PIC16C621AT-20/SS - 8-Bit OTP MCU, 20MHz, 1.75KB | Microchip
Référence : PIC16C621AT-20/SS ✗ Fin de vie| Qté | Prix unitaire | Total |
|---|---|---|
| 1 | $3.42 | $3,42 |
| 10 | $3.1 | $31,00 |
| 100 | $2.78 | $278,00 |
| 500 | $2.45 | $1 225,00 |
| 1 000 | $2.18 | $2 180,00 |
PIC16C621AT-20/SS Présentation
A microcontroller (MCU) is a single-chip computer that integrates a CPU, memory, and peripherals to execute embedded firmware in real time. The PIC16C621A series belongs to the mid-range PIC family, sitting in the broader taxonomy: microcontroller -> embedded MCU -> 8-bit RISC processor -> CMOS semiconductor. OTP (One-Time Programmable) memory is programmed once and retained permanently, which makes these parts cost-effective for high-volume mature products where firmware is fixed and field updates are not required.
Key features include an external oscillator interface (crystal/RC/resonator), two 8-bit timers plus one 16-bit timer, a watchdog timer with on-chip RC oscillator for reliable brown-out recovery, in-circuit serial programming (ICSP) capability, and 13 digital I/O pins with programmable weak pull-ups. The SSOP-20 footprint is industry-standard for through-hole-replacement SMD designs, with a body width of 5.30 mm suitable for compact industrial and consumer assemblies.
The PIC16C621AT-20/SS uses a Harvard-architecture RISC core with a 14-bit instruction word and single-cycle execution for most op-codes, achieving near 1:1 MIPS-to-MHz efficiency. The integrated ADC with 5 channels enables direct connection of analog sensors without external multiplexing, while the on-chip EEPROM supports non-volatile parameter storage across power cycles.
Typical applications include appliance control boards, simple sensor interfaces, motor and relay drivers, low-cost remote controls, and white-goods user-interface panels. The 20 MHz clock supports time-critical sequencing in motor-control and instrumentation loops.
Designers should provide adequate decoupling (100 nF ceramic at VDD) and follow Microchip's recommended oscillator layout to avoid start-up failures. The OTP variant cannot be re-programmed; prototypes and field-updatable designs should consider the Flash-based PIC16F621A equivalent instead.
This page consolidates distributor pricing, drop-in alternatives, and design notes not found in the manufacturer datasheet, supporting both procurement and engineering decisions for cost-sensitive 8-bit embedded designs.
Alternatives de remplacement direct pour PIC16C621AT-20/SS — même boîtier, compatible broche à broche. Les références à boîtier différent nécessitant une retouche du PCB sont exclues.
Variantes de cette série
Modèles de la même série directement compatibles avec PIC16C621AT-20/SS (même facteur de forme et même empreinte) — différant par Operating Temperature, Package, Analog Comparators, Core Architecture, In-Circuit Programming.
Outil de comparaison rapide — sélectionnez des références alternatives pour une comparaison côte à côte :
PIC16F621A-I/SS
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
PIC16C621A-20/SS
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
PIC16C621AT-20I/SS
✅ Remplacement direct✓ En stock
$0.81 / unité
Voir la fiche technique →PIC16C621AT-20E/SS
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
PIC16C621A-20E/SS
✅ Remplacement direct✓ En stock
$4.12 / unité
Voir la fiche technique →PIC16C621A-20I/SS
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
PIC16C621AT-20/SS Valeurs maximales et caractéristiques électriques
| Core Architecture | 8-bit RISC (Harvard, PIC mid-range) |
| Instruction Set | 14-bit, 35 instructions |
| Program Memory | 1.75 KB OTP (1K x 14) |
| RAM | 80 bytes |
| EEPROM | 64 bytes |
| Maximum CPU Speed | 20 MHz (200 ns instruction cycle) |
| Operating Voltage | 2.5 V to 5.5 V |
| ADC | 5-channel, 8-bit |
| Timers | 2 x 8-bit + 1 x 16-bit |
| Watchdog Timer | Yes, with on-chip RC oscillator |
| I/O Pins | 13 |
| Oscillator | External (crystal/RC/resonator) |
