PIC16HV540-04I/SS - 8-Bit OTP MCU w/ HV Shunt Regulator | Microchip
MPN: PIC16HV540-04I/SS ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.6418 | $1.64 |
| 10 | $1.48 | $14.80 |
| 100 | $1.32 | $132.00 |
| 500 | $1.18 | $590.00 |
| 1,000 | $1.05 | $1,050.00 |
PIC16HV540-04I/SS Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU, program memory, data RAM, and peripheral I/O. Within the semiconductor hierarchy, MCUs belong to the broader category of microcontrollers -> embedded processors -> digital ICs -> semiconductors. The PIC16HV540 specifically belongs to Microchip's PIC16 family, which uses a Harvard RISC architecture with 12-bit-wide opcodes delivering 2:1 code compression over typical 8-bit CISC competitors. Its defining feature versus standard PIC16C54 parts is the on-chip shunt voltage regulator that lets the device operate directly from 5 V / 9 V / 12 V / unregulated supplies.
Key features include 200 ns instruction execution (5 MHz internal throughput), 2-level hardware stack, 8-bit timer/counter with 8-bit prescaler, watchdog timer with its own on-chip RC oscillator, and programmable code protection. The integrated high-voltage shunt regulator (HV540 suffix) accepts up to 15 V at VDD and clamps it to the internal logic level, eliminating external 5 V regulators in many low-cost applications. Power-saving SLEEP mode reduces IPD to typical low-microamp levels.
Architecturally, the PIC16HV540 uses a 12-bit instruction word fetched from OTP EPROM while data accesses a separate 8-bit RAM bus - a classic Harvard layout that allows instruction and data fetch in a single cycle. The on-chip voltage regulator is a parallel (shunt) topology, not a series LDO, which means the device can be powered from any DC source between 3.5 V and 15 V with appropriate series resistance to limit shunt current.
Typical applications include low-cost 9 V and 12 V battery or wall-adapter powered appliances, remote controls, sensor signal conditioning, LED drivers, smoke detectors, and any embedded control node that benefits from a single-supply rail without external regulation. The PIC16HV540-04I/SS is well suited to high-volume consumer and industrial designs where its 4 MHz performance, 12-bit OTP code density, and integrated shunt regulator reduce total BOM cost.
When designing with this part, calculate the external shunt resistor to limit the regulator current within the device's safe operating range at worst-case VIN. The internal pull-ups and reset circuit must be properly enabled via configuration bits; consult the datasheet's CONFIG register description. Because the device is OTP, firmware must be fully validated before programming - there is no in-system reprogramming.
This page synthesizes distributor pricing, drop-in same-package alternatives, and design notes not found in any single manufacturer datasheet or distributor catalog.
Drop-in alternatives for PIC16HV540-04I/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 PIC16HV540-04I/SS (same form factor and footprint) — differing in Package, Program Memory Size, Program Memory Type, Timers, Watchdog Timer.
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Request AlternativesPIC16HV540-04I/SS Maximum Ratings & Electrical Characteristics
| Series | PIC 16C |
| Core Processor | PIC |
| Core Size | 8-Bit |
| Clock Speed (max) | 4 MHz |
| Instruction Cycle Time | 200 ns (single cycle) |
| Program Memory | 768 B (512 x 12) OTP EPROM |
| RAM | 25 B |
| I/O Pins | 12 |
| Supply Voltage (VDD) | 3.5 V to 15 V |
| On-chip Voltage Regulator | High-voltage shunt regulator (integrated) |
| Timers | 1 x 8-bit Timer/Counter with 8-bit prescaler |
| Watchdog Timer | Yes, with dedicated on-chip RC oscillator |
| Stack | 2-level hardware stack |
| Programmable Code Protection | Yes |
| Operating Temperature | -40C to +85C (Industrial) |
| Package | 20-SSOP (0.209", 5.30 mm width) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
| Instruction Set | 33 single-word instructions, RISC |
PIC16HV540-04I/SS Pin Configuration
| Pin 1 | RA0 — Bidirectional I/O port A bit 0 |
| Pin 2 | RA1 — Bidirectional I/O port A bit 1 |
| Pin 3 | RA2 — Bidirectional I/O port A bit 2 |
| Pin 4 | RA3 — Bidirectional I/O port A bit 3 |
| Pin 5 | MCLR — Master Clear reset input (active low) |
| Pin 6 | OSC2 — Oscillator output / CLKOUT |
| Pin 7 | OSC1 — Oscillator input / CLKIN |
| Pin 8 | VDD — Positive supply (3.5V-15V via internal shunt regulator) |
| Pin 9 | VSS — Ground reference |
| Pin 10 | T0CKI — Timer0 external clock input |
| Pin 11 | RB0 — Bidirectional I/O port B bit 0 / INT |
| Pin 12 | RB1 — Bidirectional I/O port B bit 1 |
| Pin 13 | RB2 — Bidirectional I/O port B bit 2 |
| Pin 14 | RB3 — Bidirectional I/O port B bit 3 |
| Pin 15 | RB4 — Bidirectional I/O port B bit 4 |
| Pin 16 | RB5 — Bidirectional I/O port B bit 5 |
| Pin 17 | RB6 — Bidirectional I/O port B bit 6 |
| Pin 18 | RB7 — Bidirectional I/O port B bit 7 |
| Pin 19 | RA4 — Bidirectional I/O port A bit 4 |
| Pin 20 | RA5 — Bidirectional I/O port A bit 5 |
Typical Applications
PIC16HV540-04I/SS is suitable for 6 applications: 9V/12V Battery-Powered Appliance Controller, Remote Control Transmitter (RF/IR), Sensor Signal Conditioning Node, LED Lighting Driver / Chaser Controller, Smoke / CO Detector Logic Controller, Automotive Accessory Controller (Non-Safety).
