My Inquiry
My Account
Analog Devices Inc. LT8495IUF#PBF
- Part No.:
- LT8495IUF#PBF
- Manufacturer:
- Analog Devices Inc.
- Package:
- 20-WFQFN Exposed Pad
- Datasheet:
-
LT8495IUF#PBF.pdf
- Description:
- IC REG BST CHARGE PUMP ADJ 20QFN
- Quantity:
- Payment:
- Shipping:
Inventory:2,651
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LT8495IUF#PBF from Analog Devices is a monolithic SEPIC/boost/flyback DC/DC controller with integrated 2A/70V NPN power switch, programmable POR and watchdog timer, 9µA quiescent current in active operation, and dual supply inputs (VIN/BIAS) enabling operation down to ~1V after startup. It targets battery-powered automotive ECU and portable industrial supplies requiring ultra-low IQ and fault-tolerant reset supervision.
For engineers reviewing the LT8495IUF#PBF datasheet, LT8495IUF#PBF pinout, LT8495IUF#PBF application, or LT8495IUF#PBF equivalent, key selection criteria include its 250kHz–1.5MHz adjustable switching frequency, <10mV output ripple in Burst Mode, independent CPOR/CWDT capacitor-programmed reset/watchdog timing, FMEA-fault-tolerant TSSOP/QFN package, and dual-supply efficiency optimization across 1V–60V input range.
Technical Context
The LT8495IUF#PBF implements constant-frequency current-mode control with quadratic ramp compensation, frequency foldback below 1V FB, and soft-start via external SS capacitor charged by a 256k internal resistor. Its power switch driver autonomously selects VIN or BIAS as base drive source based on real-time voltage comparison (2.4V threshold, 0.2V hysteresis), enabling seamless transition between supplies.
Reset and watchdog functions operate independently: RSTIN compares against 1.1V reference to trigger RST assertion with 8–60µs delay; CPOR sets tRST (8.5–11.85ms); CWDT sets tWDU (14.9–20.9ms) and tWDL (580–812µs). All three enable pins (SWEN/WDE/RSTIN) feature 1V rising threshold with 30mV hysteresis and sub-1µA leakage at 1.2V.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Switch Rating | 70V VCE, 2.55A peak current limit at min duty cycle - supports 60V SEPIC and 32V boost topologies with ride-through to 60V. |
| Quiescent Current | 9µA from VIN at 12VIN→5VOUT; 0.3µA shutdown - extends battery life in always-on automotive modules. |
| Output Ripple | <10mV typical in Burst Mode - eliminates need for post-regulation LDO in noise-sensitive analog/sensor rails. |
| Switching Frequency | 250kHz–1.5MHz via RT resistor - enables compact magnetics while avoiding AM band interference. |
| Feedback Voltage | 1.202V ±24mV over –40°C to 125°C - ensures stable regulation across automotive temperature range. |
| Reset Timeout | 8.5–11.85ms via CPOR capacitor - provides sufficient hold-off for microcontroller initialization sequences. |
| Watchdog Window | tWDL = 580–812µs / tWDU = 14.9–20.9ms via CWDT capacitor - configurable for diverse MCU watchdog response requirements. |
Pinout & Package
LT8495IUF#PBF uses a 20-lead (4mm × 4mm) plastic QFN package with exposed thermal pad (Pin 21 = GND). The package supports low θJA = 47°C/W and requires soldering of the exposed pad to PCB ground for thermal and electrical integrity.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| SS (Pin 1) | Soft-Start Control | Charged by 256k internal resistor to ~2.1V; external capacitor sets ramp rate for controlled inrush current. |
| RT (Pin 2) | Oscillator Frequency Set | Resistor to GND programs switching frequency; low capacitance required to avoid jitter. |
| GND (Pins 3,4,11,13,14,15,21) | Power & Signal Ground | Multiple dedicated GND pins + exposed pad minimize ground impedance and improve EMI performance. |
| RSTIN (Pin 5) | Reset Input Reference | Compares against 1.1V internal reference; resistor divider sets UVLO threshold for system-level brownout detection. |
| SWEN (Pin 6) | Switch Enable Detect | 1V rising threshold with 30mV hysteresis; enables/disables regulator and initiates soft-start sequence. |
| WDE (Pin 7) | Watchdog Timer Enable | Drives >1.1V to activate watchdog; low state disables WDO output, placing it in high-impedance state. |
| WDO (Pin 8) | Watchdog Output | Active-low open-drain output pulses low on timeout; duration set by CPOR capacitor. |
| WDI (Pin 9) | Watchdog Input | Accepts negative-edge-triggered pulses from MCU; missing edges within tWDL/tWDU window assert WDO. |
| VIN (Pin 10) | Main Supply Input | Accepts up to 60V; powers internal circuitry and supplies base current when VIN < BIAS. |
| SW (Pin 12) | Switch Collector | Connects to collector of internal 2A/70V NPN switch; minimal trace area required to reduce EMI. |
