PIC16C73B-20/SS - 20MHz 8-bit OTP MCU, 28-SSOP | Microchip
MPN: PIC16C73B-20/SS ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $7.6 | $7.60 |
| 10 | $6.84 | $68.40 |
| 100 | $6.08 | $608.00 |
| 500 | $5.32 | $2,660.00 |
| 1,000 | $4.56 | $4,560.00 |
PIC16C73B-20/SS Overview
A mid-range PIC16C family microcontroller sits within the broader 8-bit MCU taxonomy: PIC16C mid-range -> PIC16CXX family -> PIC16 8-bit core -> Microchip PIC microcontroller -> embedded controller. The PIC16C7x mid-range architecture introduced in this era extended the original PIC16C5x baseline by adding on-chip peripherals (ADC, PWM, USART, I2C/SPI) while preserving upward code compatibility with the PIC12Cxxx and PIC16C5x cores. Mid-range PIC devices are valued for predictable interrupt latency, deterministic instruction timing, and a 35-instruction RISC instruction set that engineers can master in days rather than weeks.
Key features of the PIC16C73B include 192 bytes of on-chip RAM, hardware USART, an 8-bit timer/counter with optional prescaler, a watchdog timer with on-chip RC oscillator, in-circuit serial programming capability via two pins, and brown-out reset for reliable power-on behavior. The OTP memory variant (-20/SS) is windowless and suited for production-volume applications; the UV-erasable CERDIP-28 (-JW) variant is intended for prototype development and firmware iteration. Operating voltage spans 4.0 V to 5.5 V with commercial and industrial temperature grades available.
Typical applications span consumer appliance control panels, small-format industrial sensor interfaces, low-bandwidth motor control using the on-chip CCP/PWM modules, smart-card readers, UPS monitoring, and HVAC damper/valve actuators. The 5-channel 8-bit ADC combined with two PWM channels is particularly well-matched to closed-loop fan control, LED brightness regulation, and brushed-DC motor velocity control, where a single chip handles sensing and actuation without external glue logic.
When designing with the PIC16C73B-20/SS, observe the maximum clock frequency (20 MHz) derating across temperature and voltage - operation at the upper Vdd limit of 5.5 V is required to maintain rated timing. The SSP peripheral needs accurate pull-up resistor selection on I2C lines (typically 4.7 kohm at 400 kHz), and unused I/O should be set as outputs low to minimize shoot-through current during sleep. Because the /SS package is OTP, firmware must be fully validated before committing to programming; use the CERDIP -JW variant for development.
This page synthesizes distributor pricing, drop-in same-package alternatives from the Microchip PIC16C family, and practical design notes not consolidated in the manufacturer datasheet - giving procurement and firmware engineers a single decision-ready view of the PIC16C73B-20/SS.
Drop-in alternatives for PIC16C73B-20/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 PIC16C73B-20/SS (same form factor and footprint) — differing in Core Architecture, Package, Timers, Maximum Clock Frequency, A/D Converter.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16F73-I/SS
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C73B-20I/SS
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$4.82 / Unit
View Datasheet →PIC16C73B-20E/SS
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C73B-04/SS
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$5.05 / Unit
View Datasheet →PIC16C73A-20I/SO
✅ Drop-In✓ In Stock
$9.3 / Unit
View Datasheet →PIC16C73B-20/SS Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC16C mid-range 8-bit RISC |
| Program Memory | 7 KB (4K x 14) OTP |
| RAM | 192 bytes |
| Data EEPROM | Not present (OTP family) |
| Maximum Clock Frequency | 20 MHz |
| Instruction Cycle Time | 200 ns |
| Supply Voltage (Vdd) | 4.0 V to 5.5 V |
| I/O Pins | 22 |
| ADC | 5 channels x 8-bit |
| Timers | 3 (Timer0, Timer1, Timer2) |
| CCP/PWM Modules | 2 |
| Serial Interfaces | 1x SSP (SPI or I2C), 1x USART |
| Package | 28-SSOP (5.30 mm width, 0.65 mm pitch) |
| Operating Temperature | 0C to +70C (commercial) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
| Lead-Free | Yes |
PIC16C73B-20/SS Pin Configuration
| Pin 1 | MCLR/Vpp — Master Clear (reset) input / Programming voltage |
| Pin 2 | RA0/AN0 — PORTA bit 0 / Analog input channel 0 |
| Pin 3 | RA1/AN1 — PORTA bit 1 / Analog input channel 1 |
| Pin 4 | RA2/AN2 — PORTA bit 2 / Analog input channel 2 |
| Pin 5 | RA3/AN3/Vref — PORTA bit 3 / Analog input channel 3 / ADC reference |
| Pin 6 | RA4/T0CKI — PORTA bit 4 / Timer0 clock input |
