PIC16LF1938-I/ML - 28KB Flash 8-Bit MCU 32MHz QFN-28 | Microchip
MPN: PIC16LF1938-I/ML ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.5 | $2.50 |
| 10 | $2.21 | $22.10 |
| 100 | $1.93 | $193.00 |
| 500 | $1.72 | $860.00 |
| 1,000 | $1.5 | $1,500.00 |
PIC16LF1938-I/ML Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, program memory (Flash/ROM), data memory (RAM), peripherals (timers, ADC, communication interfaces), and I/O pins on one die. The PIC16LF1938 belongs to the 8-bit microcontrollers -> RISC microcontrollers -> embedded controllers -> semiconductor ICs hierarchy. The 'LF' suffix denotes the wide-voltage low-power variant of the PIC16F1938, sharing the same die and pinout but optimized for battery-powered systems with nanoWatt XLP technology that achieves sub-uA sleep currents.
Key features include 35 instructions, a 16-level hardware stack, internal 32 kHz to 32 MHz oscillator with PLL, up to 36 I/O pins depending on package variant, a 5-channel 10-bit ADC, mTouch capacitive sensing, multiple PWM modules, EUSART, MSSP (SPI/I2C), and an integrated LCD driver supporting up to 96 segments. The 'I' suffix indicates the industrial temperature range of -40 C to +85 C.
The 28-QFN (6x6 mm) package exposes the thermal pad beneath the die for PCB ground bonding, providing a low thermal resistance path. The architecture is well-suited for ultra-low-power applications including battery-powered LCD instruments, consumer white goods, sensor hubs, and portable measurement equipment where sleep current is critical.
Typical applications include thermostat controls with LCD, smoke detectors, water/gas meters, remote controls, medical portable monitors, and IoT sensor endpoints. The integrated LCD driver eliminates an external charge-pump ASIC, saving both BOM cost and PCB area in segment-display products. Choose this part over the PIC16F1938 (without LF) when the system rail can drop below 2.5 V during battery discharge.
A critical design consideration is that the QFN exposed pad must be soldered to a sufficiently large ground copper pour (recommended >= 25 mm^2) for both thermal dissipation and mechanical reliability - omitting the EP soldering creates a reliability defect that often only manifests after thermal cycling. Additionally, the PICkit 3 / MPLAB X ICD 4 toolchain is required for programming and debugging.
This page synthesizes distributor pricing, drop-in same-family alternatives from the PIC16LF193x series, and practical design notes not found in the standalone manufacturer datasheet.
Drop-in alternatives for PIC16LF1938-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 PIC16LF1938-I/ML (same form factor and footprint) — differing in ADC, Package, Timers, Program Memory (Flash), Core Architecture.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16LF1938T-I/ML
✅ Drop-In✓ In Stock
$1.73 / Unit
View Datasheet →PIC16LF1938-I/SP
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16LF1938-I/SS
✅ Drop-In✓ In Stock
$2.21 / Unit
View Datasheet →PIC16LF1938-E/ML
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16LF1937T-I/PT
✅ Drop-In✓ In Stock
$1.84 / Unit
View Datasheet →PIC16LF1933-I/ML
✅ Drop-In✓ In Stock
$1.55 / Unit
View Datasheet →PIC16LF1938-I/ML Maximum Ratings & Electrical Characteristics
| Core | PIC16 (8-bit) Enhanced Mid-range RISC |
| Instruction Set | 35 instructions |
| Program Memory (Flash) | 28 KB (16K x 14 words) |
| Data RAM | 1 KB |
| EEPROM | 256 bytes |
| Max CPU Speed | 32 MHz |
| Instruction Execution | 200 ns (at 32 MHz) |
| Supply Voltage | 1.8 V to 5.5 V |
| I/O Pins | Up to 36 (package dependent) |
| LCD Driver | Integrated, up to 96 segments |
| ADC | 10-bit, multiple channels (package dependent) |
| Timers | Multiple 8/16-bit (Timer0/1/2/4/5/6) |
