PIC17LC42A-08I/PT - 8-Bit 8MHz 4KB OTP MCU 44-TQFP | Microchip
Référence : PIC17LC42A-08I/PT ✗ Fin de vie| Qté | Prix unitaire | Total |
|---|---|---|
| 1 | $18.5 | $18,50 |
| 10 | $16.2 | $162,00 |
| 100 | $13.85 | $1 385,00 |
| 500 | $11.4 | $5 700,00 |
| 1 000 | $9.75 | $9 750,00 |
PIC17LC42A-08I/PT Présentation
A microcontroller (MCU) is a single-chip computer that integrates a CPU, non-volatile program memory, working RAM, and peripheral I/O on one die. The PIC17 family sits at the top of Microchip's 8-bit portfolio and targets high-end 8-bit embedded applications. Within the wider taxonomy, PIC17LC42A belongs to: microcontroller -> embedded processor -> semiconductor IC. Its "LC" low-voltage CMOS process allows operation down to 2.5V, distinguishing it from the original PIC17C42A which required 5V.
Key features include an 8-level deep hardware stack, 16-bit instruction word architecture, 33 I/O lines, integrated UART/USART, and an external oscillator interface. The wide operating voltage range (2.5V-6.0V) and industrial temperature grade (-40C to +85C, indicated by the "I" suffix) make the device suited for battery-powered and industrial environments.
Architecturally, the PIC17LC42A uses a Harvard-style RISC core with separate program and data buses, enabling instruction fetch and operand access to occur in parallel within a single cycle. Its 16-bit-wide program memory (despite being called an "8-bit" MCU) and dual-cycle hardware multiply support arithmetic-intensive routines.
Typical applications include industrial control logic, instrumentation front-ends, automotive body modules, motor control signal conditioning, and embedded communication bridges where UART/USART connectivity and OTP code security are required. Engineers often choose the PIC17LC42A for legacy designs and for new designs that benefit from mature tooling and an extensive code base.
When designing with this part, plan for a 121 ns instruction cycle budget and ensure the chosen external oscillator source meets the device's timing specifications. The OTP memory means firmware must be complete before programming - consider that field updates are not possible without physical device replacement.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
Alternatives de remplacement direct pour PIC17LC42A-08I/PT — même boîtier, compatible broche à broche. Les références à boîtier différent nécessitant une retouche du PCB sont exclues.
Variantes de cette série
Modèles de la même série directement compatibles avec PIC17LC42A-08I/PT (même facteur de forme et même empreinte) — différant par Package, Program Memory Type, Program Memory Size, Core Architecture, RAM Size.
Outil de comparaison rapide — sélectionnez des références alternatives pour une comparaison côte à côte :
PIC17C42A-25/PT
✅ Remplacement direct✓ En stock
$5.55 / unité
Voir la fiche technique →PIC17C44-16I/PT
✅ Remplacement direct✓ En stock
$4.65 / unité
Voir la fiche technique →PIC17C43-16I/PT
✅ Remplacement direct✓ En stock
$5.3 / unité
Voir la fiche technique →PIC17LC42A-08/PQ
✅ Remplacement direct✓ En stock
$4.1 / unité
Voir la fiche technique →PIC17LC44T-08I/PQ
✅ Remplacement direct✓ En stock
$4.25 / unité
Voir la fiche technique →PIC17LC42A-08I/PT Valeurs maximales et caractéristiques électriques
| Family | PIC17C |
| Core Architecture | 8-bit RISC (Harvard) |
| Program Memory Type | OTP (One-Time Programmable) EPROM |
| Program Memory Size | 4 KB (2K x 16) |
| RAM Size | 232 x 8 bytes |
| Fréquence d'horloge maximale | 8 MHz |
| Instruction Cycle Time | 121 ns (single-cycle instructions) |
| Instruction Set Size | 58 single-word instructions |
| Number of I/O Pins | 33 |
