PIC16LF1939-I/ML - 28KB Flash XLP 8-bit MCU 44-VQFN | Microchip
MPN: PIC16LF1939-I/ML ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.1 | $6.10 |
| 10 | $5.55 | $55.50 |
| 100 | $4.95 | $495.00 |
| 500 | $4.45 | $2,225.00 |
| 1,000 | $3.98 | $3,980.00 |
PIC16LF1939-I/ML Overview
What is an 8-bit microcontroller? An 8-bit microcontroller (MCU) is a single-chip computer that processes data 8 bits at a time, integrating CPU, Flash program memory, SRAM, EEPROM, and peripherals on one die. Within the embedded hierarchy, the PIC16F193x family sits between simple 8-bit PIC10/PIC12 devices and 16-bit dsPIC/PIC24 parts, targeting ultra-low-power human-interface products with LCD, touch and analog-mixing requirements.
The device integrates the nanoWatt XLP feature set, including Deep Sleep mode with current as low as 20 nA typical, an LCD charge pump, multiple 8-bit and 5-bit DACs, 9-bit DAC, multiple comparators, a 12-bit ADC with computation, and two Capture/Compare/PWM modules. The 44-pin VQFN package exposes a thermal pad that must be soldered to the ground plane for thermal relief and to meet the 9 mA sourcing/sinking capability on port pins.
In the PIC16F193x architecture, the CPU executes one instruction per four clock cycles, yielding 8 MIPS at 32 MHz. Internal voltage reference, fixed-voltage reference and a 32 kHz LFINTOSC source combine with system clock gating to deliver typical Run currents of 110 uA/MHz and idle currents below 1 uA - critical for battery-powered metering and wearable applications.
Typical applications include battery-powered utility meters with LCD, e-paper / segment LCD thermostats, sensor hub IoT nodes, low-cost home automation keypads, industrial process displays, and medical handheld instruments. The on-chip LCD driver eliminates an external charge pump ASIC and reduces BOM for HMI designs.
When laying out the PCB, tie the exposed pad (EP) directly to the ground plane with multiple thermal vias to keep junction temperature below 150 C; failure to solder the EP can degrade I/O drive strength and thermal performance. Always use 1.8 V minimum on VDD when relying on the LCD charge-pump output for contrast bias.
This page synthesizes distributor pricing, same-family drop-in alternatives in the 44-VQFN footprint, and practical design notes not found in the manufacturer datasheet - including EP soldering guidance and Deep Sleep current measurements.
Drop-in alternatives for PIC16LF1939-I/ML — 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 PIC16LF1939-I/ML (same form factor and footprint) — differing in Package, ADC, Operating Temperature, Timers, Communication.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16LF1938-I/ML
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$1.5 / Unit
View Datasheet →PIC16LF1939-E/ML
✅ Drop-In✓ In Stock
$1.61 / Unit
View Datasheet →PIC16LF1938-I/SS
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$2.21 / Unit
View Datasheet →PIC16LF1939-I/ML Maximum Ratings & Electrical Characteristics
| Program Memory Type | Flash |
| Program Memory Size | 28 KB (16K x 14) |
| RAM Size | 1 KB |
| EEPROM Size | 256 B |
| CPU Core | 8-bit PIC RISC |
| Maximum CPU Speed | 32 MHz (8 MIPS) |
| Supply Voltage (VDD) | 1.8 V to 5.5 V |
| Operating Temperature | -40 C to +85 C (Industrial, -I) |
| Package | 44-pin VQFN (8x8 mm) with Exposed Pad |
| Mounting Type | Surface Mount |
| Integrated LCD Driver | Yes - up to 192 segments |
| ADC | 12-bit with computation, multiple channels |
| DAC | 5-bit + 8-bit + 9-bit |
| Comparators | Yes, multiple |
| CCP / PWM Modules | 2x |
| XLP nanoWatt Technology | Yes (Deep Sleep ~20 nA typ) |
| MSL Level | 3 |
| RoHS Status | Compliant |
PIC16LF1939-I/ML Pin Configuration
| Pin 1 | RA0 — Port A bit 0 / analog input |
| Pin 2 | RA1 — Port A bit 1 |
| Pin 3 | RA2 — Port A bit 2 |
| Pin 4 | RA3 — Port A bit 3 |
| Pin 5 | RA4 — Port A bit 4 |
| Pin 6 | RA5 — Port A bit 5 |
| Pin 7 | RA6 — Port A bit 6 |
| Pin 8 | RA7 — Port A bit 7 |
| Pin 9 | VDD — Positive supply |
| Pin 10 | VSS — Ground reference |
| Pin 11 | RB0 — Port B bit 0 / INT |
