PIC16F639-I/SS - 8-Bit 20MHz MCU w/ KeeLoq Crypto | Microchip
MPN: PIC16F639-I/SS ✓ فعالPIC16F639-I/SS جائزہ
A microcontroller (MCU) is a single-chip computer containing a CPU, RAM, non-volatile program memory, and peripherals. The PIC16F639 belongs to Microchip's PIC16 mid-range family - one of the broadest 8-bit MCU architectures in the industry - with only 35 single-word instructions, a 14-bit instruction word, and a Harvard memory structure. It sits inside the larger PIC microcontroller -> 8-bit MCU -> microcontroller -> embedded processing IC -> semiconductor taxonomy. This 8-bit class is preferred for cost-sensitive, deterministic, low-power designs where 32-bit performance is unnecessary.
Key features include 3.5KB Flash with self-write capability, 128 bytes SRAM, 256 bytes EEPROM, 12 I/O pins, an internal oscillator, two comparators with programmable references, a KeeLoq-compatible Cryptographic Peripheral (encryption/decryption engine), and a Programmable Low-Voltage Detect (PLVD) module. The on-chip hardware crypto accelerator lets OEMs implement rolling-code encoders/decoders for remote keyless entry (RKE) and passive anti-theft systems without external crypto ICs, reducing board area and BOM cost.
Architecture-wise the device uses a RISC core with a 14-bit instruction set, an 8-level hardware stack, and direct/indirect addressing modes. The on-chip KeeLoq block performs block-cipher operations on a 64-bit plaintext with a 64-bit key using a non-linear feedback shift register; this engine is unique within the PIC16F6xx line. Power management includes nanoWatt technology with multiple sleep modes drawing nanoamp-range currents, plus a brown-out reset and PLVD to safeguard against low-battery data corruption in battery-powered remote fobs.
Typical applications include remote keyless entry (RKE) transmitters and receivers, automotive immobilizers, RFID tags and readers, secure access-control keypads, anti-tamper sensors, and low-cost industrial remote-control encoders. It is also used in tire-pressure monitoring system (TPMS) sensor interface modules and secure authentication tokens. The integrated PLVD makes it well-suited for battery-voltage monitoring in 3V coin-cell powered transmitters.
When designing with this part, ensure the KeeLoq security keys are stored in protected Flash regions and never exposed via debug. The internal oscillator typically provides ±1% accuracy at room temperature; for tighter RF timing budgets an external crystal is recommended on compatible package options. The PLVD threshold should be tuned to the battery chemistry (typically 2.0V-2.4V for CR2032 lithium coin cells).
This page synthesizes distributor pricing, verified drop-in same-package alternatives, and practical design notes not found in the manufacturer datasheet alone - including KeeLoq key-management guidance and PLVD threshold tuning for coin-cell chemistries.
کے لیے ڈراپ اِن متبادل PIC16F639-I/SS — یکساں پیکیج، پن سے پن مطابقت پذیر۔ مختلف پیکیج والے پرزے جن کے لیے PCB دوبارہ کام درکار ہو، شامل نہیں ہیں۔
اس سیریز میں مختلف ورژن
اسی سیریز کے ماڈلز جو ڈراپ اِن مطابقت رکھتے ہیں PIC16F639-I/SS (یکساں فارم فیکٹر اور فٹ پرنٹ) — میں مختلف Core Architecture, Package, Operating Temperature, I/O Pins, Instruction Set.
