PIC16LC73BT-04/SO - 8-Bit 4MHz MCU, 7KB OTP, 28-SOIC | Microchip
MPN: PIC16LC73BT-04/SO ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $11.83 | $11.83 |
| 10 | $10.65 | $106.50 |
| 100 | $9.46 | $946.00 |
| 500 | $8.28 | $4,140.00 |
| 1,000 | $7.1 | $7,100.00 |
PIC16LC73BT-04/SO Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, non-volatile program memory, working RAM, and a range of peripherals onto one silicon die. The PIC16CXX mid-range family is one of Microchip's classic 14-bit instruction width architectures, positioned historically between the baseline PIC10/PIC12/PIC16 families and the high-end PIC18. Within the broader taxonomy, microcontrollers belong to the Embedded > Microcontrollers sub-category of Integrated Circuits and serve as the programmable brain of nearly every modern electronic product.
Key differentiating features include hardware peripherals: I2C (Master/Slave), SPI (Master/Slave), and UART/USART for asynchronous serial communication. The OTP program memory allows one-time factory or field programming, ideal for fixed-function, cost-sensitive applications. The 28-SOIC (0.295 inch / 7.50 mm width) package is the industry-standard wide-body SOIC footprint, compatible with hand-soldering and basic reflow profiles.
Architecturally, the PIC16LC73B uses a Harvard RISC core with separate program and data buses, 8-deep hardware stack, and a deterministic instruction cycle of 4 oscillator clocks. Brown-out Reset (BOR), Power-on Reset (POR), and a Watchdog Timer (WDT) are integrated for embedded robustness. The '04' speed suffix indicates the 4 MHz oscillator maximum.
Typical applications include industrial automation controllers, consumer appliances, low-end sensor nodes, UART/I2C/SPI peripheral interfaces, and legacy system upgrades where an OTP-programmed 8-bit MCU is sufficient.
When designing with this part, note that OTP memory cannot be re-programmed in-circuit; select a flash-based equivalent (e.g., PIC16F73) if firmware iteration is expected. Operating temperature range per commercial grade is 0 C to +70 C; for industrial environments select the 'I' suffix variant.
This page synthesizes distributor pricing, drop-in package alternatives from the same 28-SOIC footprint, and engineering design notes not found in the manufacturer datasheet.
Drop-in alternatives for PIC16LC73BT-04/SO — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with PIC16LC73BT-04/SO (same form factor and footprint) — differing in Package, Operating Temperature, Program Memory Size, Program Memory Type, RoHS Status.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16LC73BT-04/SO
✅ Drop-In✓ In Stock
$7.1 / Unit
View Datasheet →PIC16LC73B-04/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16LC73BT-04I/SO
✅ Drop-In✓ In Stock
$4.68 / Unit
View Datasheet →PIC16LC73AT-04I/SO
✅ Drop-In✓ In Stock
$4.61 / Unit
View Datasheet →PIC16F73-I/SO
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$2.45 / Unit
View Datasheet →PIC16F73A-I/SO
✅ Drop-In ⚠️ 参数待验证📋 Reference alternative (not in catalog)
PIC16LC73BT-04/SO Maximum Ratings & Electrical Characteristics
| Product Type | 8-bit Microcontroller (MCU) |
| Series | PIC 16Cxx mid-range family, PIC16LC73B |
| Core Architecture | PIC16 Harvard RISC, 14-bit instruction width |
| Program Memory Size | 7 KB (4K x 14) OTP |
| RAM | 192 bytes |
| Maximum CPU Frequency | 4 MHz |
| Supply Voltage (VDD) | 2.5 V to 5.5 V |
| I/O Pins | 22 |
| Communication Interfaces | I2C, SPI, UART/USART |
| Package | 28-SOIC (0.295"/7.50 mm body width, gull-wing) |
| Mounting Type | Surface Mount |
| Operating Temperature | 0 C to +70 C (commercial) |
| Program Memory Type | One-Time Programmable (OTP) |