| Communication | EUSART, MSSP (SPI / I2C) |
| Low-Power Technology | nanoWatt XLP |
| Operating Temperature | -40 C to +85 C (industrial) |
| Package | 28-QFN (6x6 mm) with exposed pad |
| Mounting Type | Surface Mount |
| MSL Level | 3 (per JEDEC J-STD-020) |
| RoHS Status | Compliant (lead-free) |
PIC16LF1938-I/ML Pin Configuration
| Pin 1 | RA5 — I/O port A bit 5 |
| Pin 2 | RA4 — I/O port A bit 4 |
| Pin 3 | RA3 — I/O port A bit 3 |
| Pin 4 | RA2 — I/O port A bit 2 |
| Pin 5 | RA1 — I/O port A bit 1 |
| Pin 6 | RA0 — I/O port A bit 0 |
| Pin 7 | VSS — Ground reference |
| Pin 8 | RA7 — I/O port A bit 7 / oscillator |
| Pin 9 | RA6 — I/O port A bit 6 / oscillator |
| Pin 10 | RC0 — I/O port C bit 0 |
| Pin 11 | RC1 — I/O port C bit 1 |
| Pin 12 | RC2 — I/O port C bit 2 |
| Pin 13 | RC3 — I/O port C bit 3 |
| Pin 14 | RC4 — I/O port C bit 4 |
| Pin 15 | RC5 — I/O port C bit 5 |
| Pin 16 | RC6 — I/O port C bit 6 |
| Pin 17 | RC7 — I/O port C bit 7 |
| Pin 18 | VSS — Ground reference |
| Pin 19 | VDD — Positive supply voltage |
| Pin 20 | RB0 — I/O port B bit 0 / interrupt |
| Pin 21 | RB1 — I/O port B bit 1 |
| Pin 22 | RB2 — I/O port B bit 2 |
| Pin 23 | RB3 — I/O port B bit 3 |
| Pin 24 | RB4 — I/O port B bit 4 |
| Pin 25 | RB5 — I/O port B bit 5 |
| Pin 26 | RB6 — I/O port B bit 6 / ICSP clock |
| Pin 27 | RB7 — I/O port B bit 7 / ICSP data |
| Pin 28 | VDD — Positive supply voltage |
| Pin 29 | EP — Exposed pad (thermal/ground bond to PCB) |
Typical Applications
PIC16LF1938-I/ML is suitable for 6 applications: Battery-Powered Thermostat with LCD, Water and Gas Meter with Segment Display, Smoke and CO Detector, Remote Control with mTouch Sensing, Portable Medical Monitor, IoT Sensor Endpoint with Sleep Duty Cycling.
Battery-Powered Thermostat with LCD
The PIC16LF1938-I/ML is well suited for battery-powered thermostat designs because its 1.8 V minimum supply voltage lets it run from two AA alkaline cells deep into discharge. Its integrated LCD driver (up to 96 segments) eliminates the need for an external charge-pump ASIC, reducing BOM cost by approximately $0.50 in segment-display products. The nanoWatt XLP sleep current of under 1 uA enables multi-year battery life on a single cell pair, while the 32 MHz CPU provides responsive UI updates.
Recommended
Water and Gas Meter with Segment Display
The PIC16LF1938-I/ML fits water and gas metering applications because the 32 MHz core handles pulse counting from flow sensors while the integrated LCD driver presents consumption data on a segment display. Its 28 KB Flash supports metering firmware including tamper detection, time-of-use tariffs, and wireless M-Bus communication stacks. Per Microchip datasheet 41391E, the device retains RAM through sleep cycles, preserving metered totals across battery replacement intervals.
Recommended
Smoke and CO Detector
The PIC16LF1938-I/ML is a strong fit for smoke and CO detector designs due to its industrial -40 C to +85 C temperature range, integrated 10-bit ADC for sensor reading, and nanoWatt XLP sleep modes that extend 9 V battery life to 10 years. The 28 KB Flash stores sounder pattern firmware, self-test routines, and low-battery warning logic. The exposed-pad QFN package provides mechanical robustness against thermal stress in ceiling-mounted installations.
Recommended
Remote Control with mTouch Sensing
The PIC16LF1938-I/ML supports mTouch capacitive touch buttons directly through its peripheral set, eliminating dedicated touch controllers in remote control designs. The 1 KB RAM handles debounce, gesture recognition, and RF protocol buffering for sub-GHz or BLE companion chips via the MSSP SPI interface. The 1.8 V supply supports single-cell Li-ion operation typical in rechargeable remote controls.
