My Inquiry
My Account
onsemi MC78LC40HT1
- Part No.:
- MC78LC40HT1
- Manufacturer:
- onsemi
- Package:
- TO-243AA
- Datasheet:
-
MC78LC40HT1.pdf
- Description:
- IC REG LINEAR FIXED LDO REG
- Quantity:
- Payment:
- Shipping:
Inventory:15,286
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
MC78LC40HT1 from onsemi is a fixed-output, low-dropout linear voltage regulator delivering 4.0 V at up to 80 mA with ultra-low 1.2 µA typical quiescent current, 25 mV typical dropout (at 1.0 mA), ±2.5% output voltage accuracy, and operation across −40°C to +85°C ambient. It serves as a micropower supply rail for battery-powered portable instrumentation requiring stable low-noise DC.
For engineers reviewing the MC78LC40HT1 datasheet, pinout, applications, or equivalent options, this page delivers verified package mapping (SOT-89, 3-pin), confirmed electrical specs including load regulation (50 mV max), thermal resistance (333°C/W), and real-world design context for handheld instruments, camcorders, and low-power sensor nodes.
Technical Context
The MC78LC40HT1 integrates a PMOS pass transistor, precision voltage reference, error amplifier, and internal feedback resistors - enabling fixed 4.0 V output without external components. Its architecture supports stable operation with only 0.1 µF ceramic output capacitance and tolerates input voltages up to 12 V.
Designed for micropower systems, it maintains regulation under light loads (1.0–10 mA) with <0.2%/V line regulation and ≤70 mV load regulation. Dropout voltage remains below 38 mV at 80 mA, and quiescent current stays near 1.2 µA across input voltage (6.0 V) and temperature (−40°C to +85°C).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | 4.0 V nominal, ±2.5% over −40°C to +85°C - ensures reliable logic-level compliance for 3.3 V/4.0 V I/O domains. |
| Dropout Voltage | 25 mV typical at 1.0 mA; 38 mV max at 80 mA - enables operation with minimal headroom (e.g., 4.03 V input sustains 4.0 V output). |
| Quiescent Current | 1.2 µA typical at Vin = 6.0 V - extends battery life in always-on sensor or standby circuits. |
| Load Regulation | 50 mV max (1.0 → 10 mA); 70 mV max (1.0 → 80 mA) - maintains tight output stability during dynamic current steps. |
| Line Regulation | 0.05% / V typical - rejects input ripple and variation from aging batteries or unregulated supplies. |
| Thermal Resistance | 333°C/W (Junction-to-Ambient, SOT-89) - defines power derating: max 300 mW at TA = 25°C before TJ exceeds 125°C. |
| Operating Temp | −40°C to +85°C ambient - qualified for industrial-grade portable equipment deployment. |
Pinout & Package
MC78LC40HT1 is housed in the SOT-89 (Case 1213) 3-pin surface-mount package. The exposed tab (Pin 2) is electrically connected to GND and serves as the primary thermal path. Package dimensions: 4.5 × 2.5 × 1.5 mm (L × W × H).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | GND | Power supply ground reference; connects directly to PCB ground plane and thermal pad. |
| 2 | Vin | Positive input supply; accepts 4.3 V to 12 V; requires local 0.1 µF decoupling capacitor. |
| 3 | Vout | Regulated 4.0 V output; stable with ≥0.1 µF ceramic capacitor; drives up to 80 mA load. |
Key Features
| Feature | Design Value |
|---|---|
| Ultra-low quiescent current | 1.2 µA typical at 6.0 V input - reduces standby power loss by >90% vs. standard LDOs. |
| Low-cost ceramic capacitor compatibility | Stable with 0.1 µF X7R/X5R ceramic output cap - eliminates need for tantalum or high-ESR parts. |
| High accuracy output | ±2.5% over full temperature and load range - avoids post-regulation trimming in production. |
| Robust ESD protection | 2000 V HBM per MIL-STD-883 Method 3015 - enhances handling reliability in assembly lines. |
| Industrial temperature range | −40°C to +85°C operation - supports deployment in outdoor or thermally variable enclosures. |
Applications
| Portable Medical Sensors | Handheld Test Meters |
|---|---|
