PIC16LC621AT-04I/SS - 8-Bit 4MHz OTP MCU 1.75KB 20-SSOP | Microchip
MPN： PIC16LC621AT-04I/SS ✓ 啟用中PIC16LC621AT-04I/SS 概覽
A PIC microcontroller (MCU) is a compact, self-contained computer-on-a-chip combining an 8-bit CPU, non-volatile program memory (here, OTP), volatile RAM, and configurable I/O peripherals on a single die. PIC MCUs sit in the broader hierarchy of embedded controllers -> microcontrollers -> 8-bit microcontrollers -> RISC microcontrollers -> semiconductors, and are widely used in cost-sensitive consumer and industrial control products. The 'C' in PIC16C indicates an OTP EPROM-based program memory architecture, distinguishing it from flash-based PIC16F variants.
Key features of the PIC16LC621AT-04I/SS include 12-bit wide instruction set with an 8-bit data path, seven or eight special function hardware registers, direct/indirect/relative addressing modes, and CMOS low-power technology supporting the wide 2.5 V to 6.25 V supply range. The /SS suffix denotes the 20-pin SSOP (Shrink Small Outline Package) form factor, and the '04' speed grade specifies 4 MHz maximum clock. The 'I' industrial temperature grade supports -40C to +85C ambient operation. According to the Microchip datasheet, this part belongs to the mid-range PIC16C6xx family and is suitable for products where one-time programmable memory and a small footprint are acceptable.
Typical applications span white goods and small appliance controllers, automotive body electronics (non-AEC-Q100), simple sensor interfaces, consumer remote controls, low-end timer/sequencer logic, and replacement of discrete logic in cost-optimized designs. For applications requiring in-system reprogrammability, designers should migrate to a flash-based PIC16F equivalent instead. The 20-SSOP package offers a compact 0.209 inch (5.30 mm) body width for high-density board layouts.
When designing with this device, carefully verify that OTP programming is acceptable for your production flow, since OTP parts cannot be erased or rewritten. Plan for adequate supply decoupling and ensure the WDT is enabled or disabled intentionally per the application requirement. According to the Microchip datasheet, the PIC16LC621A family is mature and may be subject to lifecycle transitions; verify current availability with Microchip before committing to new designs.
直接替換替代品，適用於 PIC16LC621AT-04I/SS — 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： PIC16LC621AT-04I/SS （相同外形與佔位） — 差異在於 Operating Temperature Range, Core Architecture, Program Memory Size, Package, RAM Size.
PIC16LC621A-04I/SS
✅ 直接替換📋 參考替代品（不在目錄中）
PIC16LC621AT-04E/SS
✅ 直接替換聯絡詢價
查看資料表 →PIC16LC621AT-04I/SO
✅ 直接替換聯絡詢價
查看資料表 →PIC16LC620A-04I/SS
✅ 直接替換聯絡詢價
查看資料表 →PIC16LC621A-04I/P
✅ 直接替換聯絡詢價
查看資料表 →PIC16LC621AT-04I/SS 最大額定值與電氣特性
| Core Processor | PIC |
| Core Size | 8-Bit |
| Core Architecture | RISC |
| Series | PIC® 16C |
| Clock Speed (Max) | 4 MHz |
| Program Memory Size | 1.75 KB (1K x 14) |
| Program Memory Type | OTP (One-Time Programmable) |
| RAM Size | 96 bytes |
| Number of I/O Pins | 13 |
| Supply Voltage Range | 2.5 V to 6.25 V |
| 工作溫度範圍 | -40C to +85C (Industrial) |
| 封裝 / 外殼 | 20-SSOP (0.209 inch, 5.30 mm body width) |
| 安裝類型 | Surface Mount |
| Instruction Set Width | 12-bit |
| Data Path Width | 8-bit |
| Stack Depth | 2-level hardware stack |
| Peripherals | Brown-out Detect (BOD), Power-On Reset (POR), Watchdog Timer (WDT) |
| Addressing Modes | Direct, Indirect, Relative |
| Number of Special Function Registers | 7 or 8 |
| RoHS 狀態 | Compliant |
PIC16LC621AT-04I/SS 腳位配置
| 腳位 1 | RA2 — GPIO / analog input |
| 腳位 2 | RA3 — GPIO / analog input |
| 腳位 3 | RA4 — GPIO / T0CKI |
| 腳位 4 | MCLR — Master Clear (Reset, active low) |
| 腳位 5 | VSS — Ground |
| 腳位 6 | RB0 — GPIO / INT |
| 腳位 7 | RB1 — GPIO |
| 腳位 8 | RB2 — GPIO |
| 腳位 9 | RB3 — GPIO |
| 腳位 10 | RB4 — GPIO |
| 腳位 11 | RB5 — GPIO |
| 腳位 12 | RB6 — GPIO |
| 腳位 13 | RB7 — GPIO |
| 腳位 14 | VDD — Positive supply voltage |
| 腳位 15 | OSC2 — Oscillator output |
| 腳位 16 | OSC1 — Oscillator input |
| 腳位 17 | RA0 — GPIO / analog input |
| 腳位 18 | RA1 — GPIO / analog input |
| 腳位 19 | RC0 — GPIO |
| 腳位 20 | RC1 — GPIO |
典型應用
PIC16LC621AT-04I/SS 適用於 6 應用s: White Goods and Small Appliance Control, Automotive Body Electronics (Non-Safety), Consumer Remote Controls and IR Transmitters, Industrial Sensor Interface and Signal Conditioning, LED Lighting Controllers and Drivers, Battery-Powered Timers and Sequencers.
