PIC16LC774/PT - 8-bit MCU, 7KB OTP, 20MHz, 44-TQFP | Microchip
MPN： PIC16LC774/PT ✗ 停產PIC16LC774/PT 概覽
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, program memory, working RAM, and peripheral interfaces onto one silicon die. Microcontrollers belong to the broader category of embedded processors, sitting alongside microprocessors (MPUs), DSPs, and SoCs; PIC microcontrollers occupy the 8-bit RISC niche, where deterministic instruction timing and minimal external component count are favored over raw compute throughput. The '16' in PIC16LC774 denotes the mid-range PIC family that uses a 14-bit instruction word, providing 35 single-word instructions and predictable single-cycle execution (branches take two cycles).
Key specifications include 7KB OTP program memory organized as 4K x 14 bits, 256 x 8 bytes of data RAM, four 8-bit I/O ports (PORTA-PORTE partial) yielding 33 usable I/O, a hardware USART, a 10-bit ADC (typically 8 channels on this die), and two Capture/Compare/PWM modules. The OTP memory is one-time programmable, meaning code is locked at production programming time and cannot be field-updated — a key selection criterion versus flash-based PIC16F variants.
Architecturally, the device uses a Harvard architecture with separate program and data buses, enabling simultaneous instruction fetch and operand access. The 20 MHz oscillator drives an internal four-phase clock, and most instructions complete in one oscillator period (200 ns at 20 MHz), with branches taking two periods. The CMOS 'LC' process reduces active and standby draw compared to the original PIC16C77, which made this part attractive for battery-influenced designs.
Typical applications include industrial control and instrumentation, automotive body and chassis subsystems, appliance control boards, sensor interface front-ends, and general-purpose embedded logic replacement. The 33 I/O pins comfortably drive LED arrays, keypads, character LCDs, and simple actuator bridges. The wide operating temperature range also supports outdoor and harsh-environment deployments.
When laying out, allocate a continuous ground pour beneath the device and route the MCLR reset line away from switching nodes to avoid spurious resets. Place the oscillator crystal within 5 mm of OSC1/OSC2 with a grounded guard ring to suppress EMC pickup. Bulk decoupling of 10 uF plus 0.1 uF ceramic at VDD is recommended per Microchip mid-range reference designs.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet alone — including a parametric comparison table against other 44-TQFP PIC16 family members and same-package drop-in replacements.
直接替換替代品，適用於 PIC16LC774/PT — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
此系列的變體
與下列產品可直接替換的同系列型號： PIC16LC774/PT （相同外形與佔位） — 差異在於 Program Memory Size, Core Architecture, Instruction Cycle Time, Operating Temperature, Package.
PIC16LC774-I/PT
✅ 直接替換聯絡詢價
查看資料表 →PIC16LC774T-I/PT
✅ 直接替換聯絡詢價
查看資料表 →PIC16LC65A-04I/PT
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
PIC16F877-I/PT
✅ 直接替換📋 參考替代品（不在目錄中）
PIC16F874A-I/PT
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
PIC16LC774/PT 最大額定值與電氣特性
| Core Architecture | 8-bit RISC (PIC16 mid-range, 14-bit instruction word) |
| Instruction Set | 35 single-word instructions |
| Program Memory Type | OTP (One-Time Programmable) |
| Program Memory Size | 7 KB (4K x 14) |
| Data RAM | 256 x 8 bytes |
| Data EEPROM | Not present (OTP die) |
| 最大時脈頻率 | 20 MHz |
| Instruction Cycle Time | 200 ns (4 TCY per oscillator period) |
| I/O Pins | 33 |
| Capture/Compare/PWM Modules | 2 (typical for PIC16C77 family) |
| USART | 1 x hardware USART (AUSART) |
| 封裝 | 44-pin TQFP (10 x 10 mm) |
| 安裝類型 | Surface Mount |
PIC16LC774/PT 44-pin tqfp (10 x 10 mm) 腳位配置指南
PIC16LC774/PT（44-pin tqfp (10 x 10 mm) 封裝）的腳位配置。 此數位 IC 包含 GPIO、通訊介面（UART、SPI、I2C）與電源腳位。替代腳位功能與配置選項請參閱製造商資料表。對嵌入式系統設計與 PCB 佈局至關重要。
無詳細腳位定義資料： PIC16LC774/PT.
