PIC16HV540-04/SO - 4MHz 8-Bit OTP MCU w/ Voltage Regulator | Microchip
MPN: PIC16HV540-04/SO ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.45 | $3.45 |
| 10 | $3.1 | $31.00 |
| 100 | $2.75 | $275.00 |
| 500 | $2.4 | $1,200.00 |
| 1,000 | $2.1 | $2,100.00 |
PIC16HV540-04/SO Overview
An 8-bit microcontroller (MCU) is a programmable logic device that integrates a CPU, memory (ROM/RAM), and I/O peripherals on a single silicon die; PIC microcontrollers use a Harvard RISC architecture that separates program and data memory buses. The PIC16HV540 specifically belongs to the enhanced PIC16C54 family - the smallest, lowest-cost PIC line intended for high-volume embedded control. Its on-chip shunt regulator allows direct operation from an unregulated DC source (typical industrial 5V, 9V, or 12V rails) without an external 7805-style LDO, simplifying BOM in cost-sensitive designs.
Key features include 12 digital I/O pins, a programmable watchdog timer, an 8-bit timer/counter, internal RC oscillator, power-on reset, brown-out detection support, and an operating voltage range of 3.5V to 15V enabled by the integrated voltage regulator. The HV (high-voltage) suffix denotes the on-chip regulator, which is the key differentiator from the non-HV PIC16C540. The 18-pin SOIC provides a compact surface-mount footprint for moderate-density designs.
Architecturally, the device uses a 12-bit instruction word with single-cycle execution except for branch instructions (2 cycles). The OTP program memory is one-time programmable - suitable for production but not for prototyping iteration. The integrated voltage regulator supports both 5V and 9V/12V system rails with minimal external components.
Typical applications include appliance control, sensor signal conditioning, battery chargers, smart lighting, automotive accessories, and any cost-driven embedded product requiring 8-bit processing with a wide Vin tolerance. The wide voltage range (3.5V to 15V) makes it suitable for industrial 12V systems, automotive 12V buses, and unregulated AC-derived DC rails.
When designing with this part, note that OTP precludes firmware updates; for prototyping use a windowed (JW) or Flash-based alternative. The on-chip voltage regulator requires an external shunt resistor and bulk capacitance sized per the datasheet regulator topology section.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for PIC16HV540-04/SO — 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 PIC16HV540-04/SO (same form factor and footprint) — differing in Core Architecture, I/O Pins, Data EEPROM, On-Chip Voltage Regulator, Operating Temperature.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16HV540T-04/SO
✅ Drop-In✓ In Stock
$1.2 / Unit
View Datasheet →PIC16HV540-04I/SO
✅ Drop-In✓ In Stock
$1.78 / Unit
View Datasheet →PIC16C540-04/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16HV540-04/SO Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC16C (8-bit RISC, Harvard) |
| Clock Speed (Maximum) | 4 MHz |
| Instruction Execution Time | 200 ns (single cycle) |
| Program Memory | 768 B (512 x 12) OTP |
| RAM | 25 B |
| Data EEPROM | Not present (OTP-only architecture) |
| I/O Pins | 12 digital I/O |
| Supply Voltage (VDD) | 3.5 V to 15 V (via on-chip shunt regulator) |
| On-Chip Voltage Regulator | Yes (shunt type, distinguishes HV variant) |
| Timers | 1 x 8-bit Timer/Counter |
| Watchdog Timer | Yes (programmable WDT) |
| Oscillator | Internal RC + external crystal/RC options |
| Instruction Set Size | 33 single-word instructions |
| Instruction Width | 12 bits |
| Package | 18-pin SOIC (SO) |
| Mounting Type | Surface Mount |
| Operating Temperature | -40C to +85C (industrial; per PIC16HV540-04/SO suffix) |
| RoHS Status | Compliant (SOIC package suffix /SO indicates lead-free) |
| AEC-Q100 Automotive | Not qualified |
PIC16HV540-04/SO Pin Configuration
| Pin 1 | RA2 — Digital I/O port A bit 2 |
| Pin 2 | RA3 — Digital I/O port A bit 3 |
| Pin 3 | RTCC — Timer/counter clock input (also digital I/O) |
