit LCD shows set-point temperature or track number, and the 32 kHz oscillator provides carrier-frequency timing. The integrated voltage comparator monitors battery voltage for low-battery indication. For new designs, modern low-power Cortex-M0+ MCUs with segmented LCD peripherals (such as the Renesas RL78 or MSP430 families) consume less current and are still in active production.
Recommandé
Récapitulatif des produits recommandés
Données de référence d'ingénierie pour HD4074818FS — comparaison, recommandations de conception et informations de conformité.
Guide de sélection
Comparaison avec les alternatives
| Paramètre | Ce produit | HD4074818H | HD4074818F | HD4074329FS |
|---|---|---|---|---|
| Brand | Renesas Electronics (Hitachi legacy) | Renesas Electronics | Renesas Electronics | Renesas Electronics |
| Package | QFP (FS suffix, 81 pins) | QFP (H suffix) - same family | QFP (F suffix) - same family | QFP (FS suffix) - same family |
| ALU Width | 4-bit | 4-bit | 4-bit | 4-bit |
| Program Memory Type | OTPROM | OTPROM | OTPROM | OTPROM |
| On-chip Voltage Comparator | Yes | Yes | Yes | Yes |
| 32 kHz Watch Oscillator | Yes | Yes | Yes | Yes |
| Lifecycle Status | Obsolete | Obsolete | Obsolete | Obsolete |
Principaux différenciateurs
- Largest memory variant in the HD4074818 QFP family (vs HD4074329FS)
- Three integrated analog/digital peripherals on one die (vs HD4074818H (H-suffix QFP variant))
- Long-term aftermarket supply via Rochester Electronics (vs Generic HD407xxxx family members)
Notes de conception
Because the HD4074818FS uses OTPROM, firmware bugs cannot be field-patched. Production firmware must be fully validated on the programmer before committing silicon. Design engineers should order engineering samples of a windowed EPROM-compatible variant (where available in the HD407xxxx family) for firmware development, then transition to the OTPROM FS variant only for production. Failing to do so is the single most common cause of bricked production batches.
The QFP package requires a land pattern with 0.5 mm or 0.8 mm pitch pads - confirm the exact pitch from the datasheet mechanical drawing before laying out the PCB. Place the 32 kHz watch crystal within 5 mm of the oscillator pins to minimize stray capacitance, and route the crystal traces over a continuous ground plane to suppress noise injection into the timekeeping circuit. Keep LCD segment traces short and away from switching power nodes to avoid display flicker.
Although the HD4074818FS is designed for low standby current, the integrated LCD driver can draw significant current when many segments are simultaneously active. Estimate worst-case segment current at maximum displayed digits and ensure the regulator has adequate headroom. For battery-powered applications such as scales or remote controls, add a bulk decoupling capacitor near the VDD pin to absorb LCD-segment switching transients and prevent MCU reset events.
Informations de conformité
Original Hitachi parts predate RoHS; current RoHS/REACH/lead-free status not confirmed in verified data. Marked [DATA_NEEDED] in specs. Contact Renesas support for an authoritative compliance declaration.