| BIAS (Pin 16) | Secondary Supply Input | Accepts up to 60V; supplies base current when BIAS < VIN; enables operation below 2.5V VIN after startup. |
| FB (Pin 17) | Output Voltage Feedback | Regulated to 1.202V; resistor divider sets output voltage; 0.1–20nA bias current minimizes divider error. |
| CPOR (Pin 18) | Reset Delay Programming | Capacitor to GND sets tRST (8.5–11.85ms); determines minimum RST assertion time after power-up or fault. |
| CWDT (Pin 19) | Watchdog Timing Programming | Capacitor to GND sets tWDL/tWDU window boundaries; enables precise MCU activity monitoring. |
| RST (Pin 20) | Active-Low Reset Output | Open-drain output asserted low during POR, RSTIN undervoltage, or watchdog timeout; sinks 1.25mA. |
Key Features
| Feature | Design Value |
|---|---|
| Low-Ripple Burst Mode | Maintains <10mV output ripple at light loads while reducing IQ to <9µA - eliminates need for secondary filtering in portable systems. |
| Dual-Supply Operation | Automatically selects lower-voltage supply (VIN or BIAS) for NPN base drive - extends runtime when main battery drops below 2.5V. |
| FMEA-Fault-Tolerant Design | Adjacent pin shorts or opens cannot raise output above programmed value - meets ASIL-B functional safety requirements for automotive ECUs. |
| Programmable UVLO | Separate SWEN and RSTIN resistor dividers enable independent input monitoring and system reset thresholds - simplifies multi-rail power sequencing. |
| Integrated Power Switch | 2A/70V NPN switch with 340mV VCE(sat) at 1.2A - reduces BOM count and layout complexity vs. external MOSFET solutions. |
Applications
| Automotive Engine Control Unit (ECU) | Portable Medical Instrumentation |
|---|---|
Use Scenario: Powers microcontroller, CAN transceiver, and sensor interface in 12V vehicle electrical system with cold-crank capability down to 4.5V. IC Role / Device Role / Timing Role: Primary DC/DC controller providing regulated 5V/3.3V rails; POR asserts reset until stable VOUT is achieved; watchdog monitors MCU firmware execution. Use Value: Dual-supply operation draws current from 5V rail when battery dips below 2.5V, maintaining ECU functionality during cranking transients. |
Use Scenario: Powers battery-operated handheld diagnostic device with Bluetooth LE and precision ADC requiring ultra-low standby current. IC Role / Device Role / Timing Role: High-efficiency boost converter delivering 3.3V from single Li-ion cell; Burst Mode maintains <10mV ripple at µA loads; RSTIN monitors battery voltage for graceful shutdown. Use Value: 0.3µA shutdown IQ extends battery life to >1 year in sleep mode without compromising wake-up responsiveness. |
| Industrial IoT Sensor Node | Ruggedized Data Acquisition Module |
Use Scenario: Supplies 3.3V to LoRaWAN transceiver and MEMS accelerometer in solar-charged remote environmental monitor. IC Role / Device Role / Timing Role: SEPIC topology accepts variable 2.5–24V input from solar panel/battery; programmable watchdog ensures MCU recovery from RF-induced lockups. Use Value: Watchdog timeout (tWDU/tWDL) configured via CWDT capacitor matches LoRa transmit/receive timing windows, preventing false resets. |
Use Scenario: Provides isolated 5V/±15V rails for 24-bit delta-sigma ADC in vibration analysis equipment operating in 0–70°C ambient. IC Role / Device Role / Timing Role: Flyback controller with external transformer; CPOR capacitor sets 10ms reset pulse to ensure ADC digital core initializes fully before sampling. Use Value: 1.202V feedback reference with ±24mV tolerance over temperature guarantees ADC reference stability within 0.1% full-scale error. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar DC/DC controller with integrated watchdog applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LTC3895EFE#PBF | Higher 60V input rating, no integrated watchdog/POR, 2-phase synchronous boost controller | Targets higher-power industrial supplies where external reset IC is acceptable | Choose LTC3895EFE#PBF when >3A output current is needed and discrete reset supervision is preferred. |
| MAX16922ATP+T | Automotive-qualified 40V buck controller with integrated watchdog, but no SEPIC/flyback support | Designed specifically for infotainment head units with strict AEC-Q100 Grade 2 requirements | Choose MAX16922ATP+T only for AEC-Q100-compliant 12V automotive applications requiring buck-only topology. |
Compared with LTC3895EFE#PBF and MAX16922ATP+T, the LT8495IUF#PBF uniquely combines SEPIC/boost/flyback flexibility, ultra-low 9µA IQ, and fully integrated POR/watchdog in a single QFN package - making it optimal for space-constrained, battery-sensitive designs requiring multi-topology adaptability.