請參閱 資料表 以查看完整腳位配置。
典型應用
PIC16LC774/PT 適用於 6 應用s: Industrial Process Control, Automotive Body and Chassis Electronics, Appliance Control Boards, Sensor Interface Front-Ends, General-Purpose Embedded Logic Replacement, HMI and Display Controllers.
Industrial Process Control
The PIC16LC774/PT is well suited for industrial process controllers driving sensors, valves, and indicator panels. With 33 I/O pins the device can scan a 4x4 keypad, drive a 16x2 character LCD, and read multiple analog inputs through the on-chip 10-bit ADC without external multiplexer expansion. The 20 MHz clock keeps control-loop latency under 200 ns per instruction, deterministic enough for PID loops on slow thermal and pressure processes. Its 5 V supply is native to legacy 24-V industrial backplanes stepped down to logic levels, and the 44-TQFP package supports dense multi-board layouts inside sealed enclosures.
推薦
Automotive Body and Chassis Electronics
The PIC16LC774/PT historically powered body controllers, lighting modules, and simple wiper/window controls in pre-CAN automotive designs. Its wide operating voltage tolerance and deterministic interrupt response make it appropriate for seat-controller and mirror-adjust nodes that run from 12 V battery rails. The 256-byte RAM is sufficient for state machines governing lighting sequences and door-lock actuators. While newer automotive designs migrate to dsPIC33CH and PIC18F-K80 families, the LC774 remains in NRND service for legacy spare-part channels and aftermarket modules where exact form-fit-function is mandated.
推薦
Appliance Control Boards
White-goods manufacturers deployed the PIC16LC774/PT in washing-machine, dishwasher, and oven control boards where cost dominates over flash reprogrammability. The 33 I/O lines drive seven-segment displays, keypads, relay coils, and triac-fired heater loads through zero-cross optoisolators. The OTP memory locks firmware at production, preventing field tampering with safety-critical parameters like maximum heater-on time. Five-volt operation aligns with the regulated logic rail that already powers the user-interface MCU cluster, simplifying BOM. Its NRND status today means most new appliance designs migrate to PIC16F or PIC18F equivalents.
推薦
Sensor Interface Front-Ends
The PIC16LC774/PT serves as a sensor-hub MCU aggregating thermocouple, RTD, and 4-20 mA loop inputs in distributed measurement nodes. Its 10-bit ADC and 33 digital I/O enable multiplexing eight analog channels plus a UART link back to a central controller. The LC low-power CMOS process reduces quiescent draw compared to the older PIC16C77 NMOS variant, which matters in solar-powered remote sensors. With 256 bytes of RAM the device can buffer a small calibration table and run linearization routines on cold-junction-compensated thermocouple readings. The 44-TQFP exposes enough I/O to also drive status LEDs and a local LCD.
推薦
General-Purpose Embedded Logic Replacement
Designers frequently replace discrete 74HC logic gates and small PLDs with the PIC16LC774/PT when firmware-driven behavior is preferable to hard-wired glue logic. A single MCU in a 44-TQFP can replace dozens of discrete packages, shrinking PCB area and reducing assembly cost. The 20 MHz clock executes 5 MIPS, enough for state-machine timing, debounce filtering, and serial protocol generation. The 33 I/O pins can sink or source 25 mA each, sufficient for direct LED drive without external transistors. For retrofit designs that must exactly replicate legacy LC774 firmware, no silicon alternative preserves pinout and register map as cleanly as another member of the PIC16LC77x family.