White Goods and Small Appliance Control
The PIC16LC621AT-04I/SS suits white goods and small appliance controllers where final firmware is locked and per-unit cost matters. Its 1.75 KB OTP program memory is sufficient for state machines controlling relays, triacs, and sensor inputs in microwaves, washing machines, and coffee makers. The 4 MHz clock handles slow electromechanical sequencing (timer ticks, button debounce, mode selection) without taxing the budget. The 13 GPIO pins map directly to keypad rows, LED indicators, and motor-driver enable lines; brown-out detect prevents erratic operation during brown-outs in mains-powered systems. Wide 2.5 V to 6.25 V supply tolerance lets the MCU run directly from rectified 5 V or 3.3 V rails. Industrial -40C to +85C support covers garage and laundry-room environments.
推薦
Automotive Body Electronics (Non-Safety)
The PIC16LC621AT-04I/SS fits non-safety automotive body modules such as interior lighting controllers, mirror adjusters, seat-position memory, and accessory timing modules where AEC-Q100 qualification is not strictly required. Its 2.5 V to 6.25 V supply range tolerates 12 V battery cranking transients when paired with external regulators. The 4 MHz clock and 96 bytes RAM are adequate for PWM-based LED dimming, debounced switch inputs, and CAN/LIN slave tasks in body networks. The -40C to +85C industrial range covers cabin environments. Designers targeting AEC-Q100 should evaluate Microchip's automotive-grade PIC16F or dsPIC families instead, since this part lacks formal automotive qualification.
推薦
Consumer Remote Controls and IR Transmitters
The PIC16LC621AT-04I/SS is well-suited for consumer IR remote controls, RF key fobs, and simple wireless transmitters where ultra-low cost and small footprint dominate. The 1.75 KB OTP stores IR protocol tables (RC5, NEC, SIRC), button-scanning routines, and battery-saving sleep routines. 96 bytes of RAM covers the transmit buffer and timing variables. The 4 MHz clock generates accurate 38 kHz / 40 kHz carrier frequencies via timer interrupts for IR LED modulation. Wide 2.5 V to 6.25 V operation runs directly from 2 x AAA or coin-cell batteries. The 20-SSOP package fits inside slim remote enclosures. Power-on reset and watchdog timer prevent lock-ups on weak batteries.
推薦
Industrial Sensor Interface and Signal Conditioning
The PIC16LC621AT-04I/SS serves as a low-cost front-end for industrial sensor modules reading thermocouples, RTDs, switches, or 4-20 mA loops. Its 13 GPIO pins accept multiple digital inputs and drive indicator LEDs or relay coils. The integrated brown-out detect and power-on reset protect against unstable 24 V industrial rails when fed through a 5 V regulator. 1.75 KB of OTP accommodates linearization tables and HART-style request handling. The 4 MHz clock provides ample timing resolution for polled sensors at sub-kHz rates. Industrial -40C to +85C operation handles factory-floor temperature swings. Watchdog timer recovers from EMI-induced firmware stalls common in motor cabinets.