| RoHS Status | ROHS3 Compliant |
| Supply Form | Tape & Reel ('T' suffix on MPN) |
PIC16LC73BT-04/SO Pin Configuration
| Pin 1 | MCLR#/VPP — Master Clear (active-low reset) / Programming voltage input |
| Pin 2 | RA0/AN0 — PORTA bit 0 / Analog input channel 0 |
| Pin 3 | RA1/AN1 — PORTA bit 1 / Analog input channel 1 |
| Pin 4 | RA2/AN2 — PORTA bit 2 / Analog input channel 2 |
| Pin 5 | RA3/AN3/VREF — PORTA bit 3 / Analog input 3 / ADC voltage reference |
| Pin 6 | RA4/T0CKI — PORTA bit 4 (open-drain) / Timer0 clock input |
| Pin 7 | RA5/AN4/SS# — PORTA bit 5 / Analog input 4 / SPI Slave Select |
| Pin 8 | VSS — Ground reference |
| Pin 9 | OSC1/CLKI — Crystal oscillator input / External clock input |
| Pin 10 | OSC2/CLKO — Crystal oscillator output / Clock output (Fosc/4) |
| Pin 11 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer1 oscillator output / Timer1 clock input |
| Pin 12 | RC1/T1OSI/CCP2 — PORTC bit 1 / Timer1 oscillator input / CCP2 PWM/Capture/Compare |
| Pin 13 | RC2/CCP1 — PORTC bit 2 / CCP1 PWM/Capture/Compare |
| Pin 14 | RC3/SCK/SCL — PORTC bit 3 / SPI clock / I2C clock |
| Pin 15 | RC4/SDI/SDA — PORTC bit 4 / SPI data in / I2C data |
| Pin 16 | RC5/SDO — PORTC bit 5 / SPI data out |
| Pin 17 | RC6/TX/CK — PORTC bit 6 / USART async transmit / USART sync clock |
| Pin 18 | RC7/RX/DT — PORTC bit 7 / USART async receive / USART sync data |
| Pin 19 | VSS — Ground reference (second VSS) |
| Pin 20 | VDD — Positive supply voltage (2.5 V to 5.5 V) |
| Pin 21 | RB0/INT — PORTB bit 0 / External interrupt input |
| Pin 22 | RB1 — PORTB bit 1 |
| Pin 23 | RB2 — PORTB bit 2 |
| Pin 24 | RB3/PGM — PORTB bit 3 / Low-voltage ICSP program clock |
| Pin 25 | RB4 — PORTB bit 4 (interrupt-on-change) |
| Pin 26 | RB5 — PORTB bit 5 (interrupt-on-change) |
| Pin 27 | RB6/PGC — PORTB bit 6 / ICSP serial clock (interrupt-on-change) |
| Pin 28 | RB7/PGD — PORTB bit 7 / ICSP serial data (interrupt-on-change) |
Typical Applications
PIC16LC73BT-04/SO is suitable for 7 applications: Industrial Automation Controllers, Consumer Appliance Control Boards, Sensor Hub / Peripheral Bridge, Legacy System Upgrade / Field Replacement, UART/I2C/SPI Peripheral Interface Bridge, Educational / Hobbyist 8-bit MCU Platform, Low-Voltage Battery-Powered Embedded Device.
Industrial Automation Controllers
The PIC16LC73BT-04/SO fits industrial controller modules such as sensor aggregators and small PLCs where deterministic 8-bit performance and UART/I2C/SPI multi-protocol peripheral connectivity are sufficient. Its 4 MHz core delivers ~1 MIPS, enough to scan 16-32 inputs and drive an RS-485 Modbus slave at 9600-115200 baud. The 22 digital I/O pins map directly to relay drivers, opto-isolated inputs, and status LEDs. Compared to a 16-bit MCU, the LC73B simplifies code review for legacy engineering teams familiar with the PIC16 mid-range instruction set. For 24V industrial bus rails, a regulated 5 V or 3.3 V LDO plus TVS protection is recommended upstream of the VDD pin.
Recommended
Consumer Appliance Control Boards
In washing machines, microwave ovens, dishwashers, and small kitchen appliances, the PIC16LC73BT-04/SO serves as the main control MCU driving keypad scan, LED/LCD indicators, and triac/SCR power control via opto-isolated drivers. The 7 KB OTP accommodates a fixed-function user-interface firmware; the 192-byte RAM is sufficient for mode state machines. The 2.5-5.5 V supply range matches the universal 5 V regulator rails common in white-goods designs. The commercial 0-70 C temperature grade covers indoor appliance environments. Watch for OTP blank-check during incoming QA, and use the LC variant to minimize standby current versus the standard C process.
