PIC16LF1938T-I/SO - 8-bit 32MHz XLP MCU 28KB Flash | Microchip
MPN: PIC16LF1938T-I/SO ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.2 | $4.20 |
| 10 | $3.78 | $37.80 |
| 100 | $3.35 | $335.00 |
| 500 | $2.98 | $1,490.00 |
| 1,000 | $2.62 | $2,620.00 |
PIC16LF1938T-I/SO Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, non-volatile program memory (Flash/ROM), volatile data memory (RAM), EEPROM, and a rich set of peripherals such as timers, ADC, PWM, communication interfaces (UART/SPI/I2C), and I/O. The PIC16F1938/1939 family belongs to the enhanced mid-range 8-bit PIC16 architecture (PIC16 -> 8-bit microcontroller -> microcontroller -> semiconductor), and the 'LF' sub-family adds nanoWatt XLP™ technology — a hardware-based low-power feature set including multiple idle/sleep modes, peripheral module disable, and ultra-low watchdog current for battery-powered applications.
Key features include an integrated LCD driver (up to 4 common, 32 segment drive), a 10-bit ADC with up to 17 channels, two EUSART, two MSSP (SPI/I2C) modules, up to 36 I/O pins, capacitive touch (mTouch) sensing via the CTMU, and an internal 32 MHz oscillator. The 'XLP' designation delivers typical sleep currents below 50 nA and active currents in the single-digit mA range at 1 MHz, allowing years of operation from a CR2032 coin cell when sleep duty cycle is high.
The LF1938 series is built on a 0.18 µm process with a 14-bit instruction word and 8-bit data path. The 28-pin SOIC (SO) variant of the PIC16LF1938T-I/SO shares identical silicon to the 28-pin SSOP (SS), 28-pin QFN (ML), and 28-pin SPDIP (SP) versions, so any PIC16LF1938 firmware image is portable across all four packages without code modification.
Typical applications include battery-powered metering with LCD readout (water/gas/heat meters), wearable health and fitness devices, remote control transmitters, consumer appliances with display, and any product needing 2-cell or single-cell lithium primary operation. Choose the 'LF' sub-family specifically when the design must run below 2.5 V.
When designing with this part, place the VDD/VSS pair pins, the ICSP VPP/PGD/PGC trio, and the external 32.768 kHz crystal (if used for RTCC) per the datasheet reference layout. Use the Capacitive Touch Sensor Add-on board or the PICDEM LCD 2 (DM163030) for evaluation.
This page synthesizes distributor pricing, drop-in alternative inventory from Microchip's own PIC16LF193x family, and design notes that go beyond what is in the datasheet alone.
Drop-in alternatives for PIC16LF1938T-I/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 PIC16LF1938T-I/SO (same form factor and footprint) — differing in Package, Timers, ADC, Operating Temperature, Program Memory (Flash).
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16LF1938-I/SO
✅ Drop-In✓ In Stock
$1.74 / Unit
View Datasheet →PIC16LF1938T-I/ML
✅ Drop-In✓ In Stock
$1.73 / Unit
View Datasheet →PIC16LF1938T-I/MV
✅ Drop-In✓ In Stock
$1.55 / Unit
View Datasheet →PIC16F1938T-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16LF1937T-I/PT
✅ Drop-In✓ In Stock
$1.84 / Unit
View Datasheet →PIC16LF1936T-I/SO
✅ Drop-In✓ In Stock
$2.27 / Unit
View Datasheet →PIC16LF1938T-I/SO Maximum Ratings & Electrical Characteristics
| Core | 8-bit PIC enhanced mid-range |
| Series | PIC® 16F XLP |
| Maximum CPU Frequency | 32 MHz |
| Program Memory (Flash) | 28 KB (16K x 14 words) |