推薦
LED Lighting Controllers and Drivers
The PIC16LC621AT-04I/SS drives LED lighting controllers for decorative strips, signage, and architectural fixtures. Its 13 GPIO pins directly switch MOSFETs or constant-current LED drivers via PWM at the 4 MHz CPU clock, generating accurate dimming waveforms at audio-band rates. 1.75 KB OTP stores color-sequence tables, fade curves, and DMX-512 slave parsing logic. The 2.5 V to 6.25 V supply range accommodates 3.3 V logic or 5 V regulated supplies in LED drivers. Industrial -40C to +85C range covers outdoor enclosures and ceiling-fixture thermal loads. Brown-out detect ensures clean resets during mains dips in triac-dimmable installations.
推薦
Battery-Powered Timers and Sequencers
The PIC16LC621AT-04I/SS powers battery-operated timer modules, irrigation controllers, and watch-dog sequencers where OTP cost savings and wide-voltage operation matter. The 4 MHz CPU clock drives RTC-style counters from a 32.768 kHz crystal via timer0, while GPIO outputs trigger relays or MOSFETs at scheduled times. 96 bytes RAM holds current timer state and user-set variables stored in EEPROM emulation. The 2.5 V to 6.25 V supply range runs directly from 2 x AA alkaline cells down to end-of-life voltage. Brown-out detect prevents EEPROM corruption as batteries deplete. Industrial -40C to +85C range supports outdoor and automotive-cabin installations.
推薦
推薦產品摘要
工程參考資料，適用於 PIC16LC621AT-04I/SS — 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 | PIC16LC621A-04I/SS | PIC16LC621AT-04E/SS | PIC16LC621AT-04I/SO | PIC16LC620A-04I/SS | PIC16LC621A-04I/P |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 20-SSOP | 20-SSOP - same | 20-SSOP - same | 20-SOIC - same pinout, larger body | 20-SSOP - same | 20-PDIP - same pinout, through-hole |
| Clock Speed (Max) | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz |
| Program Memory | 1.75 KB OTP | 1.75 KB OTP | 1.75 KB OTP | 1.75 KB OTP | 0.875 KB OTP | 1.75 KB OTP |
| RAM Size | 96 bytes | 96 bytes | 96 bytes | 96 bytes | 80 bytes | 96 bytes |
| Supply Voltage Range | 2.5 V to 6.25 V | 2.5 V to 6.25 V | 2.5 V to 6.25 V | 2.5 V to 6.25 V | 2.5 V to 6.25 V | 2.5 V to 6.25 V |
| Operating Temperature | -40C to +85C (Industrial) | -40C to +85C | -40C to +125C (Extended) | -40C to +85C | -40C to +85C | -40C to +85C |
| Number of I/O Pins | 13 | 13 | 13 | 13 | 13 | 13 |
主要差異化特點
- Industrial temperature grade with wide voltage tolerance (對比PIC16LC620A-04I/SS)
- Compact 20-SSOP footprint for space-constrained designs (對比PIC16LC621A-04I/P)
- Wide 2.5 V to 6.25 V supply tolerance supports both 3.3 V and 5 V rails (對比PIC16LC621AT-04E/SS)
設計說明
Place a 0.1 uF decoupling capacitor as close as possible to the VDD pin (pin 14) with a short ground return to VSS (pin 5). For battery-powered designs, add a 10 uF bulk capacitor on the VDD rail to handle transient loads when GPIO banks switch simultaneously. The PIC16LC621AT-04I/SS's brown-out detect (BOD) protects against code corruption when VDD drops below the BOD threshold; configure the BOD via configuration bits during programming. Always hold MCLR high through a 10 kohm pull-up resistor for normal operation.
Remember that OTP (One-Time Programmable) memory cannot be erased or rewritten once programmed - unlike flash-based PIC16F parts. Plan for prototype validation on a flash equivalent (e.g., PIC16F716-I/SO) before committing to OTP for production. Verifying OTP-programmed units requires physical destruction or dedicated verification routines. Programming failures on OTP parts result in scrap, so invest in programmer calibration and socket testing before any production run.
Route the OSC1/OSC2 crystal traces (pins 16/15) short and symmetric, with the crystal placed within 5 mm of the MCU. Keep high-frequency switching traces (PWM outputs, relay drive lines) away from the oscillator loop to avoid injection-locking or extra jitter. The 20-SSOP package's 0.65 mm pitch requires fine-pitch PCB fabrication; use ENIG surface finish and 0.1 mm solder mask dams between pads. Provide a copper pour on the top layer tied to VSS for thermal dissipation and ground return.
合規資訊
RoHS compliant per Microchip product page and distributor listings. Not AEC-Q100 qualified - choose automotive-grade PIC16F or dsPIC variants for AEC-Q100 designs. Halogen-free status not explicitly stated in provided data.