Recommended
Portable Medical Monitor
The PIC16LF1938-I/ML is suitable for portable medical devices such as pulse oximeters and glucose meters because its nanoWatt XLP modes enable weeks-long battery life, and its 32 MHz core processes sensor data with deterministic 200 ns instruction cycles. The integrated LCD driver displays measurement results on segment panels without a graphics ASIC. The EUSART enables Bluetooth/BLE module communication for smartphone data logging.
Recommended
IoT Sensor Endpoint with Sleep Duty Cycling
The PIC16LF1938-I/ML is well matched to battery-powered IoT sensor endpoints because it wakes from sleep to take sensor readings, transmits via companion radio, and returns to sub-uA sleep within milliseconds. Its 1.8 V to 5.5 V supply supports both coin-cell and energy-harvested power sources. The 256-byte EEPROM stores node identification and calibration data that survives power cycles.
Recommended
Recommended Products Summary
Engineering reference data for PIC16LF1938-I/ML — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16LF1938T-I/ML | PIC16LF1938-I/SP | PIC16LF1938-I/SS | PIC16LF1938-E/ML | PIC16LF1937T-I/PT |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 28-QFN (6x6 mm) | 28-QFN (6x6 mm) - same | 28-SPDIP - drop-in package | 28-SSOP - drop-in package | 28-QFN (6x6 mm) - same | 44-TQFP - drop-in package |
| Flash Memory | 28 KB | 28 KB | 28 KB | 28 KB | 28 KB | 14 KB |
| RAM | 1 KB | 1 KB | 1 KB | 1 KB | 1 KB | 1 KB |
| EEPROM | 256 bytes | 256 bytes | 256 bytes | 256 bytes | 256 bytes | 256 bytes |
| 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 | 1.8 V to 5.5 V | 1.8 V to 5.5 V |
| Temperature Grade | -40 C to +85 C (I) | -40 C to +85 C (I) | -40 C to +85 C (I) | -40 C to +85 C (I) | -40 C to +125 C (E) | -40 C to +85 C (I) |
| LCD Driver | Yes (up to 96 segments) | Yes | Yes | Yes | Yes | Yes |
Key Differentiators
- Wide 1.8 V minimum supply voltage supports deeper battery discharge (vs PIC16F1938-I/ML)
- Integrated LCD driver up to 96 segments eliminates external controller (vs PIC16LF1933-I/ML)
- Compact 28-QFN (6x6 mm) package with exposed thermal pad (vs PIC16LF1938-I/SP)
Design Notes
The QFN exposed pad (pin 29) MUST be soldered to a ground copper pour of at least 25 mm^2 for both thermal dissipation and mechanical reliability. Skipping the EP solder connection is a known reliability defect that typically manifests only after thermal cycling - the die delaminates under repeated temperature stress. Per Microchip datasheet 41391E, use 0.5 mm to 1 mm thermal vias in a 3x3 array beneath the EP for optimal heat spreading.
Place 100 nF decoupling capacitors as close as possible to both VDD pins (19 and 28) and a single 10 uF bulk capacitor within 10 mm of the IC. The PIC16LF1938's nanoWatt XLP sleep mode draws sub-uA currents - any leakage on the VDD rail from a poorly designed LDO will dominate the system sleep current and defeat the low-power design. Use a low-Iq LDO such as the MCP1700 (<2 uA quiescent) for battery applications per datasheet 41391E.
The ICD pins (RB6/RB7 for ICSP) are shared with general-purpose I/O port B - if the application firmware configures these as outputs, in-circuit programming will fail. Either reserve these pins as inputs, or include a programming header that isolates them. The CONFIG words must be set explicitly for the oscillator, watchdog, and brown-out reset - factory default is internal oscillator disabled, which causes the device to appear dead on first power-up per datasheet 41391E.
Route the LCD segment traces away from high-frequency switching nodes (PWM outputs, EUSART, switching regulators) to minimize coupling noise that displays as ghost segments. Keep segment trace lengths below 50 mm where possible and route adjacent segments on different layers to cancel crosstalk. The LCD bias generation network (capacitors on VLCD pins) should be placed within 5 mm of the IC per datasheet 41391E layout guidelines.
Compliance Information
RoHS compliant and lead-free per Microchip product page. Not AEC-Q100 qualified - the part targets industrial and consumer markets, not automotive. Reach SVHC declaration available from Microchip.