| Pin 4 | /MCLR — Master clear (reset) input, active low |
| Pin 5 | VSS — Ground reference |
| Pin 6 | RB0 — Digital I/O port B bit 0 |
| Pin 7 | RB1 — Digital I/O port B bit 1 |
| Pin 8 | RB2 — Digital I/O port B bit 2 |
| Pin 9 | RB3 — Digital I/O port B bit 3 |
| Pin 10 | RB4 — Digital I/O port B bit 4 |
| Pin 11 | RB5 — Digital I/O port B bit 5 |
| Pin 12 | RB6 — Digital I/O port B bit 6 |
| Pin 13 | RB7 — Digital I/O port B bit 7 |
| Pin 14 | VSS — Ground (HV regulator return) |
| Pin 15 | OSC1 — Oscillator input / external clock |
| Pin 16 | OSC2 — Oscillator output |
| Pin 17 | RA0 — Digital I/O port A bit 0 |
| Pin 18 | RA1 — Digital I/O port A bit 1 |
Typical Applications
PIC16HV540-04/SO is suitable for 7 applications: Appliance Control Boards, Automotive 12V Accessories, Battery Chargers, Smart Lighting Controls, Industrial Sensor Signal Conditioning, Toys and Consumer Electronics, HVAC Thermostats and Fan Controllers.
Appliance Control Boards
The PIC16HV540-04/SO's 3.5V-15V wide input range via on-chip shunt regulator makes it ideal for direct connection to rectified mains-derived DC rails in washing machines, microwave ovens, and dishwashers. The 12 I/O pins drive relays, triac triggers, and LED indicators without external level shifting. Its 4 MHz speed handles typical appliance state machines and timing loops; the 33-instruction RISC core simplifies coding for production. Note OTP memory locks the firmware at programming time.
Recommended
Automotive 12V Accessories
The PIC16HV540-04/SO accepts the automotive 12V bus (nominally 13.8V) directly via its on-chip shunt regulator, eliminating an external 7805 LDO. The 18-pin SOIC and -40C to +85C industrial range cover cabin and trunk environments; the watchdog timer and brown-out reset provide robustness against cranking transients. For under-hood or AEC-Q100-qualified designs, however, an AEC-Q100 part is required - the standard PIC16HV540-04/SO is NOT AEC-Q100 qualified.
Recommended
Battery Chargers
The PIC16HV540-04/SO suits low-cost NiCd/NiMH/Li-ion charger controllers where its on-chip 3.5V-15V tolerance connects directly to wall-adapter-derived DC without an external regulator. The 8-bit timer drives PWM charge profiles and termination timers; 12 I/O pins connect to current-sense, voltage-divider feedback, status LEDs, and charge-enable FET gates. The wide Vin range accommodates both 5V USB-derived and 12V adapter sources with one design.
Recommended
Smart Lighting Controls
The PIC16HV540-04/SO operates directly from AC-derived DC rails (typically 12V or 24V) in LED driver and dimmer circuits, using its on-chip regulator to eliminate external LDOs. The 33-instruction core implements 0-10V dimming, DALI-lite protocols, or simple PWM dimming. Twelve I/O pins accommodate multiple LED channels, button inputs, and 0-10V analog dimming via the firmware-controlled timing. OTP memory suits fixed-feature production runs.
Recommended
Industrial Sensor Signal Conditioning
The PIC16HV540-04/SO operates directly from industrial 24V rails (rectified to ~30V) via its 15V-tolerant shunt regulator with appropriate external resistor sizing, making it ideal for proximity sensors, photoelectric switches, and limit-switch interfaces. The on-chip timer precisely debounces mechanical inputs and triggers digital outputs. Twelve I/O pins handle two or three sensor channels with status indicators. Industrial -40C to +85C operation covers factory-floor environments.
Recommended
Toys and Consumer Electronics
The PIC16HV540-04/SO targets cost-sensitive consumer products like electronic toys, remote controls, simple games, and educational devices. The 33-instruction RISC core is easy to learn for entry-level developers; the integrated voltage regulator reduces BOM cost by eliminating an external LDO. OTP memory at $2-3 unit cost (1000-piece) suits high-volume production. Twelve I/O pins drive LEDs, sound piezos, buttons, and motor drivers. Wide Vin tolerates battery and wall-adapter sources.