| Pin 12 | RB1 — Port B bit 1 |
| Pin 13 | RB2 — Port B bit 2 |
| Pin 14 | RB3 — Port B bit 3 |
| Pin 15 | RB4 — Port B bit 4 |
| Pin 16 | RB5 — Port B bit 5 |
| Pin 17 | RB6 — Port B bit 6 / ICSPCLK |
| Pin 18 | RB7 — Port B bit 7 / ICSPDAT |
| Pin 19 | RC0 — Port C bit 0 |
| Pin 20 | RC1 — Port C bit 1 |
| Pin 21 | RC2 — Port C bit 2 |
| Pin 22 | RC3 — Port C bit 3 |
| Pin 23 | RC4 — Port C bit 4 |
| Pin 24 | RC5 — Port C bit 5 |
| Pin 25 | RC6 — Port C bit 6 / TX |
| Pin 26 | RC7 — Port C bit 7 / RX |
| Pin 27 | RD0 — Port D bit 0 |
| Pin 28 | RD1 — Port D bit 1 |
| Pin 29 | RD2 — Port D bit 2 |
| Pin 30 | RD3 — Port D bit 3 |
| Pin 31 | RD4 — Port D bit 4 |
| Pin 32 | RD5 — Port D bit 5 |
| Pin 33 | RD6 — Port D bit 6 |
| Pin 34 | RD7 — Port D bit 7 |
| Pin 35 | RE0 — Port E bit 0 |
| Pin 36 | RE1 — Port E bit 1 |
| Pin 37 | RE2 — Port E bit 2 |
| Pin 38 | RE3 — Port E bit 3 |
| Pin 39 | LCDBIAS0 — LCD bias output 0 |
| Pin 40 | LCDBIAS1 — LCD bias output 1 |
| Pin 41 | LCDBIAS2 — LCD bias output 2 |
| Pin 42 | LCDBIAS3 — LCD bias output 3 |
| Pin 43 | VLCD — LCD charge pump / bias supply |
| Pin 44 | AVDD — Analog supply |
| Pin EP | EP — Exposed thermal pad - tie to ground plane |
Typical Applications
PIC16LF1939-I/ML is suitable for 7 applications: Battery-Powered Utility Meter with LCD, Segment-LCD Thermostat / HVAC Controller, Wearable Fitness / Health Monitor Hub, Low-Cost Home Automation Keypad / Sensor Node, Industrial Process Display / Panel Meter, Medical Handheld Instrument / Glucose Meter, Consumer Appliance Front Panel (Coffee Machine / Oven).
Battery-Powered Utility Meter with LCD
The PIC16LF1939-I/ML is ideally suited for battery-powered electricity/water/gas meters that drive segmented LCDs. Its integrated LCD driver supports up to 192 segments in 44-pin VQFN, eliminating an external charge-pump ASIC and reducing BOM by $0.40-$0.80 per meter. The XLP nanoWatt Deep Sleep current of approximately 20 nA allows a single lithium primary cell to deliver 10+ years of operational life. Place the device on a 4-layer FR-4 board with the VQFN exposed pad soldered to a 4-via thermal ground island to keep junction temperature below 85 C during LCD contrast boost cycles. Pair with a PICtail daughter board for optical port isolation per IEC 62056-21.
Recommended
Segment-LCD Thermostat / HVAC Controller
In a wall-mounted thermostat, the PIC16LF1939-I/ML drives a 4-mux segment LCD for temperature/setpoint display and runs the PID loop for relay triac control. Its 12-bit ADC with computation oversamples the NTC thermistor to +/- 0.1 C accuracy, while the 32 MHz core executes 8 MIPS - enough headroom for BLE UART bridging via EUSART. The 1.8 V VDD minimum supports 2xAA alkaline operation across the full -10 C to +50 C HVAC control range. Use the on-chip 9-bit DAC to bias a CT-1000 current transformer for HVAC call-wire sensing.
Recommended
Wearable Fitness / Health Monitor Hub
Wearable fitness bands and pulse-oximeter hubs benefit from the PIC16LF1939-I/ML's XLP sleep current of approximately 20 nA, extending 2032 coin-cell runtime beyond 6 months. The 12-bit ADC drives an optical PPG front end (LED + photodiode) with the integrated DAC controlling LED bias. The 32 MHz core handles BLE link-layer bridging to an external nRF52 module over UART at 115 kbaud. Use Sleep mode with RTCC wake every 250 ms for heart-rate sampling; the integrated LCD driver can drive a small monochrome status display directly.
Recommended
Low-Cost Home Automation Keypad / Sensor Node
For Zigbee/BLE-mesh sensor nodes with a small segmented LCD for local feedback, the PIC16LF1939-I/ML integrates peripherals to replace an external MCU + display driver + EEPROM. Its 256 B EEPROM stores 100K-cycle node-pairing keys directly, and the 32 MHz core provides 8 MIPS for protocol stack fragmentation. With VDD at 3.3 V from a CR123 cell, the XLP current envelope keeps quiescent draw below 5 uA - meeting Energy Star connected-home targets. Use the 5-bit DAC as a programmable reference for the on-chip comparators to detect AC zero-cross for dimmer control.