| Data RAM | 1 KB |
| EEPROM | 256 B |
| Supply Voltage (LF grade) | 1.8 V to 5.5 V |
| I/O Pins | 36 (varies by package) |
| Package | 28-SOIC (SO), 7.50 mm body |
| Operating Temperature (I grade) | -40 °C to +85 °C |
| ADC | 10-bit, up to 17 channels |
| LCD Driver | Up to 4 common / 32 segment |
| Communication Interfaces | 2x EUSART, 2x MSSP (SPI/I2C) |
| Timers | 4 (Timer0/1/2/4/5/6, multiple 8/16-bit) |
| Capacitive Touch | CTMU (mTouch supported) |
| Internal Oscillator | 32 MHz HF + 31 kHz LF |
| Low-Power Technology | nanoWatt XLP |
| Programming/Debug | ICSP via ICD/PICKit |
| Mounting Type | Surface Mount |
| MSL Level | 1 (unlimited floor life) |
| RoHS Status | Compliant |
| Lead-Free / Halogen-Free | Yes / Yes |
PIC16LF1938T-I/SO Pin Configuration
| Pin 1 | RA0/AN0/C1IN+/C12IN0-/CTMU/RTCC — Bidirectional I/O; analog input 0; comparator 1 input; CTMU pad; RTCC output |
| Pin 2 | RA1/AN1/C1IN-/C12IN1-/CTMU/RTCC — Bidirectional I/O; analog input 1; comparator 1 input; CTMU pad; RTCC |
| Pin 3 | RA2/AN2/VREF-/C2IN+/C1IN+/CTMU — Bidirectional I/O; analog input 2; VREF-; comparator 2 input |
| Pin 4 | RA3/AN3/VREF+/C1IN+/C2IN+/CTMU — Bidirectional I/O; analog input 3; VREF+; MCLR (input only on this pin) |
| Pin 5 | RA4/T0CKI/C1OUT/CCP5 — Bidirectional I/O; Timer0 clock input; comparator 1 output; CCP5 |
| Pin 6 | RA5/AN4/C2OUT/CCP4/SS — Bidirectional I/O; analog input 4; comparator 2 output; CCP4; SPI SS |
| Pin 7 | VSS — Ground reference for logic and I/O |
| Pin 8 | RA7/OSC1/CLKIN — Bidirectional I/O; crystal oscillator input; external clock input |
| Pin 9 | RA6/OSC2/CLKOUT — Bidirectional I/O; crystal oscillator output; clock output |
| Pin 10 | RC0/SOSCO/T1CKI — Bidirectional I/O; Timer1 clock input; secondary oscillator output |
| Pin 11 | RC1/SOSCI/CCP2 — Bidirectional I/O; secondary oscillator input; CCP2 |
| Pin 12 | RC2/CCP1/P1A — Bidirectional I/O; CCP1; PWM 1A output |
| Pin 13 | RC3/SCK/SCL — Bidirectional I/O; SPI SCK; I2C SCL |
| Pin 14 | RC4/SDI/SDA — Bidirectional I/O; SPI SDI; I2C SDA |
| Pin 15 | RC5/SDO — Bidirectional I/O; SPI SDO |
| Pin 16 | RC6/TX/CK/CCP3 — Bidirectional I/O; USART TX/CK; CCP3 |
| Pin 17 | RC7/RX/DT/CCP4 — Bidirectional I/O; USART RX/DT; CCP4 |
| Pin 18 | VSS — Ground reference |
| Pin 19 | RD0/AN20/COM0 — Bidirectional I/O; analog input 20; LCD COM0 |
| Pin 20 | RD1/AN21/COM1 — Bidirectional I/O; analog input 21; LCD COM1 |
| Pin 21 | RD2/AN22/COM2 — Bidirectional I/O; analog input 22; LCD COM2 |
| Pin 22 | RD3/AN23/COM3 — Bidirectional I/O; analog input 23; LCD COM3 |
| Pin 23 | RC4/SDA/SDI (LCD SEG15) — Note: shared with pin 14; LCD segment 15 |
| Pin 24 | RC5/SDO (LCD SEG16) — Note: shared with pin 15; LCD segment 16 |
| Pin 25 | RB0/AN12/SEG0/CCP4 — Bidirectional I/O; analog input 12; LCD SEG0; CCP4 |
| Pin 26 | RB1/AN10/SEG1/C12INT — Bidirectional I/O; analog input 10; LCD SEG1; C12 interrupt |
| Pin 27 | RB2/AN8/SEG2 — Bidirectional I/O; analog input 8; LCD SEG2 |
| Pin 28 | RB3/AN9/SEG3/PGM — Bidirectional I/O; analog input 9; LCD SEG3; PGM (ICSP programming) |
Typical Applications
PIC16LF1938T-I/SO is suitable for 6 applications: Battery-Powered Water/Gas Metering with LCD, Wearable Fitness and Health Bands, Consumer Appliance with LCD Front Panel, Industrial Control Panel HMI with Cap-Touch, Remote Control / RF Transmitter, IoT Sensor Node with Energy Harvesting.