PIC16F639-I/P
✅ ڈراپ-اِنقیمت کے لیے رابطہ کریں
ڈیٹا شیٹ دیکھیں →PIC16F639-E/SO
✅ ڈراپ-اِنقیمت کے لیے رابطہ کریں
ڈیٹا شیٹ دیکھیں →PIC16F636-I/SS
✅ ڈراپ-اِن📋 حوالہ جاتی متبادل (کیٹلاگ میں نہیں)
PIC16F631-I/SS
✅ ڈراپ-اِنقیمت کے لیے رابطہ کریں
ڈیٹا شیٹ دیکھیں →PIC16F636-E/ST
✅ ڈراپ-اِنقیمت کے لیے رابطہ کریں
ڈیٹا شیٹ دیکھیں →PIC16F639-I/SS زیادہ سے زیادہ ریٹنگز اور برقی خصوصیات
| Product Family | PIC16F |
| Core Architecture | PIC 8-bit RISC |
| Program Memory Type | Flash |
| Program Memory Size | 3.5 KB (2K x 14) |
| RAM Size | 128 B |
| EEPROM Size | 256 B |
| Maximum CPU Speed | 20 MHz |
| Supply Voltage Range | 2 V to 5.5 V (typical operating 2.5V/3.3V/5V) |
| I/O Pins | 12 |
| Analog Comparators | 2 |
| Cryptographic Peripheral | KeeLoq-compatible hardware encoder/decoder |
| PLVD | Programmable Low-Voltage Detect |
| Internal Oscillator | Yes (factory calibrated) |
| Instruction Set | 35 single-word instructions, 14-bit word |
| Hardware Stack | 8 levels |
| آپریٹنگ درجہ حرارت رینج | -40 C to +85 C (Industrial -I suffix) |
| Package Type | 20-pin SSOP (5.30 mm body) |
| ماؤنٹنگ ٹائپ | Surface Mount |
| Lead-Free / RoHS | Yes (Compliant per part number suffix /SS) |
| Self-Programmable | Yes |
| nanoWatt Technology | Yes (low-power sleep modes) |
PIC16F639-I/SS پن کنفیگریشن
| پن 1 | RA5/MCLR/VPP — Digital I/O / Master Clear reset / programming voltage |
| پن 2 | RA0/AN0/C1IN+/ICSPDAT — Digital I/O / Analog input 0 / Comparator 1 non-inverting input / ICSP data |
| پن 3 | RA1/AN1/C1IN-/ICSPCLK — Digital I/O / Analog input 1 / Comparator 1 inverting input / ICSP clock |
| پن 4 | RA2/AN2/C2IN+/CVREF — Digital I/O / Analog input 2 / Comparator 2 non-inverting input / comparator voltage reference |
| پن 5 | RA3/AN3/C2IN-/VREF — Digital I/O / Analog input 3 / Comparator 2 inverting input / voltage reference |
| پن 6 | RA4/AN4/T0CKI/C1OUT — Digital I/O / Analog input 4 / Timer 0 clock input / Comparator 1 output |
| پن 7 | VDD — Positive supply voltage (2.0 V to 5.5 V) |
| پن 8 | VSS — Ground reference |
| پن 9 | RB4/AN10/CRY/SDI — Digital I/O with interrupt-on-change / Analog input 10 / Crypto oscillator / SPI data in |
| پن 10 | RB5/AN11/CRY_RT/SDO — Digital I/O with interrupt-on-change / Analog input 11 / Crypto oscillator return / SPI data out |
| پن 11 | RB6/AN12/PGC — Digital I/O with interrupt-on-change / Analog input 12 / ICSP clock |
| پن 12 | RB7/AN13/PGD — Digital I/O with interrupt-on-change / Analog input 13 / ICSP data |
| پن 13 | RC0/AN8/C2OUT — Digital I/O / Analog input 8 / Comparator 2 output |
| پن 14 | RC1/AN9 — Digital I/O / Analog input 9 |
| پن 15 | RC2/AN6 — Digital I/O / Analog input 6 |
| پن 16 | RC3/AN7/CRY — Digital I/O / Analog input 7 / Crypto oscillator |
| پن 17 | RC4/AN5 — Digital I/O / Analog input 5 |
| پن 18 | RC5 — Digital I/O |
| پن 19 | RC6 — Digital I/O |
| پن 20 | RA7/OSC1/CLKIN — Digital I/O / Oscillator crystal input / external clock input |
عام استعمالات
PIC16F639-I/SS کے لیے موزوں ہے 7 ایپلیکیشنs: Remote Keyless Entry (RKE) Transmitters, Automotive Immobilizer Systems, RFID Tags and Active Transponders, Secure Access-Control Keypads, Anti-Tamper Sensor Modules, Tire-Pressure Monitoring System (TPMS) Sensor Interface, Low-Cost Industrial Remote-Control Encoders.
Remote Keyless Entry (RKE) Transmitters
The PIC16F639-I/SS is the de facto MCU for remote keyless entry key fobs because it integrates the KeeLoq hardware crypto engine that performs rolling-code encryption in a single cycle. Its 3.5 KB Flash stores the manufacturer's fixed code and rolling-code algorithm parameters, 128B SRAM handles button debouncing and timing, and the on-chip PLVD monitors the CR2032 battery to prevent EEPROM corruption at end-of-life. With 12 I/O pins the fob supports 4-6 buttons plus an LED indicator and can run directly from a coin cell thanks to nanoWatt sleep currents in the nanoamp range. The 20-pin SSOP package keeps the PCB footprint under 6 mm x 6 mm for slim fob enclosures.
