PIC16C558-20/P - 8-Bit 20MHz OTP MCU 3.5KB | Microchip
MPN: PIC16C558-20/P β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.74 | $2.74 |
| 10 | $2.45 | $24.50 |
| 100 | $2.18 | $218.00 |
| 500 | $1.94 | $970.00 |
| 1,000 | $1.72 | $1,720.00 |
PIC16C558-20/P Overview
An 8-bit microcontroller (MCU) is a single-chip computer that integrates a CPU, program memory, data RAM, I/O peripherals, and timers on one die. Within the IC taxonomy, an 8-bit MCU sits under: microcontroller -> microprocessor -> integrated circuit -> semiconductor. The PIC16C5x family specifically targets simple control loops, sensor interfaces, and human-machine-input (HMI) tasks where 8-bit performance, low pin count, and OTP/EPROM-based code storage are sufficient. OTP memory allows the device to be programmed once during manufacturing or development, making the PIC16C558 ideal for low- to mid-volume production runs that do not require the field-reprogrammability of Flash-based PIC16F parts.
Key features include a 20MHz maximum oscillator frequency, an operating voltage range of 2.5V to 6.0V (commercial), low-power CMOS design, an 8-bit real-time clock/counter (TMR0), power-on reset, watchdog timer with its own on-chip RC oscillator for reliable operation, and a programmable code-protection mechanism. The 18-pin PDIP package provides easy through-hole prototyping on breadboards and standard 0.1-inch-pitch perfboards, while the wide 2.5-6.0V supply range supports both 3.3V and 5V system rails. Compared with the PIC16C554, the PIC16C558 doubles the RAM to 128 bytes while retaining the same 13 I/O and core 8-bit architecture.
Typical applications include consumer appliance control, automotive body electronics (non-safety), industrial sensor interfaces, LED display drivers, IR remote control transmitters, low-end motor control, battery chargers, and simple HMI panels. Its 35-instruction RISC core enables rapid development in assembly or C, and the watchdog timer makes it well suited to unattended remote nodes that must recover from firmware or environmental faults. Engineers choose the PIC16C558 when they need a proven, mature 8-bit core with OTP memory in a hobbyist-friendly DIP footprint.
When designing with this device, note that OTP memory cannot be erased, so firmware must be fully debugged on a Flash equivalent (such as the PIC16F558) before committing to a PIC16C558 production build. Always allocate a watchdog timer timeout appropriate to the main loop period, and place a 0.1uF decoupling capacitor as close as possible to the VDD pin. The 18-pin PDIP is being phased out for many new designs in favor of smaller SOIC and SSOP footprints, so consider long-term availability and the availability of Flash siblings (PIC16F558) for ongoing development.
This page synthesizes distributor pricing, drop-in Microchip replacements, and practical design notes not found in the manufacturer datasheet alone. Engineers evaluating the PIC16C558-20/P for new designs or sustaining legacy systems will find verified parametric data, cross-reference alternatives, and PCB layout guidance tailored to OTP-based PIC16C5x designs.
Drop-in alternatives for PIC16C558-20/P β 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 PIC16C558-20/P (same form factor and footprint) β differing in Mounting Type, Program Memory Size, Timers, Operating Temperature Range, Package.
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Request AlternativesPIC16C558-20/P Maximum Ratings & Electrical Characteristics
| Product Family | PIC16C5x |
| Core Architecture | 8-bit PIC RISC |
| Program Memory Type | OTP (One-Time-Programmable) EPROM |
| Program Memory Size | 3.5 KB (2K x 14) |
| RAM Size | 128 bytes |
| Maximum CPU Frequency | 20 MHz |
| Instruction Cycle Time | 200 ns |
| Instruction Set Size | 35 single-word instructions |
| Instruction Word Width | 12 bits |
| Data Path Width | 8 bits |
| I/O Pins | 13 |
| Timers | 1 x 8-bit (TMR0) |
| Watchdog Timer | Yes (with on-chip RC oscillator) |
| Hardware Stack Depth | 2 levels |
| Operating Voltage Range | 2.5 V to 6.0 V |
| Operating Temperature Range | 0C to +70C (commercial) |
| Package | 18-pin PDIP (through-hole) |
| Mounting Type | Through-Hole |
| RoHS Status | Compliant |
PIC16C558-20/P Pin Configuration
| Pin 1 | MCLR β Master clear (reset) input, active low |
| Pin 2 | RA0 β Bidirectional I/O port A bit 0 |
| Pin 3 | RA1 β Bidirectional I/O port A bit 1 |
| Pin 4 | VSS β Ground reference |
| Pin 5 | RA2 β Bidirectional I/O port A bit 2 |
| Pin 6 | RA3 β Bidirectional I/O port A bit 3 |
| Pin 7 | RA4/T0CKI β Bidirectional I/O port A bit 4 / Timer0 clock input |
| Pin 8 | OSC1 β Oscillator input / external clock input |
| Pin 9 | OSC2 β Oscillator output / instruction clock output |
| Pin 10 | RB0 β Bidirectional I/O port B bit 0 |
| Pin 11 | RB1 β Bidirectional I/O port B bit 1 |
| Pin 12 | RB2 β Bidirectional I/O port B bit 2 |
| Pin 13 | VDD β Positive supply voltage |
| Pin 14 | RB3 β Bidirectional I/O port B bit 3 |
| Pin 15 | RB4 β Bidirectional I/O port B bit 4 |
| Pin 16 | RB5 β Bidirectional I/O port B bit 5 |
| Pin 17 | RB6 β Bidirectional I/O port B bit 6 |
| Pin 18 | RB7 β Bidirectional I/O port B bit 7 |
Typical Applications
PIC16C558-20/P is suitable for 6 applications: Consumer Appliance Control, Automotive Body Electronics (Non-Safety), Industrial Sensor Interface Modules, IR Remote Control Transmitters, LED Display and Sign Drivers, Battery Chargers and Power Management.