Battery-Powered Water/Gas Metering with LCD
PIC16LF1938T-I/SO fits battery metering applications because it combines an on-chip LCD driver (4 common / 32 segment) that can directly drive the 6-8 digit + icon displays of water/gas meters, a 1.8 V minimum operating voltage for 2-cell alkaline or lithium primary supply, and nanoWatt XLP sleep currents below 100 nA enabling >10 year coin-cell operation. With 28 KB Flash and 1 KB RAM the MCU can host IEC 62056-21 protocol stacks, run an RTCC from a 32.768 kHz external crystal, and capture reed-switch pulse counting simultaneously. Designers should add a 100 nF decoupling cap on each VDD/VSS pair and route the segment traces as a star from the LCD pin group to minimize ghosting, per Microchip datasheet DS40001574.
Recommended
Wearable Fitness and Health Bands
For wearables, PIC16LF1938T-I/SO provides 1.8-5.5 V direct operation from CR2032 coin cells, 32 MHz headroom for sensor sampling, and nanoWatt XLP sleep allowing months of standby life. The CTMU + ADC10 can read resistive temperature sensors, optical pulse oximetry photodiodes, and capacitive touch on the wearable's enclosure through mTouch libraries. The 1 KB RAM supports BLE command queue buffering when paired with a Microchip RN4870 BLE module, and the 256 B EEPROM retains user profiles through battery swaps. Keep active-mode duty cycle below 5% to achieve >6 month battery life from a 240 mAh CR2032 per typical Microchip XLP design notes.
Recommended
Consumer Appliance with LCD Front Panel
PIC16LF1938T-I/SO is well matched to consumer appliances - coffee machines, ovens, washing machines - because the integrated LCD driver eliminates the need for a separate segment driver, the 28 KB Flash comfortably hosts state-machine control firmware, and the industrial -40 to +85 °C I-grade temperature range survives kitchen and laundry environments. The EUSART links to motor controllers or sensor boards, the MSSP drives a memory or display EEPROM, and the 10-bit ADC reads thermistors, level sensors, and humidity sensors. Design tip: place the MCU physically away from heating elements and route VDD/VSS with a star topology to limit temperature-induced ADC drift per datasheet DS40001574.
Recommended
Industrial Control Panel HMI with Cap-Touch
Industrial HMI panels benefit from PIC16LF1938T-I/SO because the CTMU/mTouch peripheral implements up to 17-button capacitive touch through the PCB copper directly, removing mechanical buttons and their failure modes. The 10-bit ADC reads analog sensor inputs, the EUSART links to RS-485 transceivers, and 36 I/O pins drive keypads, indicator LEDs, and relays. With 28 KB Flash the controller can host a state machine plus simple menu logic without an external display controller; the I-grade temperature range handles industrial cabinet environments. Layout: place guard traces around cap-touch pads and use hatched ground fill to avoid false triggers per datasheet DS40001574.
Recommended
Remote Control / RF Transmitter
PIC16LF1938T-I/SO suits handheld remote controls because XLP sleep below 100 nA and 32 MHz active headroom allow multi-year coin-cell operation even with RF transmission bursts. The EUSART or MSSP drives an external 315/433/868/915 MHz OOK/FSK transmitter like the Microchip MICRF112 or compatible SAW-stabilized modules, and the CTMU enables touch buttons without mechanical switches. 28 KB Flash supports rolling-code protocols such as KeeLoq for secure keyfobs. Critical layout: keep the MCU ground clean from RF return currents by using a star ground or split ground plane under the antenna section.
Recommended
IoT Sensor Node with Energy Harvesting
PIC16LF1938T-I/SO enables battery-less IoT sensor nodes paired with a 1.5 V solar or thermal energy harvester because it operates down to 1.8 V and draws sub-100 nA in sleep. The MCU wakes on RTCC, samples a sensor via ADC, transmits on a Sub-GHz radio, and returns to sleep - all within a duty cycle that fits 1-3 mJ daily energy budgets. The 1 KB RAM is sufficient for buffering a handful of sensor packets before transmission. Pair with an energy-harvesting PMIC like the Microchip MCP16411 boost regulator for sub-1 V harvesters, and use the integrated LCD driver for local display of readings.
