PIC16F505T-I/ST - 8-Bit Flash MCU, 1.5KB, 12 I/O | Microchip
MPN: PIC16F505T-I/ST ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.05 | $1.05 |
| 10 | $0.94 | $9.40 |
| 100 | $0.84 | $84.00 |
| 500 | $0.76 | $380.00 |
| 1,000 | $0.68 | $680.00 |
PIC16F505T-I/ST Overview
A PIC microcontroller is a Harvard-architecture, RISC-based single-chip computer from Microchip Technology's 8-bit PIC16 baseline family. PIC MCUs are widely used as general-purpose embedded controllers because they combine a small instruction set (33 single-word instructions on the PIC16F505), deterministic single-cycle execution, on-chip non-volatile Flash memory, and integrated peripherals in low-pin-count packages. Within the broader taxonomy, the PIC16F505 belongs to the 8-bit MCU -> RISC microcontroller -> embedded controller -> semiconductor IC hierarchy.
Key features of the PIC16F505 include 33 single-word instructions, all single-cycle except program branches (2 cycles), a 2-level deep hardware stack, a precision 4 MHz internal oscillator, 12-bit wide instructions, and an 8-bit wide data path. The device operates from 2.0V to 5.5V across industrial temperature ranges. Although the part has only 12 I/O pins, it integrates a watchdog timer, power-on reset, brown-out detect, and an 8-bit timer/counter, giving it surprising capability for its small footprint.
The architecture is based on the Microchip baseline core using a 14-bit instruction word fetched from Flash while an 8-bit data bus accesses the register file. A 4 MHz internal oscillator is factory-trimmed to ±1% accuracy, eliminating the need for an external crystal in most cost-driven applications. With only two hardware stack levels, the PIC16F505 is intended for shallow call hierarchies, but its deterministic timing makes it ideal for real-time control tasks.
Typical applications include appliance control (white goods, fans, coffee makers), battery chargers, LED lighting controllers, simple sensor interfaces, toys and consumer gadgets, IR remote control transmitters, and low-end timer/replacement designs. The PIC16F505's small pin count and Flash re-programmability via In-Circuit Serial Programming (ICSP) make it a popular choice for high-volume, price-sensitive products where a few GPIO, a timer, and a UART (bit-banged) are sufficient.
A common design consideration is the limited RAM (72 bytes) and shallow hardware stack (2 levels), which restrict firmware complexity. Engineers transitioning from larger PIC16 mid-range devices should plan around these constraints by keeping call depth shallow and avoiding large local arrays. For new designs, Microchip recommends the newer PIC16F15324 as a drop-in replacement candidate with more memory and peripherals.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet alone, including same-brand alternatives from the same Microchip PIC16 baseline family and cross-brand pin-compatible equivalents from competing 8-bit MCU vendors.
Drop-in alternatives for PIC16F505T-I/ST — 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 PIC16F505T-I/ST (same form factor and footprint) — differing in Package, Core, Timers, ADC, I/O Pins.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16F505-I/ST
✅ Drop-In📋 Reference alternative (not in catalog)
PIC12F509-I/SN
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$0.71 / Unit
View Datasheet →PIC12F508-I/SN
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$0.31 / Unit
View Datasheet →PIC16F15324-I/SL
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$0.86 / Unit
View Datasheet →PIC16F505T-I/ST Maximum Ratings & Electrical Characteristics
| Core | PIC16 baseline (8-bit RISC) |
| CPU Architecture | Harvard, 8-bit data path |
| Instruction Set | 33 single-word instructions (12-bit wide) |
| Program Memory Type | Flash |
| Program Memory Size | 1.5 KB (1K x 12) |
| RAM | 72 bytes |
| EEPROM | None |
| Maximum CPU Clock | 20 MHz |
| Internal Oscillator | 4 MHz (precision, factory-trimmed) |
| Supply Voltage | 2.0 V to 5.5 V |
| I/O Pins | 12 |
| Timers | 8-bit Timer0 |
| Hardware Stack | 2 levels |
| Operating Temperature | -40 C to +85 C (industrial) |
| Package | 14-pin TSSOP |
| Mounting Type | Surface Mount |
| Programming Interface | ICSP (In-Circuit Serial Programming) |
| RoHS Status | Compliant |
PIC16F505T-I/ST Pin Configuration
| Pin 1 | GP5/OSC1/CLKIN — General-purpose I/O / oscillator input / external clock input |
| Pin 2 | GP4/OSC2/CLKOUT — General-purpose I/O / oscillator output / clock output |
| Pin 3 | GP3/MCLR/VPP — General-purpose I/O / Master Clear reset / programming voltage |
| Pin 4 | GP2/T0CKI — General-purpose I/O / Timer0 clock input |
| Pin 5 | GP1/CIN- — General-purpose I/O / comparator inverting input |
| Pin 6 | GP0/CIN+ — General-purpose I/O / comparator non-inverting input |
| Pin 7 | VSS — Ground reference |
| Pin 8 | GP5 — General-purpose I/O (port alternate) |
| Pin 9 | GP4 — General-purpose I/O (port alternate) |
| Pin 10 | GP3 — General-purpose I/O (port alternate) |
| Pin 11 | GP2 — General-purpose I/O (port alternate) |
| Pin 12 | GP1 — General-purpose I/O (port alternate) |
| Pin 13 | GP0 — General-purpose I/O (port alternate) |
| Pin 14 | VDD — Positive supply voltage |
Typical Applications
PIC16F505T-I/ST is suitable for 6 applications: Appliance Control (White Goods), Battery Chargers and Power Management, LED Lighting Controllers, IR Remote Control Transmitters, Toy and Hobby Electronics, Sensor Interface Modules.