9V/12V Battery-Powered Appliance Controller
The PIC16HV540-04I/SS is purpose-built for 9V and 12V battery-powered consumer appliances because its integrated high-voltage shunt regulator accepts 3.5V-15V at VDD directly without any external 5V LDO, reducing BOM by 1-2 components. The device's 4 MHz clock with 200ns instruction cycle delivers ample throughput for keypad scanning, sensor sampling, and relay/LED actuation in appliances such as smoke detectors, CO alarms, garage-door remote controls, and 12V doorbell controllers. The 768B OTP holds typical 1-1.5KB effective code, which is sufficient for state-machine-driven appliance logic. Industrial -40C to +85C operation suits unheated enclosures and outdoor installations such as gate sensors and irrigation controllers.
Recommended
Remote Control Transmitter (RF/IR)
In handheld RF or IR remote control transmitters, the PIC16HV540-04I/SS can run directly from a single 9V battery or 2x CR2032 cells via its shunt regulator, eliminating the need for a boost or buck converter. Its SLEEP mode reduces current to microamp levels between button presses, extending battery life to years in typical use. The 12 digital I/O can scan a 4x4 matrix keypad with software debouncing, while the 8-bit TMR0 generates the carrier-frequency timing for 38 kHz IR or 315/433 MHz ASK/FSK RF modules. With only 768B OTP, the firmware must remain lean but is sufficient for fixed-code or simple rolling-code remotes using software-generated Manchester or PWM bit patterns.
Recommended
Sensor Signal Conditioning Node
For low-cost industrial sensor nodes - such as temperature, humidity, or limit-switch aggregators - the PIC16HV540-04I/SS provides just enough compute to debounce switches, count pulses, and serialize data over a UART bit-banged to a wireless or wired transceiver. The 3.5V-15V supply range accommodates 24V industrial bus rails via the shunt regulator, so the same board design works across 5V, 12V, and 24V installations. The 25B RAM is the limiting factor, so firmware must use loop-based scanning rather than buffering. With 12 I/O and one 8-bit timer, this part fits simple threshold-alarm sensors, water-leak detectors, and motor-current monitors that wake on interrupt and report over a 1-wire or UART link.
Recommended
LED Lighting Driver / Chaser Controller
The PIC16HV540-04I/SS drives 12 individual LEDs or a 4x3 RGB matrix directly from its I/O pins, with software PWM synthesized via the 8-bit TMR0 overflow interrupt to dim each channel. Operating from a 12V LED string supply, the integrated shunt regulator handles 12V input without external regulation. This makes the part ideal for decorative LED chasers, channel-letter signs, holiday lighting controllers, and indicator-light bar-graph drivers. The 768B OTP holds the chaser pattern tables and dim curves in program memory. For battery-powered LED candle or lantern applications, the SLEEP mode plus TMR0 wakeup keeps quiescent current in the microamp range, allowing months of operation from two AA cells in series.
Recommended
Smoke / CO Detector Logic Controller
In smoke and carbon-monoxide detectors, the PIC16HV540-04I/SS acts as the supervisory MCU that monitors the ionization chamber or electrochemical sensor, drives the piezo alarm, manages the test/hush button, and blinks the status LED. The integrated shunt regulator is a perfect fit because these detectors are powered by a 9V battery or a 3V-12V sealed lead-acid backup cell with no external regulator. The watchdog timer with dedicated RC oscillator provides the self-fail-safe watchdog that safety standards require, and SLEEP mode with TMR0 wakeup minimizes standby current to extend battery life to a year or more. With 25B RAM, the firmware keeps a rolling event log of the last few alarm/hush events for diagnostics.