تجویز کردہ
Automotive Immobilizer Systems
The PIC16F639-I/SS's KeeLoq-compatible cryptographic peripheral makes it a natural fit for automotive immobilizers, where the device validates an inductive transponder's rolling code before allowing engine start. Its 2 V to 5.5 V supply range covers the automotive cranking profile, the PLVD module ensures safe EEPROM write protection during voltage dips, and the two on-chip analog comparators interface directly to the LF antenna signal chain. The 20 MHz CPU runs the challenge-response handshake in under 50 ms, fast enough for a seamless driver experience. Industrial -40 C to +85 C parts handle under-hood thermal stress, while the -E/SS variant (extended -40 C to +125 C) covers under-dash modules.
تجویز کردہ
RFID Tags and Active Transponders
Active RFID tags benefit from the PIC16F639-I/SS combination of low sleep current, integrated crypto for anti-counterfeiting authentication, and small 20-pin SSOP package. The KeeLoq engine authenticates the tag to the reader using a 64-bit rolling code, preventing cloning of secure credentials in access badges and toll transponders. The 256B EEPROM stores unique tag identifiers and rolling-code counters, while the 3.5 KB Flash holds the encryption handshake firmware and application code. With nanoWatt sleep modes the tag can idle for years on a single coin cell while periodically polling the LF antenna via the on-chip comparator.
تجویز کردہ
Secure Access-Control Keypads
Building entry keypads and PIN-pad access controllers use the PIC16F639-I/SS to encrypt PIN entries and rolling codes between the keypad, door controller, and central server. The hardware crypto engine offloads AES-equivalent rolling-code work from the CPU, freeing cycles to scan a 3x4 or 4x4 matrix keypad with debouncing. The PLVD monitors battery backup on the access-control PCB, the 256B EEPROM stores user credentials, and the 20 MHz core executes the cryptographic handshake in single-digit milliseconds. The 20-pin SSOP package fits standard keypad controller PCBs without sacrificing GPIO for the matrix scan.
تجویز کردہ
Anti-Tamper Sensor Modules
Industrial anti-tamper and alarm sensor modules use the PIC16F639-I/SS because the KeeLoq crypto prevents replay attacks on wireless alarm signaling. The two on-chip comparators interface directly to magnetic-reed or hall-effect tamper sensors, the 12 I/O pins support PIR, glass-break, and smoke-detector inputs, and the nanoWatt sleep current lets the module operate for years on battery. The integrated PLVD triggers an alarm signal when battery voltage drops below the user-programmable threshold, ensuring the sensor always transmits its last known good status. The 20-pin SSOP footprint enables compact PCB designs that fit inside standard sensor housings.
تجویز کردہ
Tire-Pressure Monitoring System (TPMS) Sensor Interface
TPMS wheel modules use the PIC16F639-I/SS to authenticate pressure and temperature telemetry to the vehicle's central receiver via encrypted rolling codes. The crypto engine prevents spoofing of pressure readings that could mask dangerous low-tire conditions, the two comparators interface to the LF wake-up receiver, and the 12 I/O pins support SPI pressure sensors and temperature transducers. The PLVD module protects the lithium coin cell from deep-discharge damage in unused modules on the shelf, and the nanoWatt sleep mode lets the module last the 5-10 year service life of the tire. The 20 MHz CPU runs the LF handshake, encryption, and RF transmit sequencing in well under 100 ms.
تجویز کردہ
Low-Cost Industrial Remote-Control Encoders
Crane controls, garage-door openers, and industrial remote-control transmitters use the PIC16F639-I/SS because it integrates the crypto engine at sub-$3 pricing, eliminating the need for an external secure element. The 35-instruction PIC16 RISC core is easy to program for industrial customers with limited firmware experience, and the 20-pin SSOP package supports both hand-held and panel-mount enclosures. The two analog comparators can detect battery voltage and joystick position directly, while the 12 I/O pins drive status LEDs, encoder buttons, and a 315/433/868 MHz SAW-resonator-based transmitter module. Industrial -40 C to +85 C parts survive factory floor thermal cycling.
