PIC16C558-20E/SS - 8-Bit 20MHz OTP MCU, 3.5KB | Microchip
MPN: PIC16C558-20E/SS ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.95 | $3.95 |
| 10 | $3.56 | $35.60 |
| 100 | $3.16 | $316.00 |
| 500 | $2.84 | $1,420.00 |
| 1,000 | $2.53 | $2,530.00 |
PIC16C558-20E/SS Overview
An 8-bit microcontroller (MCU) is a single-chip computer containing a CPU, program memory, RAM, and peripherals designed to read sensors and drive actuators in real time. MCUs sit at the lowest tier of the compute hierarchy - below microprocessors and SoCs - and trade raw speed for deterministic I/O handling, low power draw, and predictable interrupt latency. The PIC16C family occupies the mid-range PIC tier, balancing instruction efficiency, peripheral integration, and cost for industrial and automotive embedded designs.
Key features of the PIC16C558-20E/SS include 13 digital I/O pins, a 20MHz internal oscillator (4x PLL from a 5MHz source), one 8-bit timer and one 16-bit timer, a watchdog timer with on-chip RC oscillator, and brown-out reset for power-supply monitoring. The device operates from 3.0V to 5.5V, supports in-circuit serial programming (ICSP), and integrates an 8-bit ADC on selected pins. Its 20-pin SSOP (5.30mm body) footprint makes it drop-in compatible with the PIC16C554 family.
Architecturally, the PIC16C558 uses a Harvard bus with separate program and data paths, an 8-bit ALU, and a hardware stack that supports direct, indirect, and relative addressing. The OTP program memory enables prototype-friendly one-time programming, while the EPROM-based cell supports windowed erasing during development. With 2K x 14 instructions and 128 bytes of data RAM, it targets applications that need more code space than the PIC12C/PIC16C5x baseline but less than the PIC16C7x peripheral-rich tier.
Typical applications include automotive body controllers, HVAC damper drivers, lighting ballasts, appliance control boards, security keypads, and remote sensor interfaces. The Extended temperature grade and robust brown-out reset make it particularly attractive for under-hood automotive and outdoor industrial installations.
When designing in this part, ensure your firmware budget stays under 2K words (3.5KB OTP) and that the ICSP pins are reserved on production boards to allow field reprogramming during qualification. The PIC16C554-20I/SS shares the same SSOP-20 footprint and can serve as a mask-ROM alternative once the design is frozen.
This page synthesizes distributor availability, drop-in PIC16C family alternatives, and practical design notes that go beyond the bare Microchip datasheet, helping engineers select, source, and qualify the PIC16C558-20E/SS faster.
Drop-in alternatives for PIC16C558-20E/SS — 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 PIC16C558-20E/SS (same form factor and footprint) — differing in Package, Program Memory Size, Program Memory Type, Watchdog Timer, Timers.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C558-20I/SS
✅ Drop-In✓ In Stock
$2.15 / Unit
View Datasheet →PIC16C558-20/SS
✅ Drop-In✓ In Stock
$2.05 / Unit
View Datasheet →PIC16C558T-20E/SS
✅ Drop-In✓ In Stock
$2.1 / Unit
View Datasheet →PIC16C554-20I/SS
✅ Drop-In✓ In Stock
$1.82 / Unit
View Datasheet →PIC16C554T-20I/SS
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C554T-20/SS
✅ Drop-In✓ In Stock
$1.74 / Unit
View Datasheet →PIC16C558-20E/SS Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC 8-bit RISC (Harvard) |
| Program Memory Type | OTP EPROM |
| Program Memory Size | 3.5 KB (2K x 14 words) |
| Data RAM | 128 bytes |
| Data EEPROM | Not present |
| Maximum CPU Frequency | 20 MHz |
| Instruction Cycle Time | 200 ns |
| Instruction Set Size | 35 single-word instructions |
| Supply Voltage Range | 3.0 V to 5.5 V |
| I/O Pins | 13 digital I/O |
| Timers | 1 x 8-bit, 1 x 16-bit |
| Watchdog Timer | Yes (on-chip RC oscillator) |
| Brown-out Reset | Yes |
| In-Circuit Serial Programming (ICSP) | Yes |
| Operating Temperature Grade | Extended (-40C to +125C) |