Recommended
HVAC Thermostats and Fan Controllers
The PIC16HV540-04/SO's wide 3.5V-15V Vin tolerance suits HVAC 24VAC-derived DC rails and 12V fan supplies. The 8-bit timer implements PWM fan-speed control and thermostat hysteresis loops. Twelve I/O pins accommodate temperature-sensor inputs (via firmware timing-based ADC), relay outputs for compressor/fan switching, and triac triggers. Industrial -40C to +85C range covers unconditioned equipment rooms. The on-chip regulator eliminates a separate 5V LDO stage.
Recommended
Recommended Products Summary
Engineering reference data for PIC16HV540-04/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16HV540T-04/SO | PIC16HV540-04I/SO | PIC16C540-04/SO |
|---|---|---|---|---|
| Package | 18-pin SOIC (SO) | 18-pin SOIC (SO) - same | 18-pin SOIC (SO) - same | 18-pin SOIC (SO) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Clock Speed (max) | 4 MHz | 4 MHz | 4 MHz | 4 MHz |
| Program Memory | 768 B OTP | 768 B OTP | 768 B OTP | 768 B OTP |
| On-Chip HV Regulator | Yes (3.5V-15V) | Yes (3.5V-15V) | Yes (3.5V-15V) | No (external regulator required, 2.5V-6.0V) |
| Operating Temperature | -40C to +85C | -40C to +85C | -40C to +85C (industrial grade marked) | -40C to +85C |
| I/O Pins | 12 | 12 | 12 | 12 |
| Memory Type | OTP (one-time programmable) | OTP | OTP | OTP |
| RoHS Compliance | Compliant (SO suffix) | Compliant | Compliant | Compliant |
Key Differentiators
- Integrated on-chip 3.5V-15V shunt voltage regulator eliminates external LDO (vs PIC16C540-04/SO)
- Industrial temperature grade -40C to +85C guaranteed (vs PIC16HV540T-04/SO)
- Surface-mount SOIC package for high-density designs (vs PIC16HV540/JW)
Design Notes
The PIC16HV540-04/SO on-chip shunt regulator requires an external shunt resistor between the unregulated supply (3.5V-15V) and the VDD pin. Per the datasheet regulator section, the resistor value must be calculated based on the maximum supply voltage and the device's quiescent current plus I/O sink/source current. Estimated: for a 12V supply and 25 mA total device load, a 200-300 ohm shunt resistor (1W rated) is typical. A bulk decoupling capacitor of at least 10 uF and a 100 nF ceramic at VDD are required for regulator stability.
OTP (One-Time Programmable) memory cannot be erased or rewritten after programming. Verify firmware with a windowed PIC16HV540/JW prototype before committing to OTP production parts. Also note: the PIC16HV540-04/SO is NOT AEC-Q100 qualified - for automotive applications requiring AEC-Q100, choose a different family. Brown-out reset must be enabled in the configuration word to avoid undefined behavior on slow-rising power rails.
Keep the shunt regulator resistor and VDD bypass capacitors within 5 mm of the VDD/VSS pins on the 18-pin SOIC layout. The oscillator crystal or resonator should be placed adjacent to OSC1/OSC2 with short traces to minimize EMI. The /MCLR pin requires a 10 kohm pull-up to VDD; a 100 nF capacitor to VSS on /MCLR improves noise immunity. Avoid routing high-current switching traces (relay/triac drivers) parallel to the oscillator traces to prevent injection of switching noise into the clock.
Estimated: at maximum 15V supply, 5V regulated VDD, and 25 mA load current, the on-chip shunt regulator dissipates approximately (15V-5V) * 25mA = 250 mW continuously. The 18-pin SOIC thermal resistance is approximately 75 C/W (typical), resulting in a 19C junction rise above ambient - well within the -40C to +85C operating range. At higher supply voltages (e.g., rectified 24VAC rails at 30V+), reduce load current or add a pre-regulator to keep dissipation below 500 mW.
Compliance Information
SO suffix indicates lead-free SOIC package. Microchip parts are RoHS/REACH compliant per Microchip product page. Not AEC-Q100 qualified - use non-automotive applications only.