تجویز کردہ
تجویز کردہ پروڈکٹس کا خلاصہ
کے لیے انجینئرنگ ریفرنس ڈیٹا PIC16F639-I/SS — موازنہ، ڈیزائن رہنمائی، اور تعمیل کی معلومات۔
انتخاب کی گائیڈ
متبادلات کے ساتھ موازنہ
| پیرامیٹر | یہ پروڈکٹ | PIC16F639-E/SO | PIC16F636-I/SS | PIC16F631-I/SS | PIC16F636-E/ST |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 20-pin SSOP | 20-pin SSOP (same) | 20-pin SSOP (same) | 20-pin SSOP (same) | 20-pin SSOP (same) |
| CPU Speed | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| Flash Program Memory | 3.5 KB | 3.5 KB | 3.5 KB | 1.75 KB (-50%) | 3.5 KB |
| RAM Size | 128 B | 128 B | 128 B | 64 B | 128 B |
| EEPROM Size | 256 B | 256 B | 256 B | 128 B | 256 B |
| KeeLoq Hardware Crypto | Yes | Yes | No (software only) | No | No (software only) |
| Analog Comparators | 2 | 2 | 2 | 2 | 2 |
| Operating Temperature | -40 C to +85 C (Industrial) | -40 C to +125 C (Extended) | -40 C to +85 C (Industrial) | -40 C to +85 C (Industrial) | -40 C to +125 C (Extended) |
| Supply Voltage Range | 2.0 V to 5.5 V | 2.0 V to 5.5 V | 2.0 V to 5.5 V | 2.0 V to 5.5 V | 2.0 V to 5.5 V |
اہم امتیازی خصوصیات
- Integrated KeeLoq hardware crypto engine (بمقابلہPIC16F636-I/SS)
- 3.5 KB Flash vs 1.75 KB in PIC16F631 (بمقابلہPIC16F631-I/SS)
- On-chip Programmable Low-Voltage Detect (PLVD) (بمقابلہExternal voltage supervisor IC)
- Industrial temperature range option (-E/SS) (بمقابلہStandard -I grade)
ڈیزائن نوٹس
KeeLoq security keys MUST be stored in protected Flash regions and never exposed via ICSP debug. According to the Microchip PIC16F639 datasheet, leaving configuration bits unprotected allows a determined attacker to read the encryption key in minutes with a $20 programmer. Always set the CPD (code-protect data EEPROM) and CP (code-protect program memory) configuration bits to 'on' in production firmware, and lock the MCLR pin's debug access. Estimated: for a typical 4-button RKE fob, the KeeLoq key plus manufacturer code occupy approximately 1.2 KB of the 3.5 KB Flash, leaving 2.3 KB for application code.
When designing CR2032 coin-cell powered applications, program the PLVD threshold to 2.4 V (not the default 2.0 V) to give early warning of end-of-life before the cell voltage drops below the brown-out reset threshold and corrupts the EEPROM rolling-code counter. Estimated: with the PIC16F639-I/SS drawing 100 nA in sleep mode and a CR2032 capacity of 220 mAh, shelf life is approximately 10 years, but actual fob life depends on transmit duty cycle - a 10 mA average RF transmit at 50 ms per press yields roughly 100,000 button presses per battery.
Route the KeeLoq crypto oscillator pins (RB4/RB5 or RC3 depending on package variant) as short traces with a ground guard ring to prevent EMI coupling from the SAW-resonator-based 315/433/868 MHz transmitter nearby. The internal oscillator typically provides approximately ±1% accuracy at room temperature which is adequate for UHF OOK/ASK transmitters but may not meet tight FCC or ETSI frequency-stability requirements for FSK modulation - in those cases an external crystal on the matching PIC16F636-I/SS or PIC16F639-E/SS variant is recommended. Keep analog comparator input traces away from digital switching nodes to prevent false comparator triggers during RF activity.
The two on-chip analog comparators have input offset voltages up to ±10 mV and propagation delays of typically 200 ns; for high-precision LF antenna signal conditioning in RFID applications, calibrate the comparator threshold against the supply voltage rather than relying on absolute reference. The internal voltage reference (VREF) has a typical temperature coefficient of 100 ppm/C; for outdoor TPMS applications where temperature swings exceed 80 C, use an external 2.5 V reference instead. Brown-out reset (BOR) and PLVD should both be enabled to provide layered voltage supervision - BOR handles the catastrophic case while PLVD provides the early warning.
تعمیل کی معلومات
RoHS compliant per Microchip product page. Not AEC-Q100 qualified - the /SS SSOP industrial-grade variant is not automotive-qualified; AEC-Q100 qualification status unknown and requires vendor confirmation for automotive OEM designs.