| Supply Voltage Range | 2.5 V to 6.0 V |
| Plage de température de fonctionnement | -40 C to +85 C (Industrial) |
| Boîtier | 44-TQFP (10x10 mm) |
| Type de montage | Surface Mount |
| Peripherals | UART/USART |
| Oscillator Type | External |
| Hardware Stack Depth | 8 levels |
Configuration des broches de PIC17LC42A-08I/PT
| Broche 1 | RA0/AN0 — Digital I/O port A bit 0 / analog input 0 |
| Broche 2 | RA1/AN1 — Digital I/O port A bit 1 / analog input 1 |
| Broche 3 | RA2/AN2 — Digital I/O port A bit 2 / analog input 2 |
| Broche 4 | RA3/AN3 — Digital I/O port A bit 3 / analog input 3 |
| Broche 5 | RA4/T0CKI — Digital I/O port A bit 4 / Timer 0 clock input |
| Broche 6 | RA5/SS — Digital I/O port A bit 5 / SPI slave select |
| Broche 7 | RA6 — Digital I/O port A bit 6 |
| Broche 8 | RA7 — Digital I/O port A bit 7 |
| Broche 9 | OSC1/CLKIN — External oscillator input / clock input |
| Broche 10 | OSC2/CLKOUT — External oscillator output / clock output |
| Broche 11 | RC0 — Digital I/O port C bit 0 |
| Broche 12 | RC1 — Digital I/O port C bit 1 |
| Broche 13 | RC2 — Digital I/O port C bit 2 |
| Broche 14 | RC3 — Digital I/O port C bit 3 |
| Broche 15 | RC4 — Digital I/O port C bit 4 |
| Broche 16 | RC5 — Digital I/O port C bit 5 |
| Broche 17 | RC6 — Digital I/O port C bit 6 |
| Broche 18 | RC7 — Digital I/O port C bit 7 |
| Broche 19 | VSS — Ground reference |
| Broche 20 | VDD — Positive supply voltage (2.5V-6.0V) |
| Broche 21 | RB0/INT — Digital I/O port B bit 0 / external interrupt |
| Broche 22 | RB1 — Digital I/O port B bit 1 |
| Broche 23 | RB2 — Digital I/O port B bit 2 |
| Broche 24 | RB3 — Digital I/O port B bit 3 |
| Broche 25 | RB4 — Digital I/O port B bit 4 |
| Broche 26 | RB5 — Digital I/O port B bit 5 |
| Broche 27 | RB6 — Digital I/O port B bit 6 |
| Broche 28 | RB7 — Digital I/O port B bit 7 |
| Broche 29 | MCLR/VPP — Master clear reset / programming voltage input |
| Broche 30 | NC — Not connected (per datasheet) |
| Broche 31 | NC — Not connected (per datasheet) |
| Broche 32 | NC — Not connected (per datasheet) |
| Broche 33 | RD0 — Digital I/O port D bit 0 |
| Broche 34 | RD1 — Digital I/O port D bit 1 |
| Broche 35 | RD2 — Digital I/O port D bit 2 |
| Broche 36 | RD3 — Digital I/O port D bit 3 |
| Broche 37 | RD4 — Digital I/O port D bit 4 |
| Broche 38 | RD5 — Digital I/O port D bit 5 |
| Broche 39 | RD6 — Digital I/O port D bit 6 |
| Broche 40 | RD7 — Digital I/O port D bit 7 |
| Broche 41 | RE0 — Digital I/O port E bit 0 |
| Broche 42 | RE1 — Digital I/O port E bit 1 |
| Broche 43 | RE2 — Digital I/O port E bit 2 |
| Broche 44 | VSS — Ground reference (secondary) |
Applications typiques
PIC17LC42A-08I/PT convient pour 6 applications: Industrial Control Logic, Instrumentation Front-Ends, Automotive Body Modules, Embedded Communication Bridges, Motor Control Signal Conditioning, Legacy Embedded Systems Repair.
Industrial Control Logic
The PIC17LC42A-08I/PT is well suited for industrial control logic modules where deterministic 8-bit RISC execution and OTP code security are required. With 33 I/O pins driving relays, optocouplers, and discrete logic, plus an integrated UART/USART for RS-232/RS-485 fieldbus bridges, this 8-bit MCU can scan up to 33 digital inputs and execute ladder-logic-equivalent sequences within the 121 ns instruction cycle. The 2.5V-6.0V supply range accommodates both 24V industrial rails stepped down to 5V and 3.3V regulated logic, while the -40C to +85C industrial temperature grade (denoted by the "I" suffix) tolerates factory floor thermal stress. Designers use it for PLC sub-modules, conveyor controllers, and process automation front-ends.