Recommended
Automotive Accessory Controller (Non-Safety)
For non-safety automotive accessories such as interior mood lighting, seat-heater controllers, or aftermarket alarm keypads, the PIC16HV540-04I/SS can run directly from the 12V automotive bus through its shunt regulator (with appropriate reverse-battery and load-dump protection upstream). The 4 MHz clock and 200ns instruction cycle provide responsive button-debounce and relay/LED actuation, and the watchdog timer catches lockups from load-transient noise on the vehicle harness. For safety-critical functions (airbag, ABS, steering), choose an AEC-Q100-qualified MCU such as the PIC16F1939 instead; the PIC16HV540 is industrial-grade and not automotive-qualified.
Recommended
Recommended Products Summary
Engineering reference data for PIC16HV540-04I/SS — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16HV540-04I/SO | PIC16HV540-04I/P | PIC16F648A-I/SS | PIC16F916-I/SO | PIC16F88-I/SS |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 20-SSOP (5.30 mm) | 20-SSOP family variant | 18-PDIP (through-hole) | 20-SSOP - same footprint | 28-SOIC - different footprint | 20-SSOP - same footprint |
| Program Memory | 768 B OTP EPROM | 768 B OTP EPROM | 768 B OTP EPROM | 7 KB Flash | 14 KB Flash | 7 KB Flash |
| RAM | 25 B | 25 B | 25 B | 256 B | 352 B | 368 B |
| Clock Speed | 4 MHz | 4 MHz | 4 MHz | 20 MHz | 20 MHz | 20 MHz |
| On-chip Voltage Regulator | Yes (HV shunt, 3.5-15V) | Yes (HV shunt, 3.5-15V) | Yes (HV shunt, 3.5-15V) | No (requires external 2-5.5V LDO) | No (requires external 2-5.5V LDO) | No (requires external 2-5.5V LDO) |
| I/O Pins | 12 | 12 | 12 | 16 | 24 | 16 |
| Operating Temperature | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C |
| ADC | No | No | No | Yes (8-channel 10-bit) | Yes (8-channel 10-bit) | Yes (7-channel 10-bit) |
Key Differentiators
- Integrated high-voltage shunt regulator eliminates external LDO at 9V/12V rails (vs PIC16F648A-I/SS)
- Lower cost at small quantities for ultra-low-cost 8-bit designs (vs PIC16F916-I/SO)
- Same SSOP-20 footprint family offers 100% register-compatible variants (vs PIC16F88-I/SS)
Design Notes
The PIC16HV540 on-chip shunt regulator is parallel (shunt) topology, NOT a series LDO. You MUST size the external series resistor (R-SERIES) from the high-voltage supply to VDD so that I-shunt stays within the safe operating area at maximum VIN. Per the Microchip datasheet example, for VIN=12V max and 25mA peak load, R-SERIES = (12V - VDD_clamp) / (I_load + I_shunt_min) - size this for worst-case end-of-life battery voltage. Add a bulk decoupling capacitor (10-47uF) directly at the VDD pin to absorb shunt-current transients during SLEEP-to-active wake events; otherwise the shunt transistor may oscillate.
Because the PIC16HV540 is OTP (one-time programmable), there is NO in-system reprogramming path - any firmware bug locked into silicon cannot be patched. Always validate firmware on a PIC16C540/JW (UV-erasable windowed CERDIP) prototype, then commit the validated firmware to the OTP production part via a Microchip-supported device programmer (e.g., MPLAB PM3, PICkit 3 with ICD header adapter). Also remember the baseline PIC16C54 family has only a 2-level hardware stack - deeply nested subroutine calls will overwrite the return address and cause lockups; keep call depth <= 2 or refactor into iterative code.
Place the MCLR pull-up resistor (typically 10k) and the optional reset capacitor (100nF) close to the MCLR pin to ensure clean resets. The OSC1/OSC2 traces to the crystal or ceramic resonator should be kept short (< 10 mm) and routed over a continuous ground pour to minimize EMI pickup. For the 20-SSOP footprint, allocate a thermal pad of at least 10 mm2 connected to VSS to improve heat dissipation if the device is operated at 4 MHz continuously in a high-VIN application.
Compliance Information
RoHS and lead-free compliant per Microchip product page. Not AEC-Q100 qualified; for automotive applications use PIC16F1939 or similar AEC-Q100 MCU. Halogen-free status not explicitly stated in available data.
