Analog Devices Inc. LTC1922EG-1#TRPBF

Overview

LTC1922EG-1#TRPBF from Analog Devices (formerly Linear Technology) is a synchronous phase-modulated full-bridge PWM controller IC designed for zero-voltage-switched (ZVS), isolated DC/DC converters. It delivers adaptive active/passive leg delay control, peak current mode regulation, and integrated 50mA synchronous rectifier drivers for secondary-side current-doubler topologies. Key confirmed parameters include fixed-frequency operation up to 1MHz, 4.2V UVLO hysteresis, 145µA typical start-up current, 5V/15mA LDO reference output, and 95–99.5% maximum phase shift range - enabling high-efficiency, high-density telecom and server power supplies delivering 3.3V/50W–kW outputs from 36–48V inputs.

For engineers reviewing the LTC1922EG-1#TRPBF datasheet, LTC1922EG-1#TRPBF pinout, LTC1922EG-1#TRPBF application, or LTC1922EG-1#TRPBF equivalent, this page provides verified technical context on DirectSense ZVS timing, phase modulation architecture, SSOP-20 package constraints, and real-world design trade-offs between adaptive delay accuracy and duty cycle margin in full-bridge topologies.

Technical Context

The LTC1922EG-1#TRPBF implements a peak-current-mode-controlled, phase-shifted full-bridge topology with independent adaptive delay sensing on ADLY and PDLY pins using SBUS-referenced thresholds. Its oscillator operates at 236–319kHz (typ. 277kHz) with CT = 180pF, and its phase modulator accepts COMP input from 0V to 4V to set 0.1–99.5% phase shift range.

It integrates six 50mA gate drivers (OUTA–OUTF), a 5V/15mA VREF LDO, a 10.3V shunt regulator on VCC, programmable slope compensation (35–150µA), and leading-edge blanking controlled by RLEB (40–310ns). Protection includes cycle-by-cycle current limiting (0.415V CS threshold), hiccup-mode short-circuit response, and soft-start with 7–17µA charging current.

Key Specifications

Pinout & Package

The LTC1922EG-1#TRPBF is housed in a 20-lead plastic SSOP (G-package) with 0.65mm lead pitch, JEDEC MO-153 compliant, and rated for –40°C to 85°C operation. Thermal resistance θ_JA = 110°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 and NCP1562ADR2G, the LTC1922EG-1#TRPBF uniquely integrates adaptive DirectSense ZVS, secondary SR drivers, and a 5V VREF in one SSOP-20 package - reducing total solution size by ≥30% and eliminating external timing components required by both alternatives.

Availability

LTC1922EG-1#TRPBF is available at Aetrix Electronics and suitable for telecom rectifier modules, server power supplies, and high-density power modules requiring stable component supply, long-term lifecycle support, and guaranteed SSOP-20 packaging consistency.

Supply support for LTC1922EG-1#TRPBF 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, industrial, automotive, and communications markets.

The LTC1922-1 product line was engineered specifically for zero-voltage-switched, phase-shifted full-bridge DC/DC converters - targeting high-efficiency, high-power-density isolated power supplies in telecom infrastructure and datacenter applications.

FAQ

What is the maximum operating frequency of the LTC1922EG-1#TRPBF?

The LTC1922EG-1#TRPBF has a maximum oscillator frequency of 319 kHz under specified conditions (VCC = 6.5V to 9.5V, CT = 180pF, TA = TMIN to TMAX). Typical operation is 277 kHz, and minimum is 236 kHz. This fixed-frequency range is set by the CT timing capacitor and internal oscillator circuitry - not user-programmable beyond capacitor selection. The LTC1922EG-1#TRPBF does not support frequencies above 319 kHz.

How does the LTC1922EG-1#TRPBF implement adaptive zero-voltage switching?

The LTC1922EG-1#TRPBF implements adaptive ZVS using DirectSense circuitry that monitors ADLY and PDLY pins referenced to SBUS voltage. When SBUS is set to 1.5V (e.g., via resistor divider from 48V input), ADLY and PDLY thresholds track input voltage proportionally. The LTC1922EG-1#TRPBF detects near-zero drain-source voltage on active/passive bridge legs and commands MOSFET turn-on with nanosecond-level timing - eliminating fixed-delay inaccuracies. If insufficient commutation energy exists, it overrides to forced timing.

Can the LTC1922EG-1#TRPBF drive synchronous rectifiers directly without external drivers?

Yes - the LTC1922EG-1#TRPBF provides six dedicated 50mA gate drivers (OUTA–OUTF) with ±100mA peak capability. OUTE and OUTF are specifically configured for secondary-side current-doubler synchronous rectifiers and require no external drivers when paired with low-Qg MOSFETs (e.g., ≤20nC). OUTA/OUTB/OUTC/OUTD drive primary-side full-bridge switches but may require external high-side drivers for floating gate control - the LTC1922EG-1#TRPBF itself does not integrate high-side level shifters.

What is the purpose of the RLEB pin on the LTC1922EG-1#TRPBF?

The RLEB pin on the LTC1922EG-1#TRPBF sets the duration of leading-edge blanking applied to the CS (current sense) input. A resistor from RLEB to GND (10kΩ–100kΩ) programs blanking from 40ns to 310ns, suppressing false overcurrent trips caused by gate-drive-induced voltage spikes during MOSFET turn-on. Connecting RLEB to VREF disables blanking. This function is critical for stable current-mode control in high-dV/dt full-bridge environments - and is fully integrated within the LTC1922EG-1#TRPBF.

Does the LTC1922EG-1#TRPBF include an internal voltage reference, and what is its accuracy?

Yes - the LTC1922EG-1#TRPBF includes an internal 5V reference output on pin VREF (Pin 11) with ±1.5% initial accuracy at 25°C and ±1% total variation over line, load, and temperature (–40°C to 85°C). It supplies up to 15mA and features 2–15mV load regulation and 0.1–10mV line regulation. This VREF is used internally for FB, COMP, and ADLY/PDLY thresholds - and can power external optocouplers or feedback circuitry, reducing system BOM count versus discrete references.