Analog Devices Inc. LT1302CN8#PBF

Overview

LT1302CN8#PBF from Analog Devices (formerly Linear Technology) is a micropower step-up DC/DC converter with an internal 2A NPN switch, adjustable output via feedback pin, and Burst Mode™ operation for ultra-low quiescent current. It delivers 5V at 600mA from a 2-cell alkaline supply (2.0V–2.5V), operates down to 2V input, and features 310mV typical switch saturation voltage. Used in battery-powered portable electronics requiring high efficiency across light-to-heavy loads.

For engineers reviewing the LT1302CN8#PBF datasheet, LT1302CN8#PBF pinout, LT1302CN8#PBF application, or LT1302CN8#PBF equivalent, key selection criteria include minimum input voltage (2.0V), peak switch current rating (2.8A), feedback reference voltage (1.24V), thermal shutdown protection, and compatibility with low-ESR ceramic output capacitors in compact PDIP-8 layouts.

Technical Context

The LT1302CN8#PBF employs dual-mode control: hysteretic Burst Mode™ at light load (15µA shutdown, 200µA quiescent) and current-mode regulation at heavy load for stable transient response. Its internal NPN switch supports up to 400kHz switching and handles ≥2A peak current with 310mV V_CE(SAT) at 2A.

It integrates frequency compensation via external RC on the VC pin, uses a 1.24V precision reference for feedback, and features logic-controlled shutdown (V_SHDNH = 1.8V, V_SHDNL = 0.5V) with 8µA bias current. The device is optimized for boost topologies with discontinuous or continuous conduction mode operation.

Key Specifications

Pinout & Package

LT1302CN8#PBF is housed in an 8-lead plastic DIP (N8) package with through-hole mounting and 100°C/W junction-to-ambient thermal resistance. Pins 1 and 8 are internally connected as signal ground (GND) and power ground (PGND), respectively, requiring separate low-impedance PCB traces per functional role.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar step-up DC/DC converter applications.

Compared with LT1302CS8#PBF, the LT1302CN8#PBF offers easier prototyping and thermal margin in still-air environments, while LT1302CN8-5#PBF trades flexibility for reduced component count-making the original ideal for adjustable-output, through-hole, or thermally constrained designs.

Availability

LT1302CN8#PBF is available at Aetrix Electronics and suitable for portable instrumentation, handheld computing, and battery-powered communications equipment requiring stable component supply, long-term manufacturability, and proven reliability in commercial-temperature environments.

Supply support for LT1302CN8#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 and maintains its legacy portfolio of high-performance analog and power management ICs.

The LT1302 product line was designed for micropower, high-current boost conversion in space- and battery-limited portable systems-emphasizing ultra-low IQ, robust switching, and seamless mode transition.

FAQ

What is the minimum input voltage required for LT1302CN8#PBF to start switching?

The LT1302CN8#PBF begins switching at an input voltage as low as 2.0V, verified across the 0°C to 70°C operating temperature range. This enables reliable operation from partially discharged alkaline or NiMH cells. Below 2.0V, the internal bandgap reference and oscillator fail to activate, halting regulation. The LT1302CN8#PBF maintains regulation down to 2.0V even under 600mA load, making it suitable for deep-discharge battery applications.

Can LT1302CN8#PBF be used to generate 12V output from a 2-cell supply?

Yes, the LT1302CN8#PBF can generate 12V from a 2-cell supply (e.g., 2.4V nominal), but requires discontinuous conduction mode (DCM) design due to duty cycle limitations. With a 2.4V input, the theoretical duty cycle exceeds 95%, so inductor value must be reduced (e.g., 3.3µH) to allow current to fall to zero each cycle. Efficiency drops to ~70% at 120mA, as confirmed in Figure 1 and TA04. The LT1302CN8#PBF's 95% max duty cycle and 2A switch rating make this feasible, though thermal management becomes critical.

How does the IT pin affect LT1302CN8#PBF operation and when should it be used?

The IT pin on the LT1302CN8#PBF disables Burst Mode™ when pulled to ground via a 3.3kΩ resistor, forcing continuous current-mode operation regardless of load. This eliminates low-frequency (6kHz) output ripple that can interfere with audio circuits, as shown in Figures 8a–8b. However, quiescent current rises from 200µA to ~300µA at light load, reducing battery life. Use the IT pin only when ripple-sensitive analog sections coexist with the LT1302CN8#PBF on the same board.

What type of output capacitor is recommended for stable LT1302CN8#PBF operation?

The LT1302CN8#PBF requires a low-ESR output capacitor-ideally a polymer tantalum (e.g., AVX TPS series) or OS-CON aluminum-rated ≥100µF and ≥6.3V. High-ESR electrolytics cause "mode-hopping" between Burst Mode™ and current mode, increasing ripple to >500mV_P-P and introducing low-frequency artifacts (Figure 5). Maximum allowable ESR is calculated as ESR_MAX = V_OS × V_OUT / V_REF ≈ 61mΩ. For 600mA loads, two parallel 220µF TPS caps (total ESR <30mΩ) yield <30mV_P-P ripple, as validated in Figure 4.

Is LT1302CN8#PBF RoHS compliant and lead-free?

Yes, the LT1302CN8#PBF is RoHS compliant and lead-free, as indicated by the "#PBF" suffix per Analog Devices' packaging nomenclature. It meets JEDEC J-STD-020 moisture sensitivity level 1 (MSL-1) and is rated for Pb-free reflow soldering profiles up to 260°C peak. The PDIP-8 package uses matte tin lead finish, and all die attach, bond wires, and mold compound comply with EU Directive 2011/65/EU. Full compliance documentation is available in Analog Devices' official product change notices for the LT1302 family.