| Pin 7 | RA5/AN4/SS — PORTA bit 5 / Analog input channel 4 / SPI Slave Select |
| Pin 8 | Vss — Ground reference |
| Pin 9 | OSC1/CLKIN — Oscillator input / External clock input |
| Pin 10 | OSC2/CLKOUT — Oscillator output / Clock output |
| Pin 11 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer1 oscillator output / Timer1 clock input |
| Pin 12 | RC1/T1OSI/CCP2 — PORTC bit 1 / Timer1 oscillator input / CCP2 I/O |
| Pin 13 | RC2/CCP1 — PORTC bit 2 / CCP1 I/O (PWM) |
| Pin 14 | RC3/SCK/SCL — PORTC bit 3 / SSP clock (SPI SCK / I2C SCL) |
| Pin 15 | RC4/SDI/SDA — PORTC bit 4 / SSP data in (SPI SDI / I2C SDA) |
| Pin 16 | RC5/SDO — PORTC bit 5 / SSP data out (SPI SDO) |
| Pin 17 | RC6/TX/CK — PORTC bit 6 / USART TX / USART clock |
| Pin 18 | RC7/RX/DT — PORTC bit 7 / USART RX / USART data |
| Pin 19 | Vss — Ground reference |
| Pin 20 | Vdd — Positive supply (4.0-5.5 V) |
| Pin 21 | RB0/INT — PORTB bit 0 / External interrupt |
| Pin 22 | RB1 — PORTB bit 1 |
| Pin 23 | RB2 — PORTB bit 2 |
| Pin 24 | RB3 — PORTB bit 3 |
| Pin 25 | RB4 — PORTB bit 4 |
| Pin 26 | RB5 — PORTB bit 5 |
| Pin 27 | RB6/PGC — PORTB bit 6 / ICSP clock |
| Pin 28 | RB7/PGD — PORTB bit 7 / ICSP data |
Typical Applications
PIC16C73B-20/SS is suitable for 6 applications: Consumer Appliance Control Panels, Industrial Sensor Interfaces, Brushed DC Motor Velocity Control, Smart Card and RFID Reader Front-Ends, UPS and Battery Monitor Front-End, HVAC Damper and Valve Actuators.
Consumer Appliance Control Panels
The PIC16C73B-20/SS drives user-interface control panels in white goods and small appliances, where its 5x 8-bit ADC reads keypad matrixes and front-panel potentiometers while the on-chip CCP/PWM modules modulate indicator LED brightness or buzzer tones. With 22 I/O and the integrated USART, the chip directly interfaces to character LCDs, seven-segment displays, and serial-managed peripheral boards, replacing discrete logic that previously required a dedicated display controller. The 20 MHz clock and 200 ns instruction cycle handle debounced button scanning and menu state machines in real time, and the SSOP-28 footprint is small enough for front-panel PCB real estate. At a unit price below USD 5 in volume, this is one of the lowest-cost MCU solutions for cost-sensitive consumer electronics production.
Recommended
Industrial Sensor Interfaces
The PIC16C73B-20/SS is well suited to industrial sensor signal conditioning and protocol conversion tasks such as 4-20 mA loop monitoring, thermocouple cold-junction compensation, and Modbus-over-RS485 gateway nodes. The 5 channels of 8-bit ADC read multiple analog sensors simultaneously, and the USART plus SSP peripherals implement RS-485 or I2C/SPI sensor networks on the same chip. Brown-out reset and the watchdog timer with on-chip RC oscillator deliver industrial-grade reliability against supply glitches and firmware lockups. The 4.0-5.5 V supply range accepts 24 V-bus-derived rails after local regulation. Engineers use the PIC16C73B-20/SS in PLC digital-input cards, process-control valve actuators, and HVAC damper motor controllers where 8-bit resolution is sufficient.
Recommended
Brushed DC Motor Velocity Control
Closed-loop brushed-DC motor velocity control is a natural application for the PIC16C73B-20/SS, leveraging the dual CCP/PWM channels to drive an H-bridge MOSFET driver and the 5x 8-bit ADC to read tachogenerator or back-EMF feedback. The 20 MIPS core executes PI control loops in well under 1 ms, well within the bandwidth requirements of small fans, pumps, and conveyor drives. Timer1 with the optional external crystal input provides a stable period reference for tachometer pulse-width measurement. The on-chip USART enables host-side tuning of PID coefficients over RS-232 or RS-485. Designers building conveyor speed controllers, vending-machine dispense motors, and HVAC fan-speed regulators commonly standardize on this chip.
Recommended
Smart Card and RFID Reader Front-Ends
The PIC16C73B-20/SS forms the controller front-end for low-cost smart-card and 125 kHz RFID reader modules, where its USART and SSP peripherals manage the half-duplex ISO 7816 or ISO 14443 transceive protocol. The 5x ADC channels monitor the RF envelope-detector output and supply-voltage quality for tamper and brown-out detection. The 20 MHz instruction cycle meets the 3.58 MHz smart-card clock-generation requirement with margin to spare for ATR (Answer-To-Reset) parsing. Designers standardize on this part for time-attendance terminals, door-access readers, and POS terminals where 7 KB of OTP code space is sufficient for command set handling.
