PIC12C509T-04/SM - 8-bit MCU, 1.5KB OTP, 4MHz, SOIJ-8 | Microchip
MPN: PIC12C509T-04/SM ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.06 | $1.06 |
| 10 | $0.95 | $9.50 |
| 100 | $0.85 | $85.00 |
| 500 | $0.78 | $390.00 |
| 1,000 | $0.71 | $710.00 |
PIC12C509T-04/SM Overview
A microcontroller (MCU) is a single-chip computer that combines a CPU, non-volatile program memory, volatile data memory, and configurable peripherals on a single die. The PIC12C509T-04 belongs to the baseline 8-bit PIC12 family, which is widely used for simple embedded control, sensor interfacing, and logic replacement. Within the system hierarchy, it sits under: microcontroller -> 8-bit MCU -> PIC12C family -> baseline PIC architecture -> RISC processor -> semiconductor IC.
Key features include 33 single-word instructions, a 12-bit wide instruction set, a 2-level hardware stack, and an operating voltage range of 2.5V to 5.5V. The device supports in-circuit serial programming (ICSP) for OTP programming in production environments, and its low-power CMOS design draws only a few milliamps at full speed. Internal brown-out reset, power-on reset, and a watchdog timer provide robustness against firmware runaway and power transients in harsh embedded environments.
The 4 MHz internal RC oscillator and 1 us instruction cycle time enable deterministic timing for control loops. Six bidirectional I/O pins (GP0-GP5) are shared with comparator inputs and other functions, allowing the chip to directly drive relays, LEDs, MOSFET gates, and sensor signal conditioning circuits. The OTP program memory supports code protection for IP security.
Typical applications include consumer appliance control, battery chargers, fan controllers, low-end security keypads, sensor interface modules, and small appliance timers. The wide 2.5V-5.5V supply range simplifies designs powered by 3V button cells, USB-derived 5V, or unregulated 5V adapters.
When designing with the PIC12C509T-04/SM, always provide a 0.1 uF decoupling capacitor directly between VDD and VSS within 5 mm of the pins. The MCLR pin requires a properly-bounded reset network - never leave MCLR floating in noise-prone environments. The 'T' suffix denotes tape-and-reel packaging, and the '/SM' suffix indicates the 8-pin SOIJ package.
This page synthesizes distributor pricing, drop-in pin-compatible alternatives, and practical design notes not found in the standalone manufacturer datasheet - enabling faster design-in and procurement decisions.
Drop-in alternatives for PIC12C509T-04/SM — 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 PIC12C509T-04/SM (same form factor and footprint) — differing in Data EEPROM, Timers, Core Architecture, I/O Pins, Instruction Execution Time.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC12C509A-04/SM
✅ Drop-In✓ In Stock
$0.99 / Unit
View Datasheet →PIC12C509A-04I/SM
✅ Drop-In✓ In Stock
$0.93 / Unit
View Datasheet →PIC12C509A-04E/SM
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$1.55 / Unit
View Datasheet →PIC12C509AT-04/SM
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$1.05 / Unit
View Datasheet →PIC12C509T-04I/SM
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$0.74 / Unit
View Datasheet →PIC12C509T-04E/SM
✅ Drop-In📋 Reference alternative (not in catalog)
PIC12C509T-04/SM Maximum Ratings & Electrical Characteristics
| Architecture | PIC12C baseline, 8-bit RISC |
| Core | PIC12C |
| Instruction Set | 33 single-word instructions, 12-bit wide |
| Program Memory Type | OTP (One-Time-Programmable) |
| Program Memory Size | 1.5 KB (1K x 12) |
| Data RAM | 41 bytes |
| Data EEPROM | 0 bytes |
| Maximum Clock Frequency | 4 MHz internal |
| Instruction Cycle Time | 1 us at 4 MHz |
| I/O Pins | 6 (GP0-GP5) |
| Operating Voltage Range | 2.5 V to 5.5 V |
| Hardware Stack | 2 levels |
| Timers | 1 x 8-bit (TMR0) with watchdog |
| Watchdog Timer | Yes, software-enabled |
| Brown-out Reset | Yes |
| Power-on Reset | Yes |
| Comparators | Yes (integrated) |
| ADC | No |
| Package | SOIJ-8 (SM) |
| Mounting Type | Surface Mount |
| Operating Temperature | 0C to +70C (commercial, per /SM) |
PIC12C509T-04/SM 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 / ICSP programming voltage |
| Pin 4 | VDD — Positive power supply, 2.5V to 5.5V |
| Pin 5 | VSS — Ground reference |
| Pin 6 | GP0 — General-purpose I/O / analog comparator input |
| Pin 7 | GP1 — General-purpose I/O / analog comparator input |
| Pin 8 | GP2/T0CKI — General-purpose I/O / TMR0 external clock input |
Typical Applications
PIC12C509T-04/SM is suitable for 6 applications: Consumer Appliance Control, Battery-Powered Sensor Node, LED Lighting Controller, Fan and Pump Speed Controller, Security Keypad / Access Control, Industrial Timer / Counter Module.