Recommended
Sensor Hub / Peripheral Bridge
The PIC16LC73BT-04/SO is ideal for low-cost sensor hubs that aggregate I2C or SPI sensor data and forward it over UART to a host processor. Its hardware SSP supports both SPI Master and I2C Master/Slave at up to 4 MHz bus rate, while the USART handles RS-232/RS-485 to the host. 192 bytes of RAM comfortably buffer sensor frames before transmission. The 22 I/O lines enable direct connection of multiple digital sensors and discrete inputs. For battery-powered variants, the LC process delivers lower active and sleep current than the C variant. Recommended for HVAC duct sensors, environmental monitors, and industrial Modbus RTU slaves.
Recommended
Legacy System Upgrade / Field Replacement
Designers maintaining installed PIC16C/LC73B-based systems can use the PIC16LC73BT-04/SO as a like-for-like field replacement because the part remains in Microchip's NRND lifecycle with limited distributor stock. Identical die, pinout, and instruction set across the LC73B family means no firmware recompile is required when swapping reeled versus tray versions, or commercial versus industrial temp grades. For new designs, Microchip recommends the flash-based PIC16F73/PIC16F73A as the migration path. Verify ICP (In-Circuit Programming) compatibility before deploying the swap in legacy products where MCLR/VPP programming pinout follows the SOIC standard.
Recommended
UART/I2C/SPI Peripheral Interface Bridge
The PIC16LC73BT-04/SO's three-wire serial peripherals make it well-suited for protocol-bridge modules where legacy UART equipment must be exposed to a modern I2C/SPI host. Engineers can implement bidirectional UART-SPI bridges or UART-I2C bridges in approximately 2-3 KB of code, leaving ample room for buffer management in the 192-byte RAM. At 4 MHz, the CPU can sustain 115200 baud UART while servicing interrupt-driven I2C or SPI transactions. The 28-SOIC package fits inside D-sub or USB-to-serial adapters, and the 2.5-5.5 V supply tolerates both 3.3 V and 5 V host rails.
Recommended
Educational / Hobbyist 8-bit MCU Platform
Hobbyists and students learning 8-bit embedded development benefit from the PIC16LC73BT-04/SO because it exposes the full PIC16 mid-range feature set - CCP module, 8-bit ADC, hardware USART, and SSP - in a hobbyist-friendly wide-body SOIC package. The OTP limitation forces good design practices (firmware lock-down after debug). Programming via the ICSP interface using a PICkit 3 or MPLAB ICD is standard. The 4 MHz operating ceiling allows instruction-by-instruction tracing in MPLAB X IDE without pipeline confusion. For classroom use, the flash-based PIC16F73 is recommended to enable multiple program/erase cycles.
Recommended
Low-Voltage Battery-Powered Embedded Device
The 'LC' process variant of the PIC16LC73BT-04/SO targets battery-powered designs where the 2.5 V lower VDD bound enables operation directly from two alkaline or NiMH cells (2.4-3.0 V nominal). Lower active current versus the C variant extends runtime in sleep-mode duty-cycled sensor nodes. Combined with the integrated USART for wake-on-UART, the MCU can spend most of its life in sleep and wake only to transmit sensor data. Brown-out Reset (BOR) protects against low-cell brown-out conditions; the Watchdog Timer (WDT) handles software lock-ups in remote deployments. Use a 100 nF decoupling capacitor within 5 mm of VDD.
