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Microchip Technology MCP1791-3302E/ET
- Part No.:
- MCP1791-3302E/ET
- Manufacturer:
- Microchip Technology
- Package:
- TO-263-6, D2PAK (5 Leads + Tab), TO-263BA
- Datasheet:
-
MCP1791-3302E/ET.pdf
- Description:
- IC REG LINEAR 3.3V 70MA 5DDPAK
- Quantity:
- Payment:
- Shipping:
Inventory:237
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Product details
Overview
MCP1791-3302E/ET from Microchip Technology is a 5-pin, fixed-output 3.3V automotive-grade LDO regulator designed for high-voltage DC systems. It delivers up to 70 mA at +125°C junction temperature, withstands 48V load dump transients (<500 ms), operates from 6.0V–30.0V input, and features shutdown control (SHDN) and power-good output (PWRGD). It powers microcontrollers in fire alarm sensors and HVAC controls.
For engineers reviewing the MCP1791-3302E/ET datasheet, MCP1791-3302E/ET pinout, MCP1791-3302E/ET application, or MCP1791-3302E/ET equivalent, key selection criteria include its 70 mA output capability at +125°C, ±2.5% output tolerance over temperature, 70 µA typical quiescent current, 48V transient survival, and integrated SHDN/PWRGD signals for system-level power sequencing and monitoring.
Technical Context
The MCP1791-3302E/ET implements a CMOS-based LDO architecture with internal thermal shutdown (157°C typical) and foldback short-circuit protection (99 mA typical at 3.3V). Its voltage reference and error amplifier enable tight line regulation (±0.0002%/V) and load regulation (±0.2% typical).
It integrates dedicated circuitry for VIN monitoring (startup threshold 5.5–6.0V), PWRGD open-drain output with 90% VOUT threshold and 2% hysteresis, and SHDN input with 400 ns noise immunity and 100 µs turn-on delay. The device is stable with 4.7 µF–1000 µF ceramic or 1 µF–1000 µF tantalum/electrolytic output capacitors.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 3.3V ±2.5% over −40°C to +125°C - ensures reliable MCU core/logic supply under automotive thermal stress. |
| Max Output Current | 70 mA at +125°C junction - supports full-load operation in engine bay or industrial enclosures without derating. |
| Input Voltage Range | 6.0V–30.0V continuous; 48V absolute max - compatible with 12V/24V automotive and commercial DC systems including load dump events. |
| Quiescent Current | 70 µA typical (active), 10 µA typical (shutdown) - meets automotive low-power standby requirements and extends battery life in always-on sensors. |
| PSRR | −90 dB @ 100 Hz - suppresses low-frequency ripple from alternators or switching supplies feeding the LDO input. |
| Dropout Voltage | 700 mV typical @ 70 mA - enables regulation down to VIN = 4.0V, critical for brownout resilience in 12V systems. |
| PWRGD Threshold | 90% of VOUT (2.97V) with 2% hysteresis - provides clean, glitch-free power sequencing signal for microcontroller reset management. |
Pinout & Package
SOT-223-5 surface-mount package with exposed GND tab for thermal dissipation; pin 1 = SHDN, pin 2 = VIN, pin 3 = GND (tab), pin 4 = VOUT, pin 5 = PWRGD.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - SHDN | Active-low enable input | Pulls low ≤0.8V to disable regulator and enter 10 µA shutdown; includes 400 ns noise filter to reject EMI-induced false triggers. |
| 2 - VIN | Unregulated input supply | Accepts 6.0–30.0V DC; withstands 48V transients <500 ms; internal UVLO disables output below ~5.5V. |
| 3 - GND | Ground reference & thermal path | Reference for all voltages; exposed tab connects to PCB ground plane for thermal conduction and EMI reduction. |
| 4 - VOUT | Regulated 3.3V output | Delivers up to 70 mA; requires ≥4.7 µF ceramic or ≥1 µF tantalum output capacitor for stability. |
| 5 - PWRGD | Open-drain power-good indicator | Sinks 5 mA when VOUT ≥2.97V; delays 30 µs on rise, 235 µs on fall - enables safe MCU boot and fault detection. |
Key Features
| Feature | Design Value |
|---|---|
| 48V Load Dump Protection | Survives FORD Test Pulse G Loaded (43.5V ±10%, <500 ms, 30 s repetition) - eliminates need for external TVS in cost-sensitive automotive modules. |
| Thermal & Short-Circuit Protection | 157°C shutdown with 20°C hysteresis and foldback current limiting (99 mA at 3.3V) - prevents latch-up during sustained overload or PCB trace faults. |
