My Inquiry
My Account
Analog Devices Inc. LT8494IUF#PBF
- Part No.:
- LT8494IUF#PBF
- Manufacturer:
- Analog Devices Inc.
- Package:
- 20-WFQFN Exposed Pad
- Datasheet:
-
LT8494IUF#PBF.pdf
- Description:
- IC REG BST CHARGE PUMP ADJ 20QFN
- Quantity:
- Payment:
- Shipping:
Inventory:369
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LT8494IUF#PBF from Analog Devices is a monolithic SEPIC/boost/flyback DC/DC controller with integrated 2A/70V NPN power switch, 7µA quiescent current in active operation, and programmable switching frequency from 250kHz to 1.5MHz. It operates across 1V–60V input (with 2.5V startup), supports dual supply pins (VIN/BIAS) for extended battery life, and delivers low-ripple Burst Mode® regulation for portable and automotive ECU power supplies.
For engineers reviewing the LT8494IUF#PBF datasheet, LT8494IUF#PBF pinout, LT8494IUF#PBF application, or LT8494IUF#PBF equivalent, key selection considerations include its 20-lead QFN package with exposed thermal pad, FMEA-fault-tolerant design in TSSOP variants, 1.202V feedback reference, 92% PG threshold, and UVLO programmability via SWEN pin resistor divider.
Technical Context
The LT8494IUF#PBF implements constant-frequency current-mode control with internal slope compensation, enabling stable operation up to 90% duty cycle in SEPIC/boost topologies. Its dual-supply architecture automatically selects between VIN and BIAS for NPN base drive, sustaining regulation even when VIN drops below 2.5V post-startup.
Burst Mode® operation reduces quiescent current to <3µA at light loads while maintaining <10mV output ripple via controlled single-cycle energy bursts. Frequency foldback below 1V FB and soft-start via external capacitor (charged by 256k internal resistor) ensure clean, fault-resilient startup under varying input conditions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Topology Support | SEPIC, boost, or flyback - enables flexible non-isolated step-up or buck-boost conversion without transformer isolation. |
| Input Voltage Range | 1V to 60V (2.5V min for startup); dual-supply operation extends runtime in battery-powered systems down to ~1V after startup. |
| Switch Rating | Integrated 2A/70V NPN transistor - eliminates external high-voltage switch, simplifies layout, and supports 32V boost/60V SEPIC inputs. |
| Quiescent Current | 7µA typical at 12VIN→5VOUT; 0.3µA in shutdown - critical for always-on automotive and IoT applications requiring multi-year battery life. |
| Feedback Reference | 1.202V ±24mV over –40°C to 125°C - ensures precise output voltage regulation across industrial temperature range. |
| Switching Frequency | 250kHz to 1.5MHz (RT-programmable) - allows optimization of size (higher f) vs. efficiency (lower f) and EMI filtering requirements. |
| Power Good Threshold | 92% of FB regulation voltage - provides reliable output validation before system enable, with 46mV hysteresis for noise immunity. |
Pinout & Package
LT8494IUF#PBF is housed in a 20-lead (4mm × 4mm) plastic QFN package with exposed thermal pad (Pin 21 = GND), offering θJA = 47°C/W and requiring soldering of the exposed pad to PCB ground for thermal and electrical integrity.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| SW (Pin 12) | Internal NPN collector node | High dv/dt switching node; requires minimal trace area and local ground plane to suppress EMI and reduce parasitic ringing. |
| VIN (Pin 10) | Main input supply connection | Accepts up to 60V; must be locally bypassed with low-ESR capacitor to stabilize control loop and absorb switch transients. |
| BIAS (Pin 16) | Secondary supply input | Enables automatic supply selection; allows continued operation when VIN falls below 2.5V by drawing from regulated output rail. |
| FB (Pin 17) | Output voltage feedback input | Senses divider network; regulates to 1.202V - sets VOUT = 1.202V × (1 + R2/R1); low 20nA bias current minimizes divider losses. |
| SWEN (Pin 6) | Enable/UVLO control input | Resistor-divider programmable turn-on threshold (0.9–1.1V rising); enables precise undervoltage lockout without external circuitry. |
| PG (Pin 20) | Open-drain power-good flag | Asserts high when FB ≥ 92% of target; requires external pull-up; signals valid output before downstream system activation. |
| SS (Pin 1) | Soft-start timing node | Charged by internal 256k resistor to ~2.1V; external capacitor sets ramp time - prevents inrush current and stabilizes startup. |