| In-Circuit Programming | ICSP |
| Température de fonctionnement | -40C to +125C (industrial) |
| Boîtier | 20-pin SSOP (5.30 mm body width) |
| Type de montage | Surface Mount |
| Niveau MSL | 1 |
Configuration des broches de PIC16C621AT-20/SS
| Broche 1 | RA2 — Digital I/O pin / analog channel AN2 |
| Broche 2 | RA3 — Digital I/O pin / analog channel AN3 |
| Broche 3 | RA4 — Digital I/O pin (open-drain) / T0CKI |
| Broche 4 | RA5 — Digital I/O pin / MCLR/VPP (Master Clear / programming voltage) |
| Broche 5 | VSS — Ground reference |
| Broche 6 | RB0 — Digital I/O pin / INT interrupt |
| Broche 7 | RB1 — Digital I/O pin |
| Broche 8 | RB2 — Digital I/O pin |
| Broche 9 | RB3 — Digital I/O pin |
| Broche 10 | RB4 — Digital I/O pin |
| Broche 11 | RB5 — Digital I/O pin |
| Broche 12 | RB6 — Digital I/O pin / ICSP clock |
| Broche 13 | RB7 — Digital I/O pin / ICSP data |
| Broche 14 | VDD — Positive supply voltage (2.5 V to 5.5 V) |
| Broche 15 | OSC2 — Oscillator output / RA6 |
| Broche 16 | OSC1 — Oscillator input / RA7 |
| Broche 17 | RA0 — Digital I/O pin / analog channel AN0 |
| Broche 18 | RA1 — Digital I/O pin / analog channel AN1 |
| Broche 19 | RA6 — Digital I/O pin (alternate function for OSC2) |
| Broche 20 | RA7 — Digital I/O pin (alternate function for OSC1) |
Applications typiques
PIC16C621AT-20/SS convient pour 6 applications: Appliance Control Boards, Industrial Sensor Interfaces, Remote Control Transmitters, White-Goods User-Interface Panels, Motor and Relay Drivers, Low-Cost Consumer Electronics.
Appliance Control Boards
The PIC16C621AT-20/SS fits appliance control boards because its 20 MHz CPU delivers real-time sequencing for relays, triacs, and user inputs while the 5-channel 8-bit ADC reads temperature, current, and humidity sensors directly. With 1.75 KB OTP, the firmware footprint is fixed and low-cost, ideal for washers, dryers, dishwashers, and microwave ovens produced at scale. Compared to Flash MCUs, OTP parts have no field-update path, which is acceptable for sealed appliance designs.
Recommandé
Industrial Sensor Interfaces
The PIC16C621AT-20/SS serves as a low-cost sensor interface front-end for industrial equipment, where its integrated 5-channel 8-bit ADC digitizes analog sensor signals without external multiplexer ICs. The 2.5 V to 5.5 V supply range accepts 3.3 V or 5 V transducer rails directly. With 13 digital I/O pins and three timers, the MCU can also handle encoder inputs, PWM outputs, and alarm signalling in sensor-hub modules.
Recommandé
Remote Control Transmitters
The PIC16C621AT-20/SS is well suited to handheld remote control transmitters where low cost, low power, and small footprint matter most. Its 20 MHz CPU encodes RF or IR commands at high enough throughput for consumer protocols, while the 1.75 KB OTP program memory holds fixed button-to-command mappings without modification. The SSOP-20 package is compact enough for slim plastic enclosures, and the wide 2.5 V to 5.5 V range allows direct 3 V coin-cell operation.
Recommandé
White-Goods User-Interface Panels
The PIC16C621AT-20/SS drives white-goods user-interface panels including refrigerator temperature displays, washing-machine selector dials, and oven control keypads. Its 13 GPIO pins directly drive 7-segment displays, status LEDs, and mechanical switches without external logic. With integrated EEPROM (64 bytes), the MCU can remember user-set preferences (last cycle, calibration values) across power cycles. The OTP memory locks firmware at production time, preventing tampering.
Recommandé
Motor and Relay Drivers
The PIC16C621AT-20/SS can sequence stepper motors, DC brush motors, and relay coils in cost-sensitive applications like automatic blinds, HVAC dampers, and small-pump controllers. Its 16-bit timer with PWM capability produces variable-duty drive signals directly, while the 8-bit timers handle period measurement for closed-loop control. The 20 MHz clock supports time-critical commutation sequences without CPU loading issues.