Recommended
Recommended Products Summary
Engineering reference data for PIC16LC73BT-04/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16LC73B-04/SO | PIC16LC73BT-04I/SO | PIC16LC73AT-04I/SO | PIC16F73-I/SO | PIC16F73A-I/SO |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 28-SOIC (0.295") | 28-SOIC (0.295") - same | 28-SOIC (0.295") - same | 28-SOIC (0.295") - same | 28-SOIC (0.295") - same | 28-SOIC (0.295") - same |
| Program Memory | 7 KB OTP | 7 KB OTP | 7 KB OTP | 4 KB OTP (-43%) | 7 KB Flash (reprogrammable) | 7 KB Flash + 128B EEPROM |
| RAM | 192 bytes | 192 bytes | 192 bytes | 128 bytes (-33%) | 192 bytes | 192 bytes |
| Max CPU Frequency | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 20 MHz (+400%) | 20 MHz (+400%) |
| Supply Voltage (VDD) | 2.5 V to 5.5 V | 2.5 V to 5.5 V | 2.5 V to 5.5 V | 2.5 V to 5.5 V | 2.0 V to 5.5 V (extended) | 2.0 V to 5.5 V (extended) |
| Operating Temperature | 0 C to +70 C (commercial) | 0 C to +70 C | -40 C to +85 C (industrial) | -40 C to +85 C (industrial) | -40 C to +85 C (industrial) | -40 C to +85 C (industrial) |
| Communication Peripherals | I2C + SPI + UART/USART | I2C + SPI + UART/USART | I2C + SPI + UART/USART | I2C + SPI + UART/USART | I2C + SPI + UART/USART | I2C + SPI + UART/USART |
| Lifecycle Status | NRND | NRND | NRND | NRND | Active (recommended for new designs) | Active (recommended for new designs) |
Key Differentiators
- Industrial-temperature-grade drop-in option on the same 28-SOIC footprint (vs PIC16LC73B-04/SO)
- Reel-optimized for high-volume SMT assembly (vs PIC16LC73B-04/SO (tray))
- Migrate to flash-reprogrammable F73 for new designs (vs PIC16F73-I/SO)
- Low-voltage LC process extends battery runtime (vs PIC16C73B-04/SO (standard process))
- Wide-body 28-SOIC simplifies hand prototyping (vs PIC16F73-I/SP (SPDIP))
Design Notes
Place a 100 nF ceramic decoupling capacitor within 5 mm of the VDD pin (pin 20) and another on the AVdd analog supply rail if used; bulk electrolytic 10 uF on the upstream regulator is recommended. The PIC16LC73BT-04/SO draws typical active current of a few mA at 4 MHz/5 V; the 'LC' process variant draws approximately 30-40% less than the standard 'C' variant, important for battery-powered nodes. Brown-out Reset (BOR) is enabled via the configuration bit to protect against 2.5 V undervoltage events; disable BOR only if an external supervisor is used.
At 4 MHz / 5 V active operation the MCU dissipates well under 100 mW, so no heatsink or thermal-via array is required - the 28-SOIC theta_JA of approximately 70 C/W in still air keeps the junction rise below 35 C above ambient. However, if the device is operated inside a sealed enclosure at elevated ambient (>40 C) or at sustained high duty cycle, verify by measurement. Note: SOIC packages have lower thermal mass than QFN; continuous operation near maximum temperature grade requires derating of clock frequency.
Route the crystal traces (OSC1/OSC2, pins 9/10) symmetrically and as short as possible with a grounded guard ring; keep them away from the USART TX/RX lines and switching power traces to minimize noise coupling. Place the MCLR#/VPP pin (pin 1) with a 10 kohm pull-up to VDD and a 100 nF cap to ground to suppress ESD and programming-voltage transients. For ICSP programming, expose the PGC/PGD pins (27/28) on test points or a 6-pin header. The wide-body 28-SOIC (0.295"/7.50 mm) footprint accepts hand-soldering with a 0.5 mm tip.
OTP memory cannot be re-programmed - commit firmware only after full validation; debug on a flash-based PIC16F73 or use a windowed CERDIP PIC16C73B for development, then port the validated hex to the OTP 'LC73BT-04/SO' for production. The 'T' suffix on the MPN denotes Tape & Reel packaging for SMT; for prototype builds order the non-'T' tray variant. Watch the oscillator configuration bits: XT vs HS vs RC selects different crystal gain modes - the '04' speed suffix sets the 4 MHz ceiling, but the silicon supports up to 20 MHz on flash variants (PIC16F73).
The PIC16LC73BT-04/SO's analog inputs (AN0-AN4 on PORTA pins 2-7) share pins with digital I/O; configure them as analog via the ADCON1 register before reading ADC to prevent digital-crosstalk noise. Keep analog traces short and guarded, and provide a clean AVdd rail decoupled with 100 nF + 10 uF. The I2C bus (RC3/RC4) is open-drain and requires 4.7 kohm pull-ups to VDD; verify timing at the lowest VDD (2.5 V) because I2C rise time degrades at low supply voltage. SPI bus (RC3-5) at 4 MHz CPU is limited to ~1 MHz SCK in master mode.
Compliance Information
ROHS3 Compliant per ics-embedded distributor listing. Microchip parts are generally lead-free and conflict-minerals compliant per company policy; halogen-free status not specifically stated in available data and marked 'unknown'.