| Package | 20-pin SSOP (5.30 mm) |
| Mounting Type | Surface Mount (Gull-wing) |
| RoHS Status | Compliant |
PIC16C558-20E/SS Pin Configuration
| Pin 1 | RA3/MCLR/VPP — Digital I/O / Master Clear (reset) / Programming voltage input |
| Pin 2 | RA0/AN0 — Digital I/O / Analog channel 0 |
| Pin 3 | RA1/AN1 — Digital I/O / Analog channel 1 |
| Pin 4 | RA2/AN2 — Digital I/O / Analog channel 2 |
| Pin 5 | RA4/AN3/T0CKI — Digital I/O / Analog channel 3 / Timer 0 clock input |
| Pin 6 | RA5/AN4/SS — Digital I/O / Analog channel 4 / Slave Select |
| Pin 7 | VSS — Ground reference |
| Pin 8 | OSC1/CLKIN — Crystal oscillator input / external clock input |
| Pin 9 | OSC2/CLKOUT — Crystal oscillator output / clock output |
| Pin 10 | VDD — Positive supply voltage (3.0V to 5.5V) |
| Pin 11 | RB0/INT — Digital I/O / External interrupt input |
| Pin 12 | RB1 — Digital I/O |
| Pin 13 | RB2 — Digital I/O |
| Pin 14 | RB3/PGM — Digital I/O / LVP programming input |
| Pin 15 | RB4 — Digital I/O |
| Pin 16 | RB5 — Digital I/O |
| Pin 17 | RB6/PGC — Digital I/O / ICSP clock (programming) |
| Pin 18 | RB7/PGD — Digital I/O / ICSP data (programming) |
| Pin 19 | VSS — Ground reference |
| Pin 20 | VDD — Positive supply voltage (3.0V to 5.5V) |
Typical Applications
PIC16C558-20E/SS is suitable for 6 applications: Automotive Body Control Modules, HVAC Damper and Blower Drivers, LED Lighting Ballasts and Drivers, Appliance Control Boards, Security Keypad and Access Controllers, Remote Sensor Interface Nodes.
Automotive Body Control Modules
The PIC16C558-20E/SS fits automotive body controllers because its Extended -40C to +125C temperature grade survives under-hood thermal stress and its 3.5KB OTP memory holds seat/window/mirror logic plus diagnostic state machines. The on-chip brown-out reset prevents lockups during cranking voltage drops below 5V, and the 20MHz core executes CAN-LIN gateway logic in real time. The 13 digital I/O pins directly drive relay coils and switch inputs through transient protection networks. Compared with mask-ROM alternatives, OTP enables late-binding calibration for OEM-specific trim variants.
Recommended
HVAC Damper and Blower Drivers
The PIC16C558-20E/SS is well-matched to HVAC damper and blower controllers because its 8-bit timer generates accurate PWM for triac phase-angle control and its brown-out reset handles brown-out events common in motor back-EMF environments. The 3.5KB program memory accommodates multi-zone scheduling, while 128 bytes of RAM handles real-time setpoint tracking and hysteresis state. The Extended temperature grade survives attic and rooftop HVAC cabinet environments. Compared with PIC16C5x baseline parts, the additional 2.6KB of code space supports MODBUS/RTU and fault logging.
Recommended
LED Lighting Ballasts and Drivers
The PIC16C558-20E/SS drives commercial LED ballast designs because its 16-bit timer delivers high-resolution PWM dimming down to 0.1% steps and its 20MHz core executes DALI or 0-10V dimming protocol stacks alongside closed-loop current regulation. The 13 I/O pins connect directly to MOSFET gate drivers and analog current-sense inputs. The Extended temperature grade handles the thermal rise inside enclosed luminaire fixtures. Compared with PIC16F equivalents, the OTP-only architecture reduces BOM cost in price-sensitive commercial lighting.
Recommended
Appliance Control Boards
The PIC16C558-20E/SS powers white-goods appliance controllers because its 3.5KB code space stores user-interface state machines, fault diagnostics, and energy-metering firmware for washing machines, dishwashers, and refrigerators. Its watchdog timer with on-chip RC oscillator survives ESD-induced firmware hangs common on appliance user-interface boards. Compared with PIC16F flash parts, the OTP architecture prevents field firmware tampering - a benefit for OEM warranty programs. The Extended temperature grade handles the thermal rise behind refrigerator compressor compartments.