| Ultra-Low Ground Current | 110 µA typical at 70 mA load - reduces total system power loss vs. bipolar regulators, critical for battery-powered smoke detectors. |
| High PSRR at Low Frequency | −90 dB @ 100 Hz - maintains clean 3.3V rail despite alternator ripple or noisy DC-DC pre-regulators. |
| Stable with Wide Capacitor Range | Supports 4.7 µF–1000 µF ceramic or 1 µF–1000 µF tantalum/electrolytic - simplifies BOM and layout across diverse application environments. |
Applications
| Automotive Accessory Power Adapter | Electronic Thermostat Control |
|---|---|
|
Use Scenario: Powering CAN transceiver, microcontroller, and sensor interface in 12V vehicle accessory modules. IC Role / Device Role / Timing Role: Primary 3.3V LDO supplying logic rails and enabling system-level power sequencing via PWRGD and SHDN. Use Value: 48V transient tolerance eliminates external protection components; 70 µA quiescent current meets OEM sleep-mode leakage budgets. |
Use Scenario: Regulating power for HVAC controller MCU and analog front-end in residential/commercial thermostats. IC Role / Device Role / Timing Role: Fixed 3.3V supply with PWRGD signaling MCU reset release after stable rail establishment. Use Value: Stable operation from 6–30V input accommodates wide-range 24VAC rectified supplies; ±2.5% output tolerance ensures ADC reference accuracy. |
| Low-Voltage Fire Alarm Sensor | Microcontroller Power Supply |
|
Use Scenario: Powering smoke/CO sensor nodes in 24VDC building fire alarm systems with hundreds of distributed units. IC Role / Device Role / Timing Role: Energy-efficient 3.3V regulator delivering 70 mA to sensor ICs and wireless transceivers. Use Value: 110 µA ground current reduces wiring gauge and energy consumption across large-scale deployments versus bipolar alternatives. |
Use Scenario: Providing clean, regulated 3.3V to ARM Cortex-M or PIC microcontrollers in industrial embedded gateways. IC Role / Device Role / Timing Role: Main system LDO with SHDN-controlled deep-sleep entry and PWRGD-monitored wake-up readiness. Use Value: 200 µs startup time and 30 µs PWRGD assertion enable fast, deterministic boot sequences in real-time control applications. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar LDO regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| NCP163AMX330TBG | 3.3V, 250 mA, 1.1 µA IQ, no PWRGD/SHDN - higher current but lacks power sequencing signals. | Preferred where higher load current is needed and system-level sequencing is handled externally. | Select NCP163AMX330TBG only if >70 mA output or sub-µA quiescent current is mandatory; MCP1791-3302E/ET remains optimal for automotive-safe sequencing. |
| TLE42754G | 3.3V, 150 mA, integrated watchdog, -40°C to +150°C - broader temp range but higher 120 µA IQ and no PWRGD. | Suitable for engine-control modules requiring extended temperature rating and watchdog functionality. | Choose TLE42754G for under-hood applications beyond +125°C; MCP1791-3302E/ET better fits cabin/interior modules needing precise PWRGD timing and lower IQ. |
Compared with NCP163AMX330TBG and TLE42754G, the MCP1791-3302E/ET uniquely balances automotive-grade transient robustness, integrated power sequencing (SHDN+PWRGD), and ultra-low active quiescent current - making it the preferred choice for space-constrained, safety-critical 3.3V subsystems where reliability and controlled startup/shutdown are essential.
Availability
MCP1791-3302E/ET is available at Aetrix Electronics and suitable for automotive accessory adapters, electronic thermostat controls, low-voltage fire alarm sensors, microcontroller power supplies, and HVAC control systems requiring stable component supply across extended temperature and transient conditions.
Supply support for MCP1791-3302E/ET 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
Microchip Technology is a global semiconductor company specializing in microcontrollers, analog devices, and memory products, with strong focus on automotive, industrial, and IoT applications.
The MCP1791 is part of Microchip's high-voltage LDO family engineered specifically for harsh-environment DC power regulation in automotive and commercial building systems - emphasizing load dump survivability, low quiescent current, and integrated system-monitoring functions.
FAQ
What is the maximum input voltage the MCP1791-3302E/ET can withstand during load dump events?