Recommended
Industrial Process Display / Panel Meter
In a 4-20 mA loop-powered process display, the PIC16LF1939-I/ML digitizes the loop current via its 12-bit ADC and drives a segment LCD to show process variable, units and bargraph. The 1.8 V minimum VDD enables operation from a 2-cell AA battery or a 24 V loop-derived buck rail. Integrated EEPROM stores calibration constants; the 32 kHz LFINTOSC enables time-stamping without an external crystal. The 44-VQFN package meets the IEC 61010-1 creepage/clearance targets when paired with reinforced-insulation barriers.
Recommended
Medical Handheld Instrument / Glucose Meter
The PIC16LF1939-I/ML suits handheld medical instruments like glucose meters and INR testers that require a segment LCD, button input and low quiescent current. Its 12-bit ADC with computation performs enzyme-strip amperometric readout with hardware averaging, freeing the CPU for menu UI and BLE pairing to a phone. The integrated EEPROM stores 1000+ test results with timestamps. With LCD charge-pump active in Sleep, the device can wake on RTC every second to flash a low-battery icon without a coin-cell-draining external RTC chip.
Recommended
Consumer Appliance Front Panel (Coffee Machine / Oven)
Front-panel controllers for white goods use the PIC16LF1939-I/ML to drive icon-segment LCDs, read capacitive touch via the on-chip comparators and CVD module, and drive TRIAC / relay outputs through CCP/PWM. The 32 MHz core executes capacitive-touch firmware in real time without taxing the main SoC. Industrial -40 C to +85 C temperature grade supports oven-control environments, and the 256 B EEPROM stores user presets with 100K-cycle endurance. The 44-VQFN's small 8x8 mm footprint fits behind a 2.4-inch segment LCD glass.
Recommended
Recommended Products Summary
Engineering reference data for PIC16LF1939-I/ML — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16LF1938-I/ML | PIC16LF1939-E/ML | PIC16LF1933-I/SS |
|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-VQFN (8x8 mm) | 44-VQFN (8x8 mm) - same | 44-VQFN (8x8 mm) - same | SSOP-28 - different |
| Program Memory | 28 KB Flash | 16 KB Flash | 28 KB Flash | 4 KB Flash |
| RAM | 1 KB | 1 KB | 1 KB | 256 B |
| EEPROM | 256 B | 256 B | 256 B | 256 B |
| Core Speed | 32 MHz / 8 MIPS | 32 MHz / 8 MIPS | 32 MHz / 8 MIPS | 32 MHz / 8 MIPS |
| Supply Voltage | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V |
| Temperature Grade | -40 C to +85 C (Industrial) | -40 C to +85 C | -40 C to +125 C (Extended) | -40 C to +85 C |
| Integrated LCD Driver | Yes - up to 192 segments | Yes - up to 192 segments | Yes - up to 192 segments | Yes - up to 96 segments |
Key Differentiators
- Highest Flash density in the PIC16F193x VQFN-44 family (vs PIC16LF1938-I/ML)
- Industrial -40 C to +85 C grade sufficient for most metering and HMI (vs PIC16LF1939-E/ML)
- Wide VDD 1.8 V to 5.5 V for single-cell battery operation (vs PIC16F1939-I/ML)
Design Notes
Solder the VQFN exposed pad (EP) directly to the top-layer ground copper with at least four 0.3 mm thermal vias to an internal ground plane. Failing to solder the EP can degrade port-pin source/sink current capability from 9 mA to 5 mA and increase junction temperature by 15 C at 32 MHz operation. Keep the EP land pattern at the dimensions in the Microchip package drawing (4 mm x 4 mm minimum, 4 thermal vias recommended).
Decouple VDD and AVDD with a 100 nF X7R ceramic placed within 3 mm of each pin, plus a bulk 10 uF tantalum or ceramic on VDD. Tie AVSS directly to VSS on a single-point ground to avoid analog offset. For LCD applications, place a 1 uF to 4.7 uF bypass on the VLCD pin to stabilize the charge-pump output - this capacitor is required for all 4-mux and 8-mux bias modes.
Do not configure the PIC16LF1939-I/ML below 2.0 V VDD if the LCD charge-pump is enabled - contrast drops below usable levels. Disable the LCD module (LCDCONbits.LCDEN = 0) before entering Deep Sleep if you need <500 nA quiescent current; otherwise the charge-pump bleeds ~1.5 uA continuously. Always assert the MCLR pull-up if not using external reset to avoid spurious resets on noisy industrial rails.
Route the ICSPKP22/KP23 signals (RB6/RB7) with a 4.7 kohm series termination resistor or ferrite bead to the programming header, and keep ICSPCLK/ICSPDAT traces short (<50 mm) and away from switching signals. The 44-pin VQFN pinout places RB6/7 on pins 17/18, adjacent to the analog supply pins - avoid routing noisy digital signals across this boundary.
Compliance Information
RoHS and REACH compliance per Microchip product page; conflict-minerals compliant per Microchip CMRT. Not AEC-Q100 qualified - choose automotive-grade PIC16F variants for vehicle applications.