Recommended
Security Keypad and Access Controllers
The PIC16C558-20E/SS serves security keypad controllers because its 3.5KB OTP holds encrypted credential tables and lockout-state machines, while the 13 I/O pins scan 4x4 matrix keypads and drive relay/buzzer outputs. The brown-out reset prevents unauthorized access during power-glitch attacks. The Extended temperature grade ensures outdoor keypad reliability. Compared with PIC16C554, the larger program memory supports rolling-code algorithms and audit-log buffering without external EEPROM.
Recommended
Remote Sensor Interface Nodes
The PIC16C558-20E/SS handles remote sensor nodes because its 20MHz core processes analog sensor signals at sub-millisecond intervals, and its 3.5KB program memory stores calibration tables and Modbus framing. The on-chip watchdog prevents firmware hangs in unattended field installations. The Extended temperature grade survives outdoor weather station enclosures. Compared with PIC16C554, the larger RAM and code space support multi-channel thermocouple compensation algorithms directly on-chip without external ADC plus DSP chains.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C558-20E/SS — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C558-20I/SS | PIC16C558-20/SS | PIC16C554-20I/SS |
|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | SSOP-20 | SSOP-20 (same) | SSOP-20 (same) | SSOP-20 (same) |
| Program Memory | 3.5 KB (2K x 14) | 3.5 KB | 3.5 KB | 0.9 KB |
| Data RAM | 128 bytes | 128 bytes | 128 bytes | 80 bytes |
| Maximum Frequency | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| Operating Voltage | 3.0 V to 5.5 V | 3.0 V to 5.5 V | 3.0 V to 5.5 V | 3.0 V to 5.5 V |
| Temperature Grade | Extended (-40C to +125C) | Industrial (-40C to +85C) | Commercial (0C to +70C) | Industrial (-40C to +85C) |
| On-chip ADC | 8-bit ADC | 8-bit ADC | 8-bit ADC | Not present |
Key Differentiators
- Extended automotive temperature grade for under-hood installations (vs PIC16C558-20I/SS)
- On-chip 8-bit ADC plus 3.5KB program memory (vs PIC16C554-20I/SS)
- OTP EPROM architecture for tamper-resistant OEM firmware (vs PIC16F1827)
Design Notes
The PIC16C558-20E/SS draws approximately 2-5 mA active current at 20MHz across the 3.0-5.5V supply range. Use a 100nF decoupling capacitor within 5mm of each VDD pin and a 10uF bulk capacitor at the board power-entry point. The brown-out reset trips at approximately 3.8V (factory-trimmed) - ensure your power supply ramps monotonically above 4.0V within 50ms to avoid spurious resets during cold-crank events in automotive applications.
Estimated: at 20MHz active mode, 5V supply, the SSOP-20 package dissipates approximately 25 mW with a theta_JA of approximately 100 C/W, yielding a 2.5C rise above ambient. The Extended temperature grade up to +125C means the junction can safely reach that rating with adequate PCB copper pour. In enclosed automotive under-hood enclosures with limited airflow, ensure at least 100 sq mm of exposed ground copper around the SSOP-20 footprint for additional thermal spreading.
Keep crystal traces or external clock traces within 10mm of OSC1/OSC2 pins and shield them with a ground guard ring to minimize EMI pickup. Route ICSP pins (RB6/PGC, RB7/PGD) to accessible test points or test pads - the Microchip ICD programmer requires these pins to be accessible and not strongly loaded during production programming. Avoid placing large capacitors directly on the MCLR pin - a 10k pull-up plus a small series resistor is recommended for in-circuit programming reliability.
Common pitfalls: (1) Confusing the /E, /I, and no-suffix temperature grades - /E is Extended, /I is Industrial, no suffix is Commercial. (2) OTP memory cannot be erased - firmware bugs require windowed ceramic package variants for rework. (3) The PIC16C558-20E/SS does not include data EEPROM - use the program memory for non-volatile data if needed. (4) Brown-out reset is fixed - you cannot adjust the threshold in firmware. (5) The SSOP-20 pinout is shared with PIC16C554 but NOT pin-compatible with PIC16F1827 in SSOP-20.
Compliance Information
RoHS compliant per Microchip product page. AEC-Q100 not explicitly qualified - the Extended temperature grade /E suffix indicates -40C to +125C capability but not full automotive qualification. For AEC-Q100 qualified alternatives, consider PIC16F1xx automotive-grade parts.