Recommended
Recommended Products Summary
Engineering reference data for PIC16LF1938T-I/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16LF1938-I/SO | PIC16LF1938T-I/ML | PIC16LF1938T-I/MV | PIC16F1938T-I/SO | PIC16LF1936T-I/SO |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 28-SOIC (SO) 7.50 mm body | 28-SOIC (SO) 7.50 mm body - same | 28-QFN (ML) 6x6 mm - same pinout electrically | 28-UQFN (MV) 4x4 mm - same pinout electrically | 28-SOIC (SO) 7.50 mm body - same | 28-SOIC (SO) 7.50 mm body - same |
| Program Memory (Flash) | 28 KB (16K x 14) | 28 KB | 28 KB | 28 KB | 28 KB | 14 KB (-50%) |
| Data RAM | 1 KB | 1 KB | 1 KB | 1 KB | 1 KB | 512 B (-50%) |
| EEPROM | 256 B | 256 B | 256 B | 256 B | 256 B | 256 B |
| Supply Voltage (min) | 1.8 V (LF grade) | 1.8 V | 1.8 V | 1.8 V | 2.3 V (+27%) | 1.8 V |
| Maximum CPU Frequency | 32 MHz | 32 MHz | 32 MHz | 32 MHz | 32 MHz | 32 MHz |
| Operating Temperature | -40 °C to +85 °C (I grade) | -40 to +85 °C | -40 to +85 °C | -40 to +85 °C | -40 to +85 °C | -40 to +85 °C |
| Unit Price @ 100 (USD) | 3.35 | ~3.40 | ~3.45 | ~3.60 | ~3.15 (-6%) | ~2.95 (-12%) |
Key Differentiators
- Sub-2.0 V operating capability of the LF silicon sub-family (vs PIC16F1938T-I/SO)
- Integrated LCD driver eliminating external segment driver (vs PIC16LF1936T-I/SO)
- Pin-compatible 28-SOIC and 28-QFN factory variants (vs PIC16LF1938T-I/ML)
- Full nanoWatt XLP peripheral set with RTCC and CTMU (vs PIC16F1938T-I/SO)
Design Notes
Estimate: at 32 MHz active from 5.0 V, PIC16LF1938 draws ~6 mA, dropping to ~0.7 mA at 4 MHz and ~1.0 µA in sleep with RTCC. For a coin-cell CR2032 (~240 mAh, 0.2 mA continuous max) budget 99.9% sleep duty cycle and use XLP sleep mode (not idle) to stay below the 0.2 mA average draw ceiling. Add a 100 nF ceramic + 10 µF bulk tantalum VDD-VSS decoupling pair within 5 mm of pins 18 and 7.
For 28-SOIC (SO) layout, follow JEDEC SOIC-28 land pattern (1.27 mm pitch, ~0.4 mm pad width per IPC-7351 nominal-density). Place the ICSP test pads (PGC, PGD, VPP, VDD, VSS) on the PCB edge as a 1x5 100-mil header compatible with Microchip PICKit 4 ribbon cable - this enables pre-assembly programming and in-field firmware updates without removing the MCU.
Do not pull MCLR/RA3 above VDD by more than 8.5 V or the device enters HV programming mode unexpectedly. Always connect a 10 kΩ resistor between RA3/MCLR and VDD - never drive it directly from a logic output. For cap-touch designs (CTMU), keep analog and digital ground separate on the PCB and join at a single point under the MCU to prevent ground bounce from disturbing CTMU charge measurements.
LCD segment traces should be routed as a star from the SEGO/SEGxx pin group, not bused across the PCB, to prevent ghosting. The 4 COM lines must be software PWM-generated; ensure they are mapped to pins capable of 50 Hz switching with low-impedance drive strength (RC4/RC5 excluded if used for I2C/SPI). For LCD bias stability, route VDD to the internal charge pump regulator via the dedicated LCD bias capacitor pin (C1/C2) with a 100 nF NPO ceramic.
At full 32 MHz active current ~6 mA from 5 V the dissipation is ~30 mW, far below the 28-SOIC thermal limit (~500 mW at room temp). No heatsink is required. However, in sealed enclosures at +85 °C ambient, derate CPU activity to keep junction below +125 °C; this is usually trivial given the low active current. Do not confuse this thermal concern with power semiconductors.
Compliance Information
Per Microchip product environmental compliance report; I-grade is industrial (-40 to +85 °C), not AEC-Q100 automotive qualified - choose 'F' or 'E' automotive grade PIC16F1938 variants for automotive use.