| RT (Pin 2) | Oscillator frequency set | Resistor-to-ground sets switching frequency (250kHz–1.5MHz); low capacitance required to avoid jitter and frequency drift. |
| GND (Pins 3,4,9,11,13,14,15,21) | Signal and power ground | Multiple dedicated GND pins + exposed pad ensure low-impedance return path, reduce ground bounce, and improve thermal dissipation. |
Key Features
| Feature | Design Value |
|---|---|
| Low Ripple Burst Mode® | Maintains <10mV output ripple at light loads while reducing quiescent current to <3µA - eliminates need for secondary LDO in ultra-low-power systems. |
| Dual Supply Pin Architecture | Automatically selects lower-voltage source (VIN or BIAS) for NPN base drive - extends battery life by enabling operation down to ~1V after startup. |
| Programmable UVLO | SWEN pin accepts resistor divider to set precise turn-on voltage (e.g., 3.3V, 5V, 12V thresholds) - replaces discrete supervisor ICs in multi-rail designs. |
| FMEA-Fault-Tolerant Design | TSSOP variant guarantees output voltage remains within regulation during adjacent-pin shorts or opens - meets ASIL-B functional safety requirements. |
| Frequency Foldback | Reduces switching frequency when FB < 1V - increases minimum off-time, improves current control during startup and short-circuit recovery. |
Applications
| Automotive ECU Power | Portable Medical Instrumentation |
|---|---|
Use Scenario: Powering microcontroller, CAN transceiver, and sensor interface in engine control unit with cold-crank input (4.5V–16V) and load-dump survival (up to 60V). IC Role / Device Role / Timing Role: Primary DC/DC controller managing SEPIC topology to maintain 5V/3.3V rails during wide-input transients. Use Value: 7µA quiescent current extends battery standby life; dual-supply operation sustains regulation during cranking dips; 60V absolute max rating handles load dump without external clamping. |
Use Scenario: Battery-powered glucose meter or pulse oximeter requiring regulated 3.3V rail from single Li-ion cell (2.7V–4.2V) with multi-year shelf life. IC Role / Device Role / Timing Role: Boost converter delivering 3.3V at up to 600mA with ultralow no-load consumption. Use Value: 0.3µA shutdown current and Burst Mode® operation minimize self-discharge; 1.202V reference ensures accurate ADC reference voltage stability. |
| Industrial Sensor Node | Railway Signaling Interface |
Use Scenario: Remote wireless sensor node powered by primary lithium thionyl chloride (LiSOCl₂) cell (3.6V nominal, up to 3.9V), operating at –40°C to +85°C. IC Role / Device Role / Timing Role: Boost regulator generating stable 5V for RF module and MCU, with programmable soft-start to limit inrush into large output caps. Use Value: –40°C to 125°C guaranteed operation; 95ns minimum on-time enables high-VOUT/VIN ratios; low 20nA FB bias current preserves battery capacity. |
Use Scenario: Isolated signaling interface in train control system requiring 12V rail from 72V nominal battery with EN 50155 compliance. IC Role / Device Role / Timing Role: SEPIC converter providing non-inverting step-down from 40V–100V input range to regulated 12V output. Use Value: 60V input capability covers full railway voltage envelope; FMEA-tolerant TSSOP option supports functional safety audits; PG flag validates output before enabling safety-critical logic. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar SEPIC/boost controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LTC3789EFE#PBF | 4-switch synchronous SEPIC/boost controller; no integrated power switch; requires external MOSFETs; 3.5V–36V input; 100µA IQ. | Higher efficiency at >1A loads; supports higher output currents; lacks integrated switch and ultra-low IQ for battery longevity. | Select when >2A output current or >90% efficiency at full load is required; not suitable for space-constrained or ultra-low-IQ designs. |
| LT8330EDD#PBF | 60V monolithic boost/SEPIC controller with 1.5A switch; 28µA IQ; fixed 2MHz frequency; no BIAS pin or dual-supply operation. | Smaller solution size due to higher frequency; simpler RT-free design; cannot sustain regulation below 2.5V VIN like LT8494IUF#PBF. | Select for compact, cost-sensitive boost-only applications where 7µA IQ and sub-2.5V operation are not required. |
Compared with LTC3789EFE#PBF and LT8330EDD#PBF, the LT8494IUF#PBF uniquely combines integrated 2A/70V NPN switching, 7µA quiescent current, dual-supply operation, and FMEA-ready packaging - making it optimal for space-limited, battery-dependent, or safety-conscious SEPIC/boost implementations.