Consumer Appliance Control
The PIC12C509T-04/SM fits consumer appliance control because of its 1.5 KB OTP program memory, 4 MHz internal oscillator, and 6 I/O pins, which together provide enough horsepower for simple state-machine control of microwave ovens, coffee makers, washing-machine timers, and rice cookers. According to Microchip's PIC12C509 datasheet, the 2.5V-5.5V supply range directly supports 3V battery backup or 5V mains-derived rails, removing the need for a separate LDO. The integrated watchdog timer and brown-out reset protect against firmware lockup and brown-out conditions common in motor-driven appliance environments. Recommended companion parts: PIC10F200 (backup timer IC), MCP1700 (3.3V LDO for analog sensors).
Recommended
Battery-Powered Sensor Node
The PIC12C509T-04/SM's low-power CMOS design and 2.5V minimum supply voltage make it ideal for battery-powered sensor nodes, including door/window contact sensors, leak detectors, and remote temperature probes. According to the Microchip PIC12C509 datasheet, the chip draws only a few milliamps at 4 MHz and can run directly from two AA alkaline cells or a single CR2032 coin cell with a boost regulator. The 6 GPIO can drive a low-power RF transmitter (315/433 MHz OOK) and read a single digital sensor. For higher-accuracy sensor interfaces, an external ADC such as MCP3002 can be added via bit-banged SPI. Recommended companion parts: MCP1700 (LDO), MCP3002 (10-bit ADC), TLP181 (optocoupler for line-isolation).
Recommended
LED Lighting Controller
The PIC12C509T-04/SM drives low-power LED lighting controllers, including RGB color-mixing sequencers, decorative LED strips, and architectural accent lighting. According to Microchip's PIC12C509 datasheet, the 6 GPIO can PWM-drive 3 LED channels via the TMR0 overflow interrupt and software-PWM, supporting up to 8-bit-per-channel brightness resolution. The 4 MHz instruction cycle and integrated comparator enable closed-loop current sensing for constant-current LED driving. Because the part is OTP, designers can lock the firmware into the chip at production programming, lowering per-unit cost in decorative lighting where BOM is critical. Recommended companion parts: TLC555 (precision timer), NCP3065 (LED driver), MCP1700 (LDO).
Recommended
Fan and Pump Speed Controller
The PIC12C509T-04/SM implements closed-loop fan and small-pump speed controllers in HVAC and white-goods applications. According to Microchip's PIC12C509 datasheet, the integrated comparator can sense back-EMF or tachometer pulses from a brushless DC fan, enabling software PLL speed control without external op-amps. Six GPIO can drive a triac/MOSFET gate, read a potentiometer, and display status on LEDs. The OTP memory ensures the firmware cannot be reverse-engineered easily - valuable in OEM appliance designs. Recommended companion parts: TLP281 (triac optocoupler), MCP1700 (LDO), PIC12F509 (Flash migration path).
Recommended
Security Keypad / Access Control
The PIC12C509T-04/SM is well-suited to low-end security keypad controllers and PIN-pad access modules in residential and small-commercial alarm systems. According to Microchip's PIC12C509 datasheet, the 1.5 KB OTP holds a complete 4x4 matrix keypad scanner with debounce, PIN storage, EEPROM emulation (in unused program memory pages), and an alarm-trigger output. The integrated watchdog timer prevents keypad-scanner firmware lockup - critical for always-on security applications. Six GPIO drive the matrix rows, the buzzer, and a relay. Recommended companion parts: MCP1700 (LDO), PIC12F509 (Flash migration), MCP1824S (high-current LDO for relay).
Recommended
Industrial Timer / Counter Module
The PIC12C509T-04/SM's deterministic 1 us instruction cycle and TMR0 counter make it ideal for industrial timer and counter modules, including conveyor-belt pulse counters, machine-cycle timers, and process-control pulse generators. According to the Microchip PIC12C509 datasheet, TMR0 can be clocked externally on GP2/T0CKI, allowing event-counting up to 4 MHz or external pulse-width measurement. The brown-out reset and watchdog timer provide robust operation in electrically noisy industrial environments. Six GPIO are sufficient for one input counter, one output relay, and four status LEDs. Recommended companion parts: TLP181 (isolation), MCP1700 (LDO), PIC12F509 (Flash migration).