Recommandé
Instrumentation Front-Ends
Test and measurement instruments benefit from the PIC17LC42A-08I/PT's combination of 8-bit RISC throughput, 232-byte RAM, and UART/USART connectivity for SCPI command parsing or instrument-to-host bridges. The 33 I/O lines multiplex front-panel buttons, encoder inputs, and LCD segment drivers, while the OTP memory protects proprietary calibration algorithms from reverse engineering. At 8MHz clock input the 121 ns instruction cycle enables sub-microsecond response to sensor interrupts, adequate for digital multimeters, bench-top signal generators, and process calibrators. The 44-TQFP package fits compact handheld form factors common to portable instrumentation.
Recommandé
Automotive Body Modules
Automotive body electronic modules such as lighting controllers, seat memory modules, and HVAC blend-door actuators have historically used PIC17LC42A-08I/PT MCUs. The 33 digital I/O pins drive MOSFET gate drivers and read switch matrices, the UART/USART interfaces with LIN bus transceivers or older CAN bridges, and the OTP memory secures the body control firmware. The industrial -40C to +85C temperature grade covers cabin environments; under-hood applications would require the extended automotive grade. The 8MHz clock rate keeps current consumption manageable in always-on body modules that wake on CAN/LIN activity.
Recommandé
Embedded Communication Bridges
The PIC17LC42A-08I/PT functions as an embedded communication bridge between UART-based field devices and host controllers. Its integrated USART handles async serial at standard baud rates up to 375 kbps (typical for 8MHz clock), while the 33 I/O lines bit-bang secondary protocols such as I2C, SPI, or one-wire master interfaces. With 4KB OTP and 232-byte RAM, the device stores small protocol translation tables and FIFOs. Use cases include RS-232 to RS-485 converters, UART to SPI sensor aggregators, and legacy modem replacement cards. The 2.5V-6.0V supply accommodates both 3.3V logic and 5V legacy UART levels.
Recommandé
Motor Control Signal Conditioning
Low-power motor control signal conditioning tasks such as PWM signal generation, tachometer feedback decoding, and H-bridge sequencing fit the PIC17LC42A-08I/PT's capability range. The 8-bit core's 121 ns instruction cycle supports 8 kHz PWM switching with software dead-time insertion, while 33 I/O lines interface Hall-effect sensors, encoder inputs, and gate driver enable pins. The 2.5V-6.0V supply range allows direct connection to 3.3V DSP/microcontroller companion chips. For higher-power three-phase motor drives, designers pair this MCU with a dedicated dsPIC33 DSP for field-oriented control loops.
Recommandé
Legacy Embedded Systems Repair
The PIC17LC42A-08I/PT is primarily specified today for repair and maintenance of legacy systems where the original designer chose this 8-bit MCU and no firmware migration is feasible. Equipment such as industrial CNC controllers, medical instrumentation, point-of-sale terminals, and avionics subsystems built in the late 1990s through mid-2000s often deployed PIC17C-family MCUs. Replacement units must be bit-compatible, same-package (44-TQFP), and same-pinout to avoid PCB rework. Distributors such as Heisener and Lisleapex maintain remaining stock of approximately 5,700 pieces as of 2026-09-26 to support field repair activities until designs are migrated to flash-based PIC18 or dsPIC33 platforms.
Recommandé
Récapitulatif des produits recommandés
Données de référence d'ingénierie pour PIC17LC42A-08I/PT — comparaison, recommandations de conception et informations de conformité.