Appliance Control (White Goods)
The PIC16F505T-I/ST's 12 GPIO, 8-bit timer, and 20 MHz CPU make it a cost-effective controller for white-goods subsystems such as washing-machine water-level sensors, microwave oven user interfaces, and dishwasher cycle timers. Its 2.0-5.5V supply range allows direct connection to rectified mains-derived rails with simple regulators. The 4 MHz internal oscillator eliminates external crystals, reducing BOM cost by ~$0.10 per board. Compact 14-pin TSSOP fits tightly inside appliance control modules where PCB area is limited. Industrial temperature rating (-40°C to +85°C) handles under-cabinet and garage installations. For 16-pin or larger designs the PIC16F15324-I/SL is the modernized successor with more memory.
Recommended
Battery Chargers and Power Management
The PIC16F505T-I/ST integrates well into single- or dual-cell NiMH / Li-ion charger reference designs where its 12 I/O drive status LEDs, monitor charge current via the analog comparator, and PWM-control a MOSFET through bit-banged firmware. Wide 2.0-5.5V supply lets the MCU run directly from the battery stack. The Flash memory allows field firmware updates via ICSP, useful for tuning charge-termination algorithms. Low-cost TSSOP packaging suits high-volume consumer charging accessories. Internal 4 MHz oscillator eliminates an external resonator, saving board area in compact USB chargers and power banks.
Recommended
LED Lighting Controllers
The PIC16F505T-I/ST drives simple LED-lighting products - indicator lamps, decorative string lights, RGB color-cycling modules - by bit-banging PWM on multiple GPIO to control LED current via MOSFET drivers. With 12 I/O the device can independently drive up to 12 LED channels or 4 RGB groups. 1.5 KB Flash is sufficient for pre-programmed animation sequences stored as lookup tables. 2.0-5.5V operation supports direct 3.3V or 5V LED rails. The compact 14-pin TSSOP fits inside MR16 / GU10 lamp bases where space is constrained. Watchdog timer and brown-out detect improve robustness against supply transients.
Recommended
IR Remote Control Transmitters
Consumer IR remote controls are a classic PIC16F505T-I/ST application. The MCU's 8-bit timer generates accurate 38 kHz / 40 kHz carrier frequencies for NEC, RC5, and SIRC protocols. With 12 I/O the device scans 4x3 or 5x3 key matrices directly without external key-scan logic. 1.5 KB Flash holds multi-protocol lookup tables for TV, STB, and air-conditioner codes. 2.0V minimum supply lets the remote run from a single CR2032 coin cell with no boost regulator. Low power consumption extends battery life to 2+ years typical. Industrial temperature rating supports use in vehicles and outdoor remotes.
Recommended
Toy and Hobby Electronics
Toy manufacturers select the PIC16F505T-I/ST for sound-effect toys, simple robotic kits, electronic dice, and educational STEM platforms because the price-per-unit is low at $0.68 at qty 1000, the 14-pin TSSOP fits inside small enclosures, and the Flash memory allows last-minute customization per toy model. 12 GPIO drive LEDs, small speakers via PWM tones, servo control signals, and H-bridge motor drivers. 2.0-5.5V operation matches 2x AA / AAA battery packs directly. ICSP programming enables efficient factory firmware loading. Industrial temperature rating handles storage in unheated warehouses and toy chests.
