Analog Devices Inc. LTC3722IGN-2#PBF

Overview

LTC3722IGN-2#PBF from Analog Devices is a voltage-mode, phase-shift PWM controller for zero-voltage-switched (ZVS) full-bridge DC/DC converters. It delivers adaptive and fixed ZVS delay control, 5V reference output (±1.5% initial accuracy), 24-pin SSOP package, and operates across –40°C to 85°C. It targets high-efficiency telecom and server power supplies with input ranges up to 72V.

For engineers reviewing the LTC3722IGN-2#PBF datasheet, LTC3722IGN-2#PBF pinout, LTC3722IGN-2#PBF application, or LTC3722IGN-2#PBF equivalent, this page provides verified functional identity, confirmed ZVS timing architecture, validated synchronous rectifier drive capability, and real-world design parameters including 250kHz oscillator frequency, 50mA gate drivers, and system UVLO programmability.

Technical Context

The LTC3722IGN-2#PBF implements voltage-mode control with internal RAMP input referenced to SBUS, enabling precise phase modulation without external slope compensation. Its adaptive ZVS circuitry uses PDLY and ADLY inputs to sense bridge leg voltages and dynamically adjust turn-on delays based on line voltage (SBUS) and MOSFET parasitics.

It integrates six 50mA gate drivers (OUTA–OUTF), a 5V/5mA VREF regulator, 10.25V VCC UVLO with 4.2V hysteresis, and programmable soft-start via SS capacitor. Unlike the current-mode LTC3722-1 variant, the LTC3722-2 avoids slope compensation and leading edge blanking resistors - RLEB is not connected and CS serves only as current-sense comparator input.

Key Specifications

Pinout & Package

Package: 24-lead narrow plastic SSOP (GN), 0.15mm lead thickness, JEDEC MS-013AC, thermal resistance θ_JA = 100°C/W.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar full-bridge phase-shift controller applications.

Compared with UCC28950PWPR, the LTC3722IGN-2#PBF delivers superior ZVS adaptability and integrated biasing, reducing component count by ≥4 passive parts; versus LTC3722IGN-1#PBF, it trades current-mode responsiveness for simplified layout and elimination of slope compensation tuning.

Availability

LTC3722IGN-2#PBF is available at Aetrix Electronics and suitable for telecom rectifier modules, server intermediate bus converters, and industrial 48 V DC power systems requiring stable component supply, long lifecycle support, and guaranteed parametric performance across temperature.

Supply support for LTC3722IGN-2#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, Inc. (ADI) is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving precision instrumentation, communications, and power management markets.

The LTC3722 product line delivers advanced phase-shift PWM controllers optimized for zero-voltage-switched full-bridge topologies in high-efficiency, high-reliability power conversion - targeting telecom, datacenter, and industrial infrastructure applications.

FAQ

What is the key functional difference between LTC3722IGN-2#PBF and LTC3722IGN-1#PBF?

The LTC3722IGN-2#PBF uses voltage-mode control with an internal RAMP input referenced to SBUS, eliminating the need for external slope compensation and leading edge blanking resistors. In contrast, the LTC3722IGN-1#PBF employs peak current-mode control with programmable slope compensation and RLEB-based blanking. This makes the LTC3722IGN-2#PBF simpler to implement in stable, wide-input-voltage applications where current sensing noise is not dominant - a key distinction confirmed in the Analog Devices datasheet Rev C pinout and block diagrams.

Does LTC3722IGN-2#PBF support adaptive zero-voltage switching (ZVS) across the full load range?

Yes, the LTC3722IGN-2#PBF supports adaptive ZVS using PDLY and ADLY inputs tied to voltage dividers on the bridge legs, combined with SBUS sensing of input voltage. The adaptive circuitry dynamically adjusts turn-on delays to maintain ZVS down to light loads, as verified in the Typical Application section and Timing Diagram TD01 of the official datasheet. This capability is intrinsic to the LTC3722-2 architecture and does not require external microcontroller intervention.

What is the maximum gate drive current capability of LTC3722IGN-2#PBF outputs?

All six driver outputs (OUTA–OUTF) of the LTC3722IGN-2#PBF deliver ±50 mA sink/source current, as specified in the Electrical Characteristics table on page 4 of the datasheet. This is sufficient to directly drive gate drivers such as the LTC4440 or buffer stages for discrete MOSFETs, and is validated under load conditions up to 85°C ambient. The pull-down resistance is 12–20 Ω and pull-up is 22–30 Ω, ensuring fast rise/fall times (<15 ns into 50 pF).

Can LTC3722IGN-2#PBF operate with a 72 V input supply?

Yes, the LTC3722IGN-2#PBF is designed for full-bridge converters with input ranges up to 72 V, as shown in the Typical Application schematic (TA01a) and Absolute Maximum Ratings (VCC to GND = –0.3 V to 10 V, with chip self-regulation at 10.3 V). The controller itself operates from its internal 10.3 V shunt regulator, while external gate drivers handle the high-side floating bias - making 72 V input fully supported when paired with appropriate external components.

How is system undervoltage lockout programmed on LTC3722IGN-2#PBF?

System UVLO is programmed via a resistor divider from the input rail to the UVLO pin, with a nominal 5.0 V threshold and 10 µA hysteresis current sourced from the pin. The hysteresis level is adjusted by changing the lower resistor value - for example, a 100 kΩ resistor yields ~4 V hysteresis. This configuration is explicitly detailed in the PIN FUNCTIONS section (page 7) and Electrical Characteristics table (SUVLO, SHYST parameters) of the LTC3722-1/LTC3722-2 datasheet Rev C.