Availability
LT8495IUF#PBF is available at Aetrix Electronics and suitable for automotive ECU power, portable medical instrumentation, industrial IoT sensor nodes, and ruggedized data acquisition modules requiring stable component supply across extended temperature ranges.
Supply support for LT8495IUF#PBF 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
Analog Devices (acquired Linear Technology in 2017) is a global leader in high-performance analog, mixed-signal, and power management semiconductors, serving industrial, automotive, communications, and healthcare markets.
The LT8495IUF#PBF belongs to Linear's high-reliability power controller family designed for automotive and industrial applications demanding ultra-low quiescent current, fault-tolerant operation, and integrated system supervision functions.
FAQ
What is the maximum input voltage supported by the LT8495IUF#PBF in SEPIC topology?
The LT8495IUF#PBF supports up to 60V input voltage in SEPIC topology, as specified in the Absolute Maximum Ratings and confirmed in the Applications Information section. This rating applies regardless of whether power is sourced from VIN or BIAS pins, and remains valid across the full –40°C to 125°C operating junction temperature range.
How does the LT8495IUF#PBF achieve 0.3µA shutdown current?
The LT8495IUF#PBF achieves 0.3µA shutdown current when SWEN, WDE, and RSTIN are all held low, disabling all internal circuitry including the oscillator, error amplifier, and power switch driver. This ultra-low state is measured with VIN and BIAS at 0V, and is guaranteed across temperature per the Electrical Characteristics table.
Can the LT8495IUF#PBF operate with VIN below 2.5V after startup?
Yes, the LT8495IUF#PBF can operate with VIN as low as ~1V after startup by drawing base drive current from the BIAS pin. This is enabled by the internal supply select logic that compares VIN and BIAS voltages and automatically routes the lower-voltage supply to the NPN switch driver, extending battery life in portable applications.
What is the purpose of the NC pins on the LT8495IUF#PBF QFN package?
The NC pins (Pins 4, 9, 17, 19) on the LT8495IUF#PBF QFN package are not connected to internal circuitry and must be left floating to ensure FMEA fault tolerance. Shorting or connecting these pins may compromise the device's ability to maintain safe output voltage during adjacent pin failures, as documented in the Pin Functions section.
How is the watchdog timeout period adjusted on the LT8495IUF#PBF?
The watchdog timeout period on the LT8495IUF#PBF is adjusted using an external capacitor on the CWDT pin (Pin 19). A 1nF capacitor sets tWDU = 14.9–20.9ms and tWDL = 580–812µs; values scale linearly with capacitance per the Typical Performance Characteristics graphs. The exact timing is guaranteed only for the specified capacitor value.
LT8495IUF#PBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 20-WFQFN Exposed Pad
- Packaging:
- Tube
- Product Status:
- Active
- Function:
- Step-Up, Step-Up/Step-Down
- Output Configuration:
- Positive
- Topology:
- Boost, Charge Pump, Flyback, SEPIC
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 1V
- Voltage - Input (Max):
- 60V
- Voltage - Output (Min/Fixed):
- 1.202V
- Voltage - Output (Max):
- 70V (Switch)
- Current - Output:
- 2.1A (Switch)
- Frequency - Switching:
- 250kHz ~ 1MHz
- Synchronous Rectifier:
- Both
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 20-QFN (4x4)
LT8495IUF#PBF FAQ
1.How can I place an order for LT8495IUF#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT8495IUF#PBF 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 LT8495IUF#PBF reliable?
The price and inventory of LT8495IUF#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT8495IUF#PBF is usually 5 days.
3.What payment methods are accepted for LT8495IUF#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT8495IUF#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT8495IUF#PBF?
LT8495IUF#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT8495IUF#PBF 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 LT8495IUF#PBF?
For technical support, including LT8495IUF#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT8495IUF#PBF requirements.
6.How does Aetrix verify that LT8495IUF#PBF is sourced from the original manufacturer or authorized distributors?
All LT8495IUF#PBF 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 LT8495IUF#PBF meets industry standards.
7.What is the process for return or replacement of LT8495IUF#PBF?
All LT8495IUF#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LT8495IUF#PBF, 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 LT8495IUF#PBF part is unused and in its original packaging.
Return procedure for LT8495IUF#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LT8495IUF#PBF Tags
-
TPS562201DDCR
Texas Instruments
-
MC34063ABD-TR
STMicroelectronics
-
TPS561201DDCR
Texas Instruments
-
MC33063ADR
Texas Instruments
-
MC34063ADR
Texas Instruments
-
TPS560200DBVR
Texas Instruments
-
AP3012KTR-G1
Diodes Incorporated
-
TLV61048DBVR
Texas Instruments
-
AZ34063UMTR-G1
Diodes Incorporated
-
TPS562200DDCR
Texas Instruments
-
AP62300TWU-7
Diodes Incorporated
-
MC34063EBD-TR
STMicroelectronics
Tech Hub
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…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