Consumer Appliance Control
The PIC16C558-20/P is well suited to consumer appliance control boards such as coffee makers, toaster ovens, washing machine sub-modules, and small kitchen appliances, where 8-bit RISC performance, 13 GPIO, and 3.5KB of OTP code space are sufficient. Its 200ns instruction cycle executes a 35-instruction RISC core fast enough to multiplex LED displays, scan keypads, and drive triac-based load switches in real time. The on-chip watchdog timer and power-on reset improve field reliability by recovering from brown-outs and firmware lock-ups, which are critical in unattended appliances. The 2.5-6.0V supply range accommodates both 3.3V logic-level and legacy 5V designs, and the 18-pin PDIP simplifies hand-prototyping and rework on the production line. OTP memory at 3.5KB is ideal for medium-complexity appliance firmware that does not require field updates after manufacturing.
Recommended
Automotive Body Electronics (Non-Safety)
The PIC16C558-20/P is widely used in non-safety automotive body modules such as interior lighting controllers, mirror-position drivers, seat-heater switches, and simple dashboard keypads. The industrial-temperature PIC16C558-20I/P variant operates from -40C to +85C, matching typical automotive cabin thermal requirements, while the 8-bit PIC core and 13 GPIO are well-matched to button-matrix scanning, PWM LED dimming, and LIN/CAN bus daughter-card control. The watchdog timer with its own on-chip RC oscillator provides a fail-safe against electrical noise common in automotive harnesses. OTP memory locks the firmware at production time, preventing field tampering. The 18-pin PDIP package, while less common in modern automotive designs, is still supported in aftermarket and replacement-board applications, particularly in legacy vehicle platforms.
Recommended
Industrial Sensor Interface Modules
The PIC16C558-20/P serves as a low-cost front-end for industrial sensor interface modules that digitize analog signals, perform linearization, and present the result over RS-485, 4-20mA current loop, or simple SPI/UART links. Its 8-bit ADC-friendly architecture (via comparator and TMR0 capture) and 13 I/O enable direct connection to thermocouples, RTDs, photo-diodes, and Hall-effect sensors. The 200ns instruction cycle supports up to 5MIPS of deterministic processing for sampled-data loops. The 2.5-6.0V supply range tolerates the 24V industrial bus after regulation, and the 18-pin PDIP package simplifies field-replacement in control cabinets. The 3.5KB OTP program memory fits sensor calibration tables, linearization polynomials, and Modbus RTU framing code comfortably.
Recommended
IR Remote Control Transmitters
The PIC16C558-20/P is a strong fit for handheld IR remote control transmitters used in TVs, set-top boxes, audio amplifiers, and ceiling fans. Its 8-bit RISC core and 200ns instruction cycle easily generate 36-40kHz or 56kHz carrier-modulated RC5/RC6/SONY/SIRC protocols using a single timer and one GPIO pin driving an external IR LED transistor. The 3.5KB OTP memory holds scan tables, device codes, and protocol state machines for multi-device universal remotes. Low-power CMOS design extends battery life across AAA-cell remotes, while the 13 I/O support 4x4 or 5x5 key matrices for 16-25 keys. OTP at production time prevents end-user code cloning, which is a common requirement for OEM remote control suppliers.
Recommended
LED Display and Sign Drivers
The PIC16C558-20/P drives multiplexed 7-segment LED displays, scrolling dot-matrix signs, and decorative lighting controllers in retail, hospitality, and signage applications. Its 13 I/O can sink/source a 4-digit 7-segment display directly via external transistors, or scan a small 5x7 LED matrix with row/column multiplexing. The 8-bit TMR0 provides the refresh timebase, and the 200ns instruction cycle sustains flicker-free multiplexing at 100Hz+ refresh rates. The 3.5KB OTP code space stores font tables, animation sequences, and brightness-PWM patterns. The 2.5-6.0V supply works with 3.3V logic or 5V LED strings, and OTP memory locks proprietary display patterns at production time to protect OEM branding.