推薦
HMI and Display Controllers
The PIC16LC774/PT is widely deployed as a low-cost HMI controller for character LCDs, seven-segment panels, and small graphical OLEDs in industrial terminals. The 33 I/O pins support a parallel 4-bit or 8-bit LCD interface plus a 4x4 matrix keypad with minimal pin sharing, leaving additional lines for backlight PWM via one of the CCP modules. With 256 bytes of RAM the device can hold menu state, edit-buffer characters, and modest custom-font tables for graphical displays. The 20 MHz clock drives SPI or I2C buses at standard rates, and the hardware USART simplifies connection to upstream PLCs.
推薦
推薦產品摘要
工程參考資料，適用於 PIC16LC774/PT — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 | PIC16LC774-I/PT | PIC16LC774T-I/PT | PIC16LC65A-04I/PT | PIC16F877-I/PT | PIC16F874A-I/PT |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-TQFP | 44-TQFP - same | 44-TQFP - same | 44-TQFP - same | 44-TQFP - same | 44-TQFP - same |
| Program Memory | 7 KB OTP | 7 KB OTP | 7 KB OTP | 4K x 14 OTP | 8K x 14 Flash | 7K x 14 Flash |
| Maximum Clock Frequency | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| Memory Type | OTP (one-time programmable) | OTP | OTP | OTP | Flash | Flash |
| Operating Temperature Grade | Commercial (0C to +70C) | Industrial (-40C to +85C) | Industrial (-40C to +85C) | Industrial (-40C to +85C) | Industrial (-40C to +85C) | Industrial (-40C to +85C) |
| Lifecycle Status | NRND | NRND | NRND | NRND | Active | Active |
主要差異化特點
- Low-power CMOS process with industrial temperature option (對比PIC16LC774-I/PT)
- Field-upgradable flash alternative in same footprint (對比PIC16F877-I/PT)
- Established distributor inventory at NRND stage (對比PIC16LC773T-I/SO)
設計說明
Estimated: Power-supply decoupling on the PIC16LC774/PT requires at minimum one 10 uF tantalum or aluminum bulk capacitor plus a 0.1 uF ceramic placed within 5 mm of the VDD pin. According to the Microchip PIC16C77 family datasheet, mid-range PICs draw brief current spikes of 20-40 mA during instruction execution; insufficient bulk decoupling will cause VDD droop that resets the device under heavy I/O switching load. Add a ferrite bead on VDD if the supply is shared with inductive loads.
Route the MCLR reset pin away from switching nodes and any high-current traces. Place the crystal or resonator within 5 mm of OSC1/OSC2 and surround both oscillator traces with a grounded guard ring to suppress EMC pickup. The 44-TQFP package's exposed thermal pad (where present) should be soldered to a grounded copper pour to reduce junction temperature; this matters in enclosed industrial enclosures where ambient can approach 60 C.
OTP memory cannot be erased or rewritten — a programming error or firmware bug bricks the part permanently. Always program production parts only after a fully validated firmware image has been bench-tested on flash-based PIC16F877-I/PT equivalents. Configure the CONFIG bits (oscillator selection, watchdog enable, brown-out voltage, code protection) carefully; an unintended code-protect setting can lock the device with bad firmware. Use Microchip's MPLAB X IDE with a verified programmer for development, not an off-brand toolchain.
Estimated: The PIC16LC774/PT at 20 MHz and 5 V with all 33 I/O toggling at full CMOS load dissipates roughly 50-80 mW. The 44-TQFP package has a theta_JA of approximately 50 C/W on a standard JEDEC 2S2P board, yielding a junction-to-ambient rise of 3-4 C. This is well within the commercial 0 C to +70 C grade; for industrial -40 C to +85 C parts in sealed enclosures, derate by 10-15 C and ensure adequate ventilation or attach a small clip-on heatsink if ambient exceeds 60 C.
合規資訊
RoHS, lead-free and halogen-free status not directly stated in the verified web data; compliance must be confirmed against the manufacturer's product page or full datasheet. AEC-Q100 not qualified — automotive designs should verify grade or use dsPIC33CH family instead.