Use Scenario: Battery-powered pulse oximeter with analog front-end and BLE radio. IC Role / Device Role / Timing Role: Primary 4.0 V supply for op-amps and ADC reference, isolated from noisy digital rails. Use Value: 1.2 µA quiescent current extends AA battery life beyond 12 months in sleep mode; 25 mV dropout preserves runtime as battery discharges to 4.03 V. |
Use Scenario: Pocket-sized multimeter using LCD display and microcontroller. IC Role / Device Role / Timing Role: Clean 4.0 V rail for MCU core and precision voltage reference IC. Use Value: ±2.5% output accuracy ensures consistent ADC calibration across temperature; SOT-89 thermal pad aids heat dissipation during extended measurements. |
| Digital Camcorder Power | IoT Edge Node Sensor Hub |
Use Scenario: Compact camcorder with CMOS image sensor and audio codec. IC Role / Device Role / Timing Role: Dedicated 4.0 V supply for image sensor analog bias and PLL circuitry. Use Value: 0.05%/V line regulation suppresses noise coupling from switching battery management ICs; 0.1 µF ceramic stability simplifies layout. |
Use Scenario: LoRaWAN node with environmental sensors, MCU, and RF transceiver. IC Role / Device Role / Timing Role: Low-noise 4.0 V source for precision temperature/humidity sensing and RF PA bias. Use Value: 89 µVrms output noise prevents signal corruption in 16-bit sensor readings; −40°C to +85°C rating supports outdoor deployment. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar low-dropout linear regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MCP1700T-4002E/TT | 2.5 µA quiescent current; 170 mV dropout at 250 mA; SOT-23-3 package. | Higher output current capability but higher IQ and larger dropout - less suitable for ultra-low-power sub-100 mA designs. | Select when >80 mA load or tighter transient response is required; verify thermal limits in SOT-23-3. |
| TPS78040QDRVRQ1 | 500 nA IQ; 175 mV dropout at 150 mA; AEC-Q100 qualified; 2.0 V min input. | Automotive-grade with lower IQ but higher dropout and cost - overqualified for consumer portable gear. | Choose only for automotive-qualified designs needing <1 µA standby; not recommended for cost-sensitive portable instruments. |
Compared with MCP1700T-4002E/TT and TPS78040QDRVRQ1, the MC78LC40HT1 offers the optimal balance of ultra-low IQ (1.2 µA), low dropout (25 mV), industrial temp range, and SOT-89 thermal performance - making it ideal for space-constrained, battery-critical portable instrumentation where efficiency and stability outweigh raw current capacity.
Availability
MC78LC40HT1 is available at Aetrix Electronics and suitable for portable medical sensors, handheld test meters, and digital camcorder power systems requiring stable component supply, long-term lifecycle support, and traceable sourcing.
Supply support for MC78LC40HT1 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
onsemi (formerly ON Semiconductor) is a global semiconductor supplier specializing in energy-efficient power management, analog, sensor, and connectivity solutions for automotive, industrial, and portable electronics.
The MC78LC00 series was designed specifically for micropower, battery-operated portable equipment - emphasizing ultra-low quiescent current, ceramic-capacitor compatibility, and small-footprint packaging for handheld instruments and imaging devices.
FAQ
What is the maximum input voltage for the MC78LC40HT1?
The MC78LC40HT1 supports a maximum input voltage of 12 V, as specified in its Absolute Maximum Ratings table. Operation above this level risks permanent damage. For reliable 4.0 V regulation, the recommended minimum input is 4.3 V (accounting for 30 mV worst-case dropout), and typical use cases apply 6.0 V to 8.0 V inputs per the Electrical Characteristics tables.
Does the MC78LC40HT1 require an external output capacitor?
Yes, the MC78LC40HT1 requires a minimum 0.1 µF ceramic output capacitor for stability, as explicitly stated in the Applications Information section. Larger values improve load transient response and noise rejection, but no ESR constraints apply - enabling use of low-cost X7R or X5R MLCCs without risk of oscillation.