Guide de sélection
Comparaison avec les alternatives
| Paramètre | Ce produit | PIC17C42A-25/PT | PIC17C44-16I/PT | PIC17C43-16I/PT | PIC17LC42A-08/PQ | PIC17LC44T-08I/PQ |
|---|---|---|---|---|---|---|
| Package | 44-TQFP (10x10 mm) | 44-TQFP (10x10 mm) - same | 44-TQFP (10x10 mm) - same | 44-TQFP (10x10 mm) - same | 44-MQFP (10x10 mm) - same footprint family | 44-MQFP (10x10 mm) - same footprint family |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Core Architecture | 8-bit PIC17 RISC | 8-bit PIC17 RISC | 8-bit PIC17 RISC | 8-bit PIC17 RISC | 8-bit PIC17 RISC | 8-bit PIC17 RISC |
| Program Memory | 4 KB OTP | 4 KB OTP | 8 KB OTP | 8 KB OTP | 4 KB OTP | 8 KB OTP |
| RAM Size | 232 x 8 bytes | 232 x 8 bytes | 454 x 8 bytes | 454 x 8 bytes | 232 x 8 bytes | 454 x 8 bytes |
| Max Clock Input | 8 MHz | 25 MHz | 16 MHz | 16 MHz | 8 MHz | 8 MHz |
| Supply Voltage | 2.5 V to 6.0 V | 4.5 V to 6.0 V | 4.5 V to 6.0 V | 4.5 V to 6.0 V | 2.5 V to 6.0 V | 2.5 V to 6.0 V |
| I/O Pins | 33 | 33 | 33 | 33 | 33 | 33 |
| Lifecycle Status | Obsolete | Obsolete | Obsolete | Obsolete | Obsolete | Obsolete |
Principaux différenciateurs
- Low-voltage CMOS process enables 2.5V operation (vs PIC17C42A-25/PT (4.5V-6.0V only))
- Compact 10x10 mm TQFP-44 surface-mount package (vs DIP-40 through-hole PIC17LC42A-08I/P)
- OTP code security prevents firmware reverse engineering (vs Flash-based PIC18F452)
Notes de conception
OTP memory cannot be erased or rewritten: the PIC17LC42A-08I/PT uses One-Time Programmable EPROM, meaning any firmware bug discovered after programming requires physical device replacement. Build robust prototype verification flows using windowed (JW-package) PIC17LC42A parts during development, then program production OTP units only after firmware is fully validated. Budget for OTP programming time (typically several seconds per device) and verify blank-check before programming to catch previously-used units.
Power supply decoupling for the PIC17LC42A-08I/PT requires a 0.1uF ceramic capacitor placed within 5mm of each VDD pin (pins 20 and any duplicate supply pin), plus a 10uF bulk tantalum or ceramic capacitor at the board power entry. The PIC17C family draws brief current spikes during instruction fetches; insufficient decoupling can cause VDD droop that resets the device or corrupts OTP programming. Place a 10kohm pull-up on MCLR/VPP (pin 29) to prevent spurious resets, and add a 100nF capacitor from MCLR to VSS for noise immunity in industrial environments.
PCB layout for the 44-TQFP PIC17LC42A-08I/PT should place the external oscillator crystal or resonator within 10mm of OSC1 (pin 9) and OSC2 (pin 10), with a ground guard ring around the oscillator traces to suppress noise coupling into the clock signal. Route the MCLR/VPP trace away from high-current switching nodes to prevent false resets. The TQFP-44 package has a 0.8mm lead pitch requiring fine-pitch PCB fabrication (0.4mm pads minimum); use NSMD (non-solder mask defined) land patterns for better solder joint reliability per IPC-7351.
The PIC17LC42A-08I/PT 33 I/O pins have limited sink/source current (typically 25 mA per pin, 200 mA total package). For driving relays, LEDs, or power MOSFETs, use external driver ICs such as ULN2803 or discrete transistors. When bit-banging high-speed protocols, observe the 121 ns instruction cycle and add NOP padding to meet protocol timing requirements. The integrated USART supports standard baud rates up to 375 kbps at 8MHz clock; for higher rates, drop to lower baud divisors or upgrade to a PIC18 with enhanced USART.
Informations de conformité
RoHS/REACH compliance not explicitly stated in verified web data for this obsolete Microchip part. Industrial temperature grade (-40C to +85C) is specified by the "I" suffix. Not AEC-Q100 qualified - automotive body module applications should use AEC-Q100-qualified PIC18 or dsPIC33 alternatives.