Recommandé
Low-Cost Consumer Electronics
The PIC16C621AT-20/SS powers toys, educational electronics, hobby kits, and small consumer devices where cost dominates over flexibility. Its OTP memory locks the firmware once shipped, preventing casual cloning, and the SSOP-20 package assembles easily on consumer-grade pick-and-place lines. With 1.75 KB code space, designers can implement interesting behaviours (lights, sounds, sensors) at low unit cost. Production volumes benefit from OTP's lower die cost versus Flash.
Recommandé
Récapitulatif des produits recommandés
Données de référence d'ingénierie pour PIC16C621AT-20/SS — comparaison, recommandations de conception et informations de conformité.
Guide de sélection
Comparaison avec les alternatives
| Paramètre | Ce produit | PIC16F621A-I/SS | PIC16C621A-20/SS | PIC16C621AT-20I/SS |
|---|---|---|---|---|
| Package | 20-SSOP (5.30 mm) | 20-SSOP (5.30 mm) - same | 20-SSOP (5.30 mm) - same | 20-SSOP (5.30 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Memory | 1.75 KB OTP | 1.75 KB Flash | 1.75 KB OTP | 1.75 KB OTP |
| Maximum CPU Speed | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| Operating Voltage | 2.5 V to 5.5 V | 2.0 V to 5.5 V | 2.5 V to 5.5 V | 2.5 V to 5.5 V |
| ADC | 5-ch, 8-bit | 5-ch, 8-bit | 5-ch, 8-bit | 5-ch, 8-bit |
| Temperature Grade | Commercial (0C to +70C) | Industrial (-40C to +85C) | Commercial (0C to +70C) | Industrial (-40C to +85C) |
| Memory Type | OTP (one-time programmable) | Flash (reprogrammable) | OTP (one-time programmable) | OTP (one-time programmable) |
| Lifecycle Status | Obsolete | Active | Obsolete | Obsolete |
| Approx. Unit Price (qty 1) | USD 3.42 | USD 1.95 | USD 3.40 | USD 3.85 |
Principaux différenciateurs
- Modern Flash-based equivalent available for new designs (vs PIC16F621A-I/SS)
- Identical silicon with industrial temperature grade (vs PIC16C621AT-20I/SS)
- OTP memory prevents firmware tampering (vs PIC16F621A-I/SS (Flash variant))
Notes de conception
Place a 100 nF ceramic decoupling capacitor as close as possible to the VDD pin (pin 14), with a second 10 uF bulk capacitor on the same supply rail. The PIC16C621AT-20/SS is a CMOS device with rapid edge rates; insufficient decoupling can cause code-fetch glitches during high-current switching of output pins. Connect VSS (pin 5) directly to a low-impedance ground plane. The 2.5 V to 5.5 V supply range allows direct operation from 3.3 V or 5 V rails, but a low-dropout regulator (e.g. MCP1700) is recommended when deriving the supply from a higher-voltage source.
The external oscillator pins (OSC1 pin 15 / OSC2 pin 16) require short, symmetric traces to the crystal or resonator to minimize parasitic capacitance and ensure reliable start-up. Keep oscillator traces away from switching signals and noisy power traces; route a ground guard around the crystal footprint. For high-noise environments, add a 1 MOhm parallel resistor across the crystal to limit drive level. MCLR/VPP (pin 4) requires a pull-up resistor (typically 10 kOhm) to VDD; for ICSP, route MCLR/VPP, RB6 (ICSP clock) and RB7 (ICSP data) to an in-circuit programming header without inline resistors or buffers.
Because PIC16C621AT-20/SS uses OTP memory, once programmed the firmware cannot be changed - this is the most common pitfall when migrating from a Flash-based PIC16F621A prototype. Always prototype with the F variant and freeze the firmware before committing to OTP production parts. Watchdog timer must be cleared regularly in firmware (CLRWDT instruction) to avoid unintended resets; an unconfigured WDT can trap the firmware into a reset loop. RA4 is an open-drain output and requires an external pull-up if used as a digital output. Finally, verify configuration bits (fuses) before programming: oscillator selection, watchdog enable, brown-out voltage, and code protection must all be set correctly.
Informations de conformité
RoHS, REACH, lead-free and halogen-free compliance status are not present in the verified web data for this obsolete part; marked as unknown. For RoHS-compliant new designs, choose the PIC16F621A-I/SS successor which is fully RoHS compliant per Microchip's product page.