What is the thermal resistance (RJA) of the MC78LC40HT1 in its SOT-89 package?
The MC78LC40HT1 has a junction-to-ambient thermal resistance (RJA) of 333°C/W when mounted in the SOT-89 package (H suffix), per the "Power Dissipation and Thermal Characteristics" table. This value assumes standard JEDEC test conditions; actual RJA improves with enhanced PCB copper area connected to the tab (Pin 2/GND).
Can the MC78LC40HT1 be used in automotive applications?
The MC78LC40HT1 is rated for −40°C to +85°C ambient operation and meets industrial temperature requirements, but it is not AEC-Q100 qualified. Therefore, it is not recommended for safety-critical or under-hood automotive applications. It is appropriate for cabin-mounted portable accessories or aftermarket devices operating within its specified temperature and reliability envelope.
How does the quiescent current of the MC78LC40HT1 vary with input voltage?
Per Figure 11 in the datasheet, the MC78LC40HT1 exhibits flat quiescent current behavior: 1.2 µA typical across 5.0 V to 10 V input at 25°C. At 6.0 V input (its nominal test condition), IQ remains stable at 1.2 µA typ / 3.6 µA max - confirming minimal dependency on VIN, a key advantage for battery-powered systems with varying cell voltage.
MC78LC40HT1 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-243AA
- Packaging:
- Bulk
- Product Status:
- Active
- Output Configuration:
- Positive
- Output Type:
- Fixed
- Number of Regulators:
- 1
- Voltage - Input (Max):
- 12V
- Voltage - Output (Min/Fixed):
- 4V
- Voltage - Output (Max):
- -
- Voltage Dropout (Max):
- 0.038V @ 1mA
- Current - Output:
- 65mA
- Current - Quiescent (Iq):
- 3.6 µA
- Current - Supply (Max):
- -
- PSRR:
- -
- Control Features:
- -
- Protection Features:
- -
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-89-3
MC78LC40HT1 FAQ
1.How can I place an order for MC78LC40HT1 through Aetrix?
Please submit a Request for Quotation (RFQ) for MC78LC40HT1 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for MC78LC40HT1 reliable?
The price and inventory of MC78LC40HT1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MC78LC40HT1 is usually 5 days.
3.What payment methods are accepted for MC78LC40HT1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MC78LC40HT1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MC78LC40HT1?
MC78LC40HT1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MC78LC40HT1 order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for MC78LC40HT1?
For technical support, including MC78LC40HT1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MC78LC40HT1 requirements.
6.How does Aetrix verify that MC78LC40HT1 is sourced from the original manufacturer or authorized distributors?
All MC78LC40HT1 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that MC78LC40HT1 meets industry standards.
7.What is the process for return or replacement of MC78LC40HT1?
All MC78LC40HT1 units undergo pre-shipment inspection (PSI). If there is an issue with MC78LC40HT1, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The MC78LC40HT1 part is unused and in its original packaging.
Return procedure for MC78LC40HT1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MC78LC40HT1 Tags
-
MIC5504-1.8YM5-TR
Microchip Technology
-
MIC5504-3.3YM5-TR
Microchip Technology
-
MIC5365-3.0YC5-TR
Microchip Technology
-
MIC5365-1.8YC5-TR
Microchip Technology
-
MIC5365-2.5YC5-TR
Microchip Technology
-
MIC5365-3.3YC5-TR
Microchip Technology
-
MIC5365-3.3YD5-TR
Microchip Technology
-
MIC5317-3.3YM5-TR
Microchip Technology
-
TLV1117LV33DCYR
Texas Instruments
-
MIC5317-3.3YMT-TZ
Microchip Technology
-
MIC5528-3.3YMT-TR
Microchip Technology
-
TLV75801PDRVR
Texas Instruments
Tech Hub
Counterfeit components can hide behind convincing markings and passing basic function tests. This engineering reference covers source traceability, external inspection, X-ray, XRF, electrical testing, …
A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