Recommended
Battery Chargers and Power Management
The PIC16C558-20/P can serve as the control MCU in simple NiCd, NiMH, or sealed lead-acid (SLA) battery chargers, providing charge-profile timing, voltage monitoring, and LED status indication. The 8-bit ADC-via-comparator technique monitors battery voltage on a single analog channel, while the TMR0 generates charge-time intervals. The 13 I/O support relay/SSR control of the charger FET, current-shunt amplifier enable, and status-LED multiplexing. The 2.5-6.0V supply range is compatible with 3-cell or 6-cell battery packs, and the watchdog timer protects against charger firmware lock-up. The 3.5KB OTP memory stores the multi-stage charge algorithm and end-of-charge detection logic. For lithium-ion chemistries requiring tighter accuracy, migrate to a Flash-based PIC16F1xxx with on-chip ADC.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C558-20/P β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C558-20I/P | PIC16C558-04/P | PIC16C558-04I/P | PIC16C554-20/P | PIC16F558-I/P |
|---|---|---|---|---|---|---|
| Package | 18-pin PDIP | 18-pin PDIP - same | 18-pin PDIP - same | 18-pin PDIP - same | 18-pin PDIP - same | 18-pin PDIP - same |
| Brand | Microchip Technology | Microchip Technology - same | Microchip Technology - same | Microchip Technology - same | Microchip Technology - same | Microchip Technology - same |
| Program Memory Type | OTP EPROM 3.5KB | OTP EPROM 3.5KB - same | OTP EPROM 3.5KB - same | OTP EPROM 3.5KB - same | OTP EPROM 3.5KB - same | Flash 3.5KB (reprogrammable) |
| RAM | 128 bytes | 128 bytes - same | 128 bytes - same | 128 bytes - same | 64 bytes (-50%) | 128 bytes - same |
| Max CPU Frequency | 20 MHz | 20 MHz - same | 4 MHz (-80%) | 4 MHz (-80%) | 20 MHz - same | 20 MHz - same |
| I/O Pins | 13 | 13 - same | 13 - same | 13 - same | 13 - same | 13 - same |
| Operating Temperature | 0C to +70C (commercial) | -40C to +85C (industrial) | 0C to +70C (commercial) | -40C to +85C (industrial) | 0C to +70C (commercial) | -40C to +85C (industrial) |
| Supply Voltage Range | 2.5 V to 6.0 V | 2.5 V to 6.0 V - same | 2.5 V to 6.0 V - same | 2.5 V to 6.0 V - same | 2.5 V to 6.0 V - same | 2.0 V to 5.5 V (Flash variant) |
Key Differentiators
- Doubled RAM compared to PIC16C554 (vs PIC16C554-20/P)
- 20 MHz CPU speed with 200 ns instruction cycle (vs PIC16C558-04/P)
- Drop-in industrial temperature grade (vs PIC16C558-20I/P)
Design Notes
The PIC16C558-20/P uses One-Time-Programmable (OTP) EPROM, which CANNOT be erased. Once programmed, the device is permanent. Always prototype and debug firmware on the Flash-based PIC16F558-I/P (same 18-pin PDIP footprint, same peripherals), then port the validated HEX file to the PIC16C558 for production. This avoids scrapping $2+ chips during firmware iteration. Also, the OTP bit can be set only once per memory cell, so a programming error cannot be repaired by re-programming - verify all write operations in code with read-back verification before committing the write.
Place a 0.1uF ceramic decoupling capacitor as close as physically possible to the VDD pin (pin 13) and another from VSS (pin 4) to ground. For designs that switch heavier loads, add a 10uF tantalum or aluminum bulk capacitor near the regulator output. The PIC16C558 is a low-power CMOS part, but its internal 4MHz RC oscillator and TMR0 can inject supply noise that corrupts ADC-like measurements performed with on-chip comparators. Use a star-ground topology that returns noisy digital ground currents separately from analog sensor grounds.
The 18-pin PDIP has 0.1-inch (2.54mm) pin pitch, which is breadboard-compatible. Keep the MCLR (pin 1) trace short and route it away from high-frequency switching nodes - the MCLR input is sensitive to noise and a false reset can crash the application. The OSC1/OSC2 traces (pins 8 and 9) should be short and surrounded by a ground ring or guard trace to reduce EMI radiation. If using a crystal, place the load capacitors within 0.25 inch of the OSC pins to ensure stable oscillation up to 20MHz.
The PIC16C5x family has a 2-level hardware stack, NOT the 8-level stack of the mid-range PIC16F family. Subroutine nesting beyond 2 levels will silently corrupt the return address, causing erratic firmware behavior. Structure code as small leaf functions and avoid deep call chains, or simulate a software stack in the 128-byte RAM. Also note that the OPTION register configuration bit names differ between PIC16C5x and PIC16F parts - never copy configuration bytes from PIC16F code without re-checking the option register mapping.
Compliance Information
RoHS and lead-free compliant per Microchip product page. Not AEC-Q100 qualified; for automotive safety applications, choose an AEC-Q100-qualified PIC16F1xxx. Halogen-free status not explicitly stated in available data; consult Microchip for confirmation.