Availability
LT8494IUF#PBF is available at Aetrix Electronics and suitable for automotive ECU power, portable medical instrumentation, industrial sensor nodes, and railway signaling interfaces requiring stable component supply across extended temperature and voltage ranges.
Supply support for LT8494IUF#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 precision instrumentation, industrial automation, and automotive markets.
The LT8494IUF#PBF belongs to the Linear Technology µModule®-adjacent high-voltage DC/DC controller family, designed specifically for robust, low-quiescent-current power conversion in harsh environments including automotive, aerospace, and industrial edge devices.
FAQ
What is the maximum input voltage supported by the LT8494IUF#PBF in SEPIC topology?
The LT8494IUF#PBF supports up to 60V input voltage in SEPIC topology, as confirmed by Absolute Maximum Ratings (VIN/BIAS ≤ 60V) and Electrical Characteristics specifying 60V operation. This enables direct use in 48V industrial and automotive systems without pre-regulation. The LT8494IUF#PBF maintains regulation across this full range when configured with appropriate external components and thermal management.
Does the LT8494IUF#PBF support true shutdown with near-zero current draw?
Yes - when SWEN is pulled low, the LT8494IUF#PBF enters shutdown mode with typical quiescent current of 0.3µA from VIN and 0.07µA from BIAS, verified in Electrical Characteristics tables. This ultra-low shutdown current is critical for battery-backed systems requiring multi-year storage life. The LT8494IUF#PBF achieves this via complete internal circuit disablement, not just gate drive inhibition.
Can the LT8494IUF#PBF operate with input voltage below 2.5V after startup?
Yes - the LT8494IUF#PBF can sustain regulation with VIN as low as ~1V after startup by automatically drawing supply current from the BIAS pin, which may be connected to the output rail. This behavior is explicitly documented in the "Minimum VIN Operating Voltages" table (2.4V min when BIAS < 2.5V) and Applications Information section. The LT8494IUF#PBF leverages dual-supply architecture to extend battery runtime beyond conventional controllers.
What is the purpose of the exposed pad (Pin 21) on the LT8494IUF#PBF QFN package?
The exposed pad (Pin 21) on the LT8494IUF#PBF is electrically and thermally connected to GND, and must be soldered to the PCB ground plane per manufacturer guidelines. It reduces thermal resistance (θJA = 47°C/W) and provides low-inductance grounding for high-frequency switch node return paths. Failure to solder the pad compromises both thermal performance and EMI suppression. The LT8494IUF#PBF datasheet mandates this connection for reliable operation.
How does the LT8494IUF#PBF implement programmable undervoltage lockout (UVLO)?
The LT8494IUF#PBF implements programmable UVLO using an external resistor divider from VIN to GND, connected to the SWEN pin. The internal comparator triggers at 0.9–1.1V (rising), allowing precise turn-on thresholds (e.g., 5V UVLO with 1MΩ/316kΩ divider). Hysteresis of 30mV prevents chatter near threshold. This eliminates need for external supervisors. The LT8494IUF#PBF datasheet provides detailed calculation examples and tolerance analysis for robust implementation.
LT8494IUF#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:
- 2A
- Frequency - Switching:
- 250kHz ~ 1.5MHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 20-QFN (4x4)
LT8494IUF#PBF FAQ
1.How can I place an order for LT8494IUF#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT8494IUF#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 LT8494IUF#PBF reliable?
The price and inventory of LT8494IUF#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT8494IUF#PBF is usually 5 days.
3.What payment methods are accepted for LT8494IUF#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT8494IUF#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT8494IUF#PBF?
LT8494IUF#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT8494IUF#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 LT8494IUF#PBF?
For technical support, including LT8494IUF#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT8494IUF#PBF requirements.
6.How does Aetrix verify that LT8494IUF#PBF is sourced from the original manufacturer or authorized distributors?
All LT8494IUF#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 LT8494IUF#PBF meets industry standards.
7.What is the process for return or replacement of LT8494IUF#PBF?
All LT8494IUF#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LT8494IUF#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 LT8494IUF#PBF part is unused and in its original packaging.
Return procedure for LT8494IUF#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LT8494IUF#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…