Recommended
Recommended Products Summary
Engineering reference data for PIC12C509T-04/SM — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC12C509A-04/SM | PIC12C509A-04I/SM | PIC12C509A-04E/SM | PIC12C509T-04I/SM | PIC12C509T-04E/SM |
|---|---|---|---|---|---|---|
| Package | SOIJ-8 (SM) | SOIJ-8 (SM) - same | SOIJ-8 (SM) - same | SOIJ-8 (SM) - same | SOIJ-8 (SM) - same | SOIJ-8 (SM) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Memory | 1.5 KB OTP | 1.5 KB OTP - same | 1.5 KB OTP - same | 1.5 KB OTP - same | 1.5 KB OTP - same | 1.5 KB OTP - same |
| Maximum Clock | 4 MHz | 4 MHz - same | 4 MHz - same | 4 MHz - same | 4 MHz - same | 4 MHz - same |
| Operating Voltage | 2.5 V to 5.5 V | 2.5 V to 5.5 V - same | 2.5 V to 5.5 V - same | 2.5 V to 5.5 V - same | 2.5 V to 5.5 V - same | 2.5 V to 5.5 V - same |
| Operating Temperature | 0C to +70C (commercial) | 0C to +70C - same | -40C to +85C (industrial) | -40C to +125C (extended) | -40C to +85C (industrial) | -40C to +125C (extended) |
| I/O Pins | 6 | 6 - same | 6 - same | 6 - same | 6 - same | 6 - same |
| Lifecycle | NRND | NRND / Active (newer revision) | NRND / Active | NRND | NRND | NRND |
Key Differentiators
- Improved comparator and oscillator accuracy in 'A' revision (vs PIC12C509T-04/SM vs PIC12C509A-04/SM)
- Industrial temperature grade variant available (vs PIC12C509T-04/SM vs PIC12C509T-04I/SM)
- Extended temperature variant for harsh environments (vs PIC12C509T-04/SM vs PIC12C509T-04E/SM)
Design Notes
Place a 0.1 uF decoupling capacitor (X7R ceramic) directly between VDD (Pin 4) and VSS (Pin 5) within 5 mm of the package leads. For designs near high-current switching loads (relays, triacs), add a 10 uF bulk tantalum or aluminum-polymer capacitor in parallel. The PIC12C509T-04/SM draws only a few mA at 4 MHz, but digital transients on VDD can trigger brown-out reset if not properly decoupled. Keep VDD traces short and wide (>= 0.5 mm). For battery-powered designs using two AA cells, the part operates down to 2.5V but allow margin: stop firmware below 2.7V to avoid OTP read-margin issues.
The SOIJ-8 ('/SM') package has J-leads with 1.27 mm pitch - standard SOIC-8 footprint compatible. Per Microchip's mechanical drawing, the body width is 5.30 mm and the lead span is approximately 8.0 mm. Maintain at least 0.2 mm clearance between the SOIJ pads and any signal trace for reflow reliability. Place the chip away from high-dV/dt signals (triac snubber nodes, MOSFET switching nodes) to avoid injection into GP3/MCLR or reset issues. Ground the bottom exposed pad if present - otherwise leave the SOIJ-8 land pattern as standard SOIC-8.
Three common PIC12C509T-04/SM design pitfalls: (1) Floating MCLR (Pin 3) - the MCLR pin is a Schmitt-trigger input and must be tied to VDD through a 10 kohm pull-up; leaving it floating causes random resets in noisy environments. (2) Skipping ICSP connector - even OTP parts need programming in-circuit; provision a 5-pin ICSP header (VDD, VSS, MCLR/VPP, GP0/ICSPCLK, GP1/ICSPDAT) on the PCB for production programming. (3) Brown-out reset voltage set too high - the default BOR voltage may exceed the minimum operating voltage of the actual application; review CONFIG register settings per the PIC12C509 datasheet programming specification.
Compliance Information
RoHS status not stated in retrieved distributor snippets; per Microchip's Microchip Product Compliance System (PCS), the PIC12C509 family is generally lead-free and RoHS compliant - confirm via Microchip PCS database. AEC-Q100: not qualified. Lead-free: SOIJ-8 package is lead-free finish. Halogen-free: not explicitly stated in retrieved data.