The MCP1791-3302E/ET is rated for 48V (43.5V ±10%) load dump transients lasting less than 500 ms with a 30-second repetition rate per FORD Test Pulse G Loaded. Its absolute maximum input voltage is +48.0V, and it operates continuously from 6.0V to 30.0V. This makes the MCP1791-3302E/ET suitable for direct connection to automotive battery rails without external transient suppression in many designs.
Does the MCP1791-3302E/ET require an external pull-up resistor on the PWRGD pin?
Yes, the PWRGD pin is an open-drain output and requires an external pull-up resistor to VOUT (typically 10 kΩ) to generate a valid logic-high signal when the output voltage is within regulation. The MCP1791-3302E/ET does not integrate an internal pull-up; omission will result in undefined or floating PWRGD behavior. This design allows flexible voltage-level translation and noise margin tuning in the host system.
What output capacitor types and values are supported by the MCP1791-3302E/ET?
The MCP1791-3302E/ET is stable with 4.7 µF–1000 µF X7R/X5R ceramic capacitors or 1 µF–1000 µF tantalum/aluminum electrolytic capacitors. Ceramic capacitors below 4.7 µF require a 0.3 Ω series resistor for stability. The ESR must not exceed 3 Ω. These specifications ensure compatibility with compact, low-profile, and high-reliability capacitor selections across automotive and industrial applications using the MCP1791-3302E/ET.
How does the shutdown function behave on the MCP1791-3302E/ET?
The SHDN pin is active-low: pulling it ≤0.8V disables the regulator output and reduces quiescent current to 10 µA typical, while asserting it >2.4V enables regulation. The MCP1791-3302E/ET includes 400 ns pulse rejection and a 100 µs turn-on delay to prevent noise-induced toggling. If left floating, the internal pull-down forces shutdown - ensuring fail-safe default behavior in unconnected systems.
What is the thermal shutdown behavior of the MCP1791-3302E/ET?
The MCP1791-3302E/ET activates thermal shutdown at approximately 157°C junction temperature and recovers when the die cools to ~137°C (20°C hysteresis). During shutdown, output is disabled and quiescent current drops to 10 µA. Recovery is automatic and does not require cycling VIN or SHDN. This protects against sustained overload or poor heatsinking while maintaining system integrity in the MCP1791-3302E/ET's target applications.
MCP1791-3302E/ET Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- TO-263-6, D2PAK (5 Leads + Tab), TO-263BA
- Packaging:
- Tube
- Product Status:
- Active
- Output Configuration:
- Positive
- Output Type:
- Fixed
- Number of Regulators:
- 1
- Voltage - Input (Max):
- 30V
- Voltage - Output (Min/Fixed):
- 3.3V
- Voltage - Output (Max):
- -
- Voltage Dropout (Max):
- 1.3V @ 70mA
- Current - Output:
- 70mA
- Current - Quiescent (Iq):
- 130 µA
- Current - Supply (Max):
- 210 µA
- PSRR:
- 90dB ~ 80dB (100Hz ~ 1kHz)
- Control Features:
- Enable, Power Good
- Protection Features:
- Over Temperature, Short Circuit
- Operating Temperature:
- -40°C ~ 125°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DDPAK-5
MCP1791-3302E/ET FAQ
1.How can I place an order for MCP1791-3302E/ET through Aetrix?
Please submit a Request for Quotation (RFQ) for MCP1791-3302E/ET 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 MCP1791-3302E/ET reliable?
The price and inventory of MCP1791-3302E/ET are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MCP1791-3302E/ET is usually 5 days.
3.What payment methods are accepted for MCP1791-3302E/ET?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MCP1791-3302E/ET transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MCP1791-3302E/ET?
MCP1791-3302E/ET orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MCP1791-3302E/ET 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 MCP1791-3302E/ET?
For technical support, including MCP1791-3302E/ET datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MCP1791-3302E/ET requirements.
6.How does Aetrix verify that MCP1791-3302E/ET is sourced from the original manufacturer or authorized distributors?
All MCP1791-3302E/ET 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 MCP1791-3302E/ET meets industry standards.
7.What is the process for return or replacement of MCP1791-3302E/ET?
All MCP1791-3302E/ET units undergo pre-shipment inspection (PSI). If there is an issue with MCP1791-3302E/ET, 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 MCP1791-3302E/ET part is unused and in its original packaging.
Return procedure for MCP1791-3302E/ET:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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