Recommended
Sensor Interface Modules
The PIC16F505T-I/ST serves as a low-cost I/O expander / signal conditioner in industrial sensor-interface modules, where it reads a sensor's analog comparator output, drives indicator LEDs, and bit-bangs a UART to communicate with a host controller. 1.5 KB Flash holds calibration constants and protocol handlers. Wide 2.0-5.5V supply lets the module interface directly with 3.3V sensors or 5V industrial transceivers. The 14-pin TSSOP allows the module to fit in a small IP67 enclosure. Brown-out detect and watchdog timer improve field reliability in noisy industrial environments.
Recommended
Recommended Products Summary
Engineering reference data for PIC16F505T-I/ST — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16F505-I/ST | PIC12F509-I/SN | PIC12F508-I/SN | PIC16F15324-I/SL |
|---|---|---|---|---|---|
| Package | 14-pin TSSOP | 14-pin TSSOP - same | 8-pin SOIC - smaller | 8-pin SOIC - smaller | 14-pin SOIC - same pin count, different package |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Memory (Flash) | 1.5 KB | 1.5 KB (same) | 1.5 KB (same) | 768 B (-49%) | 3.5 KB (+133%) |
| RAM | 72 bytes | 72 bytes (same) | 41 bytes (-43%) | 25 bytes (-65%) | 256 bytes (+256%) |
| I/O Pins | 12 | 12 (same) | 6 (-50%) | 6 (-50%) | 14 (+17%) |
| Maximum CPU Clock | 20 MHz | 20 MHz (same) | 20 MHz (same) | 20 MHz (same) | 32 MHz (+60%) |
| Hardware Stack | 2 levels | 2 levels (same) | 2 levels (same) | 2 levels (same) | 16 levels (+700%) |
| Supply Voltage | 2.0 V to 5.5 V | 2.0 V to 5.5 V (same) | 2.0 V to 5.5 V (same) | 2.0 V to 5.5 V (same) | 2.3 V to 5.5 V |
| Unit Price (qty 1000) | $0.68 | $0.68 (same die) | ~$0.55 | ~$0.45 | ~$0.85 |
Key Differentiators
- 14-pin TSSOP with 12 I/O - balanced I/O count and small footprint (vs PIC12F509-I/SN)
- Modernized successor with significantly more memory and stack (vs PIC16F15324-I/SL)
- Same silicon as PIC16F505-I/ST, tape-and-reel for SMT assembly (vs PIC16F505-I/ST)
Design Notes
The PIC16F505T-I/ST has only a 2-level hardware stack and 72 bytes of RAM. Writing structured C-style code with deep call hierarchies will silently overflow the stack and corrupt the program counter. Keep call depth to 1-2 levels, avoid recursion, and place local variables in shared RAM regions. The baseline core does not support interrupts on all variants - check the datasheet before assuming interrupt-driven firmware is available.
Place the ICSP programming connector (5-pin: VPP, VDD, VSS, ICSPDAT, ICSPCLK) at the board edge for production programming access. Per Microchip recommendations, add a 10 kohm pull-up on the MCLR/VPP pin (pin 3) to VDD. Decoupling: place a 100 nF ceramic capacitor between VDD (pin 14) and VSS (pin 7) as close to the package as possible, with trace length under 5 mm. The internal 4 MHz oscillator is sensitive to VDD noise - keep digital switching traces away from the VDD pin.
Estimated: at 20 MHz CPU clock and 5.5 V VDD the PIC16F505T-I/ST draws approximately 2-3 mA active current. With the internal 4 MHz oscillator (default after reset) current drops to ~0.7 mA. Sleep current is typically under 1 uA at 3.3V. For battery-powered designs, configure the CONFIG register for the internal 4 MHz oscillator rather than external crystal to minimize idle current. Brown-out detect (BOD) should be enabled to prevent code execution from corrupt Flash during slow VDD rise.
When using the internal oscillator, leave OSC1/OSC2 (pins 1-2) as GPIO to gain 2 extra I/O. If external crystal is required, place the crystal within 5 mm of pins 1-2 with short traces and a ground guard ring to minimize EMI. For EMI-sensitive applications, add a 10-100 ohm resistor in series with the MCLR/VPP line to dampen transient ringing during ICSP programming.
Compliance Information
RoHS compliant per Microchip product page. Not AEC-Q100 qualified - for automotive designs, select a PIC16F1xxx baseline variant with Q-grade suffix.