Recommended
UPS and Battery Monitor Front-End
Uninterruptible Power Supply (UPS) battery monitor and charger front-end designs leverage the PIC16C73B-20/SS 5x ADC channels to measure battery voltage, charge current, ambient temperature, and load current simultaneously, while the CCP/PWM modules drive a synchronous-rectifier MOSFET gate driver or a flyback primary switch. The USART provides status reporting to a host BMS (Battery Management System). With 7 KB OTP code space, the firmware handles cell balancing, SOC (State of Charge) estimation, and fault logging for sealed lead-acid or Li-ion packs. The wide 4.0-5.5 V supply accepts operation directly from the battery rail in many configurations, with the watchdog timer providing fail-safe recovery from brown-outs.
Recommended
HVAC Damper and Valve Actuators
HVAC damper and valve actuator controllers use the PIC16C73B-20/SS as a single-chip solution, with the 5x ADC reading temperature sensors, humidity probes, and potentiometer position feedback, while the dual PWM channels drive a brushless DC or stepper motor driver. The USART connects to a building-automation controller over RS-485 using Modbus RTU. Brown-out reset and the watchdog timer with on-chip RC oscillator provide reliability against mains-side disturbances. The 28-SSOP package fits easily inside the compact actuator housing, and the OTP memory locks down the production firmware to prevent field tampering. Engineers commonly use this chip in 24 VAC-powered damper actuators and thermostatic radiator valves.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C73B-20/SS — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16F73-I/SS | PIC16C73B-20I/SS | PIC16C73B-20E/SS |
|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 28-SSOP (5.30 mm) | 28-SSOP (5.30 mm) - same | 28-SSOP (5.30 mm) - same | 28-SSOP (5.30 mm) - same |
| Program Memory | 7 KB OTP (4K x 14) | 4 KB Flash | 7 KB OTP | 7 KB OTP |
| Maximum Clock Frequency | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| ADC Channels x Resolution | 5 x 8-bit | 5 x 8-bit | 5 x 8-bit | 5 x 8-bit |
| Operating Temperature | 0C to +70C (commercial) | -40C to +85C (industrial) | -40C to +85C (industrial) | -40C to +125C (extended) |
| USART | Yes | Yes | Yes | Yes |
| I/O Pins | 22 | 22 | 22 | 22 |
Key Differentiators
- Pin-compatible Flash alternative from same manufacturer (vs PIC16F73-I/SS)
- Extended temperature grades available in same footprint (vs PIC16C73B-20I/SS and PIC16C73B-20E/SS)
- 5x 8-bit ADC + 2x PWM + USART + SSP in single chip (vs PIC16C72-20/SS)
Design Notes
Estimated: at 20 MHz clock, Vdd = 5.0 V, and all peripherals active, the PIC16C73B-20/SS draws approximately 15-20 mA per typical Microchip datasheet figures. Add a 100 nF ceramic decoupling capacitor directly across Vdd/Vss (pin 20 and pin 19) within 5 mm of the package, plus a 10 uF bulk tantalum or aluminum polymer capacitor for Vdd transients during ADC conversions. Use a separate analog Vdd/Vss pair (AVdd/AVss) if the ADC is enabled for precision measurements - even though the PIC16C73B-20/SS shares Vdd/Vss with the digital supply, isolating the analog supply with a ferrite and 10 uF + 100 nF filter reduces ADC noise pickup from the digital switching currents.
Keep the 28-SSOP trace length from OSC1/OSC2 (pins 9/10) to the crystal or resonator under 10 mm to avoid excess parasitic capacitance that could detune the oscillator or prevent startup. Provide a solid ground pour under and around the device, and route the MCLR line (pin 1) separately from high-current switching traces. For ICSP programming access, reserve a 4-pin header footprint (or test pads) connected to MCLR, Vdd, Vss, RB6/PGC, and RB7/PGD so a PICkit or ICD can be attached without rework.
The PIC16C73B-20/SS uses OTP memory - once programmed, it cannot be erased or rewritten. Use the CERDIP PIC16C73B-20/JW variant with a quartz window for development, and only move to OTP /SS or /SO production packages after firmware is fully validated. Also note that the 8-bit ADC requires a minimum acquisition time of approximately 20 us per the datasheet - read the GO/DONE bit before changing channels, and insert the proper Tacq delay or use the built-in ADC acquisition timer to avoid undersampled readings on fast-scanning multiplexed channels.
When using the USART at 115.2 kbaud or higher with long PCB traces, add a 100 ohm series resistor at the TX pin to dampen reflections, and ensure the RX line has a clean logic-level signal with appropriate slew rate. For I2C operation above 100 kHz, use 4.7 kohm pull-up resistors on SDA and SCL (not 10 kohm) to meet the rise-time specification. If the SSP module is shared with SPI peripherals, ensure the SS (Slave Select) pin is properly driven low by the master during SPI transactions or unexpected SDA/SCK contention may occur.
Compliance Information
RoHS compliant per Microchip product page. Not AEC-Q100 qualified - use PIC16C73B-20I/SS or PIC16F73-I/SS for automotive-grade applications. Lead-free packaging confirmed by /SS surface-mount suffix.
